Sentencia libri De anima
COMMENTARY ON ARISTOTLE’S
DE ANIMA

by
Thomas Aquinas

translated by
Kenelm Foster, O.P. and Sylvester Humphries, O.P.

New Haven: Yale University Press, 1951
html edition by Joseph Kenny, O.P.


BOOK ONE

  1. Introductory. The Importance and Difficulty of the
    Study of the Soul

    Commentary: Lectio 1
    Introductory (Contd.). Questions of Method
    Commentary: Lectio 2
  2. Previous Theories. Democritus, the Pythagoreans, Anaxagoras
    Commentary: Lectio 3
    Previous Theories. Empedocles, Plato, Soul as Self-moving Number
    Commentary: Lectio 4
    Previous Theories. Soul as Identified with the Elements
    Commentary: Lectio 5
  3. Previous Theories. Soul as a Self-moving Essence
    Commentary: Lectio 6
    Soul as a Mover of the Body. Democritus and Plato
    Commentary: Lectio 7
    Soul as a Spatial Magnitude, Critique of Plato
    Commentary: Lectio 8
  4. Theory of Soul as Harmony
    Commentary: Lectio 9
    Theory of Soul as a Self-mover Reconsidered
    Commentary: Lectio 10
    Soul as a Self-moving Number
    Commentary: Lectio 11
  5. Empedocles’ Theory of Cognition. Soul Not Composed of the Elements
    Commentary: Lectio 12
    The Elements Have No Soul
    Commentary: Lectio 13
    The Unity of the Soul
    Commentary: Lectio 14

BOOK TWO

  1. The Definition of the Soul
    Commentary: Lectio 1
    The Definition Explained. Soul and Body
    Commentary: Lectio 2
  2. The Definition Justified. Modes of Life
    Commentary: Lectio 3
    Different Kinds of Soul
    Commentary: Lectio 4
  3. The Soul’s Powers in General
    Commentary: Lectio 5
    The Soul’s Powers (Contd.). Their Interrelation. How to Define Each
    Commentary: Lectio 6
  4. The Vegetative Principle. How Soul Causes Body
    Commentary: Lectio 7
    The Vegetative Principle (Contd.). Two Errors Refuted
    Commentary: Lectio 8
    The Vegetative Principle (Contd.). Nutrition
    Commentary: Lectio 9
  5. Sensitivity. Potency and Act in Sensation
    Commentary: Lectio 10
    Sensitivity. Potency and Act (Contd.)
    Commentary: Lectio 11
    Sensitivity. Actualisations of Sense and Intellect Compared
    Commentary: Lectio 12
  6. Sense Objects in General
    Commentary: Lectio 13
  1. Sight. Its Object
    Commentary: Lectio 14
    Sight. How Colour Is Seen
    Commentary: Lectio 15
  2. Sound. Its Causes. Echo
    Commentary: Lectio 16
    Hearing. Its Medium. High and Low Sounds
    Commentary: Lectio 17
    Voice
    Commentary: Lectio 18
  3. Smell. Its Object
    Commentary: Lectio 19
    Smell. How it Occurs
    Commentary: Lectio 20
  4. Taste. Its Medium, Object, Organ, Kinds of Flavour
    Commentary: Lectio 21
  5. Touch. One Sense or Many? Its Medium
    Commentary: Lectio 22
    The Medium of Touch (Contd.). its Organ and Object
    Commentary: Lectio 23
  6. General Conclusions on Sensation
    Commentary: Lectio 24

BOOK THREE

  1. Is There a Sixth Sense? The ‘Common’ Sense Objects
    Commentary: Lectio 1
  2. Subject and Object in Sensation
    Commentary: Lectio 2
    The Common Sense
    Commentary: Lectio 3
  3. Distinction of Sense from Intellect. Error, Imagination and Opinion
    Commentary: Lectio 4
    Imagination. What it Is Not
    Commentary: Lectio 5
    Imagination. What it Is
    Commentary: Lectio 6
  4. The Intellect in General
    Commentary: Lectio 7
    Intellectual Abstraction
    Commentary: Lectio 8
    Problems Arising. Intellect as Intelligible
    Commentary: Lectio 9
  5. The Agent Intellect
    Commentary: Lectio 10
  6. Intellectual Operations. Simple and Complex ‘Intelligibles’
    Commentary: Lectio 11
  7. Sense and Intellect Compared. The Practical Intellect. Abstraction Again
    Commentary: Lectio 12
  8. Recapitulation. Intellect. Sense. Imagination
    Commentary: Lectio 13
  9. The Principle of Movement in Living Beings. What it Is Not
    Commentary: Lectio 14
  10. The Principles of Movement in Living Beings (Contd.). What They Are
    Commentary: Lectio 15
  11. The Principles of Movement in Living Beings (Contd.)
    Commentary: Lectio 16
  12. Sensitivity and Life. Touch Is the Fundamental Sense
    Commentary: Lectio 17
  13. Touch, the Fundamental Sense
    Commentary: Lectio 18

BOOK I, CHAPTER I

INTRODUCTORY
THE IMPORTANCE AND DIFFICULTY OF THE STUDY OF THE SOUL

BOOK ONE
TEXT
402a1–403b2

1. Τῶν καλῶν καὶ τιμίων τὴν εἴδησιν ὑπολαμβάνοντες, μᾶλλον δ' ἑτέραν ἑτέρας ἢ κατ' ἀκρίβειαν ἢ τῷ βελτιόνων τε καὶ θαυμασιωτέρων εἶναι, δι' ἀμφότερα ταῦτα τὴν περὶ τῆς ψυχῆς ἱστορίαν εὐλόγως ἂν ἐν πρώτοις τιθείημεν. Holding as we do that knowledge is a good and honourable thing, yet that some kinds of knowledge are more so than others, either because they are more certain or because they deal with subjects more excellent and wonderful, we naturally give a primary place, for both these reasons, to an enquiry about the soul. §§ 1-6
δοκεῖ δὲ καὶ πρὸς ἀλήθειαν ἅπασαν ἡ γνῶσις αὐτῆς μεγάλα συμβάλλεσθαι, μάλιστα δὲ πρὸς τὴν φύσιν· ἔστι γὰρ οἷον ἀρχὴ τῶν ζῴων. Indeed an acquaintance with the soul would seem to help much in acquiring all truth, especially about the natural world; for it is, as it were, the principle of living things. § 7
ἐπιζητοῦμεν δὲ θεωρῆσαι καὶ γνῶναι τήν τε φύσιν αὐτῆς καὶ τὴν οὐσίαν, εἶθ' ὅσα συμβέβηκε περὶ αὐτήν· ὧν τὰ μὲν ἴδια πάθη τῆς ψυχῆς εἶναι δοκεῖ, τὰ δὲ δι' ἐκείνην καὶ τοῖς ζῴοις ὑπάρχειν. We seek then to consider and understand, first, its nature and essence, then whatever qualities belong to it. Of these, some seem to be proper to the soul alone, others to be shared in common’ and to exist in animate beings on account of it. §8
πάντῃ δὲ πάντως ἐστὶ τῶν χαλεπωτάτων λαβεῖν τινα πίστιν περὶ αὐτῆς. καὶ γάρ, ὄντος κοινοῦ τοῦ ζητήματος καὶ πολλοῖς ἑτέροις, λέγω δὲ τοῦ περὶ τὴν οὐσίαν καὶ τὸ τί ἐστι, τάχ' ἄν τῳ δόξειε μία τις εἶναι μέθοδος κατὰ πάντων περὶ ὧν βουλόμεθα γνῶναι τὴν οὐσίαν, ὥσπερ καὶ τῶν κατὰ συμβεβηκὸς ἰδίων ἀπόδειξις, ὥστε ζητητέον ἂν εἴη τὴν μέθοδον ταύτην· εἰ δὲ μὴ ἔστι μία τις καὶ κοινὴ μέθοδος περὶ τὸ τί ἐστιν, ἔτι χαλεπώτερον γίνεται τὸ πραγματευθῆναι· δεήσει γὰρ λαβεῖν περὶ ἕκαστον τίς ὁ τρόπος, ἐὰν δὲ φανερὸν ᾖ πότερον ἀπόδειξίς ἐστιν ἢ διαίρεσις ἢ καί τις ἄλλη μέθοδος, ἔτι πολλὰς ἀπορίας ἔχει καὶ πλάνας, ἐκ τίνων δεῖ ζητεῖν· ἄλλαι γὰρ ἄλλων ἀρχαί, καθάπερ ἀριθμῶν καὶ ἐπιπέδων. To ascertain, however, anything reliable about it is one of the most difficult of undertakings. Such an enquiry being Common to many topics—I mean, an enquiry into the essence, and what each thing is—it might seem to some that one definite procedure were available for all things of which we wished to know the essence; as there is demonstration for the accidental properties of things. So we should have to discover what is this one method. But if there is no one method for determining what an essence is, our enquiry becomes decidedly more difficult, and we shall have to find a procedure for each case in particular. If, on the other hand, it is clear that either demonstration, or division, or some such process is to be employed, there are still many queries and uncertainties to which answers must be found. For the principles in different subject matters are different, for instance in the case of numbers and surfaces.
δ' ἴσως ἀναγκαῖον διελεῖν ἐν τίνι τῶν γενῶν καὶ τί ἐστι, λέγω δὲ πότερον τόδε τι καὶ οὐσία ἢ ποιὸν ἢ ποσόν, ἢ καί τις ἄλλη τῶν διαιρεθεισῶν κατηγοριῶν, ἔτι δὲ πότερον τῶν ἐν δυνάμει ὄντων ἢ μᾶλλον ἐντελέχειά τις· διαφέρει γὰρ οὔ τι 402b μικρόν. σκεπτέον δὲ καὶ εἰ μεριστὴ ἢ ἀμερής, καὶ πότερον ὁμοειδὴς ἅπασα ψυχὴ ἢ οὔ· εἰ δὲ μὴ ὁμοειδής, πότερον εἴδει διαφέρουσα ἢ γένει. νῦν μὲν γὰρ οἱ λέγοντες καὶ ζητοῦντες περὶ ψυχῆς περὶ τῆς ἀνθρωπίνης μόνης ἐοίκασιν ἐπισκοπεῖν· εὐλαβητέον δ' ὅπως μὴ λανθάνῃ πότερον εἷς ὁ λόγος αὐτῆς ἐστι, καθάπερ ζῴου, ἢ καθ' ἕκαστον ἕτερος, οἷον ἵππου, κυνός, ἀνθρώπου, θεοῦ, τὸ δὲ ζῷον τὸ καθόλου ἤτοι οὐθέν ἐστιν ἢ ὕστερον, ὁμοίως δὲ κἂν εἴ τι κοινὸν ἄλλο κατηγοροῖτο· Perhaps the first thing needed is to divide off the genus of the subject and to say what sort of thing it is,—I mean, whether it be a particular thing or substance, or a quality, or quantity, or any other of the different categories. Further, whether it is among things in potency or is an actuality—no insignificant distinction. Again, whether it is divisible or indivisible, and whether every soul is of the same sort or no: and if not, whether they differ specifically or generically. Indeed those who at present talk of and discuss the soul seem to deal only with the human soul. One must be careful not to leave unexplored the question whether there is a single definition of it, as of ‘animal’ in general, or a different one for each [of its kinds]: as, say, for horse, dog, man or god. Now ‘animal’ as a universal is nothing real, or is secondary; and we must say the same of any other general predicate. §§ 9-13
ἔτι δέ, εἰ μὴ πολλαὶ ψυχαὶ ἀλλὰ μόρια, πότερον δεῖ ζητεῖν πρότερον τὴν ὅλην ψυχὴν ἢ τὰ μόρια. χαλεπὸν δὲ καὶ τούτων διορίσαι ποῖα πέφυκεν ἕτερα ἀλλήλων, καὶ πότερον τὰ μόρια χρὴ ζητεῖν πρότερον ἢ τὰ ἔργα αὐτῶν, οἷον τὸ νοεῖν ἢ τὸν νοῦν, καὶ τὸ αἰσθάνεσθαι ἢ τὸ αἰσθητικόν· ὁμοίως δὲ καὶ ἐπὶ τῶν ἄλλων. εἰ δὲ τὰ ἔργα πρότερον, πάλιν ἄν τις ἀπορήσειεν εἰ τὰ ἀντικείμενα πρότερον τούτων ζητητέον, οἷον τὸ αἰσθητὸν τοῦ αἰσθητικοῦ, καὶ τὸ νοητὸν τοῦ νοῦ. Further, if there are not many souls, but only many parts of a single one, we must ask whether one ought to look first at the whole or the parts. It is difficult to see what parts are by nature diverse from one another, and whether one ought to look first at the parts or their functions, for instance at the act of understanding or at the intellective power, at the act of sensing or at the sensitive faculty; and likewise in other in stances. But if one is to examine first the operations, it might be asked whether one should not first enquire about their objects, as, in the sensitive function, the thing sensed; and in the intellectual, the thing intelligible. § 14
402b16 ἔοικε δ' οὐ μόνον τὸ τί ἐστι γνῶναι χρήσιμον εἶναι πρὸς τὸ θεωρῆσαι τὰς αἰτίας τῶν συμβεβηκότων ταῖς οὐσίαις (ὥσπερ ἐν τοῖς μαθήμασι τί τὸ εὐθὺ καὶ τὸ καμπύλον, ἢ τί γραμμὴ καὶ ἐπίπεδον, πρὸς τὸ κατιδεῖν πόσαις ὀρθαῖς αἱ τοῦ τριγώνου γωνίαι ἴσαι), ἀλλὰ καὶ ἀνάπαλιν τὰ συμβεβηκότα συμβάλλεται μέγα μέρος πρὸς τὸ εἰδέναι τὸ τί ἐστιν· ἐπειδὰν γὰρ ἔχωμεν ἀποδιδόναι κατὰ τὴν φαντασίαν περὶ τῶν συμβεβηκότων, ἢ πάντων ἢ τῶν πλείστων, τότε καὶ περὶ τῆς οὐσίας ἕξομεν λέγειν κάλλιστα· πάσης γὰρ ἀποδείξεως ἀρχὴ τὸ τί ἐστιν, ὥστε καθ' ὅσους τῶν ὁρισμῶν μὴ συμβαίνει τὰ 403a συμβεβηκότα γνωρίζειν, ἀλλὰ μηδ' εἰκάσαι περὶ αὐτῶν εὐμαρές, δῆλον ὅτι διαλεκτικῶς εἴρηνται καὶ κενῶς ἅπαντες. Now, it seems that not only does knowledge of the essence help one to understand the causes of the accidents of any substance (as in Mathematics to know what is the straight and the curved, and what is a line and what a plane enables one to discover the number of right angles to which those of a triangle are equal) but, conversely, accidental qualities contribute much to knowing, what a thing essentially is. When we can give an account of such qualities (some or all) according to appearances, then we shall have material for dealing as well as possible with the essence. The principle of every demonstration is what a thing is. Hence, whatsoever definitions do not afford us a knowledge of accidents, or even a fair conjecture about them, are obviously vain and sophistical. § 15
ST. THOMAS’S COMMENTARY

LECTIO 1
Sicut docet philosophus in undecimo de animalibus, in quolibet genere rerum necesse est prius considerare communia et seorsum, et postea propria unicuique illius generis: quem quidem modum Aristoteles servat in philosophia prima. In metaphysicae enim primo tractat et considerat communia entis inquantum ens, postea vero considerat propria unicuique enti. Cuius ratio est, quia nisi hoc fieret, idem diceretur frequenter. 1. in studying any class of things, it is first of all necessary, as the Philosopher says in the De Animalibus [I, 5], to consider separately what is common to the class as a whole, and afterwards what is proper to particular members of the class. Such is Aristotle’s method in First Philosophy; for at the beginning of the Metaphysics he investigates the common properties of being as such, and only then does he go on to the particular kinds of being. The reason for this procedure is that it saves frequent repetition.
Rerum autem animatarum omnium quoddam genus est; et ideo in consideratione rerum animatarum oportet prius considerare ea quae sunt communia omnibus animatis, postmodum vero illa quae sunt propria cuilibet rei animatae. Commune autem omnibus rebus animatis est anima: in hoc enim omnia animata conveniunt. Ad tradendum igitur de rebus animatis scientiam, necessarium fuit primo tradere scientiam de anima tamquam communem eis. Aristoteles ergo volens tradere scientiam de ipsis rebus animatis, primo tradit scientiam de anima, postmodum vero determinat de propriis singulis animatis in sequentibus libris. Now living beings taken all together form a certain class of being; hence in studying them the first thing to do is to consider what living things have in common, and afterwards what each has peculiar to itself. What they have in common is a life-principle or soul; in this they are all alike. In conveying knowledge, therefore, about living things one must first convey it about the soul as that which is common to them all. Thus when Aristotle sets out to treat of living things, he begins with the soul; after which, in subsequent books, he defines the properties of particular living beings.
In tractatu autem de anima, quem habemus prae manibus, primo ponit prooemium, in quo facit tria quae necessaria sunt in quolibet prooemio. Qui enim facit prooemium tria intendit. Primo enim ut auditorem reddat benevolum. Secundo ut reddat docilem. Tertio ut reddat attentum. Benevolum quidem reddit, ostendendo utilitatem scientiae: docilem, praemittendo ordinem et distinctionem tractatus: attentum attestando difficultatem tractatus. Quae quidem tria Aristoteles facit in prooemio huius tractatus. Primo enim ostendit dignitatem huius scientiae. Secundo vero ordinem huius tractatus, quis sit, scilicet, et qualiter sit tractandum de anima, ibi, inquirimus autem. Tertio vero ostendit difficultatem huius scientiae, ibi, omnino autem et penitus, et difficillimorum et cetera. Circa primum duo facit. Primo enim ostendit dignitatem huius scientiae. Secundo utilitatem eius, ibi, videtur autem et ad veritatem, et cetera. 2. In the present treatise on the soul we find, first, an Introduction: in which the author does the three things that should be done in any Introduction. For in writing an Introduction one has three objects in view: first, to gain the reader’s good will; secondly, to dispose him to learn; thirdly, to win his attention. The first object one achieves by showing the reader the value of the knowledge in question; the second by explaining the plan and divisions of the treatise; the third by warning him of its difficulties. And all this Aristotle does here. First, he points out the high value of the science he is introducing. Secondly, at ‘We seek then,’ he explains the plan of the treatise. Thirdly, at ‘To ascertain anything reliable’ he warns of its difficulty. Under the first point he explains, first the dignity of this science, and then, at ‘Indeed, an acquaintance,’ its utility.
Circa primum sciendum est, quod omnis scientia bona est: et non solum bona, verum etiam honorabilis. Nihilominus tamen una scientia in hoc superexcellit aliam. Quod autem omnis scientia sit bona, patet; quia bonum rei est illud, secundum quod res habet esse perfectum: hoc enim unaquaeque res quaerit et desiderat. Cum igitur scientia sit perfectio hominis, inquantum homo, scientia est bonum hominis. Inter bona autem quaedam sunt laudabilia, illa scilicet quae sunt utilia in ordine ad finem aliquem: laudamus enim bonum equum, quia bene currit; quaedam vero sunt etiam honorabilia, illa scilicet quae sunt propter seipsa; honoramus enim fines. In scientiis autem quaedam sunt practicae, et quaedam speculativae: et hae differunt, quia practicae sunt propter opus, speculativae autem propter seipsas. Et ideo scientiarum, speculativae, et bonae sunt et honorabiles, practicae vero laudabiles tantum. Omnis ergo scientia speculativa bona est et honorabilis. 3. As regards, then, the said dignity we should note that, while all knowledge is good and even honourable, one science can surpass another in this respect. All knowledge is obviously good because the good of anything is that which belongs to the fulness of being which all things seek after and desire; and man as man reaches fulness of being through knowledge. Now of good things some are just valuable, namely, those which are useful in view of some end—as we value a good horse because it runs well; whilst other good things are also honourable: namely, those that exist for their own sake; for we give honour to ends, not means. Of the sciences some are practical, others speculative; the difference being that the former are for the sake of some work to be done, while the latter arc for their own sake. The speculative sciences are therefore honourable as well as good, but the practical are only valuable. Every speculative science is both good and honourable.
Sed et in ipsis scientiis speculativis invenitur gradus quantum ad bonitatem et honorabilitatem. Scientia namque omnis ex actu laudatur: omnis autem actus laudatur ex duobus: ex obiecto et qualitate seu modo: sicut aedificare est melius quam facere lectum, quia obiectum aedificationis est melius lecto. In eodem autem, respectu eiusdem rei, ipsa qualitas gradum quemdam facit; quia quanto modus aedificii est melior, tanto melius est aedificium. Sic ergo, si consideretur scientia, seu actus eius, ex obiecto, patet, quod illa scientia est nobilior, quae est meliorum et honorabiliorum. Si vero consideretur ex qualitate seu modo, sic scientia illa est nobilior, quae est certior. Sic ergo dicitur una scientia magis nobilis altera, aut quia est meliorum et honorabiliorum, aut quia est magis certa. 4. Yet even among the speculative sciences there are degrees of goodness and honourableness. Every science is valued first of all as a kind of activity, and the worth of any activity is reckoned in two ways: from its object and from its mode or quality. Thus building is a better activity than bed-making because its object is better. But where the activities are the same in kind, and result in the same thing, the quality ‘alone makes a difference; if a building is better built it will be a better building. Considering then science, or its activity, from the point of view of the object, that science is nobler which is concerned with better and nobler things; but from the point of view of mode or quality, the nobler science is that which is more certain. One science, then, is reckoned nobler than another, either because it concerns better and nobler objects or because it is more certain.
Sed hoc est in quibusdam scientiis diversum: quia aliquae sunt magis certae aliis, et tamen sunt de rebus minus honorabilibus: aliae vero sunt de rebus magis honorabilibus et melioribus, et tamen sunt minus certae. Nihilominus tamen illa est melior quae de rebus melioribus et honorabilioribus est. Cuius ratio est, quia sicut dicit philosophus in Lib. undecimo de animalibus, magis concupiscimus scire modicum de rebus honorabilibus et altissimis, etiam si topice et probabiliter illud sciamus, quam scire multum, et per certitudinem, de rebus minus nobilibus. Hoc enim habet nobilitatem ex se et ex sua substantia, illud vero ex modo et ex qualitate. 5. Now there is this difference between sciences, that some excel in certainty and yet are concerned with inferior objects, while others with higher and better objects are nevertheless less certain. All the same, that science is the better which is about things; because, as the Philosopher observes in Book XI of the De Animalibus, we have a greater desire for even a little knowledge of noble and exalted things—even for a conjectural and probable sort of knowledge—than for a great and certain knowledge of inferior things. For the former is noble in itself and essential, but the latter only through its quality or mode.
Haec autem scientia, scilicet de anima, utrumque habet: quia et certa est, hoc enim quilibet experitur in seipso, quod scilicet habeat animam, et quod anima vivificet. Et quia est nobilior: anima enim est nobilior inter inferiores creaturas. Et hoc est quod dicit, nos opinantes notitiam, idest scientiam speculativam omnium esse bonorum, id est de numero bonorum, et honorabilium. Sed altera scientia est magis bona et honorabilis altera dupliciter. Aut quia est magis certa, ut dictum est: unde dicit secundum certitudinem, aut ex eo quod meliorum, illorum scilicet quae sunt in sua natura bona, et mirabiliorum, idest illorum quorum causa ignoratur, propter utraque, idest propter haec duo animae historiam. Et dicit historiam, quia in quadam summa tractat de anima, non perveniendo ad finalem inquisitionem omnium quae pertinent ad ipsam animam, in hoc tractatu. Hoc enim est de ratione historiae. In primis hoc si accipiatur quantum ad totam scientiam naturalem, non dicit ordinem, sed dignitatem. Si vero ad scientiam de rebus animatis tantum, sic in primis dicit ordinem. 6. Now this science of the soul has both merits. It has certainty; for everyone knows by experience that he has a soul which is his life-principle. Also it has a high degree of nobility; for among lower things the soul has a special nobility. This is what Aristotle means here when he says, ‘Holding as we do that knowledge’, i.e. speculative science, ‘is good and honourable.’ And one science is better and nobler than another in two ways: either, as we have seen, because it is more certain—hence he says ‘more certain’,—or because it is about ‘more excellent’ things, i.e. things that are good in themselves, and ‘more wonderful things’, i.e. things whose cause is unknown. ‘For both these reasons’, he goes on to say, ‘we give a primary place to an enquiry about the soul’. He uses the term ‘enquiry’ because he is going to discuss the soul in a general way, without attempting, in this treatise, a thorough examination of all its properties. As to the words ‘a primary place’, if they are taken as applying to the whole of Natural Science, then they refer to superiority in dignity and not to priority in order; but if they refer to the science of living things only, they mean priority of order.
Consequenter cum dicit videtur autem reddit auditorem benevolum ex utilitate huius scientiae: dicens, quod cognitio de anima videtur multum proficere ad omnem veritatem, quae traditur in aliis scientiis. Ad omnes enim partes philosophiae insignes dat occasiones. Quia si ad philosophiam primam attendamus, non possumus devenire in cognitionem divinarum et altissimarum causarum, nisi per ea quae ex virtute intellectus possibilis acquirimus. Si enim natura intellectus possibilis esset nobis ignota, non possemus scire ordinem substantiarum separatarum, sicut dicit Commentator super undecimo metaphysicae. Si vero attendatur quantum ad moralem, non possumus perfecte ad scientiam moralem pervenire, nisi sciamus potentias animae. Et inde est, quod philosophus in Ethicis attribuit quaslibet virtutes diversis potentiis animae. Ad naturalem vero utilis est, quia magna pars naturalium est habens animam, et ipsa anima est fons et principium omnis motus in rebus animatis. Est enim anima tamquam principium animalium. Ly tamquam non ponitur similitudinarie, sed expressive. 7. Then, with ‘Indeed an acquaintance etc.,’ he gains the reader’s good will by showing the utility of this science. Some knowledge of the soul he says, would seem to be very useful in all the other sciences. it can be of considerable service to philosophy in general. In First Philosophy it is impossible to attain knowledge of the divine and highest causes except through what we can acquire by actualising our intellectual power; and if we knew nothing about the nature of this power we should know nothing about the immaterial substances, as the Commentator remarks à propos of Book XI of the Metaphysics. Again, as regards Moral Philosophy. We cannot master the science of morals unless we know the powers of the soul; thus in the Ethics the Philosopher assigns the virtues to the different powers. So, too, it is useful for the Natural Scientist, because many of the things he studies are animate things, all of whose movements originate in the soul: ‘for it is,’ says Aristotle, ‘as it were, the principle of living things’: the phrase ‘as it were’ does not express a comparison; it is descriptive.
Consequenter cum dicit inquirimus autem ostendit ordinem huius tractatus: dicens, quod intendimus considerare per signa scilicet, et cognoscere per demonstrationem scilicet, quid sit anima, seu naturam ipsius et substantiam, et postea quaecumque accidunt circa ipsam, idest passiones eius. Et in hoc est quaedam diversitas: quia quaedam videntur passiones animae tantum, sicut intelligentia et speculatio: quaedam vero per ipsam animam inesse videntur communiter animalibus, sicut delectatio et tristitia, sensus et phantasia. 8. Next, at ‘We seek then’, he states the plan of his treatise, saying that we are ‘to consider’, i.e. by way of outward symptoms, and ‘to understand’, i.e. by way of demonstration, what the soul really is in its nature and essence; and then whatever qualities belong to it or affect it. But in the latter a diversity appears: for while some of the soul’s modifications, such as understanding and speculative knowledge, seem to belong to the soul of and in itself, others, such as pleasure and pain, the senses and imagination, though they depend on some soul or other, seem to be common to all animals.
Consequenter cum dicit omnino autem ostendit difficultatem huius tractatus. Et hoc quantum ad duo. Primo quantum ad cognoscendum substantiam animae. Secundo quantum ad cognoscendum accidentia, seu proprias passiones, ibi, dubitationem autem, et cetera. Quantum autem ad primum, ostendit duplicem difficultatem. Et primo quantum ad modum definiendi ipsam. Secundo quantum ad ea quae intrant definitionem, ibi, primum autem fortassis, et cetera. 9. Then at ‘To ascertain’, he introduces the difficulty of this study; and this from two points of view. It is hard, first, to know the essence of the soul, and secondly to know its accidents or characteristic qualities. As to the essence, there is a double difficulty: first, as to how it ought to be defined, and then as to the elements of the definition (this point comes at ‘Perhaps the first thing needed’).
Dicit ergo: quamvis sit utilis scientia de anima, tamen difficile est scire de anima quid est: et haec est difficultas in qualibet re, cum sit una communis quaestio animae et multis aliis, circa substantiam eorum, et circa quod quid est. Est ergo prima difficultas, quia nos nescimus per quam viam procedendum sit ad definitionem: quia quidam dicunt, quod demonstrando: quidam, quod dividendo: quidam vero, quod componendo. Aristoteles autem voluit, quod componendo. He remarks, therefore, that while knowledge of the soul would be valuable, it is not easy to know just what the soul is. Now this is a difficulty in studying anything; for the question about substance and essence is common to the study of soul and of many other things; the first difficulty being that we do not know what method to use; for some say we should use deductive demonstration, others the method of elimination, others one of comparison. Aristotle himself preferred the method of comparison.
Secunda difficultas est de his quae ponuntur in definitione. Definitio enim notificat essentiam rei, quae non potest sciri nisi sciantur principia: sed diversorum sunt diversa principia: et ideo difficile est scire, ex quibus sumantur principia. Illa ergo quae ingerunt difficultatem ponentibus et inquirentibus definitionem, reducuntur ad tria, quorum primum est circa substantiam animae; secundum circa partes eius; tertium circa adiutorium, quod necessarium est in definitionibus ex accidentibus animae. 10. The second difficulty concerns the elements of the definition. A definition manifests a thing’s essence; and this cannot be grasped apart from the principles on which it depends. But different things have different principles, and it is hard to see which principle is involved in any particular thing. Hence, in formulating or seeking for a definition of soul we encounter three main difficulties: (a) concerning its essence; (b) concerning its parts; (c) concerning that necessary contribution to a definition which comes from knowing the soul’s accidental qualities.
Circa substantiam est dubitatio de genere. Hoc enim primo quaerimus in definitione cuiuslibet rei, ut scilicet sciamus genus. Et ideo quaerendum est in quo genere sit ponenda anima; utrum scilicet in genere substantiae, vel in quanto, vel in quali. Et non solum est accipere genus supremum, sed propinquum. Neque enim quando hominem definimus, substantiam accipimus, sed animal. Et si anima invenitur in genere substantiae, adhuc, cum unumquodque genus dicatur dupliciter, hoc quidem potentia, hoc autem actu, quaerendum erit utrum sit potentia, vel actus. Item quia substantiarum quaedam sunt compositae, quaedam simplices, quaerendum erit, utrum anima sit composita, aut simplex; et utrum partibilis vel impartibilis. Est etiam quaestio utrum sit unius speciei omnis anima ad omnem animam, aut non. Et si non sit unius speciei, adhuc est quaestio utrum differant etiam genere, vel non. Item adhuc dubitatio est circa ea quae participant definitione. Quaedam enim definiuntur ut genus, quaedam vero ut species. Et ideo videtur esse quaestio, utrum definitio animae sit sicut generis, aut sicut speciei specialissimae. 11. As regards the essence of soul, there is a doubt about that which is the first thing to be looked for in defining anything, i.e. the genus to which it belongs. What is the genus of soul? Is it a substance or a quantity or a quality? And not only must we decide upon the ultimate genus, but also on the proximate one; thus we do not define man as a substance, but as an animal. And if soul is found to belong to the genus of substance we shall still have to decide whether it is actual or potential substance, since every genus can be regarded both as potential and as actual. Also, since substances are either composite or simple, we shall have to ask which is one or the other and whether it is divisible or indivisible. There is also the question whether all souls are of the same species or not; and if they are not, whether they are generically different or not. Again there is uncertainty as to what is to be included in the definition, some things being defined in terms of genus, some as species; hence the question whether we should define soul in terms of genus or as the specification of a species.
Nam aliqui quaerentes de anima videntur intendere solum de anima humana. Et quia apud antiquos philosophos erat duplex opinio de anima. Platonici enim, qui ponebant universalia separata, scilicet quod essent formae et ideae, et erant causae rebus particularibus cognitionis et esse, volebant quod esset quaedam anima separata per se, quae esset causa et idea animabus particularibus; et quod quicquid invenitur in eis, derivetur ab illa. Naturales autem philosophi volebant, quod non essent substantiae universales nisi particulares tantum, et quod universalia nihil sint in rerum natura. Et propter hoc est quaestio, utrum sit quaerenda solum una communis ratio animae, sicut dicebant Platonici: vel huius vel illius animae, sicut dicebant naturales, scilicet ut animae equi, vel hominis, aut Dei. Et dicit Dei quia credebant corpora caelestia esse deos, et dicebant ea esse animata. 12. For some enquirers seem to have in view only the human soul. Among the earlier philosophers there were two opinions about soul. The Platonists, holding that universals existed separately as the Forms or Ideas that caused knowledge and being in individual things, maintained that there was a Soul-in-Itself which was the cause and ‘idea’ of particular souls and from which all that we find in these drew its origin. On the other hand were the Natural Philosophers who maintained that no universal substances existed in the real world, that the only real things were individuals. And this raises the question for us, whether we, like the Platonists, ought to look for one common idea of Soul; or rather, as the Natural Philosophers said, study this or that particular soul, e.g. of horse or man, or god. He says ‘or god’ because at that time men believed that the heavenly bodies were gods, and that they were alive.
Aristoteles autem vult quod quaeratur ratio utriusque: et communis animae, et cuiuslibet speciei. Quod autem circa hoc dicit animal autem universale, aut nihil est, aut posterius: sciendum est, quod de animali universali possumus loqui dupliciter: quia aut secundum quod est universale, quod scilicet est unum in multis aut de multis: aut secundum quod est animal: et hoc, vel secundum quod in rerum natura, vel secundum quod est in intellectu. Secundum autem quod est in rerum natura, Plato voluit animal universale aliquid esse, et esse prius particulari; quia, ut dictum est, posuit universalia separata et ideas. Aristoteles autem vult quod ut sic, nihil est in rerum natura. Et si aliquid est, dixit illud esse posterius. Si autem accipiamus naturam animalis non secundum quod subiacet intentioni universalitatis, sic aliquid est, et prius, sicut quod est in potentia, prius est, quam id quod est actu. 13. However, Aristotle chose to seek a definition of both—of Soul in general and of each kind of soul. But when he says, on this point, that ‘animal as universal is nothing real, or is secondary’, we must understand that one can speak of a ‘universal animal’ in two ways: either as universal, i.e. as one nature existing in, or predicated of, many individuals; or as animal. And both these aspects can be regarded either in relation to existence in the real world or as existing in the mind. As regards existence in the real, world, Plato held that the universal animal did so exist and existed prior to particular animals; because, as has been said, he thought that there were universals and ideas with an independent existence. Aristotle, however, said that the universal as such had no real existence, and that if it was anything at all it came after the individual thing. But if we regard the nature of animals from a different point of view, i.e. not as a universal, then it is indeed something real, and it precedes the individual animal as the potential precedes the actual.
Consequenter cum dicit amplius autem tangit difficultates, quae emergunt circa potentias animae. In anima enim sunt partes potentiales, scilicet intellectivum, sensitivum et vegetativum. Est ergo quaestio, utrum hae sint diversae animae, sicut Platonici volebant, et etiam ponebant: an sint partes potentiales animae. Et si sint partes potentiales animae, quaeritur etiam, utrum primo debeamus quaerere potentias ipsas quam actus, aut primo actus quam potentias, ut intelligere ante intellectum, et sentire, quod est actus, ante sensitivum quod est potentia, et similiter in aliis potentiis et actibus. Et si primo debemus quaerere actus quam potentias, adhuc erit quaestio utrum sint prius quaerenda obiecta horum actuum quam potentiae, ut puta prius debeat quaeri sensibile quam sensitivum, aut intelligibile quam intellectivum. 14. Then, at ‘Further, if there are not many’, Aristotle touches on the difficulties that arise concerning the soul’s potentialities. For, in, the soul are ‘parts’ that exist as potencies: the intellectual and sensitive and vegetative ‘parts’. The question is whether these are different souls, as the Platonists liked to think (and even maintained), or are only potencies in the soul. And if they are potencies, we must further decide whether to enquire first into the potencies themselves, and then into their acts, or into the acts first and then the potencies—e.g. into the act of understanding before the intellect. And if we take the acts first, there is still the question whether the objects of these acts should be studied before the faculties, e.g. the sense-object before the sense-faculty or the thing understood before the understanding.
Consequenter etiam cum dicit videtur autem ponit difficultates, quae emergunt quantum ad illa quae sunt in adiutorium definitionis animae. Quia in definitione oportet non solum cognoscere principia essentialia, sed etiam accidentalia. Si enim recte definirentur et possent cognosci principia essentialia, definitio non indigeret accidentibus. Sed quia principia essentialia rerum sunt nobis ignota, ideo oportet quod utamur differentiis accidentalibus in designatione essentialium: bipes enim non est essentiale, sed ponitur in designatione essentialis. Et per eas, scilicet per differentias accidentales, devenimus in cognitionem essentialium. Et ideo difficile est, quia oportet nos prius cognoscere quod quid est animae, ad cognoscendum facilius accidentia animae: sicut in mathematicis valde utile est praeaccipere quodquid erat esse recti et curvi et plani ad cognoscendum quod rectis trianguli anguli sint aequales. E converso etiam accidentia, si praeaccipiantur, multum conferunt ad cognoscendum quod quid erat esse, ut dictum est. Si quis ergo assignet definitionem, per quam non deveniatur in cognitionem accidentium rei definitae, illa definitio non est realis, sed remota et dialectica. Sed illa definitio per quam devenitur in cognitionem accidentium, est realis, et ex propriis, et essentialibus rei. 15. Next, at ‘Now it seems’, he states the difficulties that arise with regard to those accidental qualities which contribute to a definition of the soul. These are relevant here because a definition ought to reveal a thing’s accidental qualities, as well as its essential principles. If indeed the latter could be known and correctly defined there would be no need, to define the former; but since the essential principles of things are hidden from us we are compelled to make use of accidental differences as indications of what is essential. Thus to be two-footed is not of the essence of anything, yet it helps to indicate an essence. By such accidental differences we are led towards knowledge of the essential ones. It would indeed be easier to grasp even What is accidental to the soul if we could only first understand its essence, just, as in mathematics, it is a great help towards understanding that the angles of a triangle are equal to (two) right angles to know first what is meant by straight, curved and plane. Hence the difficulty of our present position. On the other hand a prior examination of the accidental factors is a considerable help towards knowing the essence, as has been said. if, therefore, one were to propose a definition from which no knowledge of the accidental attributes of the defined thing could be derived, such a definition would not be real, but abstract and hypothetical. But one from which a knowledge of the accidents flows is a real definition, based on what is proper and essential to the thing.

TEXT
403a 2-403 b 23
BOOK I, CHAPTER, I, CONTINUED

INTRODUCTION CONTINUED
QUESTIONS OF METHOD

403a3   ἀπορίαν δ' ἔχει καὶ τὰ πάθη τῆς ψυχῆς, πότερόν ἐστι πάντα κοινὰ καὶ τοῦ ἔχοντος ἢ ἔστι τι καὶ τῆς ψυχῆς ἴδιον αὐτῆς· The modifications of the soul present a problem: are they all shared by what has soul, or are some proper to the soul alone? § 16
τοῦτο γὰρ λαβεῖν μὲν ἀναγκαῖον, οὐ ῥᾴδιον δέ. φαίνεται δὲ τῶν μὲν πλείστων οὐθὲν ἄνευ τοῦ σώματος πάσχειν οὐδὲ ποιεῖν, οἷον ὀργίζεσθαι, θαρρεῖν, ἐπιθυμεῖν, ὅλως αἰσθάνεσθαι, μάλιστα δ' ἔοικεν ἰδίῳ τὸ νοεῖν· εἰ δ' ἐστὶ καὶ τοῦτο φαντασία τις ἢ μὴ ἄνευ φαντασίας, οὐκ ἐνδέχοιτ' ἂν οὐδὲ τοῦτ' ἄνευ σώματος εἶναι. It is necessary indeed, but not easy, to deal with this problem. For in most cases there is, apparently, no action or being acted on without the body; as in anger, desire, confidence, and sensation in general. Understanding however would seem especially proper to the soul. Yet if this too is a sort of imagination, or never occurs without it, not even this exists, in fact, apart from the body. § 17-20
εἰ μὲν οὖν ἔστι τι τῶν τῆς ψυχῆς ἔργων ἢ παθημάτων ἴδιον, ἐνδέχοιτ' ἂν αὐτὴν χωρίζεσθαι· εἰ δὲ μηθέν ἐστιν ἴδιον αὐτῆς, οὐκ ἂν εἴη χωριστή, ἀλλὰ καθάπερ τῷ εὐθεῖ, ᾗ εὐθύ, πολλὰ συμβαίνει, οἷον ἅπτεσθαι τῆς [χαλκῆς] σφαίρας κατὰ στιγμήν, οὐ μέντοι γ' ἅψεται οὕτως χωρισθέν τι εὐθύ· ἀχώριστον γάρ, εἴπερ ἀεὶ μετὰ σώματός τινος ἐστιν. But if the soul has some operation or affection exclusive to itself, then it could exist as a separate entity. If, however, there is nothing thus proper to it, then it is not separable, but is like a straight line, which has, as such, many properties—such as being able to touch a bronze sphere at a given point; but straightness separated does not touch it; not being in fact separable, since it is always with a bodily subject. § 21
ἔοικε δὲ καὶ τὰ τῆς ψυχῆς πάθη πάντα εἶναι μετὰ σώματος, θυμός, πραότης, φόβος, ἔλεος, θάρσος, ἔτι χαρὰ καὶ τὸ φιλεῖν τε καὶ μισεῖν· ἅμα γὰρ τούτοις πάσχει τι τὸ σῶμα. μηνύει δὲ τὸ ποτὲ μὲν ἰσχυρῶν καὶ ἐναργῶν παθημάτων συμβαινόντων μηδὲν παροξύνεσθαι ἢ φοβεῖσθαι, ἐνίοτε δ' ὑπὸ μικρῶν καὶ ἀμαυρῶν κινεῖσθαι, ὅταν ὀργᾷ τὸ σῶμα καὶ οὕτως ἔχῃ ὥσπερ ὅταν ὀργίζηται. ἔτι δὲ μᾶλλον τοῦτο φανερόν· μηθενὸς γὰρ φοβεροῦ συμβαίνοντος ἐν τοῖς πάθεσι γίνονται τοῖς τοῦ φοβουμένου. εἰ δ' οὕτως ἔχει, δῆλον ὅτι τὰ πάθη λόγοι ἔνυλοί εἰσιν· ὥστε οἱ ὅροι τοιοῦτοι οἷον "τὸ ὀργίζεσθαι κίνησίς τις τοῦ τοιουδὶ σώματος ἢ μέρους ἢ δυνάμεως ὑπὸ τοῦδε ἕνεκα τοῦδε", Now all the soul’s modifications do seem to involve the body—anger, meekness, fear, compassion, and joy and love and hate. For along with these the body also is to some degree affected. An indication of this is that sometimes violent and unmistakable occurrences arouse no excitement or alarm; while at other times one is moved by slight and trifling matters, when the physical system is stimulated to the condition appropriate to anger. This is still more evident fearful being present, feelings occur as in one when, nothing who is frightened. If this is the case, it is evident that the passions are material principles; hence such terms as ‘becoming angry’ mean a motion of such and such a body, or of a part or power proceeding from and existing for the body. § 22
καὶ διὰ ταῦτα ἤδη φυσικοῦ τὸ θεωρῆσαι περὶ ψυχῆς, ἢ πάσης ἢ τῆς τοιαύτης. For this reason, therefore, the natural scientist ought to examine the soul, either all kinds, or this kind. § 23
διαφερόντως δ' ἂν ὁρίσαιντο ὁ φυσικὸς [τε] καὶ ὁ διαλεκτικὸς ἕκαστον αὐτῶν, οἷον ὀργὴ τί ἐστιν· ὁ μὲν γὰρ ὄρεξιν ἀντιλυπήσεως ἤ τι τοιοῦτον, ὁ δὲ ζέσιν τοῦ περὶ καρδίαν αἵματος 403b καὶ θερμοῦ. τούτων δὲ ὁ μὲν τὴν ὕλην ἀποδίδωσιν, ὁ δὲ τὸ εἶδος καὶ τὸν λόγον. ὁ μὲν γὰρ λόγος ὅδε τοῦ πράγματος, ἀνάγκη δ' εἶναι τοῦτον ἐν ὕλῃ τοιᾳδί, εἰ ἔσται· ὥσπερ οἰκίας ὁ μὲν λόγος τοιοῦτος, ὅτι σκέπασμα κωλυτικὸν φθορᾶς ὑπ' ἀνέμων καὶ ὄμβρων καὶ καυμάτων, ὁ δὲ φήσει λίθους καὶ πλίνθους καὶ ξύλα, ἕτερος δ' ἐν τούτοις τὸ εἶδος <οὗ> ἕνεκα τωνδί. τίς οὖν ὁ φυσικὸς τούτων; πότερον ὁ περὶ τὴν ὕλην, τὸν δὲ λόγον ἀγνοῶν, ἢ ὁ περὶ τὸν λόγον μόνον; The natural scientist and the dialectician will define each of those modifications differently. Take the question, what is anger? The latter will say, a desire for retaliation, or something similar; the former, an effervescence of blood or heat about the heart. Of these, the natural scientist designates the matter, the dialectician, the form or idea. For this ‘idea’ is the thing’s form. This however must have existence in material of the sort in question; if it is a house, one formula will be, ‘a covering to prevent destruction from wind and rain and excessive heat’; the other, ‘stones and beams and timber’; another, ‘the form; in these materials; for those reasons. Which is the physical definition? That which states the matter and ignores the idea? Or that which states the idea only?
ἢ μᾶλλον ὁ ἐξ ἀμφοῖν; ἐκείνων δὲ δὴ τίς ἑκάτερος; ἢ οὐκ ἔστιν εἷς ὁ περὶ τὰ πάθη τῆς ὕλης τὰ μὴ χωριστὰ μηδ' ᾗ χωριστά, ἀλλ' ὁ φυσικὸς περὶ ἅπανθ' ὅσα τοῦ τοιουδὶ σώματος καὶ τῆς τοιαύτης ὕλης ἔργα καὶ πάθη, ὅσα δὲ μὴ τοιαῦτα, ἄλλος, καὶ περὶ τινῶν μὲν τεχνίτης, ἐὰν τύχῃ, οἷον τέκτων ἢ ἰατρός, τῶν δὲ μὴ χωριστῶν μέν, ᾗ δὲ μὴ τοιούτου σώματος πάθη καὶ ἐξ ἀφαιρέσεως, ὁ μαθηματικός, ᾗ δὲ κεχωρισμένα, ὁ πρῶτος φιλόσοφος; Or rather, the compound of both? What then of the other two? Now there is no one who deals with inseparable qualities of matter, precisely as inseparable from it; but he who is concerned with the affections and activities of the special matter of this or that body is the natural scientist; whereas whatever things are not specifically such, another considers; in certain matters it may perchance be a technical expert, a carpenter or physician. Concerning however what is inseparable from matter, and yet as not involved in the specific qualities of this or that body, but abstracted from any, the mathematician; and concerning what is separable, the ‘first philosopher’. § 24-9
ἀλλ' ἐπανιτέον ὅθεν ὁ λόγος. ἐλέγομεν δὴ ὅτι τὰ πάθη τῆς ψυχῆς οὕτως ἀχώριστα τῆς φυσικῆς ὕλης τῶν ζῴων, ᾗ γε τοιαῦθ' ὑπάρχει <οἷα> θυμὸς καὶ φόβος, καὶ οὐχ ὥσπερ γραμμὴ καὶ ἐπίπεδον. To return from our digression. We were saying that the passions, of the soul are not separable from the physical material of animals (anger and fear having this kind of existence), and yet also that they differ, in this, from the line and the surface.
ΚΕΦΑΛΑΙΟΝ Β' CHAPTER II
403b20   Ἐπισκοποῦντας δὲ περὶ ψυχῆς ἀναγκαῖον, ἅμα διαποροῦντας περὶ ὧν εὐπορεῖν δεῖ προελθόντας, τὰς τῶν προτέρων δόξας συμπαραλαμβάνειν ὅσοι τι περὶ αὐτῆς ἀπεφήναντο, ὅπως τὰ μὲν καλῶς εἰρημένα λάβωμεν, εἰ δέ τι μὴ καλῶς, τοῦτ' εὐλαβηθῶμεν. Investigating the soul, it is necessary, while suspending judgment on matters which should be held uncertain, that we study the opinions of certain thinkers who have dealt with the subject, so as to take note of anything they said pertinently, whilst avoiding their mistakes. § 30
ST. THOMAS’S COMMENTARY

LECTIO 2
Postquam philosophus ostendit difficultatem, quae est in scientia de anima ex parte substantiae, et quod quid est animae: hic consequenter ostendit difficultatem, quae est ex parte passionum et accidentium animae. Et circa hoc duo facit. Primo movet dubitationem circa passiones animae, et solvit eam. Secundo ex huiusmodi solutione ostendit, quod cognitio de anima pertinet ad philosophum naturalem, seu ad physicum, ibi, et propter hoc igitur iam physici, et cetera. Dicit ergo primo, quod dubitatio est circa passiones animae, et operationes, utrum scilicet essent animae propriae sine communicatione corporis, ut Platoni videbatur: vel nulla sit propria animae, sed omnes sint communes corporis et compositi. 16. Having stated the difficulty of this science in respect of the problem of the soul’s substance and essence, the Philosopher proceeds to the problem of its modifications and accidental qualities. And here he does two things: he states, first, and solves a difficulty concerning the soul’s modifications; and then, using this solution, ‘he shows that knowledge of the soul pertains to natural science or ‘physics’, where he says, ‘For this reason, therefore, the natural scientist’. As to the first point, he says it is a problem whether the soul’s modifications and activities belong to it independently of the body, as Plato thought, or are none of them peculiar to the soul, being all shared by soul and body together.
Deinde cum dicit hoc enim circa hoc duo facit. Primo enim ostendit difficultatem huiusmodi quaestionis. Secundo vero necessitatem, ibi, si quidem igitur est aliquid. Dicit ergo primo, quod accipere hoc, scilicet utrum passiones et operationes animae sint communes vel propriae, est necessarium, et non est leve, sed valde difficile. Et quod sit difficile, ostendit dicens: quod causa difficultatis est, quia in apparenti videtur, quod multae passiones sint communes, et non sit pati sine corpore, ut puta irasci et sentire et huiusmodi, quorum nihil patitur anima sine corpore. Sed si aliqua operatio esset propria animae, appareret hoc de operatione intellectus. Intelligere enim, quae est operatio intellectus, maxime videtur proprium esse animae. 17. Going on at ‘It is necessary,’ he again does two things. First he shows the difficulty of the question, and then, at ‘But if the Soul,’ the necessity of putting it. He begins then by observing that we cannot avoid the question whether the soul’s modes and activities are proper to it or shared by the body, and that this is not an easy question but a very difficult one. The difficulty, as he explains, arises from the fact that many activities seem to be common to soul and body and to require the body, for instance, getting angry and having sensations and so on; which all involve body as well as soul. If there is anything peculiar to the soul it would appear to be the intellectual activity or understanding; this seems to belong to the soul in a special way.
Si quis tamen recte consideret, non videtur proprium animae intelligere. Cum enim intelligere, vel sit phantasia, ut Platonici ponebant, aut non sit sine phantasia: (fuerunt enim quidam sicut antiqui naturales qui dicebant, quod intellectus non differebat a sensu, et si hoc esset, tunc intellectus in nullo differret a phantasia; et ideo Platonici moti sunt ad ponendum intellectum esse phantasiam). Cum ergo phantasia indigeat corpore, dicebant quod intelligere non est proprium animae, sed commune animae et corpori. Si autem detur, quod intellectus non sit phantasia, nihilominus tamen non est intelligere sine phantasia. Restat igitur quod intelligere non est proprium animae, cum phantasia indigeat corpore. Non ergo contingit hoc, scilicet intelligere, esse sine corpore. 18. And yet, on closer consideration, even understanding would not seem to pertain to the soul alone. For either it is the same as imagination, as the Platonists thought, or it does not occur without the use of imagination (for there used to be men, such as the early natural philosophers, who said that intellect in no way differed from the senses, which would imply that it does not differ from the imagination; as indeed the Platonists were led to say). As, then, imagination presupposes the body and depends on it, they said that understanding was common to soul and body together, rather than the work of the soul alone. And even granted that intellect and imagination are not identical, still the one cannot function without the other. It would follow that understanding is not of the soul alone, since imagining presupposes the body. Understanding then, it seems, does not occur where there is no body.
Quamvis autem hoc Aristoteles scilicet aperte manifestet in tertio huius, nihilominus tamen quantum ad hoc aliquid exponemus. Nam intelligere quodammodo est proprium animae, quodammodo est coniuncti. Sciendum est igitur, quod aliqua operatio animae aut passio est, quae indiget corpore sicut instrumento et sicut obiecto. Sicut videre indiget corpore, sicut obiecto, quia color, qui est obiectum visus, est in corpore. Item sicut instrumento; quia visio, etsi sit ab anima, non est tamen nisi per organum visus, scilicet pupillam, quae est ut instrumentum; et sic videre non est animae tantum, sed est organi. Aliqua autem operatio est, quae indiget corpore, non tamen sicut instrumento, sed sicut obiecto tantum. Intelligere enim non est per organum corporale, sed indiget obiecto corporali. Sicut enim philosophus dicit in tertio huius, hoc modo phantasmata se habent ad intellectum, sicut colores ad visum. Colores autem se habent ad visum, sicut obiecta: phantasmata ergo se habent ad intellectum sicut obiecta. Cum autem phantasmata non sint sine corpore, videtur quod intelligere non est sine corpore: ita tamen quod sit sicut obiectum et non sicut instrumentum. 19. Now although Aristotle clears up this problem in Book III, we shall say something about it here. Understanding, then, is in one sense, proper to the soul alone, and in another sense common to both soul and body. For it should be realised that certain activities or modifications of the soul depend on the body both as an instrument and as an object. Sight, for instance, needs a body as object—because its object is colour, which is only found in bodies;—and also as an instrument—because, while the act of seeing involves the soul, it cannot occur except through the instrumentality of a visual organ, the pupil of the eye. Sight then is the act of the organ as well as of the soul. But there is one activity which only depends on the body to provide its object, not its instrument; for understanding is not accomplished with a bodily organ, though it does bear on a bodily object; because, as will be shown later, in Book III, the phantasms in the imagination are to the intellect as colours to sight: as colours provide sight with its object, so do the phantasms serve the intellect. Since then there cannot be phantasms without a body, it seems that understanding presupposes a body-not, however, as its instrument, but simply as its object.
Ex hoc duo sequuntur. Unum est, quod intelligere est propria operatio animae, et non indiget corpore nisi ut obiecto tantum, ut dictum est: videre autem et aliae operationes et passiones non sunt animae tantum, sed coniuncti. Aliud est, quod illud, quod habet operationem per se, habet etiam esse et subsistentiam per se; et illud, quod non habet operationem per se, non habet esse per se. Et ideo intellectus est forma subsistens, aliae potentiae sunt formae in materia. Et in hoc erat difficultas huiusmodi quaestionis, quia scilicet omnes passiones animae secundum apparentiam videntur esse coniuncti. 20. Two things follow from this. (1) Understanding is an act proper to the soul alone, needing the body, as was said above, only to provide its object; whereas seeing and various other functions involve the compound of soul and body together. (2) Whatever operates of itself independently, has also an independent being and subsistence of its own; which is not the case where the operation is not independent. Intellect then is a self-subsistent actuality, whereas the other faculties are actualities existing in matter. And the difficulty in dealing with this type of question arises simply from the fact that all functions of the soul seem at first sight to be also functions of the body.
Consequenter cum dicit si quidem assignat causam necessitatis huius quaestionis, quia scilicet ex hoc habetur unum quod omnes maxime scire desiderant circa animam, utrum scilicet contingat animam separari: dicens, quod si contingat aliquam propriam operationem aut passionem animae esse, utique continget ipsam animam separari a corpore; quia, ut dictum est, quod habet operationem per se, habet etiam esse et subsistentiam per se. Si vero non esset aliqua propria operatio seu passio animae, eadem ratione non contingeret ipsam animam separari a corpore, sed erit de anima sicut de recto. Licet enim multa accidant recto inquantum rectum, scilicet tangere aeneam sphaeram secundum punctum, non tamen accidit ei nisi in materia: non enim tangit rectum in puncto aeneam sphaeram nisi in materia. Sic erit de anima, si non habet propriam operationem, quod licet ei multa accidant, non tamen accidunt ei nisi in materia. 21. After this, when Aristotle says ‘But if the soul’, he states a reason for putting this question, namely, that on its answer depends the answer to a question that everyone asks very eagerly about the soul: whether it can be separated from the body. So he says that if the soul has any function proper to itself it can certainly be separated, because, as was pointed out above, whatever can operate on ,its own can exist on its own. Conversely, if the soul had no such proper function it would not be separable from the body; it would be in the same case as a straight line—for though many things can happen to a straight line qua straight line, such as touching a brass sphere at a certain point, still they can only come about in a material way: a straight line cannot touch a brass sphere at any point except materially. So also with the soul; if it has no activity proper to itself, then, however many things affect it, they win do so only in a material way.
Consequenter cum dicit videntur autem manifestat illud quod supra supposuerat, quod scilicet quaedam passiones animae sunt coniuncti, et non animae tantum. Manifestat autem hoc ex uno, quod consistit ex duobus. Cuius ratio talis est. Omne ad quod operatur complexio corporis non est animae tantum, sed etiam corporis: sed complexio corporis operatur ad omnes passiones animae, ut puta ad iram, mansuetudinem, timorem, confidentiam, misericordiam et huiusmodi: videntur ergo animae passiones omnes esse cum corpore. Et quod ad huiusmodi passiones operetur complexio corporis, probat dupliciter. Primo sic. Quia nos videmus quod aliquando superveniunt durae et manifestae passiones, et homo non provocatur, neque timet; sed si accendatur ex furore, seu ex complexione, corpus a valde parvis et debilibus movetur, et sic se habet sicut cum irascitur. Secundo probat dicens adhuc fit magis manifestum quod ad huiusmodi passiones operetur complexio corporis. Videmus enim quod etiam si nullum immineat periculum, fiunt in aliquibus passiones similes his passionibus quae sunt circa animam, ut puta melancholicis frequenter, si nullum periculum immineat, ex ipsa complexione inordinata fiunt timentes. Ergo, quia sic se habet, scilicet quod complexio operetur ad passiones huiusmodi, manifestum est quod huiusmodi passiones sunt rationes in materia, idest habentes esse in materia. Et propter hoc termini tales, idest definitiones harum passionum, non assignantur sine materia: sicut si definiatur ira, dicetur quod est motus talis corporis sive cordis, aut partis, aut potentiae: et hoc dicit quantum ad substantiam seu causam materialem: ab hoc quantum ad causam efficientem: gratia huius quantum ad causam finalem. 22. Next, when he says ‘Now all the soul’s,’ he draws out what had been presupposed above, namely that certain modifications affect soul and body together, not the soul alone. And this he shows by one argument in two parts; which runs as follows. Whenever the physical constitution of the body contributes to a vital activity, the latter pertains to the body as well as the soul; but this happens in the case of all the ‘modifications’ of the soul, such as anger, meekness, fear, confidence, pity and so forth, hence all these ‘modifications’ would seem to belong partly to the body. And to show that the physical constitution plays a part in them he uses two arguments. (1) We sometimes see a man beset by obvious and severe afflictions without being provoked or frightened, whereas when he is already excited by violent passions arising from his bodily disposition, he is disturbed by mere trifles and behaves as though he were really angry. (2) At ‘This is still more evident:’ what makes this point even clearer is that we see in some people, even when there is no danger present, passions arising that resemble one such ‘modification’ of the soul; for instance melancholy people, simply as a result of their physical state, are often timid when there is no real cause to be. Obviously then, if the bodily constitution has this effect on the passions, the latter must be ‘material principles’, i.e. must exist in matter. This is why ‘such terms,’ i.e. the definitions of these passions, are not to be predicated without reference to matter; so that if anger is being defined, let it be called a movement ‘of some body’ such as the heart, or ‘of some part or power’ of the body. Saying this he refers to the subject or material cause of the passion; whereas ‘proceeding from’ refers to the efficient cause; and ‘existing for’ to the final cause.
Consequenter cum dicit et propter concludit ex his, quae dicta sunt, quod consideratio de anima pertinet ad naturalem. Et hoc ex modo definiendi concludit. Et ideo hic duo facit. Primo probat propositum. Secundo insistit circa definitiones, ibi, differenter autem definiet et cetera. Probat autem propositum hoc modo. Operationes animae et passiones sunt operationes corporis et passiones, ut ostensum est. Omnis autem passio, cum definitur, oportet quod habeat in sui definitione illud cuius est passio; nam subiectum semper cadit in definitione passionis. Si ergo passiones huiusmodi non sunt tantum animae, sed etiam corporis; de necessitate oportet quod in definitione ipsarum ponatur corpus: sed omne, in quo est corpus, seu materia, pertinet ad naturalem: ergo et passiones huiusmodi pertinent ad naturalem. Sed cuius est considerare passiones, eius est considerare subiectum ipsarum. Et ideo iam physici est considerare de anima aut omni simpliciter aut huiusmodi scilicet de ea quae est affixa corpori. Et hoc dicit, quia reliquerat sub dubio utrum intellectus sit potentia affixa corpori. 23. Then at ‘For this reason,’ he concludes from the foregoing that the study of the soul pertains to natural science—a conclusion following from the way the soul is defined. So he does two things here: (1) he proves his statement; (2) he pursues his discussion of definitions, where he says ‘the natural scientist and the dialectician’. The proof of his statement runs thus. Activities and dispositions of the soul are also activities and dispositions of the body, as has been shown. But the definition of any disposition must include that which is disposed; for its subject always falls within the definition of a disposition. If, then, dispositions of this kind are in the body as well as in the soul, the former must be included in their definition. And since everything bodily or material falls within the scope of natural science, so also must the dispositions of which we speak. Moreover, since the subject of any dispositions enters into the study of them, it must be the task of the natural scientist to study the soul—either absolutely ‘all’ souls, or ‘of this kind’, i.e. the soul that is joined to a body. He adds this because he has left it uncertain whether intellect is joined to the body.
Consequenter cum dicit differenter autem insistit circa definitiones. Quia enim ostendit, quod in definitionibus passionum animae, aliquae sunt, in quibus ponitur materia et corpus, aliquae vero in quibus non ponitur materia, sed forma tantum, ostendit quod huiusmodi definitiones sunt insufficientes. Et circa hoc investigat differentiam, quae invenitur in istis definitionibus. Aliquando enim datur aliqua definitio, in qua nihil est ex parte corporis, sicut quod ira est appetitus vindictae; aliquando assignatur aliqua definitio, in qua est aliquid ex parte corporis seu materiae, sicut quod ira est accensio sanguinis circa cor. Prima est dialectica. Secunda vero est physica, cum ponatur ibi aliquid ex parte materiae; et ideo pertinet ad naturalem. Hic enim, scilicet physicus, assignat materiam, cum dicit, quod est accensio sanguinis circa cor. Alius vero, scilicet dialecticus, ponit speciem et rationem. Hoc enim, scilicet appetitus vindictae, est ratio irae. 24. Where he says ‘The natural scientist and the dialectician,’ he continues his discussion of definitions. Explaining that, while some definitions of the dispositions of the soul include matter and the body, others exclude matter and refer only to the form, he shows that the latter kind of definition is inadequate. This leads him to go into the difference between these types of definition. Sometimes the body is omitted, as when anger is defined as a desire of revenge; and sometimes the bodily or material factor is included, as when anger is called a heating of blood round the heart. The former is a logical definition, but the latter is physical, since it includes a material factor, and so pertains to the natural scientist. The natural scientist points to the material factor when he says that anger is a heating of blood round the heart; whereas the dialectician points to the species or formal principle; since to call anger a desire of revenge is to state its formal principle.
Quod autem definitio prima sit insufficiens, manifeste apparet. Nam omnis forma, quae est in materia determinata, nisi in sua definitione ponatur materia, illa definitio est insufficiens: sed haec forma, scilicet appetitus vindictae est forma in materia determinata: unde cum non ponatur in eius definitione materia, constat quod ipsa definitio est insufficiens. Et ideo necesse est ad definitionem, quod in definitione ponatur hoc, scilicet forma, esse in materia huiusmodi, scilicet determinata. 25. Now the first type of definition is obviously inadequate. The definition of any form existing in a particular matter must take account of the matter. This form, ‘the desire for retaliation’, exists in a definite matter, and if the matter is not included, the definition is clearly inadequate. The definition, then, must state that this thing, i.e. the form, has being in this particular sort of matter.
Et sic habemus tres definitiones, quia una assignat speciem et speciei rationem, et est formalis tantum, sicut si definiatur domus quod sit operimentum prohibens a ventis et imbribus et caumatibus. Alia autem assignat materiam, sicut si dicatur quod domus est operimentum quoddam ex lapidibus, lateribus et lignis. Alia vero assignat idest in definitione ponit utrumque, materiam scilicet et formam; dicens, quod domus est operimentum tale constans ex talibus, et propter talia, scilicet ut prohibeat ventos etc. et ideo dicit quod alia definitio scilicet, tria ponit in his scilicet lignis lapidibus quae sunt ex parte materiae speciem idest formam propter ista scilicet ut prohibeat ventos. Et sic complectitur materiam cum dicit in his et formam cum dicit speciem et causam finalem cum dicit propter ista: quae tria requiruntur ad perfectam definitionem. 26. Thus we have three kinds of definition. The first states the species and specific principle of a thing, and is purely formal—as if one were to define a house as a shelter from wind, rain and heat. The second kind indicates the matter, as when a house is called a shelter made of stones and beams and wood. But the third kind includes in the definition ‘both’, namely matter and form, calling a house a particular kind of shelter, built of particular materials, for a particular purpose—to keep out the wind, etc. So he says that ‘another’ definition has three elements: the material, ‘in these’, i.e. beams and stones; the formal, ‘the form’; and the final, ‘for those reasons’, i.e. to keep out the wind. So matter is included when he says ‘in these’. form when he says ‘form’. and the final cause when he says ‘for those reasons’. All three are needed for a perfect definition.
Sed si quaeratur quae istarum definitionum sit naturalis, et quae non: dicendum, quod illa, quae considerat formam tantum, non est naturalis, sed logica. Illa autem, quae est circa materiam, ignorat autem formam, nullius est nisi naturalis. Nullus enim habet considerare materiam nisi naturalis. Nihilominus tamen illa quae ex utrisque est, scilicet ex materia et forma, est magis naturalis. Et duae harum definitionum pertinent ad naturalem: sed una est imperfecta, scilicet illa quae ponit materiam tantum: alia vero perfecta, scilicet illa quae est ex utrisque. Non enim est aliquis qui consideret passiones materiae non separabiles, nisi physicus. 27. To the question which of these types of definition pertains to the natural scientist, I answer that the purely formal one is not physical but logical. That which includes matter but omits the form pertains to no one but the natural scientist, because only he is concerned with matter. Yet that which includes both factors is also in a special way the natural scientist’s. Thus two of these definitions pertain to natural science, but of the two the merely material one is imperfect, while the other, that includes the form also, is perfect. For only the natural scientist studies the inseparable dispositions of matter.
Sed quia sunt aliqui, qui aliter considerant passiones materiae, ideo ostendit qui sint, et qualiter considerent: et dicit quod sunt tres. Unum genus est quod differt a naturali quantum ad principium, licet consideret passiones prout sunt in materia; sicut artifex, qui considerat formam in materia, sed differunt, quia huiusmodi principium est ars, physici vero principium est natura. Aliud genus est quod quidem considerat ea quae habent esse in materia sensibili, sed non recipit in definitione materiam sensibilem; sicut curvum, rectum et huiusmodi, licet habeant esse in materia, et sint de numero non separabilium, quantum ad esse, tamen mathematicus non determinat sibi materiam sensibilem. Cuius ratio est, quia res aliquae sunt sensibiles per qualitatem, quantitates autem praeexistunt qualitatibus, unde mathematicus concernit solum id quod quantitatis est absolute, non determinans hanc vel illam materiam. Aliud genus est quod quidem considerat illa quorum esse vel non est in materia omnino, vel quorum esse potest esse sine materia; et hic est philosophus primus. 28. But there are various ways of studying the dispositions of matter, as Aristotle now proceeds to show. He divides the students of these dispositions into three classes. One class consists of those who, while they study material dispositions, differ from the natural scientist in their point of view; thus the craftsman differs from the scientist in that he starts from the point of view of art, but the natural scientist from that of real nature. Another class consists of those who, though they consider forms that exist in sense-perceptible matter, do not include such matter in their definitions. The forms referred to are such as curved, straight, and so on, which, though they exist in matter and are, in fact, inseparable from it, are not, by the mathematician, regarded under their sense-perceptible aspect. The reason is that if it is through its quality that a thing is sense-perceptible, quality presupposes quantity; hence the mathematician abstracts from this or that particular material factor in order to attend exclusively to the purely quantitative. Finally, the third class studies things whose existence is either completely independent of matter or can be found without matter. This is First Philosophy.
Et notandum quod tota ratio divisionis philosophiae sumitur secundum definitionem et modum definiendi. Cuius ratio est, quia definitio est principium demonstrationis rerum, res autem definiuntur per essentialia. Unde diversae definitiones rerum diversa principia essentialia demonstrant, ex quibus una scientia differt ab alia. 29. Note that this division of Philosophy is entirely based on definition and the method of defining. The reason is that definition is the principle of demonstration. Since things are defined by their essential principles, diverse definitions reveal a diversity of essential principles; and this implies a diversity of sciences.
Consequenter cum dicit sed redeundum quia videbatur fecisse quasdam digressiones ex hoc quod institit ad inquisitionem definitionum, reducit se ad materiam propriam, dicens quod redeundum est ad materiam propriam, unde est sermo habitus, scilicet quod passiones animae, ut amor, timor et huiusmodi, non sunt separabiles a physica materia animalium, inquantum tales existunt, scilicet inquantum passiones quae non sunt sine corpore, et non sunt sicut linea et planum, idest superficies, quae ratione possunt separari a materia naturali. Si ergo ita est, ad naturalem spectat consideratio earum, et etiam animae, sicut supra dictum est. 30. Then at ‘To return,” he comes back to the matter in hand after the apparent digression about definitions. The point under discussion was that such modifications of the soul as love, fear and so forth are inseparable from physical animal matter inasmuch as they have this sort of existence, i.e. as passions in the body; in which they differ from lines, plane-surfaces and so on, which can be considered by the mind apart from the matter that they naturally imply. If this is the case then the study of such dispositions, and even of the soul itself, becomes, as has been said, the affair of the natural scientist.
De qua, scilicet anima, intendentes ad praesens necesse est accipere opiniones antiquorum, quicumque sint qui aliquid enunciaverunt de ipsa. Et hoc quidem ad duo erit utile. Primo, quia illud quod bene dictum est ab eis, accipiemus in adiutorium nostrum. Secundo quia illud, quod male enunciatum est, cavebimus. And ‘concerning this’ i.e. the soul, we must, at our present stage, take account of the opinions of the ancients no matter who they were, provided they had anything to say about it. This win be useful in two ways. First, we shall profit by what is sound in their views. Secondly, we shall be put on our guard against their errors.

TEXT
403b24–404b7
BOOK I, CHAPTER II, CONTINUED

PREVIOUS THEORIES
DEMOCRITUS, THE PYTHAGOREANS, ANAXAGORAS

ἀρχὴ δὲ τῆς ζητήσεως προθέσθαι τὰ μάλιστα δοκοῦνθ' ὑπάρχειν αὐτῇ κατὰ φύσιν. τὸ ἔμψυχον δὴ τοῦ ἀψύχου δυσὶ μάλιστα διαφέρειν δοκεῖ, κινήσει τε καὶ τῷ αἰσθάνεσθαι. παρειλήφαμεν δὲ καὶ παρὰ τῶν προγενεστέρων σχεδὸν δύο ταῦτα περὶ ψυχῆς· Our enquiry must begin with a statement of what seems most to belong by nature to the soul. The animated being would appear to differ from the inanimate in two primary respects: by motion and by sense-perception. And these two notions are roughly what our predecessors have handed down to us concerning the soul. § 31-2
φασὶ γὰρ ἔνιοι καὶ μάλιστα καὶ πρώτως ψυχὴν εἶναι τὸ κινοῦν, οἰηθέντες δὲ τὸ μὴ κινούμενον αὐτὸ μὴ ἐνδέχεσθαι κινεῖν ἕτερον, τῶν κινουμένων τι τὴν ψυχὴν ὑπέλαβον εἶναι. For some say that the soul is principally and primarily what moves. Holding that what does not itself move moves no other moving thing, they thought that the soul too was thus. § 33
ὅθεν Δημόκριτος μὲν 404a πῦρ τι καὶ θερμόν φησιν αὐτὴν εἶναι· ἀπείρων γὰρ ὄντων σχημάτων καὶ ἀτόμων τὰ σφαιροειδῆ πῦρ καὶ ψυχὴν λέγει (οἷον ἐν τῷ ἀέρι τὰ καλούμενα ξύσματα, ἃ φαίνεται ἐν ταῖς διὰ τῶν θυρίδων ἀκτῖσιν), ὧν τὴν μὲν πανσπερμίαν στοιχεῖα λέγει τῆς ὅλης φύσεως (ὁμοίως δὲ καὶ Λεύκιππος), τού- των δὲ τὰ σφαιροειδῆ ψυχήν, διὰ τὸ μάλιστα διὰ παντὸς δύνασθαι διαδύνειν τοὺς τοιούτους ῥυσμοὺς καὶ κινεῖν τὰ λοιπά, κινούμενα καὶ αὐτά, ὑπολαμβάνοντες τὴν ψυχὴν εἶναι τὸ παρέχον τοῖς ζῴοις τὴν κίνησιν· διὸ καὶ τοῦ ζῆν ὅρον εἶναι τὴν ἀναπνοήν· συνάγοντος γὰρ τοῦ περιέχοντος τὰ σώματα καὶ ἐκθλίβοντος τῶν σχημάτων τὰ παρέχοντα τοῖς ζῴοις τὴν κίνησιν διὰ τὸ μηδ' αὐτὰ ἠρεμεῖν μηδέποτε, βοήθειαν γίνεσθαι θύραθεν ἐπεισιόντων ἄλλων τοιούτων ἐν τῷ ἀναπνεῖν· κωλύειν γὰρ αὐτὰ καὶ τὰ ἐνυπάρχοντα ἐν τοῖς ζῴοις ἐκκρίνεσθαι, συνανείργοντα τὸ συνάγον καὶ πηγνύον· καὶ ζῆν δὲ ἕως ἂν δύνωνται τοῦτο ποιεῖν. Hence Democritus, said it was a kind of fire or heat. There exist an infinite number of shapes and atoms, and those of the spherical kind are, he said, fire and soul: like the dust-motes in the air called ‘atomies’ seen in the rays of the sun in doorways; and of all the seeds of these, he said, are the elements of all Nature. Leucippus had a similar opinion. Those round in shape make the soul, because they are most able to penetrate everywhere, and since they move of themselves, they have also the power to move everything else. The soul, they maintained, is what causes movement in living things: and accordingly breathing is coterminous with living. That which envelops all bodies expels by compression the atoms [within], thus causing movement in animals, for these [atoms] are never at rest. A reinforcement must come therefore [he said] from without; in that other atoms enter by respiration, preventing from dispersal those that are within the animate body, and which simultaneously resist the constraining and compressing environment; and that animals live so long as they can do this. § 34-5
404a16 ἔοικε δὲ καὶ τὸ παρὰ τῶν Πυθαγορείων λεγόμενον τὴν αὐτὴν ἔχειν διάνοιαν· ἔφασαν γάρ τινες αὐτῶν ψυχὴν εἶναι τὰ ἐν τῷ ἀέρι ξύσματα, οἱ δὲ τὸ ταῦτα κινοῦν, περὶ δὲ τούτων εἴρηται ὅτι συνεχῶς φαίνεται κινούμενα, κἂν ᾖ νηνεμία παντελής. The teaching of the Pythagoreans seems to have had much the same purport. Some of these said the soul consisted of atoms in the air; others, that it was what sets these in motion. And these atoms are mentioned. because they seem to be always moving, even if the soul be quite tranquil. § 36
ἐπὶ ταὐτὸ δὲ φέρονται καὶ ὅσοι λέγουσι τὴν ψυχὴν τὸ αὑτὸ κινοῦν· ἐοίκασι γὰρ οὗτοι πάντες ὑπειληφέναι τὴν κίνησιν οἰκειότατον εἶναι τῇ ψυχῇ, καὶ τὰ μὲν ἄλλα πάντα κινεῖσθαι διὰ τὴν ψυχήν, ταύτην δ' ὑφ' ἑαυτῆς, διὰ τὸ μηθὲν ὁρᾶν κινοῦν ὃ μὴ καὶ αὐτὸ κινεῖται. All who say that the soul is a thing that moves itself tend in the same direction; all seem to hold that movement is what is most proper to the soul, and accordingly that all things are in motion on account of the soul, but the soul itself on its own account; because one sees nothing moving other things that is not itself moving. § 37
ὁμοίως δὲ καὶ Ἀναξαγόρας ψυχὴν εἶναι λέγει τὴν κινοῦσαν, καὶ εἴ τις ἄλλος εἴρηκεν ὡς τὸ πᾶν ἐκίνησε νοῦς· οὐ μὴν παντελῶς γ' ὥσπερ Δημόκριτος. Anaxagoras likewise said that the soul is a mover, as also did anyone else who held that a Mind moves all things. But his view is not exactly Democritus’. § 38
ἐκεῖνος μὲν γὰρ ἁπλῶς ταὐτὸν ψυχὴν καὶ νοῦν (τὸ γὰρ ἀληθὲς εἶναι τὸ φαινόμενον, διὸ καλῶς ποιῆσαι [τὸν] Ὅμηρον ὡς ὁ Ἕκτωρ "κεῖτ' ἀλλοφρονέων"· οὐ δὴ χρῆται τῷ νῷ ὡς δυνάμει τινὶ περὶ τὴν ἀλήθειαν, ἀλλὰ ταὐτὸ λέγει ψυχὴν καὶ νοῦν)· He [Democritus], asserts that intellect and soul are absolutely identical; and that what appears is the truth. And therefore that Homer aptly says of Hector that he lay ‘other-minded’. He does not use the term intellect to denote a definite faculty concerned with truth, but identifies soul and intellect. § 39
404b Ἀναξαγόρας δ' ἧττον διασαφεῖ περὶ αὐτῶν· πολλαχοῦ μὲν γὰρ τὸ αἴτιον τοῦ καλῶς καὶ ὀρθῶς τὸν νοῦν λέγει, ἑτέρωθι δὲ τὸν νοῦν εἶναι ταὐτὸν τῇ ψυχῇ· ἐν ἅπασι γὰρ ὑπάρχειν αὐτὸν τοῖς ζῴοις, καὶ μεγάλοις καὶ μικροῖς, καὶ τιμίοις καὶ ἀτιμοτέροις· Anaxagoras is less definite about these matters. He often says that the cause of being right or good is intellect, and that this is the soul. For it is, he says, in all animals, great and small, noble and base. § 40
οὐ φαίνεται δ' ὅ γε κατὰ φρόνησιν λεγόμενος νοῦς πᾶσιν ὁμοίως ὑπάρχειν τοῖς ζῴοις, ἀλλ' οὐδὲ τοῖς ἀνθρώποις πᾶσιν. It does not seem, however, that there exists mind, in the sense of prudence, alike in all animals: nor even in all men. § 41
ὅσοι μὲν οὖν ἐπὶ τὸ κινεῖσθαι τὸ ἔμψυχον ἀπέβλεψαν, οὗτοι τὸ κινητικώτατον ὑπέλαβον τὴν ψυχήν· All those therefore who have regarded life from the point of view of movement have held soul to be pre-eminently a moving force. § 42
ST. THOMAS’S COMMENTARY

LECTIO 3
Supra posuit philosophus prooemium, in quo intentionem suam, quid agendum, et difficultatem huius operis ostendit: hic vero prosequitur tractatum secundum ordinem promissum. Dividitur autem tractatus iste in duas partes. Primo enim tractat de natura animae secundum opinionem aliorum philosophorum. Secundo vero secundum veritatem; et hoc in secundo libro. Prima pars dividitur in duas partes. Primo enim narrat opiniones aliorum philosophorum de anima. Secundo vero inquirit de opinionibus illis, ibi, considerandum est autem et cetera. Prima pars dividitur in duas. Primo enim ostendit ex quibus philosophi habuerunt viam ad investigandum de anima. Secundo vero ostendit quomodo diversi devenerunt in diversas opiniones de anima, ibi, dicunt enim. 31. So much by way of Introduction. The Philosopher has stated his aim in general and the difficulty of the undertaking; which he now proceeds to carry out in the order already indicated. The whole treatise divides into two parts. In the first the soul’s nature is discussed as other philosophers have regarded it; but in the second as it is in reality. The latter section begins at Book II. The first part itself has two parts. The former simply relates the opinions of other philosophers; the second, beginning at ‘The first thing to be considered,’ examines them. The former part itself divides into two parts, in the first of which Aristotle distinguishes between the starting points of the other philosophers, while in the second, starting at ‘For some say’, he shows how they severally came to hold their different opinions.
Dicit ergo primo, quod principium nostrae quaestionis, idest inquisitionis, est apponere omnia quae secundum naturam videntur inesse animae. Circa quod sciendum est, quod quando invenimus aliqua differre secundum aliquid manifestum, et secundum aliud immanifestum, certum est quod per id quod est manifestum, venimus in notitiam illius quod est immanifestum. Et hunc modum tenuerunt philosophi ad inveniendum naturam de anima. Animata enim ab inanimatis differunt, per hoc quod animata habent animam, inanimata vero non. Sed quia natura animae erat immanifesta, et non poterat investigari nisi per aliqua manifesta, in quibus differunt animata ab inanimatis, invenerunt illa, et secundum illa conati sunt devenire in cognitionem naturae animae. Illa autem manifesta in quibus animata differunt ab inanimatis, sunt duo, scilicet sentire et moveri. Nam animata videntur differre ab inanimatis maxime motu, ut scilicet moveant seipsa, et sensu seu cognitione. Unde credebant quod quando scirent principia istorum duorum, scirent quid est anima. Unde laboraverunt causam motus et sensus scire, ut per hoc scirent naturam animae: et credebant quod id quod est causa motus et sensus, esset anima: et in hoc omnes antiqui philosophi conveniebant. Sed ex hoc antiqui in diversas opiniones divisi sunt. Nam aliqui conati sunt devenire in cognitionem animae per motum, aliqui vero per sensum. 32. First of all then he says that one ought to start by gathering together everything that would seem to belong to the soul by nature. As to this, we should note that when we find things differing both by clear and understandable differences and by differences that are still obscure, we must assuredly take the former as a means to arrive at knowledge of the latter. This was the method used by the philosophers in their study of the soul. Living things differ from non-living in having ‘souls’; but because the nature of the soul was not evident and could not be investigated except by way of certain more obvious notes which differentiate animate from inanimate things, the philosophers first took these more evident characteristics and tried, through them, to come to knowledge of the soul’s nature. These evident notes are two: sensation and movement. Animate things seem to be characterised chiefly by movement, in that they move themselves, and by having sense awareness or perception. So the ancients thought that if they could discover the principle of these two factors they would know the soul; hence their efforts to discern the cause of movement and sensation. They all agreed in identifying the soul with the cause of movement and sense-perception. But just at this point also their differences began; for some tried to arrive at the soul by way of movement, and others by way of sense-perception.
Et ideo cum dicit dicunt enim ostendit horum diversitatem. Et primo de illis, qui inquirebant naturam animae a motu. Secundo de illis, qui inquirebant eam a cognitione seu sensu, ibi, quicumque autem ad cognoscere et sentire. Tertio eorum qui inquirebant naturam eius ex utroque, ibi, quoniam autem et motivum. Circa primum sciendum est, quod illis, qui inquisierunt animae naturam a motu, erat unum commune, scilicet quod si moventur animata, quod anima sit movens et mota. Et huius ratio est, quia existimabant quod id quod non movetur, non contingit movere alterum, idest quod nihil movet nisi moveatur. Si ergo anima movet animata, et nihil movet alterum nisi moveatur ipsum, manifestum est, quod anima maxime movetur. Et hoc est, propter quod antiqui naturales arbitrati sunt animam esse eorum, quae moventur. Sed ex hoc etiam diversae opiniones provenerunt. 33. Hence at ‘For some say’ he states these differences: taking those of his predecessors first who started their enquiry from movement; and then, at ‘All who have considered’, those who started from knowledge; and thirdly, at ‘But since the soul’, those who started from both. With regard to the first group we should note that it had one principle in common, namely, that if living things are moving things, the soul must be both moving and moved. They assumed this because they, thought that one thing could only move another if it were itself already moved; that is, only what is moved moves. So if living things are moved, by the soul, then clearly the soul itself, and preeminently, must be moved. It was this that led the early students of Nature to class the soul among things that are moved. But about this also different opinions arose.
Et ideo cum dicit unde Democritus ponit primo opinionem Democriti, de anima, dicens, unde Democritus, quidam scilicet antiquus philosophus, qui excogitans illud, quod maxime movetur, esse naturam animae: et quia illud quod maxime movetur, videtur esse de natura ignis: ideo dicit ipsam animam esse ignem quemdam aut calorem. Et opinio sua fuit talis. Ipse enim nihil ponebat esse in rerum natura nisi sensibile et corporale: et volebat quod principia omnium rerum sint corpora indivisibilia, et infinita, quae vocabat atomos. Quae quidem dixit esse unius naturae, sed differre ab invicem figura, positione, et ordine: licet hic tantum ponat de figura, quia haec sola differentia, quae est secundum figuram, necessaria est. Et ista differentia, quae est secundum figuram, est quod quaedam erant rotunda, quaedam quadrata, quaedam pyramidalia et huiusmodi. Ponebat etiam haec esse mobilia, et nunquam quiescentia, et ex concursu ipsorum atomorum casu esse mundum factum aiebat. Et quod haec indivisibilia corpora sint mobilia, dabat exemplum de decisionibus, quae moventur in aere, etiam si nulla tempestas sit, sicut apparet per portas in radiis solis. Unde, cum ista sint multo minora, quia sunt indivisibilia, illae vero quae apparent in radiis decisiones, sunt divisibiles, manifeste apparet, quod sint maxime mobilia. Et quia inter alias figuras, figura rotunda est magis apta ad motum, cum non habeat angulos, quibus impediatur a motu; et quia credebant animam maxime moveri, ex eo, quod arbitrati sunt animam efficere motum animalibus, ideo inter ista infinita corpora, illa quae erant inter illa rotunda corpora, dicebat esse animam. 34. When therefore he says, ‘Hence Democritus’, Aristotle states first of all the view of Democritus, one of the early philosophers, who, thinking that the soul by nature was in a state of maximum movement, which state seems natural to fire, maintained that the soul ‘was a kind of fire or heat’. Such was his view. For he did not admit the existence of anything in Nature except what is sense-perceptible and corporeal; and the first principles, he said, of all things are indivisible bodies, infinite in number, which he called atoms. These atoms, he said, are all the same by nature, differing from each other only in shape, position and arrangement (though here only the difference of shape is alluded to, as being the only necessary one. This consists in some being round, some square, some pyramids, and so on). He also maintained that the atoms were mobile and never ceased moving, and that the world had come into being through their fortuitous coming together. And to illustrate the mobility of these bodies he took the example of the particles that move in the air even when no wind blows, as we can see when a sunbeam shines through a doorway. Since the atoms, being indivisible, are much smaller than such particles, they must obviously be extremely mobile. And because the spherical is, of all shapes, the one best suited for movement—having no angles to impede it,—and since the soul, as the cause of movement in living was thought to have maximum mobility, Democritus concluded that among these infinitely numerous bodies the spherical ones were the soul.
Huius etiam opinionis fuit Leucippus, qui fuit socius eius. Et ad hoc habebat unum signum: quia voluit Democritus terminum vitae, idest rationem consistere in respiratione, licet insufficienter, quia non omnia viva respirant: quae quidem respiratio necessaria erat secundum eum, quia corpora rotunda implent corpus, cum sint causa motus in corpore animalis secundum eum, et sunt in continuo motu, et eo quod continet, idest corpora nostra aere constringente, et extrudente idest exterius mittente illas, quae sunt de numero figurarum, quae sunt praebentes animalibus motum, ex eo quod nullo modo quiescunt; ne forte eis omnino expulsis a corporibus nostris deficerent corpora, ideo necessaria est respiratio, per quam et intromittantur alia corpora, et ea quae sunt intus ab istis, quae per respirationem intrant, impediantur ab exitu. Et tamdiu dixit vivere animalia, quamdiu possunt hoc facere, scilicet respirare. Et vis huiusmodi signi est, quia cum respiratio ex hoc dicatur esse ratio vitae, quod continet ipsa corpora rotunda in corporibus animalium, et immittit etiam ea intus, ne propter exeuntia corpora, quae continue moventur, deficiat corpus animalis; manifestum est, quod ipsa corpora sint anima: quae quidem corpora voluit Democritus esse de natura ignis, et ex eis causari calorem. 135. Leucippus, a companion of Democritus, held the same opinion. And Democritus thought the following was a sign of its truth. He maintained that ‘coterminous with’, or essential to, life is respiration (a short-sighted view since not all living things breathe), and that respiration is necessary because the body is full of small ever-moving spherical particles (the cause, as he thought, of all movement in animal bodies) and that the surrounding air compresses what it ‘envelops’, i.e. our bodies, and ‘expels’, i.e. thrusts out of them, those particles which are so shaped as to impart movement to animals, being never at rest themselves. Lest, therefore, our bodies should decay with the loss of all these particles, he said that respiration is necessary whereby fresh particles may be brought in, and those already within prevented from leaving by those that inhaling brings in. And he said that animals can live as long as they can do this, i.e. as long as they can breathe. The point of the argument is that if breathing is called the cause of life because it keeps the spherical particles inside the animal body, and also introduces fresh ones lest the body should decay through loss of particles by movement, then it is clearly implied that the particles ate the soul itself. They are indeed the same particles that Democritus said were fiery by nature and the cause of heat.
Secundo cum dicit videtur autem ponit opinionem quorumdam Pythagoricorum, quae similis erat opinioni Democriti: nam illud quod Pythagorici dicunt de anima, eamdem habet intelligentiam cum eo quod dicit ipse Democritus, licet Pythagorici in eamdem sententiam non conveniant. Nam quidam ipsorum convenientes cum Democrito dixerunt animam esse decisiones, quae sunt in aere, idest corpora indivisibilia et infinita, sicut Democritus dicebat. Alii vero ex ipsis philosophis non dixerunt ipsa corpora indivisibilia, et mobilia esse animam, sed illam virtutem quae movet ea corpora, animam dicebant. Et huius opinionis fuit quidam Archelaus philosophus magister Socratis, ut Augustinus narrat in libro de civitate Dei. Et ratio horum, scilicet quare dicebant huiusmodi corpora esse animam, dicta est: quia sicut iam patet, volebant quod illud quod maxime movetur est anima: unde propter hoc quod haec corpora continue moveri videbantur, sicut apparet in aere, in quo moventur, etiam si sit tranquillitas, dicebant ista corpora esse animam. 36. Next, at ‘The teaching of the Pythagoreans,’ Aristotle mentions a view of certain Pythagoreans which resembles that of Democritus; for their statement and his seem to mean the same’ although the Pythagoreans themselves do not all agree. Some of them, agreeing with Democritus, said that motes in the air, i.e. indivisible, infinitely numerous particles, were the soul. Others, however, of the same school, said that the soul was rather the force that moved those particles. Of this opinion was a certain Archelaus, the master of Socrates, as Augustine remarks in the De Civitate Dei [VIII, 2]. The reason why the soul has been thus identified with these particles has been already given—namely, that as the soul was regarded as being especially mobile, and as those particles seem to be always moving (even when the air is calm) they identified the one with the other.
Consequenter cum dicit in idem reducit in quamdam summam opinionem plurium philosophorum de anima ad has opiniones; dicens, quod omnes illi, qui definientes animam a motu, dixerunt ipsam esse illud quod seipsum movet, feruntur in idem id est in eamdem intelligentiam cum praedictis. Omnes enim concordant in hoc et conveniunt, quod videntur existimasse motum maxime et praecipue esse proprium animae, et quicquid movetur, movetur ab anima, ipsam vero animam moveri a seipsa. Et ratio horum, sicut iam tactum est, erat, quia communiter opinati sunt quod nihil movet alterum nisi moveatur et ipsum. Unde, cum anima moveat alia, credebant animam maxime et praecipue moveri. 37. Then, at ‘All who say,’ he summarises the views of a number of philosophers, saying that all who have defined the soul in terms of movement and called it that which moves itself, ‘tend in the same direction’, i.e. the same as those mentioned already. All these, it seems, agreed -in thinking that the soul’s first and chief characteristic was movement; all things being moved by soul, and soul by itself. The reason for this was, as has been noted, that they all thought that only what was itself in motion could move other things. Since the soul moves other things, they thought the soul especially and principally was in motion.
Tertio cum dicit similiter autem ponit opinionem Anaxagorae de natura animae. Et primo ponit in quo Anaxagoras concordabat cum superioribus, dicens, quod Anaxagoras et quicumque alius dixit quod intellectus movet omnia, dicit animam esse moventem omnia, sicut et illi dicunt. Sed in hoc differt, quia noluit quod omne quod movet alterum, moveatur et ipsum: immo dixit esse unum intellectum separatum et immixtum qui alia moveat, eo non moto: et de natura huiusmodi dicit esse animam. Unde ex hoc insurrexit error quorumdam, qui dicerent animam esse de natura divina. Sic ergo patet in quo concordabat cum superioribus, in hoc scilicet quod dixit animam esse moventem. Sed differebat in hoc, quod dixit animam non moveri, cuius contrarium illi dicebant. Differebat etiam a Democrito in acceptione intellectus. 38. In the third place, at ‘Anaxagoras likewise’, he states the view of Anaxagoras. He first shows how this philosopher agrees with those already mentioned, saying that he, and anyone else who held that Intellect moved all things, really agreed with them that the source of all movement was a soul. Anaxagoras, however, differed in this that he denied that every mover was itself in motion, and maintained the existence of a pure and transcendent Intellect which, motionless itself, moved all other things; and that the soul was of this nature too. (This view led some into the error of divinising the soul.) Thus Anaxagoras agreed with the other philosophers in calling the soul a principle of movement, but disagreed with them in saying that it was not itself moved (for they said the contrary). And he also differed from Democritus in what he understood by intellect.
Et ideo cum dicit ille quidem ponit hanc differentiam. Et primo opinionem Democriti: dicens, quod ille scilicet Democritus dixit simpliciter idest ubique et universaliter intellectum et animam esse idem. Cuius ratio est, quia Democritus credebat quod nihil esset in mundo nisi sensibilia: et sicut nihil erat in mundo nisi sensibilia, ita dicebat, quod nulla vis apprehensiva erat in anima, nisi sensitiva. Unde fuit huius opinionis, quod nulla veritas determinate haberetur de rebus, et quod nihil determinate cognoscitur, sed quicquid apparet, verum esset; et non magis illud quod cogitat unus de re aliqua, quam illud quod cogitat alius de eadem re, eodem tempore, verum esse: et ex hoc sequebatur, quod poneret contradictoria simul esse vera. Cuius ratio est, quia ipse, ut dictum est, non utebatur intellectu, qui est circa veritatem, idest virtute intellectiva, per quam anima intelligit intelligibilia, sed solum vi sensitiva; et quod nihil cognosceretur nisi sensibile, cum nihil poneret in rerum natura nisi sensibile. Unde, cum sensibilia sint in continuo motu et fluxu, opinatus est nullam veritatem determinatam esse in rebus. Et quia non pervenit ad hoc quod cognosceret intellectum esse potentiam quamdam quae est circa veritatem idest cuius obiectum est verum, et excedit omnes alias potentias animae, sed accepit tantum potentias animae sensitivas; ideo communiter et indifferenter idem dicit animam et intellectum, quem quidem intellectum dicit transmutari secundum hominis transmutationem. Et propter hoc commendat Homerum, qui dixit, quod Hector iacet aliud sapiens idest quod secundum sui mutationem, mutatus est intellectus eius, dum aliud saperet victus, et aliud invictus. 39. When Aristotle therefore says ‘He (i.e. Democritus) asserts’, he states this last difference, first stating Democritus’ opinion that intellect and soul were ‘absolutely’, i.e. everywhere and in all respects, the same. Democritus said this because he held that only sense-perceptible things existed in the real world, and that no cognitive faculty existed in the soul except sensitivity. From this he inferred that no definite truth about things was attainable, that nothing could be definitely known with certainty: truth being simply what appears to be true; and what one man thought about anything being never any nearer the truth than what another man thought about the same thing at the same time. in consequence he maintained that contradictories were both true at the same time; and this because, as we have said, he took intellect to be, not the faculty for knowing truth and understanding intelligible objects, but a mere sense-faculty. Only the sensible, he thought, could be known, since only the sensible existed. And because the latter is continually changing there could be no certain truth about anything. Never attaining to an understanding of the intellect as the supreme faculty ‘concerned with truth’, i.e. which bears on true being, and admitting only the faculties of sense, he completely ‘identifies soul and intellect’. The intellect changed, he said, as the whole man changed. Hence his approval of Homer’s Phrase ‘Hector lies other-minded’, i.e. Hector’s mind was altered by Hector’s condition; for he thought one thing as conqueror, another as conquered.
Secundo cum dicit Anaxagoras autem ostendit in quo differebat Anaxagoras a Democrito. Et circa hoc duo facit. Primo ponit opinionem Anaxagorae. Secundo reprobat eam, ibi, non videtur autem et cetera. Dicit ergo primo, quod Anaxagoras loquitur de anima magis dubie, et minus certificat de ipsa. Nam ipse Anaxagoras multoties dicit in intellectu esse causam eius, quod est bonum operari, idest bonae operationis. Alibi vero, idest in aliis locis, dicit hunc intellectum, scilicet qui est causa bonae operationis, et animam esse idem; et hoc apparet, quia constat quod anima inest omnibus animalibus tam vilibus quam honorabilibus, et tam magnis quam parvis. Unde, cum in omnibus his dicat intellectum esse, manifestum est, quod idem dicit animam et intellectum. 40. Next, at ‘Anaxagoras is less definite’, he shows how Anaxagoras differed from Democritus, first stating the former’s opinion and then, at ‘it does not seem’, criticising it. First then he observes that Anaxagoras spoke with less certainty and less conclusively about the soul. He often said that intelligence was the cause of right actions, whilst elsewhere he also identifies intelligence with the soul; for it is agreed that a soul is found in all animals, the lower as well as the higher, the smaller as well as the larger; and Anaxagoras said that intelligence was in all of them. Clearly then he identifies soul and intelligence.
Secundo cum dicit non videtur ostendit contrarietatem esse in huiusmodi acceptione intellectus secundum Anaxagoram, scilicet aliquando hoc, quod dicit intellectum non esse idem cum anima, aliquando vero dicit ipsum et animam esse idem: quae sunt contradictoria, et non possunt simul stare. Et hoc probat tali ratione. Constat quod bene operari est proprium intellectus secundum prudentiam perfecti, quia bene operari pertinet ad prudentiam. Si ergo idem esset intellectus, qui est causa bonae operationis, cum anima, sequeretur quod intellectus prudens idem esset cum anima. Sed hoc est falsum, quia anima inest omnibus animalibus. Intellectus autem secundum prudentiam dictus, non videtur inesse, non solum omnibus animalibus, sed nec omnibus hominibus: ergo non est idem quod anima. 41. Secondly, at ‘It does not seem’, he shows the inconsistency of Anaxagoras’ use of the term intellect. For sometimes Anaxagoras distinguishes between soul and intellect, but sometimes also he identifies them. These are contradictory statements which cannot both be true; as Aristotle proceeds to show. Right action, he says, admittedly derives from intellect perfected by prudence. If then the intellect that causes right action is the same thing as the soul, it follows that intellect perfected by prudence is the same as the soul. But this is false; because, while all animals have souls, not all—not even all men—are prudent. Therefore the soul is something else.
Deinde cum dicit quicumque quidem ostendit, quod omnes illi, qui consideraverunt animata secundum motum, idest secundum id quod est moveri a seipsis, opinati sunt animam esse illud quod maxime est motivum, sicut patet in opinionibus iam dictis. 42. Lastly, at ‘All those therefore,’ he states that all who have regarded animate beings from the standpoint of movement, i.e. as self-movers, thought that the chief mover in them was the soul, as the above-mentioned opinions show.

TEXT
404 b 8-404 b 29
BOOK 1, CHAPTER II, CONTINUED

PREVIOUS THEORIES
EMPEDOCLES, PLATO, SOUL AS SELF-MOVING NUMBER

ὅσοι δ' ἐπὶ τὸ γινώσκειν καὶ τὸ αἰσθάνεσθαι τῶν ὄντων, οὗτοι δὲ λέγουσι τὴν ψυχὴν τὰς ἀρχάς, οἱ μὲν πλείους ποιοῦντες, ταύτας, οἱ δὲ μίαν, ταύτην, All who have considered it as knowing and perceiving realities identify the soul with the [elemental] principles,—some making several principles, others one. § 43-4
ὥσπερ Ἐμπεδοκλῆς μὲν ἐκ τῶν στοιχείων πάντων, εἶναι δὲ καὶ ἕκαστον ψυχὴν τούτων, λέγων οὕτως, Empedocles, for instance, says that it is composed of all elements, and that each of these is a soul, saying,
         γαίῃ μὲν γὰρ γαῖαν ὀπώπαμεν, ὕδατι δ' ὕδωρ,
         αἰθέρι δ' αἰθέρα δῖαν, ἀτὰρ πυρὶ πῦρ ἀΐδηλον,
         στοργῇ δὲ στοργήν, νεῖκος δέ τε νείκεϊ λυγρῷ·

As by earth we know earth, by ether divine ether,
By water water, by fire, it is clear, fire mysterious and hidden;
Love by love, hate by sad hate. §45

τὸν αὐτὸν δὲ τρόπον καὶ Πλάτων ἐν τῷ Τιμαίῳ τὴν ψυχὴν ἐκ τῶν στοιχείων ποιεῖ· γινώσκεσθαι γὰρ τῷ ὁμοίῳ τὸ ὅμοιον, τὰ δὲ πράγματα ἐκ τῶν ἀρχῶν εἶναι. In the same way Plato in the Timaeus constitutes the soul from the elements. For like [he says] is known by like; and things are made up of elements. §§46-7
ὁμοίως δὲ καὶ ἐν τοῖς περὶ φιλοσοφίας λεγομένοις διωρίσθη, αὐτὸ μὲν τὸ ζῷον ἐξ αὐτῆς τῆς τοῦ ἑνὸς ἰδέας καὶ τοῦ πρώτου μήκους καὶ πλάτους καὶ βάθους, τὰ δ' ἄλλα ὁμοιοτρόπως· In the lectures ‘On Philosophy’ he likewise lays it down that the animate itself is compounded of the idea of the One, together with the primary Length and Depth and Breadth; other things existing in the same manner. § 48-50
ἔτι δὲ καὶ ἄλλως, νοῦν μὲν τὸ ἕν, ἐπιστήμην δὲ τὰ δύο (μοναχῶς γὰρ ἐφ' ἕν), τὸν δὲ τοῦ ἐπιπέδου ἀριθμὸν δόξαν, αἴσθησιν δὲ τὸν τοῦ στερεοῦ. οἱ μὲν γὰρ ἀριθμοὶ τὰ εἴδη αὐτὰ καὶ αἱ 404b25 ἀρχαὶ ἐλέγοντο, εἰσὶ δ' ἐκ τῶν στοιχείων, κρίνεται δὲ τὰ πράγματα τὰ μὲν νῷ, τὰ δ' ἐπιστήμῃ, τὰ δὲ δόξῃ, τὰ δ' αἰσθήσει· εἴδη δ' οἱ ἀριθμοὶ οὗτοι τῶν πραγμάτων. Again, rather differently, that intellect is the One, knowledge the Two (for [this proceeds] as one to one), and the number of the Plane belongs to opinion, and that of the Solid to sensation. For he said that numbers are the specific forms and principles of beings, and are themselves constituted from elements. Some things are discerned by understanding, some by science, some by opinion, some by sensation. But these same numbers are the specific forms of things. § 51
404b27 ἐπεὶ δὲ καὶ κινητικὸν ἐδόκει ἡ ψυχὴ εἶναι καὶ γνωριστικὸν οὕτως, ἔνιοι συνέπλεξαν ἐξ ἀμφοῖν, ἀποφηνάμενοι τὴν ψυχὴν ἀριθμὸν κινοῦνθ' ἑαυτόν. But since the soul seems to be both a moving and a knowing principle, some have made it out to be a combination of these two, stating that it is a self-moving number. § 52
ST. THOMAS’S COMMENTARY

LECTIO 4
Superius ostendit philosophus quomodo aliqui venerunt in cognitionem animae per motum: hic vero ostendit quomodo aliqui venerunt in cognitionem animae per sensum, seu cognitionem. Et circa hoc duo facit. Superius ostendit philosophus quomodo aliqui venerunt in cognitionem animae per motum: hic vero ostendit quomodo aliqui venerunt in cognitionem animae per sensum, seu cognitionem. Et circa hoc duo facit. 43. Having shown how some have approached a knowledge of soul through movement, the Philosopher now turns to those who came to it by way of sensation or knowledge. He does this in. two stages. First he shows where the latter were in agreement; and secondly, at ‘Empedocles, for instance,’ where they disagreed.
Primo enim ostendit, in quo convenerunt philosophi, qui consideraverunt animam ex sensu. Secundo vero in quo differunt, ibi, sicut Empedocles quidem, et cetera. Dicit ergo primo, quod omnes quicumque venerunt in cognitionem animae quantum ad cognoscere et sentire, idest per cognitionem et sensum, in hoc conveniebant, quia dicebant animam esse ex principiis: quae quidem principia alii faciebant, idest ponebant, esse plura, alii vero unum tantum. Ad ponendum autem animam esse ex principiis constitutam movebantur, quia ipsi antiqui philosophi quasi ab ipsa veritate coacti, somniabant quodammodo veritatem. Veritas autem est, quod cognitio fit per similitudinem rei cognitae in cognoscente: oportet enim quod res cognita aliquo modo sit in cognoscente. Antiqui vero philosophi arbitrati sunt, quod oportet similitudinem rei cognitae esse in cognoscente secundum esse naturale, hoc est secundum idem esse quod habet in seipsa: dicebant enim quod oportebat simile simili cognosci; unde si anima cognoscat omnia, oportet, quod habeat similitudinem omnium in se secundum esse naturale, sicut ipsi ponebant. Nescierunt enim distinguere illum modum, quo res est in intellectu, seu in oculo, vel imaginatione, et quo res est in seipsa: unde quia illa, quae sunt de essentia rei, sunt principia illius rei, et qui cognoscit principia huiusmodi cognoscit ipsam rem, posuerunt quod ex quo anima cognoscit omnia, esset ex principiis rerum. Et hoc erat omnibus commune. He begins then by saying that all who studied the soul in or through its knowing and sensing agreed in holding that the soul was composed of the principles of things; but some ‘made’, i.e. posited, many such principles, while others posited only one. Even the earliest philosophers assumed these principles to be in the soul, as though compelled by the force of truth itself; they dreamed, as it were, of the truth. The truth, in fact, is that knowledge is caused by the knower containing a likeness of the thing known; for the latter must be in the knower somehow. The early philosophers, however, thought that it existed in the knower in its own natural being, i.e. with the being that it has in itself. Like, they said, must be known by like. If then the soul is to know all things it must contain a likeness of all things according to their natural mode of being. They could not distinguish between the mode of existence that a thing has in the mind or the eye or the imagination from that which it has in itself. Therefore, since whatever is of a thing’s essence is a constituent principle of the thing, and to know its constituent principles is to know the thing itself, these philosophers maintained that the reason why the soul can know all things is that it is made up of the principles of all things. This theory was common to them all.
Sed diversificati sunt secundum quod differebant in principiis quae ponebant. Non enim omnes ponebant eadem principia, sed unus plura, alius unum, unus hoc, alius illud: et secundum hoc differunt in ponendo principia, ex quibus principiis anima constituatur. 44. But they differed about these principles. They did not all admit the same; one admitted many, another only one, and one this and another that. Hence they disagreed also about the constituents of the soul.
Et ideo consequenter cum dicit sicut Empedocles ponit quomodo differunt. Et primo ponit opinionem Empedoclis, dicens quod antiqui philosophi, qui per sensum consideraverunt animam, dicunt ipsam constare ex elementis. Et illi quidem, qui unum faciunt principium, illud unum dicunt esse animam. Et qui plura, ex illis eam componi: sicut Empedocles dicit animam esse ex omnibus elementis, et unumquodque horum dicit animam. Circa quod sciendum est, quod Empedocles posuit sex principia: quatuor materialia, scilicet terram, aquam, aerem et ignem: et duo activa et passiva, scilicet litem et amicitiam. Et ideo, ex quo ponebat animam omnia cognoscere, dixit animam esse ex huiusmodi principiis, quae ponebat. Secundum enim quod ex terra, terram cognoscimus; et secundum quod ex aethere, idest ex aere aerem, et ex aqua aquam: sed et ignem ex igne manifestum esse: et per concordiam cognoscimus concordiam: et ex tristi discordia cognoscimus discordiam: et ponit ibi, tristi quia Empedocles metrice composuit libros suos. 45. So, at ‘Empedocles, for instance,’ Aristotle states these differences. He gives first the opinion of Empedocles, saying that the early philosophers who studied the soul by way of its sense-perceptions thought it was composed of the elements. Those who admitted only one principle said that this precisely was the soul; and those who admitted many said that the soul was made up of many; thus Empedocles held that the soul was constituted by all the elements, and that each of these was itself a soul. Note that Empedocles admitted six principles: four material, namely earth, water, fire and air; and two active and passive principles, namely strife and friendship. And since he assumed that the soul knew all things, he said it, was composed of all these principles. Thus as earthy we know earth; as ethereal or airy we know air; as aequous we know water; and as fiery, of course, we know fire. Through love we know love, and through ‘sad hate’ we know hatred. ‘Sad’ comes in here because Empedocles wrote in verse.
Secundo cum dicit eodem autem ponit opinionem Platonis, dicens quod Plato etiam facit animam ex elementis, idest dicit animam ex principiis constitutam esse. Et quod hoc sit verum, scilicet quod Plato dicat animam compositam ex principiis rerum, probat per triplex dictum Platonis. Primum est, quod ipse dicit in Timaeo. Ibi enim dicit duo esse elementa seu principia rerum, scilicet idem et diversum. Quaedam enim natura est, quae semper eodem modo se habet, et est simplex, sicut sunt immaterialia; et hanc naturam vocat idem. Quaedam vero natura est, quae non semper eodem modo se habet, sed transmutationem suscipit et divisionem, sicut sunt materialia, et hanc vocat diversum. Et ex istis duobus, scilicet ex eodem et diverso, animam dicit esse compositam: non quod sint ista duo in anima ut partes, sed quod sunt quasi media, et quod natura rationalis animae superioribus et omnino immaterialibus sit inferior et deterior, et materialibus et inferioribus sit nobilior et superior. 46. Next, when he says ‘In the same way Plato’ Aristotle states the opinion of Plato who also, he says, made the soul consist of elements, i.e. be constituted by the, principles of things. And as evidence for this statement he takes three passages from Plato. The first is from the Timaeus, where Plato says that there are two elements or first principles, Identity and Difference. For there is a certain kind of nature that is simple and unchanging, as are immaterial things; and this nature he calls Identity. And there is another kind which does not stay the same, but undergoes change and division, as do material things; and this nature he calls Difference. And it is of these two principles, of Identity and Difference, that the soul, he says, is composed; not that the two are in the soul as its parts; but rather as in the mean between extremes; for the rational soul is by nature lower and less noble than the higher and purely immaterial substances, but it is higher and nobler than inferior material things.
Et ratio huius erat, sicut dictum est, simile cognoscitur simili: unde si anima cognosceret omnia, et idem et diversum sunt principia, ponebat animam esse ex istis duobus compositam eo modo quo dictum est, ut inquantum habet de natura identitatis, cognosceret ea quae ponit idem; inquantum vero de natura eorum quae vocat diversum, cognosceret diversum, scilicet materialia. Unde et hac cognitione utitur. Nam quando colligit genera et species, tunc dicit eam repraesentare idem, seu identitatem. Quando vero differentias et accidentia assumit, alteritatem adinvenit. Sic ergo patet quomodo Plato in Timaeo dicit animam ex principio componi. 47. Now this opinion rests on the principle already mentioned, that like is known by like. For it seemed to Plato that if the soul knew all things, and if Identity and Difference were fundamental principles, then the soul itself must be constituted of Identity and Difference; in so far as it participated in ‘Identity’ the soul, he thought, knew the ‘identical’, while so far as it participated in ‘Difference’ it knew the ‘different’, i.e. material things. Hence the actual process of the soul in knowing things. For when it gathers things together under genera and species, then, said Plato, it manifests Sameness or Identity, but when it attends to accidents and differentiations he finds in it Difference. That is how Plato in the Timaeus understood the soul as made up of principles.
Secundum dictum Platonis, per quod ostenditur, quod dixit animam ex principiis esse, ponitur cum dicit similiter autem ubi ostendit animam esse ex principiis similiter. Circa quod sciendum est quod Plato posuit, quod intelligibilia essent per se substantia et separata, et essent semper in actu, et essent causa cognitionis et esse rebus sensibilibus. Quod Aristoteles tamquam inconveniens volens evitare, coactus est ponere intellectum agentem. Unde sequebatur ex positione Platonis, quod secundum quod aliqua sunt abstracta per intellectum, sic essent aliqua, quae essent per se subsistentia et in actu. Habemus autem duplicem modum abstractionis per intellectum: unum qui est a particularibus ad universalia; alium per quem abstrahimus mathematica a sensibilibus. Et sic cogebatur ex hoc ponere tria subsistentia, scilicet sensibilia, mathematica et universalia, quae essent causa, ex quorum participatione, res etiam sensibiles et mathematicae essent. 48. The second passage, showing that this was Plato’s theory, Aristotle refers to when he says ‘In the lectures “On Philosophy”.’ Here too the soul is represented as constituted from principles. Note, in this connection, that Plato took the objects known by the intellect to be things in themselves, existing apart from matter in perpetual actuality, and the causes of knowledge and of being in things of sense. For Aristotle this view involved so many difficulties that he was compelled to excogitate the theory of the ‘agent intellect’. But from Plato’s position it followed that to what could be thought of in the abstract corresponded subsistent and actual realities. We can, however, form abstractions in two ways: one is by proceeding from particulars to universals; and the other is that by which mathematical objects are abstracted from objects of sense. So Plato found himself obliged to posit three types of subsistent being: the objects of sense-perception; mathematical objects; and universal ideas-these last being the cause, by participation, of the other two types.
Item ponebat Plato numeros esse causam rerum: et hoc faciebat, quia nescivit distinguere inter unum quod convertitur cum ente, et unum quod est principium numeri, prout est species quantitatis. Ex quo sequebatur, quod cum universale separatum poneret causam rerum, et numeros esse substantiam rerum, quod huiusmodi universalia essent ex numeris. Dicebat enim quod principia omnium entium essent species et numerus specificus, quem vocabat specificum tamquam compositum ex speciebus. Nam et ipsum numerum reducebat, tamquam in principia et elementa, in unum et dualitatem. Nam cum ex uno nihil procederet, ideo necessaria fuit ipsi uni aliqua subiecta natura, a qua multitudo produceretur: et hanc vocavit dualitatem. 49. Plato also held that numbers were causes of real things, being unaware of the distinction between unity as identical with being, and unity as the principle of the number that is a kind of quantity. Hence he inferred that universals were of the nature of number; for the universal existing separately is the cause of things whose substance is numerical. He said indeed that the constituent principles of all beings were ‘species’ and ‘specific number’, which he called specific in the sense of being constituted from ‘species’. And he reduced number itself to unity and duality as to its fundamental elements; for, as nothing can proceed from one alone, there must, he thought, be some nature, subordinate to unity, whence multiplicity might proceed; and this nature he called duality.
Et secundum ordinem materialitatis ordinabat illa tria. Quia enim sensibilia sunt magis materialia quam mathematica, et universalia immaterialiora mathematicis: ideo primo posuit sensibilia, supra quae posuit mathematica, et supra haec, universalia separata et ideas: quae differunt a mathematicis: quia in mathematicis in una specie sunt aliqua quae differunt secundum numerum, sed in ideis et substantiis separatis non inveniuntur aliqua unius speciei quae differant numero: unius enim speciei unam posuit ideam. Quas ideas dicit esse ex numeris, et secundum numeros in eis esse rationes rerum sensibilium, quae quidem constant ex longitudine, latitudine et profunditate. Et ideo dixit ideam longitudinis esse primam dualitatem, longitudo enim est ab uno ad unum, scilicet de puncto ad punctum. Latitudinis autem primam Trinitatem, nam figura triangularis est prima superficialium figurarum. Profunditatis autem quae continet longitudinem et latitudinem, ideam dixit esse primam quaternitatem: prima enim figura corporum est pyramis, quae quatuor angulis consistit: unde, cum Plato poneret animam sensibilem, posuit animam separatam, quae esset causa eius; et hanc, sicut alia separata et ideas, dixit esse ex numeris, scilicet ex unitate et dualitate quae ponebat principia rerum. 50. Thus Plato envisaged three classes of beings, graded according to their connection with matter. As sensible objects are more material than the objects considered in mathematics, and the latter more so than the universal ideas, he placed sense-objects on the lowest level, and above them mathematical objects, and above these the separately existing universals and ideas. Universals differ from mathematical objects in this that the latter include numerical differences Within the same species, whereas ideas and separated substances exhibit no numerical differences in the one species; there is but ore idea for each species. These ideas, he said, are numerical in nature, and from them are derived such numerical qualities of sensible things as length, breadth and depth. Hence he said that the idea of length was the primary duality, for length is from unit to unit, from point to point; and that of breadth was the first trinity, for the triangle is the first of plane figures; and that of depth, which includes both length and breadth, was the first quaternity, for the first solid figure is the pyramid which is constructed of four angles. So too the sensitive soul, in Plato’s system, implied a Soul existing separately as its cause, and constituted, like the other ‘separate’ things and ideas, by number, that is, by the unity and duality which for him were fundamental in things.
Tertio cum dicit adhuc autem ponit tertium dictum Platonis, per quod apparet quod ipse dixerat animam compositam ex principiis. Plato enim posuit numeros, sicut dictum est, species et principia rerum: unde, cum loqueretur de anima, posuit eam secundum hoc venire in cognitionem entium, quod erat composita ex principiis, scilicet ex numeris, et omnes operationes eius ab eis procedere. Invenimus enim in anima diversas potentias ad apprehensionem entium; scilicet intellectum, scientiam, opinionem et sensum. Dicit ergo animam habere intellectum et eius operationem ex idea unius, quia scilicet est in una natura unitatis; intellectus enim una apprehensione apprehendit unum. Item scientiam ex prima dualitate; scientia enim est ab uno ad unum, scilicet de principiis ad conclusionem. Opinionem vero ex prima Trinitate: opinio enim est de uno ad duo, est enim de principiis ad conclusionem cum formidine alterius; et sic sunt ibi tria; principium, et duae conclusiones, una conclusa et alia formidata. Sensum autem habet anima a prima quaternitate: est enim quaternitas prima, idea corporis, quod consistit ex quatuor angulis, ut dictum est: sensus autem corporum est. Cum ergo res omnes cognoscantur istis quatuor, scilicet intellectu, scientia, opinione et sensu, et has potentias dicit habere animam secundum quod participat naturam unitatis, dualitatis, ternarii et quaternarii, manifestum est, quod dixit animam separatam, quam posuit ideam huius animae, compositam ex numeris, qui sunt principia et elementa rerum. Et sic patet, quod Plato dixit animam esse compositam ex principiis. 51. Then at ‘Again, rather differently,’ Aristotle alludes to the third text adduced to show that for Plato the soul was made up of elements or principles. As we have said, it was Plato’s view that the specific forms and, principles of things were numbers; so when he came to treat of the soul he based its knowledge of things on its fundamentally numerical composition; all of its activities, he maintained, sprang from this source. Take for instance the diverse apprehensive functionings of the soul: simple understanding, science, opinion and sensation. Simple understanding Plato connected with the idea of One; it has the nature of Unity; for in one act it apprehends a unity. Again, science for him relates to Duality since it proceeds from one to one, i.e. from principles to conclusions. And opinion relates to the first Trinity, proceeding from one to two, i.e. from principles to a conclusion which is accompanied by the fear that a different conclusion may be true; so forming a triad out of one principle and one admitted and one feared conclusion. Finally, sensation derives from the first Quaternity, i.e. from the notion of a solid body constructed (as we have said) from four angles; for bodies are the object of sensation. Since then all knowing is contained in these four, i.e. in simple understanding, science, opinion and sensation, all of which, said Plato, are in the soul in virtue of its participating in the nature of Unity, Duality, Trinity and Quaternity, it obviously follows that for Plato the separated Soul, the ‘idea’, as he called it, of particular souls, was constituted by numbers, which are the elements or principles of reality. So much to show that Plato regarded the soul as made up of principles.
Consequenter cum dicit quoniam autem ponit quod quidam philosophi definierunt et venerunt in cognitionem animae ex motu et sensu simul, seu cognitione, dicens: quia anima videbatur eis esse motiva per se et cognoscitiva, complexi sunt ista duo, et definierunt animam ex utrisque, scilicet motu et cognitione, dicentes, quod anima est numerus movens seipsum. Per numerum quidem insinuantes potentiam cognoscitivam, quia secundum quod suprapositum est, ex hoc dicebant habere animam vim cognoscitivam rerum, quod participabat naturam numeri specifici, quod erat de opinione Platonis: per movere autem seipsam, insinuantes potentiam motivam in anima. 52. Next at ‘But since the soul seems,’ Aristotle observes that some philosophers defined the soul, and came to know something about it, through both movement and sensation or knowledge. He says that, as the soul seemed to them to be both self-moving and cognitive, they joined the two aspects in their definition and called it a ‘self-moving number’. ‘Number’ refers to the cognitive power because they thought, in accordance with what has been said already, that the soul was able to know in virtue of its participating in the nature of specific number (Plato’s opinion). ‘Self-moving’ refers to the soul’s motive power.

TEXT
404b30–405b30
BOOK I, CHAPTER, II, CONTINUED

PREVIOUS THEORIES
SOUL AS IDENTIFIED WITH THE ELEMENTS

διαφέρονται δὲ περὶ τῶν ἀρχῶν, τίνες καὶ πόσαι, μάλιστα μὲν οἱ σωματικὰς ποιοῦντες τοῖς ἀσωμάτους, 405a τούτοις δ' οἱ μίξαντες καὶ ἀπ' ἀμφοῖν τὰς ἀρχὰς ἀποφηνάμενοι. διαφέρονται δὲ καὶ περὶ τοῦ πλήθους· οἱ μὲν γὰρ μίαν οἱ δὲ πλείους λέγουσιν. ἑπομένως δὲ τούτοις καὶ τὴν ψυχὴν ἀποδιδόασιν· τὸ γὰρ κινητικὸν τὴν φύσιν τῶν πρώτων ὑπειλήφασιν, οὐκ ἀλόγως. Opinions differ however as to the elemental principles—what they are, how many they are; and the difference is greatest between those who make these corporeal and those who make them incorporeal. But some, making a mixture, have defined the principles in terms of both. They differ also as to the number, some positing one, others several. And they assign a soul to these [principles] accordingly. (For they not unreasonably assumed that what by nature causes movement was primary.) §§ 53-4
ὅθεν ἔδοξέ τισι πῦρ εἶναι· καὶ γὰρ τοῦτο λεπτομερέστατόν τε καὶ μάλιστα τῶν στοιχείων ἀσώματον, ἔτι δὲ κινεῖταί τε καὶ κινεῖ τὰ ἄλλα πρώτως. Δημόκριτος δὲ καὶ γλαφυρωτέρως εἴρηκεν ἀποφαινόμενος διὰ τί τούτων ἑκάτερον· ψυχὴν μὲν γὰρ εἶναι ταὐτὸ καὶ νοῦν, τοῦτο δ' εἶναι τῶν πρώτων καὶ ἀδιαιρέτων σωμάτων, κινητικὸν δὲ διὰ μικρομέρειαν καὶ τὸ σχῆμα· τῶν δὲ σχημάτων εὐκινητότατον τὸ σφαιροειδὲς λέγει· τοιοῦτον δ' εἶναι τόν τε νοῦν καὶ τὸ πῦρ. Hence some have held it to be fire; for this is the most subtle, and much the least corporeal of the elements; moreover, it moves itself, being the first cause of movement in other things. Democritus said something which rather neatly gives the reason for either fact. He said that soul is the same as mind, and that this originates in primary indivisible particles and that it causes motion by its fineness and shape. He says that the sphere is the most light and mobile of shapes, and that fire and mind must both be of such a nature. §§ 55-6
Ἀναξαγόρας δ' ἔοικε μὲν ἕτερον λέγειν ψυχήν τε καὶ νοῦν, ὥσπερ εἴπομεν καὶ πρότερον, χρῆται δ' ἀμφοῖν ὡς μιᾷ φύσει, πλὴν ἀρχήν γε τὸν νοῦν τίθεται μάλιστα πάντων· μόνον γοῦν φησὶν αὐτὸν τῶν ὄντων ἁπλοῦν εἶναι καὶ ἀμιγῆ τε καὶ καθαρόν. ἀποδίδωσι δ' ἄμφω τῇ αὐτῇ ἀρχῇ, τό τε γινώσκειν καὶ τὸ κινεῖν, λέγων νοῦν κινῆσαι τὸ πᾶν. Anaxagoras, however (as we said above), seems to speak of soul and mind as diverse, yet he employs both terms as for a single essence. Nevertheless, he posits Intellect as the principle par excellence of the Universe, saying that this alone among beings is simple, unmixed and pure. He attributes, indeed, to the same principle both knowing and moving; saying that the Intellect moves all things. § 57
ἔοικε δὲ καὶ Θαλῆς ἐξ ὧν ἀπομνημονεύουσι κινητικόν τι τὴν ψυχὴν ὑπολαβεῖν, εἴπερ τὴν λίθον ἔφη ψυχὴν ἔχειν, ὅτι τὸν σίδηρον κινεῖ· It seems that Thales, from what they recollect of him, was also of opinion that the soul was a cause of motion,—if it is a fact that he said that the magnet had a ‘soul’ because it attracts iron. §58
Διογένης δ' ὥσπερ καὶ ἕτεροί τινες ἀέρα, τοῦτον οἰηθεὶς πάντων λεπτομερέστατον εἶναι καὶ ἀρχήν· καὶ διὰ τοῦτο γινώσκειν τε καὶ κινεῖν τὴν ψυχήν, ᾗ μὲν πρῶτόν ἐστι, καὶ ἐκ τούτου τὰ λοιπά, γινώσκειν, ᾗ δὲ λεπτότατον, κινητικὸν εἶναι. Now Diogenes, like certain others, held that air is the most subtle of all things and is their principle; and is the cause of the soul’s knowing and moving. As primary, it is cognitive of all else: and as the most subtle thing, it is the motive force. § 59
καὶ Ἡράκλειτος δὲ τὴν ἀρχὴν εἶναί φησι ψυχήν, εἴπερ τὴν ἀναθυμίασιν, ἐξ ἧς τἆλλα συνίστησιν· καὶ ἀσωματώτατόν τε καὶ ῥέον ἀεί· τὸ δὲ κινούμενον κινουμένῳ γινώσκεσθαι· ἐν κινήσει δ' εἶναι τὰ ὄντα κἀκεῖνος ᾤετο καὶ οἱ πολλοί. Heraclitus, however, says that soul, as a principle, is some vapour of which it is constituted, since this is the least corporeal of substances and is always flowing; and that any moving object is known by a moving object—he and many others holding that all realities are in movement. § 60
παραπλησίως δὲ τούτοις καὶ Ἀλκμαίων ἔοικεν ὑπολαβεῖν περὶ ψυχῆς· φησὶ γὰρ αὐτὴν ἀθάνατον εἶναι διὰ τὸ ἐοικέναι τοῖς ἀθανάτοις· τοῦτο δ' ὑπάρχειν αὐτῇ ὡς ἀεὶ κινουμένῃ· κινεῖσθαι γὰρ καὶ τὰ θεῖα πάντα συνεχῶς 405b ἀεί, σελήνην, ἥλιον, τοὺς ἀστέρας καὶ τὸν οὐρανὸν ὅλον. Alcmaeon seems to have held opinions on the soul similar to these. For he said it was immortal because it. bore a resemblance to immortal beings. And this he attributed to it because it always moves; all heavenly things seem to be in motion continually—the sun, the moon, the stars, all heaven. § 61
τῶν δὲ φορτικωτέρων καὶ ὕδωρ τινὲς ἀπεφήναντο, καθάπερ Ἵππων· πεισθῆναι δ' ἐοίκασιν ἐκ τῆς γονῆς, ὅτι πάντων ὑγρά. καὶ γὰρ ἐλέγχει τοὺς αἷμα φάσκοντας τὴν ψυχήν, ὅτι ἡ γονὴ οὐχ αἷμα· ταύτην δ' εἶναι τὴν πρώτην ψυχήν. Some cruder thinkers, like Hippo, thought it was water. They seem to have been persuaded of this because semen is liquid in all animals. For he confutes those who say the soul is the blood, on the ground that semen, which is the inchoate Soul, is not blood. § 62
ἕτεροι δ' αἷμα, καθάπερ Κριτίας, τὸ αἰσθάνεσθαι ψυχῆς οἰκειότατον ὑπολαμβάνοντες, τοῦτο δ' ὑπάρχειν διὰ τὴν τοῦ αἵματος φύσιν. Others, such as Critias, held it was blood; that sensation was most distinctive of the soul; and that it was due to the nature of blood that this power was in it.
πάντα γὰρ τὰ στοιχεῖα κριτὴν εἴληφε, πλὴν τῆς γῆς· ταύτην δ' οὐθεὶς ἀποπέφανται, πλὴν εἴ τις αὐτὴν εἴρηκεν ἐκ πάντων εἶναι τῶν στοιχείων ἢ πάντα. For opinions have been given in favour of every element excepting earth: which no one has proposed, unless whosoever may have said it was derived from all the elements, or was identical with them, did so. § 64
ὁρίζονται δὴ πάντες τὴν ψυχὴν τρισὶν ὡς εἰπεῖν, κινήσει, αἰσθήσει, τῷ ἀσωμάτῳ· τούτων δ' ἕκαστον ἀνάγεται πρὸς τὰς ἀρχάς. διὸ καὶ οἱ τῷ γινώσκειν ὁριζόμενοι αὐτὴν ἢ στοιχεῖον ἢ ἐκ τῶν στοιχείων ποιοῦσι, λέγοντες παραπλησίως ἀλλήλοις, πλὴν ἑνός· φασὶ γὰρ γινώσκεσθαι τὸ ὅμοιον τῷ ὁμοίῳ· ἐπειδὴ γὰρ ἡ ψυχὴ πάντα γινώσκει, συνιστᾶσιν αὐτὴν ἐκ πασῶν τῶν ἀρχῶν. ὅσοι μὲν οὖν μίαν τινὰ λέγουσιν αἰτίαν καὶ στοιχεῖον ἕν, καὶ τὴν ψυχὴν ἓν τιθέασιν, οἷον πῦρ ἢ ἀέρα· οἱ δὲ πλείους λέγοντες τὰς ἀρχὰς καὶ τὴν ψυχὴν πλείω ποιοῦσιν. All, taken together, define soul, we may say, by three things: by movement, by sensation, and by immateriality. And each of these is reduced to elemental principles. Hence, in defining it as cognitive, they make it either an element or consist of several elements, one saying much the same as another (with a single exception). For they say that anything is known by what resembles it, and as the soul knows all things, go they constitute it of all principles: some saying that there is one cause and one element, and that the soul is a single thing—fire or water, for example; others that there are several principles, and that the soul is multiple. § 65
Ἀναξαγόρας δὲ μόνος ἀπαθῆ φησιν εἶναι τὸν νοῦν, καὶ κοινὸν οὐθὲν οὐθενὶ τῶν ἄλλων ἔχειν. τοιοῦτος δ' ὢν πῶς γνωριεῖ καὶ διὰ τίν' αἰτίαν, οὔτ' ἐκεῖνος εἴρηκεν οὔτ' ἐκ τῶν εἰρημένων συμφανές ἐστιν. But Anaxagoras, standing alone, says that mind is beyond the reach of influence and has nothing in common with other things. But, granted that this be true, he, did not explain how it acquires knowledge, in virtue of what cause; nor is this made clear by anything else he said. § 66
ὅσοι δ' ἐναντιώσεις ποιοῦσιν ἐν ταῖς ἀρχαῖς, καὶ τὴν ψυχὴν ἐκ τῶν ἐναντίων συνιστᾶσιν· οἱ δὲ θάτερον τῶν ἐναντίων, οἷον θερμὸν ἢ ψυχρὸν ἤ τι τοιοῦτον ἄλλο, καὶ τὴν ψυχὴν ὁμοίως ἕν τι τούτων τιθέασιν. διὸ καὶ τοῖς ὀνόμασιν ἀκολουθοῦσιν, οἱ μὲν τὸ θερμὸν λέγοντες, ὅτι διὰ τοῦτο καὶ τὸ ζῆν ὠνόμασται, οἱ δὲ τὸ ψυχρόν, <διὰ τὸ> διὰ τὴν ἀναπνοὴν καὶ τὴν κατάψυξιν καλεῖσθαι ψυχήν. Those who posit contraries as first principles also maintain that the soul consists of such contraries, while those who favour some one among contraries (hot or cold, or some other like these) make the soul, accordingly, one of these. Whence also some follow names, as those who allege that it is heat, because life is due to heat and is named from it. But those who identify the soul with cold say that it is named from respiration and breathing.
τὰ μὲν οὖν παραδεδομένα περὶ ψυχῆς, καὶ δι' ἃς αἰτίας λέγουσιν οὕτω, ταῦτ' ἐστίν. Such then are the opinions that have been transmitted to us about the soul, together with the reasons given for them. § 67
ST. THOMAS’S COMMENTARY

LECTIO 5
In praecedentibus ostendit in quo antiqui philosophi conveniebant quantum ad considerationem de anima; in hoc scilicet, quod anima est principium motus et cognitionis. In parte autem ista ostendit qualiter dicti philosophi diversificati sunt circa hoc commune. Dividitur autem pars ista in partes tres. Primo enim ponit radicem diversitatis philosophorum quantum ad considerationem de anima. Secundo vero illam diversitatem specialiter enumerat, ibi, unde quibusdam, et cetera. Tertio colligit et epilogat ea, quae circa huiusmodi diversitates consideranda sunt, ibi, definiunt autem omnes et cetera. Radix autem diversitatis philosophorum in consideratione de anima est, quia ipsi attribuebant animam principiis, sicut dictum est: et ideo secundum differentiam dictorum philosophorum circa considerationem principiorum, est etiam differentia ipsorum in consideratione de anima. Dicti vero philosophi, licet omnes ponant animam componi ex principiis, non tamen conveniunt quod ponant animam componi ex eisdem principiis: sed sicut differunt de principiis, ita etiam differunt de consideratione animae. 53. In the preceding chapters Aristotle has shown the old philosophers agreeing in their analysis of the soul, in that they all regarded it as the origin of movement and knowledge. in the section beginning now he shows how they variously interpreted that common presupposition. This section falls into three parts: in the first he shows the root of the divergence of these philosophers in their teaching on the soul; the second enumerates the various points of difference (beginning at ‘Hence some’); the third summarises all that we have to consider in these differences (at ‘All, taken together’). The root of the divergence of the philosophers in their teaching on the soul is to be looked for in the way they analysed it into its ultimate elements; as they disagreed about these elements so did they differ about the soul. They all agreed that the soul was made up of ultimate elements, but they could not agree that it was made up of the same elements; and, differing as to the elements, they differed in their theories of the soul.
Differunt autem de principiis quantum ad duo. Primo quantum ad substantiam principiorum, quae scilicet sint, et quantum ad numerum, quot scilicet sint. Quantum autem ad substantiam quidem, quia quidam ponebant principia corporalia: illi scilicet qui posuerunt ignem, aut aquam aut aerem: quidam vero incorporalia et immaterialia, sicut qui posuerunt numeros et ideas: quidam vero miscentes utraque, sicut Platonici, qui posuerunt principia sensibilia et separata. Circa numerum vero, seu multitudinem differunt: quia quidam posuerunt tantum unum primum principium, sicut Heraclitus, qui posuit aerem, et alius ignem; quidam vero dicunt plura prima principia, sicut Empedocles qui posuit quatuor elementa. Et secundum has suppositiones de principiis consequenter assignant animam his principiis; quia qui ponebant principia materialia, dixerunt animam ex ipsis componi, sicut Empedocles; et similiter hi, qui ponebant immaterialia: sicut Plato. Omnes autem existimaverunt animam esse id quod maxime motivum est. 54. They differ in two ways about the ultimate elements: first, as to their essential nature, i.e. ‘what’ they are; secondly, as to their number, ‘how many’ they are. As regards their essential nature, some said these principles were corporeal (fire or water or air) while others said they were incorporeal and immaterial, such as those who spoke of numbers and ideas; and there were others, like the Platonists, who blended both views and allowed that there existed both sensibly perceptible and separate immaterial principles. As to their number or multiplication, there were some who admitted only one principle. Heraclitus, for instance, said it was air; and someone else, fire; while others said there were many principles—Empedocles for instance, who maintained the theory of the four elements. And their theories of the soul in respect of the elements followed these various hypotheses concerning ultimate elements. Those who held to a theory of material first principles, like Empedocles, said the soul was composed of such; and those, like Plato, who held to immaterial principles, said that the soul was composed of these. But one and all considered the soul to be the chief source of movement.
Consequenter cum dicit unde quibusdam enumerat diversitatem philosophorum in speciali. Sciendum autem est, quod inter illos qui ponebant unum corporum esse principium rerum, nullus dignatus est ponere solam terram; sed alii posuerunt ignem primum principium: alii aerem, alii aquam, terram vero nullus posuit nisi qui posuit omnia elementa quatuor esse primum principium. Et ratio huius est, quia terra propter suam grossitiem, magis videbatur esse composita ex principiis, quam ipsa esset principium. Et ideo circa hanc partem tria facit. Primo enim ponit opiniones illorum, qui posuerunt primum principium et animam esse ignem. Secundo vero ponit opinionem illorum, qui posuerunt primum principium et animam esse aerem, ibi, Diogenes autem et cetera. Tertio vero ponit opinionem illorum qui posuerunt aquam esse primum principium et animam, ibi, magis autem rudium. 55. Next, at ‘Hence some’, he proceeds to run through the more particular differences between the philosophers. it should be noted that of those who thought that a corporeal thing was the first principle, not one deigned to identify this with mere earth. Some said it was fire, others air, others water, but nobody said it was earth, except those who thought that all the four elements together were the first principle. (The reason being that, with its density, earth seemed always to presuppose some more ultimate principle). Aristotle, then, does three things here. He gives first the views of those who identified the first principle and the soul itself with fire; secondly, of those who held that they were air (at ‘Now Diogenes’); and thirdly, the opinion of those who held that water was both the first principle and the soul (beginning at: ‘Some cruder thinkers’).4
Circa primum sciendum est, quod propter hoc quod animae attribuitur motivum et cognoscitivum, visum est quibusdam animam esse illud quod est maxime motivum et cognoscitivum; et quia illud quod est maxime subtile videbatur eis esse maxime motivum et cognoscitivum, ideo dixerunt animam esse ignem, qui est inter corpora magis subtilis et activus. Et licet plures essent huius opinionis, et sic opinarentur animam esse ignem, Democritus tamen subtilius et rationabilius dixit hoc enuncians propter quid utrumque eorum idest rationem motus et cognitionis magis expressit. Volebat enim, sicut dictum est, quod omnia essent composita ex atomis. Et licet secundum eum huiusmodi atomi essent principium omnium rerum, nihilominus tamen volebat, quod atomi, qui sunt figurae rotundae, essent de natura ignis: et ideo dicebat animam componi ex illis, qui sunt figurae sphaericae. Et haec, inquantum sunt prima principia, dicebant habere rationem cognoscendi; inquantum vero rotunda, rationem movendi; et ideo inquantum anima erat composita ex huiusmodi corporibus indivisibilibus rotundis, dicebat eam cognoscere et movere omnia. Unde ponens illa corpora rotunda de natura ignis, concordabat cum istis quod omnia essent de natura ignis. 56. As to the first of these groups, we should note that since movement and knowledge were ascribed to the soul, it appeared to some that the soul possessed these properties in the highest degree; and as movement and knowledge seemed to connote what is lightest and most rarified, they concluded that the soul was fire, which is the lightest and most rarified of bodies. And. while many were of this opinion and thought the soul was fire, Democritus more subtly and rationally explained ‘the reason for either fact’, that is, he expressed more clearly the nature of movement and of knowledge. He held, as we have seen,, that all things are made of atoms; and though for him these atoms were primary he maintained, nevertheless, that the round ones were of the nature of fire, so that the soul, he said, was composed of spherical atoms. Considered as first principles, these atoms were by nature cognitive, but considered as spherical they were mobile; hence he said that the soul knows and moves all things precisely because it is made up of these round, indivisible bodies. And in assuming that they were of the nature of fire, he agreed with those who thought that everything was fiery.
Consequenter cum dicit Anaxagoras autem ponit Anaxagorae opinionem: qui in hoc concordabat cum praecedentibus, quod eidem, scilicet animae, attribuit rationem cognoscendi et movendi. Hic autem aliquando videtur alterum dicere esse animam et intellectum, sicut dictum est superius sed aliquando utitur utrisque, scilicet anima et intellectu, sicut una natura. Ipse enim dicebat animam esse motivam et cognoscitivam: unde, cum ipse poneret intellectum moventem omnia et cognoscentem, pro eodem accipiebat animam et intellectum. Sed in hoc differebat ab aliis: quia Democritus ponebat animam esse naturae corporeae, utpote ex materialibus principiis compositam: Anaxagoras vero dicit intellectum esse simplicem ut excludat diversitatem in essentia, immixtum ut excludat componi cum alio, et purum ut excludat additionem ab alio. Sed movere et cognoscere assignat eidem principio, scilicet intellectui: nam intellectus ex natura sua habet quod sit cognoscens: motum autem habet, quia ipse, sicut dictum est, dicit intellectum omnia movere. 57. Then at ‘Anaxagoras, however’, Aristotle gives the view of Anaxagoras who agreed with the others already mentioned in ascribing knowledge and motion to the soul. Anaxagoras, as we saw, sometimes appears to distinguish between soul and intellect, but sometimes he uses both terms as though they meant the same thing. He ascribes to the soul motive power and knowledge, but he also says that intellect knows and moves all things, thus identifying the soul and the intellect. But he differed from the others in this, that whereas Democritus held that the soul was corporeal by nature, being composed of material elements, Anaxagoras said that intellect was ‘simple’, excluding intrinsic division from its essence, and ‘unmixed’, excluding composition with anything else, and ‘pure’, excluding any addition to it from outside. But he ascribed movement and knowledge to one and the same principle, i.e. the intellect; for intellect of its nature knows; and movement pertains to it, so he said, because it moves everything else.
Consequenter cum dicit videtur autem ponit opinionem cuiusdam philosophi, scilicet Thaletis; qui in hoc solum concordat cum superioribus, quia illud dicit esse animam, quod habet virtutem motivam. Hic enim, scilicet Thales, fuit unus de septem sapientibus. Et cum omnes alii studerent circa moralia, hic solus dedit se inquisitioni rerum naturalium, et est primus naturalis philosophus. Et ideo dicit, ex quibus reminiscuntur, scilicet qui volunt quod aqua esset principium omnium rerum. Hic enim secundum considerationem principii in rebus animatis opinabatur esse principium omnium rerum. Unde, cum principia seu semina omnium animatorum sint humida, voluit quod illud esset principium omnium rerum quod est maxime humidum; et quia huiusmodi est aqua, dixit aquam esse principium omnium rerum. Sed tamen non consequitur opinionem suam in hoc quod diceret animam esse aquam; sed illud dixit animam, quod habet virtutem motivam. Unde, cum lapis quidam, scilicet magnes, moveat ferrum, dixit illum habere animam. Ponantur ergo Anaxagoras et Thales cum istis; non quod dicant animam esse ignem; sed quia dicunt illud esse animam, quod habet rationem sensus et cognitionis, sicut dixit Anaxagoras: seu motus, sicut dixit Thales. 58. Next, at ‘It seems that Thales’, he states the opinion of a philosopher called Thales who had only this in common with the others mentioned above, that he identified soul with a motive force. This Thales was one of the Seven Wise Men; but while the others studied moral questions, Thales devoted himself to the world of nature and was the first natural philosopher. Hence Aristotle remarks ‘from what they recollect etc.’, referring to those who said that water was the basic principle of things. For Thales thought that the way to find the principle of all things was by searching into the principle of living things, and since all the principles or seeds of living things are moist, he thought that the absolutely first principle must be the most moist of things; and this being water, he said water was that principle. Yet he did not follow his theory to the point of saying that soul was water; rather, he defined it as that which has motive force. Hence he asserted that a certain stone, the magnet, had a soul because it moved iron. Anaxagoras and Thales, then, are included in the present list; not for identifying the soul with fire, but because the former said that the soul was the source of knowledge and sensation, and the latter that it was at the ,origin of movement.
Deinde cum dicit Diogenes autem ponit opiniones illorum, qui dicunt aerem esse primum principium et animam. Et ii quidem sunt tres. Primo ponit opinionem Diogenis, qui volebat quod aer esset principium omnium, et esset subtilissimum omnium corporum. Unde et animam dixit esse aerem, et ex hoc habere virtutem cognoscendi et movendi. Virtutem quidem cognoscendi habet, quia aer, secundum eum, est principium omnium. Cum enim cognitio fiat per simile, sicut dictum est, oportebat quod si anima cognosceret omnia, esset composita ex principiis omnium rerum. Virtutem vero movendi habet, quia aer est subtilissimum omnium corporum, et ideo maxime mobilis. 59. Where he says, ‘Now Diogenes’, Aristotle alludes to those who thought that air was the first principle and the soul. There were three of these. First there was Diogenes who held that air was the first principle and also the finest-grained of all bodies, and that the soul therefore was air,—hence its power to know and move. The knowing power was due to the fact that air was (as he said) the first principle; for as knowledge is through likeness, as we have seen, the soul could not know all things unless it included the principles of all. And the moving power was due, he said, to the fact that air was the finest-grained of bodies and therefore the most mobile.
Secundo cum dicit Heraclitus autem ponit opinionem Heracliti; qui non dicebat simpliciter aerem esse principium rerum, sed aliquod coniunctum aeri, scilicet vaporem, qui est medius inter aerem et aquam. Hic enim non posuit aquam, seu ignem vel aerem principium rerum, sed aliud medium, quia non posuit nisi materialia tantum: unde illud voluit esse principium rerum, quod esset magis remotum a contrarietate. Et hoc videbatur ei quod esset vapor: et ideo secundum hoc voluit, quod anima esset vapor, quia ex hoc dicebat animam maxime cognoscitivam et motivam esse. Ipse enim fuit huius opinionis, quod omnia essent in continuo fluxu, et quod nihil vel ad horam quiesceret, nec poterat aliqua oratio determinate dici. Unde cum vapor esset inter alia maxime fluxibilis, dixit illum esse omnium rerum principium. Et hunc dicit esse animam. Et dixit quod naturam cognoscitivam habet ex hoc quod est principium: motivam vero ex hoc quod est incorporalissimum et fluxibile. 60. Then at ‘Heraclitus, however’ he states the second opinion, that of Heraclitus who thought that not mere air but vapour, the blend of air and water, was the first principle. He could not allow that this was either water by itself, or fire, or air; it had to be something betwixt and between, because, being a materialist, he was concerned to find a principle midway between the opposite extremes of material quality. Thinking that vapour answered this requirement most precisely, he said that the soul was vapour; which explained its extraordinary capacity to know and to move. His view was, indeed, that everything was in continual flux, that nothing stayed the same even for one hour, and that no definite statement could be made about anything. And it was just because vapour is so unstable that he identified it with the first principle of all things; which, he said, was a soul. As the first principle, soul has the power to know, whilst as the least material and most fluid of things it has movement.
Tertio vero cum dicit similiter autem ponit opinionem Alchmaeonis, qui concordabat cum istis quantum ad motum tantum, qui dicebat animam esse quid mobilissimum. Unde quia semper movetur, assimilatur immortalibus, scilicet corporibus caelestibus: et ideo dicit eam immortalem, sicut corpora caelestia, et sic esse de natura caelesti et divina, quae semper movetur, ut luna, et sol, et huiusmodi, quae semper moventur et immortalia sunt. Nam secundum eum, sicut motus causat in eis immortalitatem, ita et in anima quae naturae mobilissimae est. 61. Thirdly, at ‘Alcmaeon seems,’ he gives the third opinion, Alcmaeon’s, which agrees with the others only as regards movement. This man said that the soul was pre-eminently a thing in motion, resembling in this the immortal heavenly bodies with their heavenly and divine nature. For he thought that the perpetual movement of the sun and moon and the rest, was the cause of their being immortal; and that the same inference was valid in the case of the soul.
Deinde cum dicit magis autem hic ponit opinionem illorum qui posuerunt aquam primum principium omnium rerum. Fuerunt enim quidam rudes discipuli, et sequaces Thaletis, qui, sicut dictum est, voluerunt comparare principium unius rei ad principium totius naturae: et isti videbant, quod principium omnium viventium sit humidum: unde opinabantur, quod eodem modo principium omnium rerum sit humidum. Cum igitur aqua sit humidius elementum inter cetera, dixerunt ipsam esse principium omnium rerum: et usque ad hoc secuti sunt magistrum suum, scilicet Thaletem. Sed in hoc differunt: quia Thales, licet poneret aquam esse omnium principium, non tamen dixit animam esse aquam, sed virtutem moventem, sicut dictum est. Isti vero de numero rudium dixerunt animam esse aquam, ut Hippo. Hic namque arguebat quosdam qui dicebant, animam esse sanguinem, ex hoc quod sanguis non est genitura seu semen rerum animatarum, quam dicebant esse primam animam: et hoc attribuebant aquae propter humiditatem. 62. Then at ‘Some cruder thinkers’, Aristotle states an opinion of some who made water the first principle. For there were certain rather crude followers of Thales who tried to make the principle of one particular thing an analogy of the first principle of Nature as a whole. Observing that moisture was fundamental to living things they concluded that it must be the first principle of an things; in short, that the latter was water. So far indeed they followed their master, Thales; but whereas he, though admitting water to be the first principle, would not, as we have seen, allow that the soul was water, but rather a motive force, his cruder disciples (such as Hippo) asserted that it was water. Hippo tried to refute those who said the soul was blood with the argument that blood is not the generating seed (which they called ‘the inchoate soul’) of animate things. He identified this with water on account of its humidity.
Consequenter cum dicit alii autem ponit opinionem cuiusdam philosophi, qui magis considerans animam quantum ad cognitionem, adhuc grossius locutus est de ipsa: dicens ipsam esse sanguinem. Cuius ratio est, quia in animali non est sensus sine sanguine; et ideo, cum anima sit principium cognoscendi, dixit ipsam esse sanguinem, sine quo non est sensus animali: exanguia enim, puta ossa, et ungues, et dentes, sine sensu sunt, licet nervi sine sanguine existentes maxime sensitivi sint. Et hoc dixit Critias. 63. Next, at ‘Others, such as Critias’ he alludes to a philosopher who was more interested in the soul’s knowledge. He was still cruder in his expressions, saying that the soul itself was blood. His reason was that sense-perception only takes place in animals through the medium of blood: for the bloodless organs, such as bones, nails and teeth are without sensation (he forgot the nerves which are extremely sensitive and yet bloodless). If then, he said, the soul is the root of knowledge, the soul must be blood. it was Critias who said this.
Quia vero posset quaeri, quare in consideratione de anima non facit mentionem de terra sicut de aliis elementis, ideo excusat se cum dicit omnia enim dicens quod secundum hoc opinati sunt de anima, sicut de principiis. Unde terra nullum iudicem accepit, idest nullus iudicavit eam esse principium, et per consequens nullus dixit animam esse terram, nisi forte aliquis dixerit animam componi ex omnibus principiis, sicut Empedocles, aut omnia principia, sicut Democritus. 64. In case anyone should wonder why he has not mentioned earth along with the other elements, Aristotle, at, ‘Opinions have etc.,’ explains that his predecessors’ views on the soul followed on what they thought about the first principles; and as nobody judged earth to be a first principle, nobody said it was the soul; unless we count those—such as Democritus and Empedocles—who said that soul was, or was composed of, all the principles.
Deinde cum dicit definiunt autem epilogat et colligit ex his omnibus, quae dixit, suam intentionem. Et primo quantum ad ipsa principia. Secundo vero quantum ad contrarietates, quae sunt in ipsis principiis, ibi, quicumque autem contrarietates et cetera. 65. Then, at ‘All, taken together,’ he summarises, concluding this part of the enquiry; and first with reference to the elements or principles themselves, and then with regard to the contrarieties that are found in them.
Quantum vero ad ipsa principia: quia ipsi tria attribuebant animae: scilicet quod sit quid subtilissimum, quod sit quid cognoscitivum, et quod sit quid motivum: et haec tria, scilicet sensus, motus et incorporeum, reducuntur in principium. Illud enim dicunt esse principium, quod est simplex. Item principium ex se habet, quod sit cognoscitivum, quia sicut dictum est, simile simili cognoscitur: unde et dicebant animam componi ex elementis, aut esse elementa, quia dicebant, quod simile simili cognoscitur, praeter Anaxagoram qui ponebat intellectum immixtum. Item, quia principium est subtilissimum, dicebant illud maxime motivum; et quia anima cognoscit omnia, dicunt ipsam componi ex omnibus principiis. Et hoc dicunt omnes: quia secundum quod ponunt principia, ita ponunt animam. Unde quicumque ponunt unam aliquam causam seu principium et elementum unum, isti dicunt animam esse illud unum, sicut iam patet: ut ignem, aut aerem, seu aquam. Item illi, qui dicunt plura principia esse, isti similiter aiunt animam esse plura illa, sive ex his componi. First, then, he notes that the soul has been described by all-in terms of these three notes: fineness of grain or texture (incorporeality); knowledge; movement; and that each of these notes has been also traced back to a first principle. For that is called a principle which is simple. Also a principle, it is said, is essentially cognitive (for, to recall what, was said above, I since like is known by like, they said that the soul was composed of, or even was, the elements of all things. Anaxagoras, to be sure, is an exception with his pure unmixed Intellect). Again, they identified the chief motive-force in things with a ‘principle’ since a principle is what is least corporeal. And the soul’s knowledge of all things proves, they said, that it was composed of all the principles or elements. All their theories turn on this correspondence between the soul and the first principles. Whoever posited some one cause or principle or element, such as fire, air or water, identified just that one with the soul. So, too, whoever upheld many principles either identified them with the soul. or with its component elements.
Et quia dixerat, quod omnes conveniunt in hoc, quod dicunt animam componi ex principiis, quia oportet cognosci simile simili: praeter unum, scilicet Anaxagoram: ideo cum dicit: Anaxagoras autem solus ostendit qualiter differt ab eis: dicens quod Anaxagoras solus dixit intellectum esse impassibilem, nec habere aliquid commune alicui, idest nulli eorum quae cognoscit similem. Sed qualiter cognoscit intellectus, neque Anaxagoras dixit, neque est manifestum ex his quae dicta sunt. 66. Having excepted Anaxagoras, touching the theory of the soul’s composition, he goes on, at ‘But Anaxagoras’ to show how this man differed from the others. He alone, says Aristotle, denied the passivity of the intellect, its share in the nature of the things that it knows. But how intellect knows, Anaxagoras does not say; nor can one infer anything certain from what he does say.
Consequenter etiam cum dicit quicumque autem colligit intentionem suam quantum ad contrarietates, quae in ipsis principiis sunt: dicens, quod quidam ponunt principia rerum contraria; et ii constituunt animam ex principiis contrariis, sicut Empedocles. Dans enim elementis caliditatem, frigiditatem, humiditatem et siccitatem, dat et animae inesse contrarietates has. Dixit enim, quod terra terram intuemur, aquam autem aqua, et cetera. Quidam vero posuerunt principium omnium esse unum elementorum, et illius qualitatem apposuerunt animae: ii quidem ignis caliditatem, qui dixerunt principium omnium esse ignem: illi vero qui dicunt primum principium aquam, apponunt animae frigiditatem. Unde secundum qualitates principiorum, quae ponunt, dicunt similiter esse animam, ut de natura caloris, aut frigoris, et huiusmodi. Et hoc etiam ostendunt ex nominibus, quibus nominant ipsam animam; quia illi, qui dicebant animam esse de natura caloris, denominabant eam a zaein vel zooein, idest vivere, quod denominatum est a zeein, quod est fervere. Illi vero, qui dicebant animam de natura frigoris, nominabant eam psychron, quod est frigidum, unde et ab hoc venit Psychi, idest anima propter refrigerationem, quae salvat animal ex respiratione. Sic ergo patet, quod alii nominabant animam a vita, scilicet illi qui dicebant ipsam de natura caloris. Alii autem respirationem, scilicet illi qui dicebant, quod erat de natura frigoris. Ex his omnibus concludit dicens, quod haec sunt, quae tradita sunt de anima, et propter quas causas sic dicunt de ipsa. 67. To end this section, Aristotle summarises what he has to say touching the contrariety of the above-mentioned principles to one another. Some, he says, arrange the first principles of things in pairs of opposites; and the soul also they regard as a synthesis of contraries. Thus Empedocles thought that the heat and cold, the moisture and dryness which he found ‘in the elements were intrinsic to the soul also. As earthy, he said, we know earth, as watery water, and so on. Others found their first principle in only one element, whose particular quality they then attributed to the soul. If it was fire, then the soul, they said, was hot; if water, then the soul was cold. According to the principle assumed so was the quality attributed to the soul, as though it shared in the nature of heat or cold etc. This is clear from the names they gave to the soul. Those who said it was hot gave it names derived from zaein or zooein, meaning to live, which itself comes from zeein, meaning to boil; while others who said it was cold called it psychron, meaning cold, whence comes psyche, a term applied to the soul because the coolness caused by breathing preserves animal life. Those who thought the soul by nature hot, named it from life; those who thought it by nature cold, from respiration. And Aristotle concludes by saying that the foregoing are the opinions handed down about the soul, together with the grounds on which they are maintained.

TEXT
405b32–406b14
BOOK I, CHAPTER III
ΚΕΦΑΛΑΙΟΝ Γ'

PREVIOUS THEORIES
SOUL AS A SELF-MOVING ESSENCE

405a31   Ἐπισκεπτέον δὲ πρῶτον μὲν περὶ κινήσεως· ἴσως γὰρ οὐ μόνον ψεῦδός ἐστι τὸ τὴν οὐσίαν αὐτῆς τοιαύτην εἶναι οἵαν 406a φασὶν οἱ λέγοντες ψυχὴν εἶναι τὸ κινοῦν ἑαυτὸ ἢ δυνάμενον κινεῖν, ἀλλ' ἕν τι τῶν ἀδυνάτων τὸ ὑπάρχειν αὐτῇ κίνησιν. ὅτι μὲν οὖν οὐκ ἀναγκαῖον τὸ κινοῦν καὶ αὐτὸ κινεῖσθαι, πρότερον εἴρηται. διχῶς δὲ κινουμένου παντός-ἢ γὰρ καθ' ἕτερον ἢ καθ' αὑτό· καθ' ἕτερον δὲ λέγομεν ὅσα κινεῖται τῷ ἐν κινουμένῳ εἶναι, οἷον πλωτῆρες· οὐ γὰρ ὁμοίως κινοῦνται τῷ πλοίῳ· τὸ μὲν γὰρ καθ' αὑτὸ κινεῖται, οἱ δὲ τῷ ἐν κινουμένῳ εἶναι (δῆλον δ' ἐπὶ τῶν μορίων· οἰκεία μὲν γάρ ἐστι κίνησις ποδῶν βάδισις, αὕτη δὲ καὶ ἀνθρώπων· οὐχ ὑπάρχει δὲ τοῖς πλωτῆρσι τόδε) -διχῶς δὴ λεγομένου τοῦ κινεῖσθαι νῦν ἐπισκοποῦμεν περὶ τῆς ψυχῆς εἰ καθ' αὑτὴν κινεῖται καὶ μετέχει κινήσεως. The first thing to be considered is movement. For perhaps it is not only false to say that this is the essence of the soul, as some mean when they say the soul is self-moving, or is able to move itself, but that there should be movement in it at all is an impossibility. It has already been stated that it is not necessary that everything that causes motion be itself moving. For everything moves in one of two ways: either by another, or of itself. We say, ‘by another’, of anything that moves through being in that which moves, like sailors; for these are not in motion in the same way as the ship. The latter moves of itself, but they through being in what moves. This is evident if we consider their parts. Walking is the proper motion of the feet—and also of men—; but for the time being the sailors do not walk. Movement being thus predicated in two ways, we now turn to the soul, asking whether it moves of itself and participates in motion. §§ 68-74
406a12 τεσσάρων δὲ κινήσεων οὐσῶν, φορᾶς ἀλλοιώσεως φθίσεως αὐξήσεως, ἢ μίαν τούτων κινοῖτ' ἂν ἢ πλείους ἢ πάσας. εἰ δὲ κινεῖται μὴ κατὰ συμβεβηκός, φύσει ἂν ὑπάρχοι κίνησις αὐτῇ· εἰ δὲ τοῦτο, καὶ τόπος· πᾶσαι γὰρ αἱ λεχθεῖσαι κινήσεις ἐν τόπῳ. εἰ δ' ἐστὶν ἡ οὐσία τῆς ψυχῆς τὸ κινεῖν ἑαυτήν, οὐ κατὰ συμβεβηκὸς αὐτῇ τὸ κινεῖσθαι ὑπάρξει, ὥσπερ τῷ λευκῷ ἢ τῷ τριπήχει· κινεῖται γὰρ καὶ ταῦτα, ἀλλὰ κατὰ συμβεβηκός· ᾧ γὰρ ὑπάρχουσιν, ἐκεῖνο κινεῖται, τὸ σῶμα. διὸ καὶ οὐκ ἔστι τόπος αὐτῶν· τῆς δὲ ψυχῆς ἔσται, εἴπερ φύσει κινήσεως μετέχει. Since there are four kinds of movement (local, by alteration, by increase, by decrease) its motion must be one of these, or some, or all. But if its movement is not incidental, then motion will be in it by nature: and if so, it will be [in] place; for all the aforesaid movements are in place. If it is the essence of the soul to move itself, to be in motion will not be in it incidentally, as in what is white or three cubits long; for these also participate in movement, but incidentally. For what moves is the body in which these inhere; hence of themselves they have no place; but the soul has it, if indeed it naturally participates in motion. §§ 75-7
ἔτι δ' εἰ φύσει κινεῖται, κἂν βίᾳ κινηθείη· κἂν εἰ βίᾳ, καὶ φύσει. τὸν αὐτὸν δὲ τρόπον ἔχει καὶ περὶ ἠρεμίας· εἰς ὃ γὰρ κινεῖται φύσει, καὶ ἠρεμεῖ ἐν τούτῳ φύσει· ὁμοίως δὲ καὶ εἰς ὃ κινεῖται βίᾳ, καὶ ἠρεμεῖ ἐν τούτῳ βίᾳ. ποῖαι δὲ βίαιοι τῆς ψυχῆς κινήσεις ἔσονται καὶ ἠρεμίαι, οὐδὲ πλάττειν βουλομένοις ῥᾴδιον ἀποδοῦναι. Further, if it moves by nature, so it will move by force; and if by force, then, by nature. And its rest will be in the same way. Whithersoever it moves by nature, there it will come to rest by nature; and likewise wheresoever it is moved by force, there it will come to rest by force. But what kind of enforced motions and rests will there be in the soul? To find an answer is not easy, nor, even to imagine one! §§ 78-9
ἔτι δ' εἰ μὲν ἄνω κινήσεται, πῦρ ἔσται, εἰ δὲ κάτω, γῆ· τούτων γὰρ τῶν σωμάτων αἱ κινήσεις αὗται· ὁ δ' αὐτὸς λόγος καὶ περὶ τῶν μεταξύ. Again, if it moves upwards, it will be fire; and if downwards, earth; for such are the movements of these bodies; and the same holds of the intermediate [elements]. § 80
ἔτι δ' ἐπεὶ φαίνεται κινοῦσα τὸ σῶμα, ταύτας εὔλογον κινεῖν τὰς κινήσεις ἃς καὶ αὐτὴ κινεῖται. εἰ δὲ τοῦτο, καὶ ἀντιστρέψασιν εἰπεῖν ἀληθὲς ὅτι ἣν τὸ 406b σῶμα κινεῖται, ταύτην καὶ αὐτή. τὸ δὲ σῶμα κινεῖται φορᾷ· ὥστε καὶ ἡ ψυχὴ μεταβάλλοι ἂν κατὰ τὸ σῶμα ἢ ὅλη ἢ κατὰ μόρια μεθισταμένη. εἰ δὲ τοῦτ' ἐνδέχεται, καὶ ἐξελθοῦσαν εἰσιέναι πάλιν ἐνδέχοιτ' ἄν· τούτῳ δ' ἕποιτ' ἂν τὸ ἀνίστασθαι τὰ τεθνεῶτα τῶν ζῴων. Since it seems to move the body, it would seem reasonable [to say] that it does so by the same motions as those by which it moves itself. If so, then it is true to say, conversely, that just as the body moves, the soul also moves. Now the body moves by change of place; hence the soul too will move in accordance with the body, either the whole or the parts being transposed. If this is so, then it might happen that after leaving the body it could return to it. (But it is utterly impossible that the dead rise again.) And it would follow that dead animals could rise again. §§ 81-83
τὴν δὲ κατὰ συμβεβηκὸς κίνησιν κἂν ὑφ' ἑτέρου κινοῖτο· ὠσθείη γὰρ ἂν βίᾳ τὸ ζῷον. οὐ δεῖ δὲ ᾧ τὸ ὑφ' ἑαυτοῦ κινεῖσθαι ἐν τῇ οὐσίᾳ, τοῦθ' ὑπ' ἄλλου κινεῖσθαι, πλὴν εἰ μὴ κατὰ συμβεβηκός, ὥσπερ οὐδὲ τὸ καθ' αὑτὸ ἀγαθὸν ἢ δι' αὑτό, τὸ μὲν δι' ἄλλο εἶναι, τὸ δ' ἑτέρου ἕνεκεν. If it does move, however, by something else, its motion will be incidental; for certainly an animal can be driven by force. But what has self-movement as of its essence cannot be moved by another, save incidentally; as that which is good in itself or for its own sake cannot exist for the sake of another, or on account of another.
τὴν δὲ ψυχὴν μάλιστα φαίη τις ἂν ὑπὸ τῶν αἰσθητῶν κινεῖσθαι, εἴπερ κινεῖται. One might certainly say that, if the soul is moved at all, it is moved by the objects of sensation. §§ 84-5
ἀλλὰ μὴν καὶ εἰ κινεῖ 406b12 γε αὐτὴ αὑτήν, καὶ αὐτὴ κινοῖτ' ἄν, ὥστ' εἰ πᾶσα κίνησις ἔκστασίς ἐστι τοῦ κινουμένου ᾗ κινεῖται, καὶ ἡ ψυχὴ ἐξίσταιτ' ἂν ἐκ τῆς οὐσίας, εἰ μὴ κατὰ συμβεβηκὸς ἑαυτὴν κινεῖ, ἀλλ' ἐστὶν ἡ κίνησις τῆς οὐσίας αὐτῆς καθ' αὑτήν. But if it moves itself it also is in motion. Hence if all motion is a displacement of the moved as such, then the soul must be displaced from its own essence by itself, unless its movement be incidental; but [in fact] this is a self-movement of its essence. § 86
ST. THOMAS’S COMMENTARY

LECTIO 6
Supra posuit philosophus opiniones aliorum philosophorum de anima: hic consequenter disputat contra eas. Sunt autem tria, quae dicti philosophi attribuebant animae: scilicet quod sit principium motus, quod sit principium cognitionis, et quod sit incorporalissimum. Inter quae duo ex eis, quae sunt quasi principalia, quae primo et per se animae attribuebant; scilicet quod sit principium motus, et quod sit principium cognitionis. Tertium autem, quod attribuebant animae, scilicet quod sit subtilissimum quantum ad aliquid bene dicitur, quantum ad aliquid male. Si enim subtilissimum accipiatur simpliciter dictum de anima, sic bene dicitur, quia sine dubio anima incorporalissima et subtilissima est. Si autem non accipiatur simpliciter, sed cum corpore, ut dicatur anima subtilissimum corpus, sic male dicitur. Et ideo philosophus non utitur nisi duobus tantum, scilicet motu et cognitione. 68. The Philosopher now begins to criticise the theories he has been recounting. These theories amount to three statements about the soul: that it is the source of movement and of knowledge, and that it is in a special way incorporeal. The two former attributions, the principal ones, have been predicated of the soul in an absolute sense, as referring directly to its essence. The third is, however, true in one sense and false in another. For if immateriality is taken as predicated simply and absolutely of the soul, then the statement is true; for soul is certainly the least material and most rarified of things. But if it is predicated only in relation to the body, as if to say that soul is the least material of bodies, then the statement is not true. Hence the Philosopher sets to work only with the two former attributions, of movement and of knowledge.
Dividitur autem pars ista in tres partes. Primo enim inquirit de anima contra opiniones philosophorum secundum quas dixerunt ipsam animam esse principium motus. Secundo contra opiniones eorum qui dixerunt ipsam esse principium cognitionis, ibi, tribus autem modis traditis, et cetera. Tertio vero movet quamdam quaestionem, utrum scilicet movere, sentire et cognoscere attribuantur animae sicut uni principio, vel sicut diversis, ibi, quoniam autem cognoscere animae est. Prima pars dividitur in duas. In prima disputat contra ea quae dicuntur de anima secundum quod est principium motus, ex eo quod ponunt ipsam principium motus. Secundo contra quamdam opinionem, quia supra hoc quod dixerant animam esse principium motus, quidam attribuunt ipsi animae aliquid aliud, scilicet quod sit numerus movens seipsum, ibi, multo autem his quae dicta sunt irrationabilius. Prima pars dividitur in duas. Primo enim disputat contra opiniones illorum, qui attribuebant motum animae, secundum quod ipsi attribuunt animae motum. Secundo inquirit, utrum per aliquam aliam viam, motus animae attribui possit, ibi, rationabilius autem dubitabit et cetera. Pars prima dividitur in duas. Primo enim disputat in communi contra illos, qui dicunt animam principium motus. Secundo vero descendit ad quasdam quaestiones in speciali, ibi, quidam autem et movere, et cetera. Prima pars dividitur in duas. Primo enim manifestat suam intentionem. Secundo ponit rationes ad propositum ostendendum, ibi, quatuor autem motus cum sint et cetera. 69. This part of the treatise falls into three divisions. Aristotle first argues against the philosophers who had made the soul the source of movement; then at ‘There are then three ways’ against those who regarded it as the seat of knowledge; and thirdly, at ‘Since knowledge pertains’ he raises the question whether movement, feeling and knowing ought to be attributed to the soul as to one principle or several. The first of these divisions is again divided. He first adduces objections against simply identifying the soul itself with a source of movement; and then against an opinion, proceeding from this identification, according to which the soul was also a self-moving number. (This comes at ‘Much the most unreasonable’. ) The former argument again subdivides into, first a criticism of the way in which these philosophers had predicated movement of the soul, and secondly, at ‘One might with more reason,’ a query whether this predication might have been made differently. Then the criticism is divided into, first, a general argument against all who said that the soul was the source of movement; and secondly, at ‘Some say that a soul moves’ a series of particular discussions of special points. Finally, the general argument is subdivided. First, he says what he intends to do; secondly, he argues ‘in support of his own opinion. The latter begins at ‘Since there are four kinds of movement’.
Dicit ergo primo, quod sicut ex superioribus habetur, philosophi ex duobus venerunt in cognitionem animae, scilicet motu et sensu. Et inter haec primo considerandum est de motu. Omnes autem philosophi, qui venerunt in cognitionem animae ex motu, hoc principium habebant commune, scilicet quod omne quod movet, movetur: unde quia naturale est animae quod moveret, credebant quod ei sit connaturale quod moveretur; et hoc habere animam ex substantia sua: unde et ponebant in eius definitione motum, dicentes animam esse quid movens seipsum. 70. He begins then by remarking that philosophers have studied the soul from two points of view, from motion and from knowledge. This is clear from what has been said. And Aristotle says that he will start from motion. Now all the others who started from this point of view had one notion in common, that everything that produces movement is itself moving. They thought therefore that if soul is by nature a cause of movement, it must be by its nature a moving essence. So they put movement into its definition, calling it something that moves itself.
Est ergo hic contra duo disputandum: scilicet contra rationem positionis, et contra ipsam positionem. Utrumque enim est falsum. Nam et ratio positionis istorum falsa erat, et eorum positio. Hoc enim quod supponebant tamquam per se verum, scilicet quod omne quod movet movetur, falsum est, sicut satis probatur in octavo physicorum: ubi ostenditur, quod est quoddam movens immobile. Et quantum ad hoc pertinet, breviter potest ostendi, quod si aliquid movet, non oportet quod moveatur. Constat enim quod secundum quod movet, est in actu, secundum quod movetur, est in potentia; et sic idem et secundum idem esset in actu et potentia: quod est inconveniens. 71. Now here there are two disputable points; the theory itself is disputable, and so is the principle upon which it rests. The principle presupposed as a self-evident truth, namely that every active mover is itself in movement, is in fact not true, as is clearly enough shown in Book VIII of the Physics, where Aristotle proves the existence of an unmoved mover. And as to this, we may give here a short proof that if a thing produces movement it does not have to be in movement itself. It is clear that in so far as a thing produces movement it is in act, and in so far as it is caused to move, it is in potency. (if then as causing movement it were moved), the same thing would be in act and potency in the same respect; which hardly makes sense.
Sed hoc praetermisso, disputemus ad positionem eorum, utrum scilicet anima moveatur. Dicebant autem isti, duo: scilicet quod anima movetur, et quod motus esset de substantia animae. Aristoteles autem utrumque negat, dicens, quod fortassis. Hoc dicit, quia nondum probaverat hoc quod dicit, non solum falsum est, quod motus sit de substantia animae, secundum quod dicunt definientes ipsam, dicentes animam esse quod est seipsum movens, aut possibile movere; sed totaliter impossibile est ipsi animae convenire, quod moveatur. 72. But even setting this difficulty aside, the theory that the soul is in movement is disputable. Its upholders indeed added the further proposition, that movement was of the soul’s essence; but Aristotle denies both parts of this theory where he says, ‘For perhaps’, etc. He puts it like this because he has not yet proved his assertion, namely that not only is it false to say that movement is of the essence of the soul (which is what they imply when they define the soul as an actual or potential self-mover) but that it is also quite impossible that the soul should move at all.
Et hoc prius dictum est, scilicet in octavo physicorum, videlicet quod non sit necesse omne movens moveri. In movente etiam seipsum duo sunt: unum movens, et aliud motum: et impossibile est, quod illud quod est movens, moveatur per se. In animalibus autem licet non moveatur per se pars movens, movetur tamen per accidens. Omne enim quod movetur, movetur dupliciter: quia vel secundum se, vel secundum alterum, seu per accidens. Secundum se, quando res ipsa movetur, ut navis: per accidens, vel secundum alterum, quando non movetur ipsum, sed illud in quo est: sicut nauta in navi movetur, non quia ipse moveatur, sed quia navis movetur. Unde haec est vera, scilicet navis movetur secundum se, nauta vero secundum accidens. Et quod non movetur nauta per se, patet: quia quando aliquis movetur per se, movetur secundum partes suas; sicut in ambulatione prius est pedum ambulatio, et hoc, cum est nauta in navi, non inest ei. Sic ergo patet, quod moveri dicitur dupliciter: secundum se et secundum accidens. Sed isti attribuebant animae moveri secundum se. Et ideo praetermisso ad praesens utrum anima moveatur per accidens, intendamus de anima si movetur secundum se et participat motu, sicut isti dicebant. 73. That not everything which causes movement need itself be moved was shown in an earlier work, Book VIII of the Physics. Now in any self-mover there are two things to be considered, the thing moving, and the thing moved; and the former cannot as such be the same as the latter. In living things, however, though the moving part is not moved in itself, absolutely speaking, yet it is moved indirectly. For there are two kinds of movement, direct and indirect: direct, when a thing itself is moving, e.g. a ship; indirect when a thing itself is at rest, but moved with the movement of something else which contains it, as the sailor on board ship moves with the ship’s movement, not his own. So the ship moves directly and in itself, but the sailor only in an accidental way or relatively. This is clear if we consider that when anything moves in itself, its parts are moving, as in walking the feet make the first movement; but once the sailor is on board this does not happen. Movement then can be taken in either of these two senses; but since the philosophers we are discussing said that the soul is moved in itself, directly, we can forgo at present the question whether it is moved indirectly, and consider only whether it is directly affected by movement, as they maintained.
Et quod non movetur per se, probat Aristoteles sex rationibus. Circa quas rationes considerandum est, quod licet rationes Aristotelis parum videantur valere, nihilominus sunt efficaces, quia sunt ad positionem: aliter enim argumentandum est ad eum qui simpliciter intendit veritatem, quia ex veris oportet procedere: sed qui arguit ad positionem, procedit ex datis: et ideo frequenter Aristoteles, et quando argumentatur ad positiones, videtur quod inducat rationes parum efficaces, quia procedit ex datis ad interimendum positionem. 74. To show that the soul does not move in itself, Aristotle uses six arguments, with regard to which we should note that, while they may not appear very cogent, still they are effective in relation to the theory he is criticising. For it is one thing to argue out the simple truth of a question, and another to reason against a particular theory; in the former case you have to make sure that your premises are true, but in the latter you proceed from what your adversary concedes or asserts. Hence it is that when Aristotle criticises the views of others, he often seems to use rather weak arguments. In each case he is, in fact, destroying his adversary’s position by drawing out its logical consequences.
Sic ergo primam rationem ponit ibi quatuor autem quae talis est. Si anima movetur, aut movetur per se, aut per accidens. Si per accidens, tunc motus non erit substantia animae: quod est contra eos; sed movetur sicut album et tricubitum, quae moventur secundum accidens, et ideo non exigitur ad hoc locus ipsis. Si vero movetur per se, ergo movetur aliqua specie motus. Species autem motus sunt quatuor: scilicet secundum locum, augmenti et decrementi, et alterationis. Generatio enim et corruptio non sunt proprie motus, sed mutationes; quia motus sunt successivi, sed generatio et corruptio sunt mutationes instantaneae. Ergo anima movebitur aliqua specie istorum motuum: vel secundum locum, vel secundum augmentum, vel secundum decrementum, vel secundum alterationem. Si ergo movetur aliquo istorum, et omnes hi motus sunt in loco: ergo anima erit in loco. 75. The first argument begins at ‘Since there are four kinds’, and may be stated as follows. If the soul moves, its movement is either direct (in the sense explained) or indirect. if indirect, then it is not of the essence of the soul (which is against their opinion), and the soul moves in the same way as whiteness or 3 inches, which are accidental qualities moving only with the thing that is white or 3 inches long, and not themselves, as such, requiring a position in space. But if the soul moves in itself, it moves in one of the four kinds of movement: change of place, growth, decrease or alteration. Coming-to-be and passing-away are not movements, strictly speaking, but changes, because they are instantaneous, whilst movements are successive. Hence the soul will have to move in one of these four ways—from place to place; by increase or decrease in size; or by qualitative alteration. But if all these movements involve position in space, the soul will then be localised in space.
In hac autem ratione videntur esse duo dubia. Unum de hoc, quod quidem de locali et de motu augmenti et decrementi manifestum est: sed de alteratione videtur difficile. Quod quidem sic intelligitur ab aliquibus: quia enim omne quod alteratur est corpus, et corpus est in loco, ideo alteratio dicitur fieri in loco. Sed hoc non salvat literam Aristotelis; quia Aristoteles dicit quod huiusmodi motus sunt in loco et non sunt secundum locum. Et ideo dicendum quod sine dubio alteratio est in loco. Aliud enim est motus in loco, et aliud motum esse secundum locum. Alteratio non est secundum locum, sed in loco. Nam in alteratione oportet quod sit appropinquatio alterantis ad alteratum, et sine hoc nihil alteratur. Unde cum appropinquatio fiat per motum localem, oportet quod sit ibi motus localis ut causa. 76. There seem to be two doubtful points in this argument. The first is that, while it is clear enough as regards locomotion, growth and decrease, it suggests a difficulty about alteration. Some meet this difficulty by saying that as only bodies are subject to alteration, and all bodies are in place, alteration itself may be said to occur in place. But this does not keep to the letter of the argument: Aristotle says that this kind of movement is in place and not merely according to place. Movement in place is quite different from movement according to place; and, following Aristotle, I maintain that alteration certainly occurs in place. Of itself, and not simply because of its localised subject, it is in place; for, when any alteration occurs, the agent producing it must draw near to the thing altered; otherwise nothing would ever be altered. And since drawing near is a local movement, it follows that here and now the cause of a given alteration is a change in place.
Secundum dubium est, quia secundum istos non erit inconveniens si anima esset in loco, cum ponerent eam moveri per se; et ideo non videtur valere sua ratio. Ad hoc autem potest responderi dupliciter. Uno modo, quod istud inconveniens deducitur per sequentes rationes. Alio modo, quia propter hoc est inconveniens, quia si anima esset in loco, oporteret quod assignaretur sibi locus proprius in corpore separatus, et sic non esset forma totius corporis. 77. The second difficulty is that these philosophers do not in fact see anything unreasonable in the soul’s being in place, since they maintain that it moves in itself, absolutely. So Aristotle’s objection seems to misfire. To this two answers might be given, (a) that the objection to the soul’s being in place will become clearer as we proceed, and (b) that if the soul were in place, it would have to be assigned a definite position in the body and thus would not be the form of the whole body. This reinforces the objection to the soul’s being in place.
Secundam rationem ponit cum dicit amplius autem quae talis est. Si anima movetur per se secundum locum, movetur naturaliter: omne autem quod movetur naturaliter, movetur violenter: sed si movetur naturaliter quiescit naturaliter, et si quiescit naturaliter quiescit violenter; ergo anima movetur violenter, et quiescit violenter. Sed hoc est impossibile, scilicet quod moveatur violenter et quiescat violenter, quia motus animae et quies sunt voluntarii. 78. The second argument, at ‘Further, if it moves’, is this. If the soul moves ‘absolutely’ from place to place, the movement must be natural to it. But anything that can be moved naturally can be moved violently.’ Now its natural movement implies a natural ceasing to move; and therefore also its enforced, violent movement implies an enforced ceasing to move. Hence the soul may both move and stop moving under compulsion; which is impossible if by nature both its movement and ceasing to move are spontaneous.
In hac autem ratione videtur dubium esse: scilicet quod id quod movetur naturaliter, non tamen violenter. Ad hoc dicendum est, quod illa propositio secundum veritatem falsa est, sed secundum positionem vera; quia isti nullum corpus ponebant naturaliter motum, nisi quatuor elementa, in quibus videmus motus et quietes naturaliter et violenter fieri; et secundum hoc procedit ratio. 79. A difficulty here seems to be that what moves naturally does not in fact move under compulsion. I answer that what Aristotle says is false absolutely speaking, but true relative to the theory under discussion. For these philosophers maintained that the only bodies that moved with a natural movement were the four elements; in which we do observe both natural and enforced movement and ceasing to move. This opinion is presupposed by the argument.
Tertiam rationem ponit cum dicit amplius si quidem quae talis est. Illi dicunt quod anima movetur, et ex hoc movet corpus: et hunc motum dicunt habere ab aliquo elementorum: aut ergo sequitur motum ignis, aut terrae, aut aliorum elementorum. Si ergo participat motum ignis, movebitur solum sursum: si terrae, deorsum. Sed hoc est falsum, quia anima movet ad omnem partem. Et haec ratio procedit ex suppositione. 80. The third argument, at ‘Again, if,’ runs as follows: these men who ascribe movement primarily to the soul, and to the body only as derived from the soul, also say that this movement is due to one or other of the elements, fire or earth or one of the others. But if the soul moved with the nature of fire it would only rise; if with the nature of earth it would only sink; whereas in fact it moves in all directions. This argument also is ad hominem.
Quartam rationem ponit cum dicit quoniam autem quae talis est. Vos dicitis animam ex hoc moveri, quod movet corpus; ergo rationabile est dicere, quod illis motibus movet corpus, quibus ipsa movetur: et e converso, verum erit dicere, quod illis motibus movetur, quibus movet corpus. Sed corpus movetur secundum loci mutationem: ergo anima movetur secundum locum. Sed si moveri animam secundum locum est mutare corpus, contingit ipsam animam exeuntem iterum intrare corpus. Et quia animam ingredi corpus est vivificare corpus: sequitur ad hoc, mortua de numero animalium, secundum naturam resurgere, quod est impossibile. 81. The fourth argument comes at ‘Since it seems’. It is this. You say that it is in moving the body that the soul moves. Logically, then, it follows that it moves the body by its own movements; and conversely that it is moved by the same movements which move the body. But the body moves by changing position in space; so also then the soul. But if the soul’s local movements affect the body, the soul might, after leaving the body, enter it once more. And since it is the soul’s presence that gives life to the body, it follows that dead animals might, even naturally, come back to life: which is impossible.
Contra hanc rationem aliqui obiiciunt, dicentes, quod hoc scilicet quod anima moveat eisdem motibus quibus movetur, non est verum, quia anima non movetur nisi secundum appetitum et voluntatem, movet autem corpus aliis motibus. Ad quod dicendum, quod appetere, et velle, et huiusmodi, non sunt motus animae, sed operationes. Motus autem et operatio differunt, quia motus est actus imperfecti, operatio vero est actus perfecti. Nihilominus tamen vera est illa propositio secundum positionem; quia illi dicebant animam non aliter mobilem, nisi secundum quod movet corpus. 82. Against this argument some have objected that it ignores the difference between the movements which affect the soul itself and those by which it moves other things, including the body. The former are movements of desire and will; not so the latter. But in reply one may say that desires and volitions and so on are not properly ‘movements’ of the. soul but ‘operations’. ‘Movements’ and ‘operations’ are different: a movement is an act of something that is incomplete, whereas an operation is an act of a subject already possessing full actuality. Still, what Aristotle says is true relative to the theory under discussion; for this had identified all the movements of the soul with those by which it moved the body.
Sed numquid sequitur illud inconveniens, quod resurgant corpora animalium, si anima movetur secundum locum? Dicendum, quod quidam dixerunt quod anima est commixta toti corpori, et unita secundum quamdam proportionem, et quod non separatur nisi solvatur illa proportio: unde quantum ad istos non sequitur. Sed quantum ad illos qui dicunt animam esse in corpore ut in loco seu in vase, et intrare et egredi aliquando, sequitur illud inconveniens Aristotelis. 83. But is it true that if the soul had local movement dead animals would come to life again? Well, some philosophers have maintained that the soul pervades the whole body, forming a unity with it through some kind of proportion, and that the two cannot be separated without this proportion being destroyed; so that, so far as this view is concerned, the conclusion would not follow. But it does follow from—and is a valid objection against—the opinion of those who say the soul is located in the body as in a vessel which it sometimes enters and sometimes leaves.
Quintam rationem ponit cum dicit movet autem quae talis est. Constat, quod illud quod secundum se inest alicui rei, non est necesse quod insit ei secundum aliud, nisi forte per accidens. Si ergo inest animae quod moveatur secundum se et secundum naturam suam, necessarium est quod anima sit mobilis secundum se; ergo non indiget quod moveatur per aliud et ab alio. Sed nos videmus, quod movetur a sensibilibus in sentiendo, et ab appetibilibus in appetendo; non ergo anima per se movetur. 84. The fifth argument comes at ‘If it does move’, and runs as follows. It is clear that when anything is of the essence of a given subject its presence in the latter does not need, except incidentally, to be explained by anything else. If then the soul is essentially moving, it is mobile of its own nature; it does not need to be moved through or by anything else. But we know that it is in fact moved by sensible objects when it senses, and by things desirable when it desires; therefore it does not move of itself.
Ad hoc obviant Platonici, dicentes, quod anima non movetur a sensibilibus, sed occurrunt motui animae, inquantum anima discurrit per ea. Sed hoc est falsum; quia sicut Aristoteles probat, intellectus possibilis reducitur per ipsa, scilicet per species rerum sensibilium, in actum; et ideo oportet quod moveatur ab eis hoc modo. 85. The Platonists meet this argument by denying that the soul is moved by sensible objects; these, they say, are merely involved in the soul’s own movement when it passes from one object to another. But this is untrue. As Aristotle has proved, the intellectual potency is brought into act precisely by means of the sensible objects as apprehended; so that it is moved by them in this way.
Sextam rationem ponit cum dicit at vero quae talis est. Si anima movet seipsam, constat quod ipsa movebitur secundum suam substantiam: sed omne quod movetur, distat vel exit ab eo a quo et secundum quod movetur; sicut si aliquid movetur a quantitate, exit et distat ab ipsa quantitate qua movetur. Si ergo anima movetur a substantia sua et a seipsa, sicut illi dicunt; et distabit et exibit a substantia sua; et sic motus erit sibi causa corruptionis: quod est contrarium illis, qui dicebant animam propter motum ipsum assimilari divinis et immortalem esse, ut superius patet. Et haec ratio procedit quantum ad eos, qui non distinguebant inter operationem et motum. Operatio enim non facit distare, sed perficit operantem: sed in motu oportet quod sit exitus. 86. The sixth argument begins at ‘But if it moves itself’. Clearly, if the soul is self-moving, its own essence governs its movement. But in every movement the moving thing comes away or proceeds from that which moves it and governs its movement; for instance, if anything is moved by a quantity, it departs and proceeds from the latter. If then the soul is moved by its own essence (as they say) it must depart or proceed from its own essence; which is as much as to say that it causes its own destruction. How then could it be through movement that the soul becomes god-like and immortal, as some philosophers whom we have mentioned supposed?, This argument bears against those who did not distinguish between movement proper and operation. For movement implies that what is moved comes away from the cause of movement; but operation is a perfection intrinsic to the operating agent itself

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406b15–407a2
BOOK I, CHAPTER III, CONTINUED

SOUL AS A MOVER OF THE BODY
DEMOCRITUS AND PLATO

ἔνιοι δὲ καὶ κινεῖν φασι τὴν ψυχὴν τὸ σῶμα ἐν ᾧ ἐστιν, ὡς αὐτὴ κινεῖται, οἷον Δημόκριτος, παραπλησίως λέγων Φιλίππῳ τῷ κωμῳδοδιδασκάλῳ· φησὶ γὰρ τὸν Δαίδαλον κινουμένην ποιῆσαι τὴν ξυλίνην Ἀφροδίτην, ἐγχέαντ' ἄργυρον χυτόν· ὁμοίως δὲ καὶ Δημόκριτος λέγει· κινουμένας γάρ φησι τὰς ἀδιαιρέτους σφαίρας, διὰ τὸ πεφυκέναι μηδέποτε μένειν, συνεφέλκειν καὶ κινεῖν τὸ σῶμα πᾶν. Some say that a soul moves the body in which it dwells just as it moves itself; as did Democritus, who spoke like Philip the comic poet; for the latter relates that Daedalus made a wooden Venus mobile by pouring quicksilver into it. Democritus, then, spoke in like manner, saying that there are in movement indivisible globules of which the nature is to be never at rest, and which therefore draw together and move the whole body. §§ 87-8
ἡμεῖς δ' ἐρωτήσομεν εἰ καὶ ἠρέμησιν ποιεῖ τοῦτο αὐτό· πῶς δὲ ποιήσει, χαλεπὸν ἢ καὶ ἀδύνατον εἰπεῖν. Now, what we would ask is, whether this is also the cause of coming to rest? How it could be, on this hypothesis, is difficult to see, indeed impossible. § 89
ὅλως δ' οὐχ οὕτω φαίνεται κινεῖν ἡ ψυχὴ τὸ ζῷον, ἀλλὰ διὰ προαιρέσεώς τινος καὶ νοήσεως. The soul seems, in general, not to move the animate being in this way, but rather by a sort of choice and understanding. § 90
τὸν αὐτὸν δὲ τρόπον καὶ ὁ Τίμαιος φυσιολογεῖ τὴν ψυχὴν κινεῖν τὸ σῶμα· τῷ γὰρ κινεῖσθαι αὐτὴν καὶ τὸ σῶμα κινεῖν διὰ τὸ συμπεπλέχθαι πρὸς αὐτό. In the same way, the Timaeus sets out a physical theory as to how the soul moves the body. For, from the fact that the soul moves itself, it moves the body, as a result of its connection with the body. § 91
συνεστηκυῖαν γὰρ ἐκ τῶν στοιχείων καὶ μεμερισμένην κατὰ τοὺς ἁρμονικοὺς ἀριθμούς, ὅπως αἴσθησίν τε σύμφυτον ἁρμονίας ἔχῃ καὶ τὸ πᾶν φέρηται συμφώνους φοράς, ‘Being compounded of the elements and divided according to harmonic numbers, so that it have a connatural sense of harmony, and the whole be borne along with well attuned motions, §§ 92-8
τὴν εὐθυωρίαν εἰς κύκλον κατέκαμψεν· καὶ διελὼν ἐκ τοῦ ἑνὸς δύο κύκλους δισσαχῇ συνημμένους 407a πάλιν τὸν ἕνα διεῖλεν εἰς ἑπτὰ κύκλους, ὡς οὔσας τὰς τοῦ οὐρανοῦ φορὰς τὰς τῆς ψυχῆς κινήσεις. [God] bent the straight line into a circle, and, dividing it, made out of one two circles, adjusted at two points; and, again, he divided one of these into seven circles, as though the heavenly motions were the soul’s motions.” §§ 99-106
ST. THOMAS’S COMMENTARY

LECTIO 7
Supra posuit philosophus rationes in communi contra eos qui posuerunt animam secundum se moveri: hic vero ponit rationes in speciali contra quosdam qui aliquid specialis difficultatis videntur dixisse circa opinionem eorum de motu animae. Et circa hoc tria facit. Primo enim ponit rationes ad opinionem Democriti. Secundo vero ad opinionem Platonis, ibi, eodem autem modo et cetera. Tertio vero ad quamdam aliam opinionem, ibi, alia autem quaedam opinio, et cetera. Circa primum duo facit. 87. Having argued in a general way against the view that movement pertains essentially to the soul, the Philosopher now brings forward arguments against particular philosophers whose theories of the movement of the soul seem to give rise to some special difficulty. These arguments fall into three groups. First, he opposes an opinion of Democritus; then, at ‘In the same way’, one of Plato; and thirdly, at ‘There is another opinion’ another theory.
Primo enim ponit opinionem Democriti de motu animae, et exponit eam. Secundo vero obiicit in contrarium, ibi, nos autem interrogabimus. He begins, then, by stating the view of Democritus on the soul’s movement; and then brings objections against it.
Circa primum sciendum est quod in praecedentibus ponitur in una ratione, scilicet in quarta Aristotelis contra illos, qui ponunt animam moveri secundum se et ex hoc movet corpus. Quod si anima movet corpus, necesse est, quod illis motibus moveat, quibus ipsa movetur. Et hoc concedebant quidam, qui dicunt animam movere corpus in quo est, sicut ipsa movetur, idest illis motibus movere, quibus ipsa movetur. Et hic fuit Democritus. Et inducebat ad hoc similitudinem: quia erat quidam magister comoediarum nomine Philippus. Hic recitavit in libris suis, quod quidam nomine Daedalus fecit statuam ligneam deae Veneris, et haec statua erat mobilis ex eo, quod erat intus argentum fusile, idest vivum, et movebatur motu ipsius argenti vivi. Simile ergo huic dicit Democritus in opinione sua de motu animae. Dicit enim quod anima est composita ex indivisibilibus sphaeris, ut superius patet. Et quia huiusmodi indivisibiles sphaerae, idest atomi, sunt figurae rotundae, continue moventur, et ex eo quod numquam quiescunt, contrahunt et movent totum corpus secundum quod ipsae moventur. 88. This theory has already been referred to by Aristotle in his fourth objection to the view that the soul moves in itself and by this movement makes the body move. If the soul moves the body, he has said, it must do so in virtue of its own movement. This was admitted by those who said that each soul moved its own body in a manner corresponding to the movement in itself; among whom was Democritus who made use of the following illustration. There was a certain comic dramatist called Philip who tells somewhere of one Daedalus, that he made a wooden statue of the goddess Venus, and that this statue, being filled with quicksilver, was able to move. It moved as the quicksilver moved. And what Democritus said of the soul’s movement was rather similar. The soul, he said, (as has been noted above) was composed of indivisible spheres or atoms which, being round in shape, were always moving about, and by their incessant movement made the whole body cohere and move accordingly.
Deinde cum dicit nos autem obiicit Aristoteles contra hanc opinionem Democriti, duabus rationibus. Prima ratio talis est. Constat, quod anima non solum est causa motus in animali, sed quietis. Sed secundum opinionem Democriti, anima non est causa quietis, licet sit causa motus in animali: quia difficile aut impossibile est dicere, quod illa corpora sphaerica indivisibilia quiescant, cum nunquam immota permaneant, ut dictum est. 89. Then, at ‘Now, what we, etc.’, Aristotle puts two objections to this. First, it is agreed that in animals the soul is the cause of resting, as well as the cause of movement. But according to Democritus the soul is never the cause of rest, though it is the cause of animal movements. For he could hardly maintain that those spherical atoms ever rested if they never cease to move.
Secundam rationem ponit cum dicit omnino autem quae talis est. Constat quod motus, quem argentum vivum causat in statua, non est motus voluntarius, sed violentus. Sed motus animae non est violentus, sed voluntarius, quia movet per voluntatem et intellectum, et ideo nulla, ut videtur est positio Democriti. 90. Again, at ‘The soul seems’ he puts a second objection. The movement caused by quicksilver in the statue is obviously not spontaneous; it is a compelled movement. On the contrary, that of the soul is spontaneous, proceeding from mind and will. Hence the view of Democritus seems worthless.
Deinde cum dicit eodem autem ponit opinionem Platonis. Et circa hoc duo facit. Primo enim ponit opinionem Platonis. Secundo reprobat eam, ibi, primum quidem igitur et cetera. Circa primum duo facit. Primo ostendit similitudinem opinionis Platonicae ad opinionem Democriti. Secundo explicat opinionem Platonis de anima, ibi, constitutam autem ex elementis et cetera. Dicit ergo primo, quod sicut Democritus posuit corpus moveri ab anima inquantum anima coniuncta ipsi movetur, ita et Timaeus qui introducitur a Platone loquens, assignat rationem qualiter anima movet corpus. Dicit enim, quod anima movet corpus inquantum ipsa movetur, propter hoc quod anima coniuncta est corpori per modum cuiusdam colligationis. 91. Then at ‘In the same way’ he first states the opinion of Plato, which, at ‘Now in the first place,’ he will reject. But before explaining what Plato said about the soul he shows its similarity to the theory of Democritus. As Democritus had supposed that the soul’s movements moved the body to which it was joined, so also did Timaeus, a speaker introduced by Plato. For he said that soul moves body in so far as soul itself moves; because the two are, as it were, bound up together.
Deinde cum dicit constitutam autem explicat opinionem Platonis. Et primo exprimit constitutionem substantiae ipsius. Secundo exponit quomodo ex ea procedit motus, ibi, aspectum rectum in circulum reflexit. Circa primum sciendum est, quod Plato haec verba, quae hic ponuntur, in Timaeo prosequitur loquens de anima mundi, quam imitantur, secundum ipsum, inferiores animae. Et ideo per hoc quod hic tangitur de natura animae mundi, tangitur quodammodo natura omnis animae. Sciendum est igitur, quod sicut supra dictum est, Plato posuit substantiam omnium rerum esse numerum, ratione superius dicta. Elementa autem numeri ponebat unum quasi formale, et duo quasi materiale. Ex uno enim et duobus omnes numeri constituuntur. Et quia impar numerus quodammodo retinet aliquid de indivisione unitatis, posuit duo elementa numeri, par et impar; et impari attribuit identitatem et finitatem, pari autem attribuit alteritatem et infinitatem. 92. With ‘Being compounded, etc.’ Aristotle makes Plato’s view explicit; first as to what constitutes the essence of the soul, at ‘God bent, etc.,’ as to how movement proceeds from it. Regarding the former question, note that the words quoted here are used by Plato in the Timaeus and refer to the Soul of the world which, according to him, is imitated by inferior souls. So when he touches, as here, on the nature of the World-Soul, he refers also, in a way, to any soul. Now Plato, for the reason already given, maintained that the essence of all things was numerical; and that in number the formal element, so to say, was one and the material element two—all numbers being made up of one and two. And as odd numbers retain something of the indivision of one, he laid down two elements of number, the even and the odd, attributing to the odd identity and finitude, but to the even difference and infinity.
Cuius signum tangitur in tertio physicorum; quia si supra unitatem impares numeri per ordinem adduntur, semper producitur eadem figura numeralis. Puta, si supra unum addantur tria, qui est primus impar consurgunt ipsum quatuor, qui est numerus quadratus: quibus rursus si addatur secundus impar, scilicet quinarius, consurgit novenarius, qui item est numerus quadratus, et sic semper in infinitum. Sed in numeris paribus semper surgit alia et alia figura. Si enim unitati addatur binarius, qui est primus par, consurgit ternarius, qui est numerus triangularis; quibus si rursus addatur quaternarius, qui est secundus par, consurgit septenarius, qui est septangulae figurae, et sic in infinitum. Sic ergo Plato ponebat idem et diversum esse elementa omnium rerum, quorum unum attribuebat numero impari, aliud vero numero pari. 93. Some explanation of this theory may be found in the Physics, Book III. If odd numbers are added to unity in sequence the same type of number 2 always results; e.g. if 3, the first odd number, is added to 1, you get the square number 4; if to 4 You add the second odd number, 5, you get 9, Which is also a square number; and so on to infinity. But with even numbers the result is always a different type of number. Add 2, the first even number, to 1, the result is the ‘triangular’ number 3; to which if you add 4 the second even number, you get 7 which is ‘septangular’; and so on to infinity. Hence Plato made Identity and Difference the first elements of all things, attributing the former to odd numbers, the latter to even.
Quia vero substantiam animae ponebat mediam inter substantias superiores, quae semper eodem modo se habent, et substantias corporeas in quibus alteritas et motus invenitur: posuit animam constare ex his elementis, scilicet ex eodem et diverso, et ex numeris paribus et imparibus. Medium enim debet esse affine utrique extremorum. Et ideo dicit, quod posuit eam constitutam ex elementis. 94. And because he placed the soul mid-way between the higher substances, which never change, and corporeal substances, which change and move, he thought that the soul was constituted of the elements of Identity and Difference, and so of odd and even numbers. For the mean must participate in both extremes. This is why Aristotle says that Plato held the soul to be constituted by these elements.
Item sciendum est, quod in numeris sunt diversae proportiones, et infinitae; quarum aliquae sunt harmonicae, idest consonantiarum causa. Nam dupla proportio est causa consonantiae, quae dicitur diapason; sesquialtera proportio causat consonantiam, quae dicitur Diatessaron; sesquioctava proportio causat tonum; et aliae consonantiae, quibusdam aliis proportionibus causantur. Puta, ea quae est composita ex diapason et diapente, causatur ex tripla: ea quae sub diapason causatur ex quadrupla, quam quidem Pythagoras deprehendit, ut Boetius refert in musica, ex percussione quatuor malleorum, qui consonantes sonos reddebant secundum praedictas proportiones. Puta si unus martellus ponderaret duodecim uncias, alius novem, alius octo, alius sex, ille qui esset duodecim haberet duplam proportionem ad eum qui sex, et redderetur cum eo consonantia diapason. Ille autem qui est duodecim ad eum qui octo sub sesquialtera proportione, et consonat secundum diapente; et similiter qui novem ad eum qui sex. Item qui duodecim ad eum qui novem est in sesquitertia proportione, et consonat cum eo Diatessaron; et similiter qui octo ad eum qui sex. Qui autem novem ad eum qui octo, cum sit in sesquioctava proportione, consonat secundum totum. 95. Again, we should note that in numbers there are different proportions and infinities, of which some are harmonic, i.e. the cause of harmony. The double proportion causes the harmony called a whole octave; that of 3 to 2 causes the harmony called a fifth; (that of 4 to 3 causes the harmony called a fourth); that of 9 to 8 causes a tone; and the other harmonies are caused by other proportions: for example the harmony composed of an octave and a fifth is caused by the triple proportion; that of the double octaves is caused by the quadruple proportion which was discovered by Pythagoras, as Boethius [De Musica, I, 10] relates, from the striking of four hammers which sounded in harmony according to the aforesaid proportions. Thus if one hammer weighed twelve ounces, one nine, one eight and one six, the one that weighed twelve ounces would be in the proportion of two to one to the one weighing six, and the two together would render the harmony of the octave. Again, the one weighing twelve ounces would be as three to two to the one that weighed eight, and the harmony produced would be that of a fifth; similarly in the case of those that weighed nine ounces and six ounces. Again, the one weighing twelve ounces is in the proportion of from four to three to the one weighing nine, and makes with it the harmony of a fourth; so also does the one that weighs eight with that weighing six; while the one weighing, nine is proportioned to the one that weighs eight, and produces with it the harmony called a tone.
Licet autem Plato posuerit res omnes ex numeris constitui, non tamen ex numeris habentibus proportiones harmonicas: sed animam posuit esse constitutam secundum numeros habentes huiusmodi proportiones. Et ideo dicit, quod posuit eam dispartitam, idest quasi dispensatam, secundum harmonicos numeros, idest secundum numeros proportionatos adinvicem secundum musicam proportionem. Posuit enim ex his numeris animam constitutam, scilicet ex uno, duobus, tribus, quatuor, octo, novem, vigintiseptem, in quibus huiusmodi proportiones inveniuntur. 96. But if Plato reduced everything to numbers, these were not harmonic numbers, except in the case of the soul. Hence Aristotle gives it as Plato’s view that the soul was ‘divided’. or, as it were, weighed out, ‘according to harmonic numbers’, i.e. to numbers related to each other in musical proportions. He said that the soul was constituted of the numbers 1, 2, 3, 4, 8, 9 and 27; in which these harmonic proportions are found.
Duplici autem ex causa animam posuit constitutam ex numeris harmonicis. Una est, quia unumquodque delectatur in eo quod est sibi simile et connaturale. Videmus autem quod anima delectatur in omnibus harmonizatis, et offenditur ex his quae sunt praeter debitam harmoniam, tam in sonis quam in coloribus, quam etiam in quibuscumque sensibilibus: unde videtur harmonia de natura animae esse. Et hoc est quod dicit anima habet sensum, idest cognitionem connaturalem harmoniae. 97. And he had two reasons for thinking this. One was the fact that similarity and connaturality are always a cause of pleasure. We find the soul taking pleasure in all harmonies and disliking whatever is unharmonious in sounds and colours and indeed in any sensible quality. So harmony seems to be natural to the soul. This is what he means by saying that the soul has ‘a connatural sense (i.e. knowledge) of harmony’.
Alia ratio est, quia Pythagorici et Platonici posuerunt ex motibus caelorum provenire sonos optime harmonizatos; et quia motus caelestes ponebant esse ab anima mundi, posuerunt animam esse ex numeris harmonicis, ut posset causare motus harmonizatos. Et hoc est quod dicit: et ut omne, idest universum feratur secundum consonantes motus. 98. The second reason is that the Pythagoreans and Platonists thought that beautifully harmonious sounds resulted from the movements of the heavenly bodies; and since they supposed these movements to be caused by the World-Soul they naturally concluded that the soul was made up of harmonic numbers. Hence Aristotle says ‘that the whole (i.e. Universe) be borne along with well-attuned motions’.
Deinde cum dicit aspectum rectum docet quomodo ex anima procedat motus caelestis. Ubi considerandum est, quod omnes numeri secundum naturalem ordinem accepti, linealiter dispositi sunt secundum rectitudinem, prout unus addit super alterum. Sed ex naturali serie numerorum potest aliquis accipere plures series: puta si accipiat homo quasi in una rectitudine totam seriem duplorum, et in alia totam seriem triplorum, et in alia totam seriem quadruplorum, et sic de aliis. Quia igitur homo sua cognitione potest circa numeros operari: hoc et Deus facit constituendo substantias rerum ex numeris. Unde in constituendo substantiam animae ex numeris supradictis, qui omnes naturali ordine sunt in una rectitudine, quasi duas lineas divisit: unam duplorum, et alteram triplorum; hae enim proportiones omnes harmonicas continent. Nam dupla proportio dividitur in sesquialteram et sesquitertiam. Et tripla in duplam et sesquialteram. Igitur in praedictis numeris accipitur series duplorum usque ad numerum cubicum: ut puta unum, duo, quatuor, octo; et alia series triplorum eodem modo, ut puta unum, tria, novem, vigintiseptem: quae quidem duae series in unitate coniunguntur ac si essent duae lineae rectae angulum continentes. 99. Next, when he says ‘God bent, etc.” Aristotle explains how the World-Soul is the cause of heavenly movements. Taking all numbers ‘in their natural order, we must think of them as laid in a straight line, each one adding to the preceding one. Now the natural numerical series can give rise to several other series; for example, one might take the geometrical series whose common ratios are 2 or 3 or 4, and so on for other ratios. As then man, by thought, can manipulate numbers, so does God in building up the substances of things from numbers. In constructing the soul’s substance out of the aforesaid numbers, namely all those placed in a straight line series according to their natural order, he divides them into two series: one, the geometrical series whose common ratio is 2; the other, the geometrical series whose common ratio is 3; because these two embrace all the harmonic proportions. For the double proportion is divided into the ratios 3:2 and 4:3; the triple into 2:1 and 3:2. Therefore the above-mentioned numbers are taken, in the geometrical series with common ratio 2, up to the first cube number, e.g. 1,2,4 up to 8; so also with the series with common ratio 3, e.g., 1,3,9,27. These two series meet at unity like two straight lines containing an angle.
Rursus, si unitati coniungantur quae sunt in linea triplorum, resultabunt numeri qui sunt in linea duplorum: puta si unitati addatur trinarius, fient quatuor; et e converso, si unitati addatur binarius fient tria. Et sic constituentur quasi duae lineae sese invicem intersecantes, secundum modum literae Graecae quae vocatur XI. 100. Moreover, if the numbers in the series whose common ratio is three are joined to unity we get as a result the numbers of the series whose common ratio is 2; e.g. if to 1 is added 3 the result is 4. Conversely, if to 1 is added 2 the result is 3. Thus it is as if two lines were drawn intersecting each other like the Greek letter X.
Si autem procedatur ulterius, redibitur ad eosdem numeros. Nam a quatuor proceditur ad octo, et a tribus redibitur ad vigintiseptem, et sic utrobique concluditur: quasi quidam circulus. 101. if we proceed further we return to the same numbers. For from 4 we go on to 8 and from 3 to 27; both series concluding with the same type of number, as though we were going round in a circle.
Sciendum autem est, quod Plato ea quae inveniebantur in natura magis composita, dicebat provenire ex proprietate naturae magis simplicis, sicut consonantias sonorum ex proportionibus numerorum. Substantiam autem animae ponebat mediam inter numeros, qui sunt maxime abstracti, et inter substantiam sensibilem; et ideo proprietates animae deducebat ex proprietatibus praedictis numerorum. Nam in anima est considerare primo aspectum rectum, secundum quod aspicit directe ad suum obiectum; et postea reditur in circulum inquantum intellectus reflectit se supra seipsum. Invenitur etiam in anima intellectiva quasi circulus parium et imparium, inquantum cognoscit ea quae sunt eiusdem, et quae sunt diversae naturae; et hoc ulterius protenditur usque ad substantiam sensibilem caeli, quam anima movet. 102. We must realise that for Plato the more complex things found in nature are composed of simpler natures, just as the harmonies of sounds arise from the proportions between numbers. He put the essence of the soul mid-way between numbers, which are eminently abstract, and sensible substances; and so deduced the soul’s properties from the said numbers. Thus in the soul we find, first, a direct knowing, in that it looks directly at its object; and then the circular return by which the intellect reflects upon itself. So too the intellectual soul moves in a sort of circle with respect to the even and the odd in knowing things both like and unlike itself. And this principle is extended to the substance of the visible heavens moved by the World-Soul.
Nam in caelo consideratur duplex motus circularis: unus simplex et uniformis, secundum quem caelum movetur seu revolvitur motu diurno ab oriente in occidentem, qui quidem fit secundum circulum aequinoctialem. Alius autem motus est planetarum, qui est ab occidente in orientem secundum circulum zodiacum, qui intersecat aequinoctialem in duobus solstitialibus punctis, scilicet in principio cancri, et Capricorni. 103. For in the heavens we find two circular movements. One is simple and uniform by which the heavens move or revolve daily from east to west according to the equinoctial circle. The other is that of the planets, which is from west to east according to the circle of the zodiac, intersecting the equinoctial circle at the two points of solstice, i.e. at the beginning of Cancer and of Capricorn.
Et quia motus primus est uniformis, ideo non dividitur in plures motus, et assimilatur circulo imparium, et propter hoc etiam circulus primus maior est. Nam impares numeri superius positi maiores sunt. 104. And since the former motion is uniform, it is not divided into several motions; and in this it resembles the circle of the odd numbers; which is also why it is the greatest circle; for the odd numbers referred to are greater than the even.
Secundus autem motus facit multam diversitatem; et ideo videtur pertinere ad circulum parium; et dividitur in septem circulos secundum sex interstitia duplorum et triplorum numerorum, ut dicitur in Timaeo. Ubi enim sunt sex divisiones, necesse est esse septem divisa. Unde et isti circuli minores sunt, et continentur a supremo circulo qui est imparium. Sic ergo legenda est litera: ut omne, idest universum, feratur secundum consonantes motus, idest ut ex harmonia animae deriventur motus caelestes harmonizati aspectum rectum. Deus reflexit in circulum eo modo quo est expositum, et secundum proprietatem numeri, et secundum proprietatem animae, et dividens ex uno, propter unam naturalem seriem numeri, et unam vim intellectivam animae, in duos circulos, scilicet parium et imparium quantum ad numeros, intelligentiam mobilium et immobilium quantum ad animam, motum secundum aequinoctialem et zodiacum quantum ad caelum. 105. The second motion, however, is very much diversified, and seems therefore to answer to the circle of even numbers. It divides into seven circles according to the intervals between the numbers in the two series of multiples of 2 and of 3, as is said in the Timaeus. Where there are six points of division there must be seven parts divided off. Hence these circles are smaller and are contained by the highest circle which is that of the odd numbers. So the text is to be interpreted thus: ‘As the whole’, i.e. the Universe, is ‘borne along with well-attuned motions’, that is to say, as the harmonised movements of the heavens are due to the harmony of the World-Soul, God ‘bent the straight line into a circle’ in the manner described, according to the properties of number and of the soul; and dividing this one circle—one by the unity of the natural series of numbers, or by that of the intellectual power of the soul—into two, he forms the pair of numerical circles, the odd and the even, ,and the pair of circles in the soul, the understanding of moving and of motionless objects, and the pair of heavenly circles, the equinoctial and zodiacal motions.
Addit autem dupliciter coordinatos, quia duo circuli se intersecantes tangunt se in duobus punctis. Iterum unum, scilicet inferiorem, divisit in septem circulos quasi planetarum, tamquam caeli motus essent animae motus, idest ac si caelum moveretur per motum animae. 106. He adds, however, ‘adjusted at two points’, because any two intersecting circles touch each other at two points. And ‘again one’, i.e. the inferior one,’ he divided into seven circles’, as if of the planets, ‘as though the heavenly motions were the soul’s motions, i.e. as if the heavens moved by the movement of the World-Soul.

TEXT
1407a3–407b25
BOOK I, CHAPTER III, CONTINUED

SOUL AS A SPATIAL MAGNITUDE
CRITIQUE OF PLATO

407a2 πρῶτον μὲν οὖν οὐ καλῶς τὸ λέγειν τὴν ψυχὴν μέγεθος εἶναι· τὴν γὰρ τοῦ παντὸς δῆλον ὅτι τοιαύτην εἶναι βούλεται οἷόν ποτ' ἐστὶν ὁ καλούμενος νοῦς (οὐ γὰρ δὴ οἷόν γ' ἡ αἰσθητική, οὐδ' οἷον ἡ ἐπιθυμητική· τούτων γὰρ ἡ κίνησις οὐ κυκλοφορία)· ὁ δὲ νοῦς εἷς καὶ συνεχὴς ὥσπερ καὶ ἡ νόησις· ἡ δὲ νόησις τὰ νοήματα· ταῦτα δὲ τῷ ἐφεξῆς ἕν, ὡς ὁ ἀριθμός, ἀλλ' οὐχ ὡς τὸ μέγεθος· διόπερ οὐδ' ὁ νοῦς οὕτω συνεχής, ἀλλ' ἤτοι ἀμερὴς ἢ οὐχ ὡς μέγεθός τι συνεχής. Now in the first place it is not correct to say, that the soul is a magnitude. For that of the Whole he (Plato) regards as of the same nature as what is sometimes called mind, not as the sensitive or the appetitive soul; for the movement of these is not circular. Now mind is one and continuous, as is the act of understanding, which in turn consists of thoughts. But these have unity by succession, like number, not like extension. Therefore neither is mind thus continuous; but it is either indivisible, or not continuous in the way that anything extended is. §§ 107-11
πῶς γὰρ δὴ καὶ νοήσει, μέγεθος ὤν, πότερον ὁτῳοῦν τῶν μορίων τῶν αὑτοῦ, μορίων δ' ἤτοι κατὰ μέγεθος ἢ κατὰ στιγμήν, εἰ δεῖ καὶ τοῦτο μόριον εἰπεῖν; εἰ μὲν οὖν κατὰ στιγμήν, αὗται δ' ἄπειροι, δῆλον ὡς οὐδέποτε διέξεισιν· εἰ δὲ κατὰ μέγεθος, πολλάκις ἢ ἀπειράκις νοήσει τὸ αὐτό. φαίνεται δὲ καὶ ἅπαξ ἐνδεχόμενον. εἰ δ' ἱκανὸν θιγεῖν ὁτῳοῦν τῶν μορίων, τί δεῖ κύκλῳ κινεῖσθαι, ἢ καὶ ὅλως μέγεθος ἔχειν; εἰ δ' ἀναγκαῖον νοῆσαι τῷ ὅλῳ κύκλῳ θιγόντα, τίς ἐστιν ἡ τοῖς μορίοις θίξις; How would it understand, if it were an extended quantity? As a whole, or by each of its parts? If by its parts, then by an extended part or by a point, if one may call a point a part. If by a point (of which there is an infinite, number) it is evident that it will. never complete the process. If by an extended part, it will understand the same thing many times over, even to infinity. Yet it seems to do so once for all. But if it is sufficient that it make contact with any one of its parts, why should it move in a circle or have any magnitude at all? But if it is necessary that it understand by contact with the whole of its circumference, what is the contact it makes by its parts? §§ 112-16
ἔτι δὲ πῶς νοήσει τὸ μεριστὸν ἀμερεῖ ἢ τὸ ἀμερὲς μεριστῷ; Again, how can the divisible be understood by the indivisible, or the indivisible by the divisible? § 117
ἀναγκαῖον δὲ τὸν νοῦν εἶναι τὸν κύκλον τοῦτον· νοῦ μὲν γὰρ κίνησις νόησις κύκλου δὲ περιφορά· εἰ οὖν ἡ νόησις περιφορά, καὶ νοῦς ἂν εἴη ὁ κύκλος οὗ ἡ τοιαύτη περιφορὰ νόησις. ἀεὶ δὲ δὴ τί νοήσει (δεῖ γάρ, εἴπερ ἀΐδιος ἡ περιφορά); τῶν μὲν γὰρ πρακτικῶν νοήσεων ἔστι πέρατα (πᾶσαι γὰρ ἑτέρου χάριν), αἱ δὲ θεωρητικαὶ τοῖς λόγοις ὁμοίως ὁρίζονται· λόγος δὲ πᾶς ὁρισμὸς ἢ ἀπόδειξις· αἱ μὲν οὖν ἀποδείξεις καὶ ἀπ' ἀρχῆς καὶ ἔχουσαί πως τέλος, τὸν συλλογισμὸν ἢ τὸ συμπέρασμα (εἰ δὲ μὴ περατοῦνται, ἀλλ' οὐκ ἀνακάμπτουσί γε πάλιν ἐπ' ἀρχήν, προσλαμβάνουσαι δ' ἀεὶ μέσον καὶ ἄκρον εὐθυποροῦσιν· ἡ δὲ περιφορὰ πάλιν ἐπ' ἀρχὴν ἀνακάμπτει)· οἱ δ' ὁρισμοὶ πάντες πεπερασμένοι. It is necessary that intellect, be this circle; for as the movement of the intellect is to understand, and that of the circle is to revolve, if, then, understanding is a revolving, the intellect must be a circle whose revolving is thinking., But then it will always think something—since revolving goes on for ever. Practical thoughts, however, have limits, each being for the sake of something else; while speculative thinking likewise is limited by ideas and every idea is either a definition or a demonstration. But demonstrations begin from principles, and have as their term a conclusion or an inference. Even if they do not reach a conclusion, they do not come round again to their starting-point; they always take a new middle term and conclusion, and proceed straight forward. But revolving returns again to the beginning. Definitions too are all finite. §§ 118-21
ἔτι εἰ ἡ αὐτὴ περιφορὰ πολλάκις, δεήσει πολλάκις νοεῖν τὸ αὐτό. Further, if the same revolving occurs many times over, there will be a multiple understanding of the same thing. §§ 122-4
ἔτι δ' ἡ νόησις ἔοικεν ἠρεμήσει τινὶ καὶ ἐπιστάσει μᾶλλον ἢ κινήσει· τὸν αὐτὸν δὲ τρόπον καὶ ὁ συλλογισμός. Moreover, intelligence is better compared with stillness and rest than with motion,—and the same holds of logical deduction. §§ 123-6
ἀλλὰ μὴν οὐδὲ μακάριόν γε τὸ μὴ 407b ῥᾴδιον ἀλλὰ βίαιον· εἰ δ' ἐστὶν ἡ κίνησις αὐτῆς ᾗ οὐσία, παρὰ φύσιν ἂν κινοῖτο. Again, that will not be content which is not at ease but in a state of strain. But if movement is not of the essence of the soul, it will only move unnaturally. § 127
ἐπίπονον δὲ καὶ τὸ μεμῖχθαι τῷ σώματι μὴ δυνάμενον ἀπολυθῆναι, καὶ προσέτι φευκτόν, εἴπερ βέλτιον τῷ νῷ μὴ μετὰ σώματος εἶναι, καθάπερ εἴωθέ τε λέγεσθαι καὶ πολλοῖς συνδοκεῖ. It must be burdensome for the soul to be entangled with the body without possibility of release; and indeed this should be shunned if it is better for the mind not to dwell in the body as is commonly said, and as seems true to many. § 128
ἄδηλος δὲ καὶ τοῦ κύκλῳ φέρεσθαι τὸν οὐρανὸν ἡ αἰτία· οὔτε γὰρ τῆς ψυχῆς ἡ οὐσία αἰτία τοῦ κύκλῳ φέρεσθαι, ἀλλὰ κατὰ συμβεβηκὸς οὕτω κινεῖται, οὔτε τὸ σῶμα αἴτιον, ἀλλ' ἡ ψυχὴ μᾶλλον ἐκείνῳ. ἀλλὰ μὴν οὐδ' ὅτι βέλτιον λέγεται· καίτοι γ' ἐχρῆν διὰ τοῦτο τὸν θεὸν κύκλῳ ποιεῖν φέρεσθαι τὴν ψυχήν, ὅτι βέλτιον αὐτῇ τὸ κινεῖσθαι τοῦ μένειν, κινεῖσθαι δ' οὕτως ἢ ἄλλως. ἐπεὶ δ' ἐστὶν ἡ τοιαύτη σκέψις ἑτέρων λόγων οἰκειοτέρα, ταύτην μὲν ἀφῶμεν τὸ νῦν. It is not clear why the Heavens move by circular movement; for the essence of the soul is not the cause of the soul moving in a circle, for such movement is only incidental to soul. Still less is the body the cause, but rather the soul a cause for the body. Nor is this alleged as for the best; yet the reason why God made the soul revolve must have been because it is more worthy for it to move than to remain stationary, and to move in this way rather than in any other. But this speculation is better suited to other contexts, so let us now dismiss it. § 129
ἐκεῖνο δὲ ἄτοπον συμβαίνει καὶ τούτῳ τῷ λόγῳ καὶ τοῖς πλείστοις τῶν περὶ ψυχῆς· συνάπτουσι γὰρ καὶ τιθέασιν εἰς σῶμα τὴν ψυχήν, οὐθὲν προσδιορίσαντες διὰ τίν' αἰτίαν καὶ πῶς ἔχοντος τοῦ σώματος. καίτοι δόξειεν ἂν τοῦτ' ἀναγκαῖον εἶναι· διὰ γὰρ τὴν κοινωνίαν τὸ μὲν ποιεῖ τὸ δὲ πάσχει καὶ τὸ μὲν κινεῖται τὸ δὲ κινεῖ, τούτων δ' οὐθὲν ὑπάρχει πρὸς ἄλληλα τοῖς τυχοῦσιν. οἱ δὲ μόνον ἐπιχειροῦσι λέγειν ποῖόν τι ἡ ψυχή, περὶ δὲ τοῦ δεξομένου σώματος οὐθὲν ἔτι προσδιορίζουσιν, ὥσπερ ἐνδεχόμενον κατὰ τοὺς Πυθαγορικοὺς μύθους τὴν τυχοῦσαν ψυχὴν εἰς τὸ τυχὸν ἐνδύεσθαι σῶμα. δοκεῖ γὰρ ἕκαστον ἴδιον ἔχειν εἶδος καὶ μορφήν, παραπλήσιον δὲ λέγουσιν ὥσπερ εἴ τις φαίη τὴν τεκτονικὴν εἰς αὐλοὺς ἐνδύεσθαι· δεῖ γὰρ τὴν μὲν τέχνην χρῆσθαι τοῖς ὀργάνοις, τὴν δὲ ψυχὴν τῷ σώματι. Another absurdity arises in this argument and in many others dealing with the soul. They conjoin body and soul, placing the soul in the body without stating anything definite as to the cause of this, or how the body is disposed. Yet this explanation is surely necessary, for it is in virtue of something in common that one is an agent, the other acted upon, one moves and the other is moved. No such correlations are to be found at random. These thinkers only endeavour to state what the soul is, without determining anything about the body which receives it, as if it happened that any soul entered any body, as in the fables of the Pythagoreans. For each body seems to have its own proper form and species. It is like saying that carpentry enters into flutes; for each art must use its tools, and the soul its body. §§ 130-1
ST. THOMAS’S COMMENTARY

LECTIO 8
Posita opinione Platonis, hic Aristoteles reprobat eam. Ubi notandum est, quod plerumque quando reprobat opiniones Platonis, non reprobat eas quantum ad intentionem Platonis, sed quantum ad sonum verborum eius. Quod ideo facit, quia Plato habuit malum modum docendi. Omnia enim figurate dicit, et per symbola docet: intendens aliud per verba, quam sonent ipsa verba; sicut quod dixit animam esse circulum. Et ideo ne aliquis propter ipsa verba incidat in errorem, Aristoteles disputat contra eum quantum ad id quod verba eius sonant. 107. Having stated Plato’s opinion, Aristotle now proceeds to its refutation. Here we should note that often, in criticising Plato, it is not precisely Plato’s own meaning that Aristotle criticises, but the obvious sense of his words. He has to do this because Plato’s method of teaching was faulty; he constantly used figures of speech, teaching by symbols and giving his words a meaning quite other than their literal sense; as when he calls the soul a circle. So lest anyone should be led astray by this literal sense, Aristotle sometimes argues precisely against it, in criticising Plato.
Ponit autem Aristoteles rationes decem ad destruendum suprapositam opinionem: quarum quaedam sunt contra eum, et quaedam contra verba eius. Non enim Plato voluit, quod secundum veritatem intellectus esset magnitudo quantitativa, seu circulus, et motus circularis; sed metaphorice hoc attribuit intellectui. Nihilominus tamen Aristoteles, ne aliquis ex hoc erret, disputat contra eum secundum quod verba sonant. 108. Against the above-mentioned opinion, then, he brings ten arguments, some of which bear on Plato’s own view, and some on the literal sense of his words. Plato did not really mean that the intellect was anything quantitative or circular; he was talking metaphorically. Still, lest there should be any mistake about this, Aristotle argues on a literal interpretation of the words.
Primo ergo Aristoteles circa primam rationem, manifestat de qua anima Plato intellexit, scilicet de anima universi. Et hanc scilicet animam, quae est omnis, idest universi, vult esse intellectivam tantum. Non enim est vegetabilis, quia non indiget nutrimento: nec est sensibilis, quia caret organo: nec est desiderativa, quia desiderativa consequitur sensitivam. Et dixit ideo animam universi non esse sensibilem neque desiderativam, quia ipse voluit quod motus animae universi esset circularis. Unde cum motus harum, scilicet sensibilis et desiderativae, non sit circularis (non enim sensus reflectitur super seipsum, intellectus vero reflectitur super seipsum, homo enim intelligit se intelligere); ideo dicit illam animam intellectivam tantum esse; et ideo dicit intellectum esse magnitudinem quamdam et circulum. 109. In the first argument, then, he explains what ‘soul’ Plato had in mind, that it was the Soul of the Universe, and that ‘that’ (soul) which is ‘of the whole’, i.e. of the Universe, is exclusively intellectual, according to Plato. It is not vegetative, since it needs no nourishment; nor sensitive since it has no organs of sense; nor appetitive since appetite follows sensitivity. Indeed it could not in any sense be sensitive or appetitive, granted that the movement of the Universal Soul is circular; because neither sense nor appetite moves in a circle (for sense does not reflect upon itself) but. only the intellect (which does reflect upon itself, as when a man knows that he knows). So Plato concluded that the World-Soul was only intellectual, and said that intellect itself was a sort of spatial magnitude and a circle.
Et hoc Aristoteles reprobat dicens, quod Plato non bene dixit animam esse magnitudinem. Et quod locutus est de ea sicut de magnitudine circulari, dividens eam in duos circulos, male fecit. 110. Aristotle denies this, saying that Plato was wrong in representing the soul as a spatial magnitude circular in shape, and in dividing it into two circles.
Et quod male fecerit ostendit. In natura enim animae hoc est, ut iudicium de aliqua potentia animae sumatur ex actu seu operatione ipsius potentiae, iudicium vero operationis ex obiecto: potentiae enim cognoscuntur per actus, actus vero per obiecta: et inde est, quod in definitione potentiae ponitur eius actus et in definitione actus ponitur obiectum. Constat autem quod res ab eo a quo habet esse et speciem, ab eo etiam habet unitatem. Si ergo intellectus sit et sortiatur speciem ab intelligibili, cum sit eius obiectum (dico intellectum in actu, cum nihil sit ante intelligere), manifestum est, quod si sit unus et continuus sicut Plato posuit, quod eodem modo intellectus erit unus et continuus, quo intelligibilia sunt unum et continuum; intellectus enim non est unus nisi sicut intelligentia, idest operatio eius quae est intelligere, nec actus est unus nisi sicut obiectum eius est unum, quia actus distinguuntur penes obiecta. Unde, cum obiectum intellectus sint intelligibilia, haec autem, scilicet intelligibilia, non sunt unum ut magnitudo seu continuum, sed sicut numerus, eo quod consequenter se habeant, manifestum est, quod intellectus non est magnitudo, sicut Plato dicebat. Sed aut est impartibilis, sicut se habet ratio primorum terminorum, aut non est continuus sicut aliqua magnitudo, sed sicut numerus, inquantum unum post aliud intelligimus, et saepe plures terminantur in unum, sicut in syllogismis terminantur proportiones in conclusionem. 111. And he points out where Plato went astray. In this matter of the nature of the soul we have to base our judgement concerning any of its faculties upon the act or operation of that faculty, and our judgement concerning the act or operation upon the object of this act or operation; for faculties are known by their acts, and acts by their objects. Thus in the definition of a faculty is included its act, and in the definition of an act its object. Now it is clear that a thing gets its unity from whatever gives it being and specific nature. If then the intellect gets its being and specific nature from the intelligible which is its object (I speak of the intellect in act, which as such is nothing before the act of understanding occurs), it is clear that if it is one and continuous, as Plato held, it will be so in the same way as intelligible objects are one and continuous. For the intellect is one only in the same way as its operation (understanding) is one; and its operation is one only in the same way as its object is one; since acts are differentiated according to their objects. Since then the intellect’s object is intelligibles, and intelligibles compose a unity, not like a magnitude or a continuum, but like numbers which follow in a series, it is clear that the intellect is not, as Plato thought, a magnitude. It is either indivisible, as it is the nature of first principles to be, or, if it is continuous, it is so not as a magnitude but as number is; for as one number leads to another, so do we understand one object after another. And frequently several numbers terminate in one, as the premises in a syllogism terminate in one conclusion.
Secundam rationem ponit ibi qualiter autem quae talis est. Posset aliquis dicere, quod Plato non posuit magnitudinem in intellectu propter multa intelligibilia; sed oportet quod sit in intellectu magnitudo etiam propter unumquodque intelligibilium. 112. The second argument comes at ‘How would it understand’. For it might be answered that Plato’s reason for attributing magnitude to the intellect was not that there are many intelligibles, but that each intelligible by itself shows it to be a magnitude.
Contra. Hoc non potest esse. Plato enim ponit, et opinatus est, quod intelligere non fiat per acceptionem specierum in intellectu, sed quod intellectus intelligat per quemdam contactum, inquantum scilicet occurrit et obviat speciebus intelligibilibus; et istum contactum attribuit circulo, sicut supra dictum est. Quaero ergo a te, si intellectus est magnitudo, et intelligit secundum contactum, qualiter intelligat. Aut enim hoc quod intelligit, tangit secundum totum, aut secundum partem eius: si secundum totum contingens intelligit totum, tunc partes non erunt necessariae, sed erunt frustra; et sic non est necesse, quod sit intellectus magnitudo et circulus. Si vero secundum partes contingens, intelligit partes, aut hoc erit secundum plures partes, aut secundum unam tantum: si secundum unam tantum, sic idem quod prius, quia aliae erunt superfluae, et sic non erit necessarium ponere intellectum habere partes. Si vero contingens secundum omnes partes, intelliget, aut hoc erit secundum partes punctales, aut secundum partes quantitativas: si secundum partes punctales, tunc, cum in qualibet magnitudine sint infinita puncta, oportet quod infinities tangat antequam intelligat; et sic nunquam intelliget, cum non sit infinita pertransire. 113. But this will not do. For Plato maintained that the act of understanding was not a reception of intelligible forms into the mind, but a sort of contact (as of a circle, we have seen) due to the mind’s going out to meet intelligible forms. But I ask you, how precisely does the mind understand by contact, if it is a magnitude? it must touch its object either with the whole of itself or with a part. But if with the. whole of itself, then its parts are not needed and there is no necessity for supposing that the intellect is a magnitude or a circle. If, on the other hand, it touches with some of its parts, and thus understands in part, then either several of its parts are involved or only one. If only one, then again the other parts are superfluous and we need not suppose that the intellect has parts. But if it understands by touching with all its parts, these must be either points or quantities; and if points, then, since the number of points in any magnitude is infinite, the intellect would have to touch its object an infinity of times before it understood the latter at all; and thus it never would understand, since infinity cannot be traversed.
Dicit autem partes punctuales, non quod velit magnitudinem in partes punctales dividi, sed disputat ad rationem Platonis, qui fuit huius opinionis, quod corpus componeretur ex superficiebus, et superficies ex lineis, et linea ex punctis. Quod ipse improbat in sexto (in principio) physicorum, ubi ostendit quod punctum additum puncto nihil addit. 114. Aristotle says ‘points’ not because he thought that a magnitude could be partitioned into points, but as disputing with Plato who regarded bodies as composed of planes, planes of lines, and lines of points; an opinion refuted by Aristotle in the Physics, Book VI, where it is shown that a point added to a point makes no difference.
Si vero intelligit contingens secundum partes quantitativas, tunc, cum quaelibet pars dividatur in multas partes, sequitur, quod multoties intelligat, idem. Item cum omnis quantitas sit divisibilis in infinitum secundum eamdem proportionem, et non secundum eamdem quantitatem, sequitur quod infinities intelligat, quod est inconveniens. Videtur ergo quod non contingat nisi semel; et sic nullo modo debet attribui intellectui magnitudo, neque quantum ad multa intelligibilia, neque quantum ad unum. 115. But if the mind understands by touching with quantitative parts, then, as each part is divisible into many, it must understand the same object many times over. Again, since any quantity is infinitely divisible into parts that are proportionately, not quantitatively, the same, it would follow that the mind understands the same thing an infinite number of times,—which raises difficulties. it would seem then that it touches its object once only, and that it cannot be called a magnitude, either with respect to many intelligibles or to only one.
Et notandum, quod hic Aristoteles occulte ostendit, quod intellectus de natura sua non est partibilis, sed quid impartibile. Intelligibile enim in unaquaque re est quidditas, et natura rei est tota in qualibet parte, sicut natura speciei est tota in quolibet individuo: tota enim natura hominis est in quolibet individuo, et hoc est indivisibile: unde illud quod est intelligibile in qualibet re, est indivisibile, et per consequens intellectus. 116. Notice that Aristotle is implying here that intellect is indivisible of its nature. What is intelligible in any thing is its essence or nature; which is present wholly in every part of it, as the specific nature is wholly present in each individual of the species; the whole nature of man in each individual man; and the individual as such is indivisible. Hence what is intelligible in anything is indivisible; and therefore so is the intellect.
Tertiam rationem ponit cum dicit amplius quomodo quae talis est. Constat quod si nos ponimus intellectum impartibilem, de facili patebit ratio, quomodo intelligat impartibile et partibile: quia impartibile intelliget secundum proprietatem suae naturae, eo quod impartibilis est, ut dictum est; partibile vero intelliget abstrahendo a partibili. Sed si intellectus ponatur partibilis secundum quod Plato vult, impossibile erit invenire rationem quomodo intelligit impartibile. Et sic videtur, quod inconvenienter Plato ponat intellectum esse magnitudinem seu partibilem. 117. The third argument comes at ‘Again, how’. Granted that the mind is indivisible, we can easily see how it can understand both the indivisible and the divisible. It understands the indivisible in virtue of its own nature which is indivisible; and the divisible by abstracting from divisibility. But once allow, with Plato, that mind is divisible, it becomes impossible to understand how it can think of the indivisible. ‘Hence the difficulty of admitting Plato’s theory.
Quartam rationem ponit cum dicit necessarium autem quae talis est. Tu dicis intellectum esse circulum, et dicis intellectum moveri: sed motus circuli est circulatio, motus vero intellectus est intelligentia, hoc est intelligere: ergo si intellectus est circulus, de necessitate intelligentia erit circulatio. Sed hoc est falsum; quia cum in circulatione non sit invenire actu principium neque finem, ut probatur in octavo physicorum, sequitur etiam quod intelligentia seu operatio ipsius intellectus, quae est intelligere, nunquam terminatur. Sed hoc est falsum: quia intelligentia habet actu et principium et finem: ergo intelligentia et circulatio non sunt idem, et per consequens nec intellectus est circulus. 118. The fourth argument begins at ‘It is necessary’. It runs thus. You say that intellect is circular and in movement. Now the movement of circles is a circling and that of the intellect is understanding; hence if intellect is a circle, understanding must be a circling. But this is false; for, since circular movement has no actual beginning or end, as is shown in the Physics, Book VIII, it would follow that understanding, the proper act of the intellect, never reached a term. But understanding has an actual beginning and end: hence it is not the same as circular movement, and therefore the intellect is not a circle.
Quod autem intelligentia habeat principium et finem actu, probatur: quia omnis intelligentia aut est practica, aut speculativa: sed constat quod practicarum intelligentiarum termini sunt, idest fines. Nam omnes sunt alterius causa, scilicet operis, et ad opus terminantur. Speculativae etiam intelligentiae finem habent, scilicet rationes, omnes enim terminantur ad aliquas rationes: quae quidem rationes, aut sunt definitio, scilicet in simplici intelligentia, aut demonstratio, scilicet cum componit et dividit. Sed demonstrationes primae ex principiis certis sunt, et habent quodammodo finem syllogismum aut conclusionem. 119. That understanding has an actual beginning and end can be proved in this way. All thinking is either practical or speculative. Clearly all practical thinking reaches a term or end; for it is all for the sake of something else, namely a work to be done, and in this work it terminates. And speculative thinking too has its proper end, namely ideas; for it always comes to rest in some idea: either, in a definition, when the mind simply apprehends something, or in demonstrations, when it combines and distinguishes things. But the first demonstrations begin from absolute first principles and terminate, in their turn, in the conclusions of syllogisms.
Et si dicatur, quod ex una conclusione sequitur alia, et sic non terminatur; nihilominus tamen potest dici, quod conclusiones non sunt circulares, quia non est circulo demonstrare, ut probatur in primo posteriorum, sed tendunt in rectum; et impossibile est in rectum invenire motum infinitum seu processum. 120. If it be objected that one conclusion follows another, and thus there is no definite end, I answer that conclusions are nevertheless not circular. For, as is shown in the Posterior Analytics, Book I, demonstration cannot go in a circle; it always goes in a straight line; and an infinite movement or progression in a straight line is impossible.
Definitiones etiam habent principium et finem, quia non est ascendere in infinitum in generibus, sed accipitur quasi primum genus generalissimum: nec etiam est descendere in infinitum in speciebus, sed est stare in specie specialissima. Unde genus generalissimum est principium, species vero specialissima sicut terminus seu finis in definitionibus. Et sic patet, quod omnis intelligentia principium habet et finem actu. 121. Definitions too have a beginning and an end, for you cannot go on to infinity in the enumeration of genera; the most general genus has to be taken as the first one. Similarly in enumerating species; you cannot particularise to infinity, but must stop at the most particular species. Hence the most general genus is the beginning, and the most particular species is the term or end, in definitions. Clearly, then, every act of the mind has an actual starting point and term.
Quintam rationem ponit cum dicit amplius autem quae pendet quodammodo ex praecedenti, et est quasi quoddam membrum eius. Supra enim probatum est, quod si intellectus est circulus, sicut Plato posuit, intelligentia erit circulatio; et probavit superiori ratione, quod intelligentia non est circulatio: et hoc idem probat hic tali ratione. Videmus quod haec differentia est inter circulationem et alios motus, quia impossibile est in aliis motibus, unum et eumdem motum reiterari super eamdem quantitatem multoties. Et hoc apparet deducendo per singulas species motus. In alteratione enim impossibile est eumdem motum super idem reiterari: non enim idem secundum idem de albo fit nigrum, et de nigro album. In motu etiam augmenti impossibile est unum et idem secundum idem augmentari et diminui. In motu etiam locali impossibile est eumdem motum secundum idem reiterari, quia in motu locali secundum rectum semper sunt duo termini, scilicet actu. Unde si reiteraretur, oportet termino ad quem uti bis, quia ut fine et principio, et de necessitate interveniret ibi quies, et sic non esset idem motus numero. In circulatione vero solum hoc contingit, quod unus et idem motus secundum eamdem quantitatem multoties reiteraretur. Cuius ratio est, quia in circulatione non sunt aliqui termini actu; et ideo, quantumcumque reiteretur, non intervenit quies, nec variatur motus. 122. The fifth argument begins at ‘Further, if’. In a sense this argument depends on the previous one and is a part of it. It has been shown that if the intellect were a circle, as Plato thought, understanding would be a circling; and in the preceding argument Aristotle has shown that understanding is not a circling; which he now proves once more in the following way. The difference between a circular motion and any other motion lies in this, that the latter can never be repeated on the same quantity. This becomes clear if we think of the different kinds of movement in particular. Thus the movement of ‘alteration’ cannot be repeated in the same subject in the same respect; for the same thing is not in the same respect changed from white to black and black to white. So too in the movement of growth, the same thing cannot in the same respect both increase and diminish. So also in local movement; if this goes in a straight line it must have two actual terms; and if it is to be repeated, the term at the end of the movement must be used twice, once as end and once as beginning, and, since there must intervene a moment of rest at that term, it is not exactly the same movement. In circular motion alone can one and the same movement be many times repeated according to the same quantity; the reason being that in circular motion there are no actual terms; hence, no matter how often it is repeated, no interval of rest intervenes nor does the motion vary in any way.
Ex hoc ergo sic arguit: tu dicis, quod intellectus est circulus: ergo et intelligentia sic circulatio est: sed hoc est inconveniens, scilicet quod intelligentia sit circulatio: ergo et primum. 123. This being granted, Aristotle argues as follows. If you say that the intellect is a circle, then the act of thinking must be a circular motion. But this consequence is not admissible; therefore neither is the premise.
Quod sit inconveniens ostendit. Constat quod eadem circulatio secundum unum et idem multoties est, idest reiteratur: ergo si intelligentia est circulatio, sicut dicis, intelligentia multoties secundum unum et eumdem motum, et super idem multoties reiterabitur, et sic multoties intelliget idem: intellectus enim movendo se tangit, et tangendo intelligit, sicut ipsi dicunt, et circulariter multoties tangit idem, et sic multoties intelliget idem, quod est inconveniens. 124. He then shows that the consequence is not admissible. Granted, he says, that the same circular movement is multiplied, that is, repeated, in the same respect. If thinking, then, is a circular movement, as you say, it will be repeated again and again as one and the same movement bearing upon one and the same object; and so the mind will think the same thing many times over. For the mind, in moving, touches and by this touching it thinks, as they say. If then its motion is circular it touches and thinks the same thing over and over again; which gives rise to difficulties.
Sextam rationem ponit cum dicit adhuc autem quae talis est. Si intelligentia circulatio est, ut tu dicis, debet assimilari motui: sed nos videmus totum contrarium, quia intelligentia magis assimilatur quieti, quam motui: ergo intelligentia non est circulatio. Quod autem magis assimiletur quieti quam motui, patet, quia, sicut ipse dicit in septimo physicorum, non potest fieri aliquis sapiens, quando motus eius non resident nec quiescunt. Unde in pueris, et in omnibus in quibus motus non quiescunt, non de facili invenitur sapientia. Sed tunc aliquis sapientiam acquirit, quando quiescit: unde dicit, quod in quiescendo et sedendo, anima fit sapiens et prudens. 125. The sixth argument, at ‘Moreover, intelligence’ is as follows. if thinking is, as you say, a circular motion, it should be associated with movement, but in fact the contrary is true; thinking is associated rather with repose. This Aristotle himself teaches in Book VII of the Physics, where he says that if a man is to become wise he must first achieve an inward tranquillity; which is why the young and the restless are not, as a rule, wise. Wisdom and prudence are acquired, says Aristotle, by one who is content to sit down and be quiet.
Sed quia posset dici, quod hoc verum est de simplici intelligentia, sed non de syllogismo, ideo Aristoteles dicit quod eodem modo et syllogismus assimilatur magis quieti quam motui. Et hoc patet. Ante enim quam sit syllogizatum de aliqua re, intellectus et mens hominis fluctuat ad unam et ad aliam partem, et non quiescit in aliqua. Sed quando iam est syllogizatum, determinate inhaeret uni parti, et quiescit in illa. 126. But lest it be said that, while this is true of simple apprehension, it is not true of syllogistic reasoning, he adds that reasoning also is more like a repose than a movement. Because, of course, before the syllogism is complete the mind and intellect are swaying from one conclusion to another and resting in neither; but when it is finished the mind holds on to one conclusion and rests in it.
Septimam rationem ponit cum dicit at vero quae talis est. Constat quod beatitudo animae est in intelligendo: sed beatitudo non potest esse in eo quod est violentum et praeter naturam, cum sit perfectio et finis ultimus animae: ergo, cum motus non sit secundum naturam et secundum substantiam animae, sed praeter naturam eius, impossibile est quod intelligere, quod est operatio animae et in quo est beatitudo animae, sit motus, ut Plato dicebat. Quod autem motus sit praeter naturam animae, patet ex positione Platonis. Ipse enim dixit animam componi ex numeris, et postea dixit eam dispartitam in duos circulos, et reflexit in septimo: et ex hoc sequitur motus: ex quo apparet, quod motus non inest ei naturaliter, sed per accidens. 127. The seventh argument, at ‘Again, that, etc.’, runs as follows. Let us agree that thinking makes the soul happy. Now happiness cannot reside in anything violent or coercive, since it is the soul’s perfection and last end. As then movement is not of the soul’s essential nature, but is indeed alien to it, that operation in which the soul finds its happiness, namely, understanding, cannot be a movement, as Plato maintained. But that movement is not of the soul’s nature is implied by Plato’s own theory, for he said that the soul was first constituted by numbers, and then that it divide into two circles and was reflected into seven, from which followed movement. According to this view, then, movement is in the soul not naturally but accidentally.
Octavam rationem ponit cum dicit laboriosum autem quae talis est: videtur quod secundum opinionem Platonis, anima de sua natura non sit unita corpori. Nam ipse posuit eam primo compositam ex elementis, et postea complexam et adunatam corpori, et inde non posse recedere cum vult. Inde sic. Quandocumque est aliquid unitum contra naturam suam alicui, et non potest inde cum vult recedere, ei est poenale: et quandocumque aliquid in unione ad aliud deterioratur, est fugiendum et nocivum. Sed anima unitur corpori contra naturam suam, ut dictum est, nec potest inde recedere cum vult, nec non et deterioratur in unione ad corpus, sicut consuetum est dici a Platonicis et multis ex eis. Videtur ergo quod animae poenale est et fugiendum, esse cum corpore. Non ergo conveniens est dictum Platonis, scilicet quod anima composita ex elementis, primo commisceatur corpori. 128. The eighth argument, at ‘It must be burdensome’, goes as follows. It seems to have been Plato’s view that it was not of the nature of the soul to be joined to the body; for he said that it was first constituted of the elements and then compacted with the body, so that it cannot leave the body at will. Well then; whenever one thing is united against its nature to another, and cannot leave it at will, the resulting state is painful; and whenever a thing deteriorates through its union with another thing the union is harmful and to be avoided. But ex hypothesi the union of soul and body is contrary to the soul’s nature; nor can the soul break away at will; and the result is bad for the Soul, as the Platonists are always saying. Apparently, then, union with the body is a painful and fearful thing for the soul; which hardly squares with Plato’s own theory that the soul is composed of elements and compacted with its body from the beginning.
Nonam rationem ponit cum dicit immanifesta autem quae talis est. Plato loquitur de anima universi, et dicit eam moveri circulariter: sed secundum opinionem suam causa quare caelum movetur circulariter est immanifesta, idest non assignatur. Si enim caelum movetur circulariter, aut ergo hoc erit propter principia naturaliter, aut propter finem. Si dicatur quod naturaliter propter principia, aut erit propter naturam animae, aut propter naturam corporis caelestis. Sed non est propter naturam animae, quia moveri circulariter non inest animae secundum substantiam suam, sed per accidens, quia, ut dictum est, anima movetur per se et secundum suam substantiam motu recto, et deinde aspectum rectum reflexit in circulos. Nec etiam propter naturam ipsius corporis caelestis, quia corpus non est causa motus animae, sed anima est magis corpori causa quod moveatur. Si autem dicatur quod propter finem, non potest assignari aliquis finis determinatus secundum eum, cum quaeritur quare sic movetur, et non alio motu, nisi quod sic Deus voluerit eum moveri. Sed Deus propter aliquam causam dignatus est caelum potius moveri quam manere, et moveri sic, idest circulariter, quam alio motu, quam causam Plato non assignat. Sed quia hanc assignare est magis proprium aliis rationibus, idest in alio tractatu, scilicet in libro de caelo, ideo dimittamus ipsam ad praesens. 129. The ninth argument, at ‘It is not clear’, is as follows. Plato speaks of the Soul of the Universe and says it moves round in a circle. But this provides no explanation of the circular movement of the heavens; that is to say, it does not define the cause of it. For if the heavens move in a circle, this must be due either to intrinsic principles or to some extrinsic purpose. If intrinsic principles are the cause, the ‘nature’ in question will be either that of the soul or of the heavenly bodies. But it cannot be the soul’s nature, for circular movement is not of the essence of the soul, but is accidental to it; for, as we have said, the nature of the soul is to move in a straight line, which is then ‘bent into circles’. Nor can the cause be the nature of the heavenly bodies, for body as such is not the cause of the soul’s movements, but rather the soul of the body’s. But, if the cause is an extrinsic purpose, one cannot, on Plato’s principles, point to any definite end in answer to the question why the heavens move in a circle rather than in any other way; unless one brings in the will of God. God has indeed, for some reason, chosen to move the heavens rather than leave them motionless, and to move them in a circular way. But why he does this Plato cannot tell. However, as this matter belongs rather to ‘other contexts’, i.e. to another treatise (the De Coelo). We can leave it aside for the present.
Decimam rationem ponit cum dicit illud autem quae non solum est contra Platonem, sed etiam contra multos alios; et ducens est ad inconvenientia, et ostendens eorum positiones deficientes. Quae talis est. Constat quod inter movens et motum est aliqua proportio, et inter agens et patiens, et inter formam et materiam. Non similiter enim quaelibet forma cuilibet corpori convenit et unitur, neque omne agens agit in omne patiens. Neque quodlibet movens movet quodlibet motum, sed oportet quod sit inter ea aliqua communicatio et proportio, ex qua hoc sit aptum natum movere, illud vero moveri. Patet autem quod isti philosophi posuerunt animam esse in corpore, et movere corpus: cum ergo loquantur de ipsa natura animae, videtur etiam necessarium, quod aliquid dixissent de natura corporis, propter quam causam uniatur corpori, et quomodo se habeat corpus ad eam, et quomodo comparatur corpus ad animam. Non ergo sufficienter determinant de anima dum conantur dicere solum quale quid sit anima, et negligunt ostendere quale quid sit corpus suscipiens ipsam. 130. The tenth argument starts at ‘Another absurdity’. It is effective not only against Plato, but against many others also. It runs thus. It is dear that there must always be some proportion between mover and moved, agent and patient, form and matter. Not every form suits every body in the same way, nor does every agent act upon every patient. Nor, again, does every principle of movement move everything capable of receiving movement. There must be some correlation and proportion between them by which the one is naturally the mover, the other the moved in each case. Now obviously these philosophers admitted that the soul was in the body and moved it. Since then they spoke of the nature of the soul, it seems that they should also have had something to say about the nature of the body; about why the soul is joined to the body and how the body is related to and contrasts with the soul. Their study of the soul was inadequate so long as they discussed it alone and neglected to explain the nature of the body that receives it.
Ex quo convenit eis illud quod in fabulis Pythagoricis habetur, quod quaelibet anima in quodlibet corpus ingrediatur, puta si casu contingat in corpus elephantis intrare animam muscae. Quamvis hoc non possit esse, cum unumquodque corporum, et maxime animalium, habeat propriam formam et propriam speciem, et proprium movens et proprium motum, et multum differat corpus vermis a corpore canis, et corpus elephantis a corpore culicis. Hoc tamen dicentes, scilicet quod quaelibet anima quodlibet corpus ingreditur, dicunt simile, ac si quis dicat artem textrinam ingredi in fistulas, et aerariam in telariam. Et tamen si ipsis artibus inesset natura ingrediendi corpora, seu organa ex seipsis, non quaelibet in quodlibet ingrederetur, sed fistulativa ingrederetur in fistulas, non in lyras, cytharativa autem in cytharas, et non in fistulas: eodem igitur modo si animae cuilibet sit corpus, unaquaeque anima non quodlibet corpus ingreditur, immo ipsa anima idoneum format sibi corpus, et non assumit paratum. Sic ergo Plato et alii philosophi loquentes tantum de animae natura, insufficienter dixerunt, non determinantes quod sit corpus conveniens cuilibet animae, et qualiter et quale existens uniatur sibi. 131. Indeed, we may associate their thesis (Aristotle goes on to say) with the Pythagorean fable that any soul can enter any body; the soul of a fly for instance might perchance enter the body of an elephant. This cannot in fact happen; for the body of each particular thing, and especially of living things, has its own form and species and type of movement: hence there are great differences between the bodies of a worm, a dog, an elephant and a gnat. When they say that any soul can enter any body, it is as if one were to say that the art of weaving could enter flutes, or that the art of the coppersmith could enter a weaver’s loom. If it was in the power of these arts to enter bodies or instruments they would not do so indiscriminately, but the art of playing the flute would enter flutes, and not lyres, while the art of playing stringed instruments would enter stringed instruments and not flutes. In the same way, if there is a body for every soul, any soul does not enter any body; rather the soul shapes the body fit for itself; it does not enter a ready-made body. Plato and the others who speak only about the soul are too superficial; they fail to define which body answers to which soul, and the precise mode of existence of each in union with the other.

BOOK I, CHAPTER, IV
ΚΕΦΑΛΑΙΟΝ Δ'

THEORY OF SOUL AS HARMONY

407b27   Καὶ ἄλλη δέ τις δόξα παραδέδοται περὶ ψυχῆς, πιθανὴ μὲν πολλοῖς οὐδεμιᾶς ἧττον τῶν λεγομένων, λόγον δ' ὥσπερ εὐθύνοις δεδωκυῖα κἀν τοῖς ἐν κοινῷ γεγενημένοις λόγοις. ἁρμονίαν γάρ τινα αὐτὴν λέγουσι· There is another opinion handed down about the soul, acceptable to many, and in no way inferior to the theories already discussed, yet chastised, as it were, and condemned, even in public discussions. For some call the soul a kind of harmony. §§ 132-3
καὶ γὰρ τὴν ἁρμονίαν κρᾶσιν καὶ σύνθεσιν ἐναντίων εἶναι, καὶ τὸ σῶμα συγκεῖσθαι ἐξ ἐναντίων. And they say that harmony is a composition or tempering of opposites, and that the body is compounded of opposites. § 134
καίτοι γε ἡ μὲν ἁρμονία λόγος τίς ἐστι τῶν μιχθέντων ἢ σύνθεσις, τὴν δὲ ψυχὴν οὐδέτερον οἷόν τ' εἶναι τούτων. Yet a harmony is either a proportion in the components [of a compound] or the composition itself; and the soul cannot be either of these. § 135
ἔτι δὲ τὸ κινεῖν οὐκ ἔστιν ἁρμονίας, ψυχῇ δὲ 408a πάντες ἀπονέμουσι τοῦτο μάλισθ' ὡς εἰπεῖν. Further [active] movement, which all attribute to the soul, does not pertain to harmony. § 136
ἁρμόζει δὲ μᾶλλον καθ' ὑγιείας λέγειν ἁρμονίαν, καὶ ὅλως τῶν σωματικῶν ἀρετῶν, ἢ κατὰ ψυχῆς. φανερώτατον δ' εἴ τις ἀποδιδόναι πειραθείη τὰ πάθη καὶ τὰ ἔργα τῆς ψυχῆς ἁρμονίᾳ τινί· χαλεπὸν γὰρ ἐφαρμόζειν. It would be more appropriate to call health a harmony, and in general the powers of the body, rather than of the soul. This is evident if one tries to explain the passions and operations of the soul by some harmony: it is difficult indeed to correlate these! § 137
ἔτι δ' εἰ λέγομεν τὴν ἁρμονίαν εἰς δύο ἀποβλέποντες, κυριώτατα μέν, τῶν μεγεθῶν ἐν τοῖς ἔχουσι κίνησιν καὶ θέσιν, τὴν σύνθεσιν αὐτῶν, ἐπειδὰν οὕτω συναρμόζωσιν ὥστε μηδὲν συγγενὲς παραδέχεσθαι, ἐντεῦθεν δὲ καὶ τὸν τῶν μεμιγμένων λόγον-οὐδετέρως μὲν οὖν εὔλογον, ἡ δὲ σύνθεσις τῶν τοῦ σώματος μερῶν λίαν εὐεξέταστος. πολλαί τε γὰρ αἱ συνθέσεις τῶν μερῶν καὶ πολλαχῶς· τίνος οὖν ἢ πῶς ὑπολαβεῖν τὸν νοῦν χρὴ σύνθεσιν εἶναι, ἢ καὶ τὸ αἰσθητικὸν ἢ ὀρεκτικόν; ὁμοίως δὲ ἄτοπον καὶ τὸ τὸν λόγον τῆς μίξεως εἶναι τὴν ψυχήν· οὐ γὰρ τὸν αὐτὸν ἔχει λόγον ἡ μίξις τῶν στοιχείων καθ' ἣν σὰρξ καὶ καθ' ἣν ὀστοῦν. συμβήσεται οὖν πολλάς τε ψυχὰς ἔχειν καὶ κατὰ πᾶν τὸ σῶμα, εἴπερ πάντα μὲν ἐκ τῶν στοιχείων μεμιγμένων, ὁ δὲ τῆς μίξεως λόγος ἁρμονία καὶ ψυχή. Further, we speak of harmony with two considerations in mind. Primarily as a correctly proportioned measurement, in what has motion and position, of component parts, so that nothing is missing that is becoming to them. secondly, the ratio of this composition. In neither way is this [predication of harmony to the soul] reasonable. The composition of the parts of the body is very easy to examine, for there are many and various such compositions. Of what and how can one suppose the mind to be a composition? Or sensation? Or appetite? It is no less absurd to account the soul the ratio of a composition. The synthesis of elements for bone is not the same as that for flesh. There would have to be many souls [in one body]; and indeed [a soul] for every body, if each is a mixture of elements, and the ratio of the mixture a harmony and a soul. §§ 138-40
ἀπαιτήσειε δ' ἄν τις τοῦτό γε καὶ παρ' Ἐμπεδοκλέους· ἕκαστον γὰρ αὐτῶν λόγῳ τινί φησιν εἶναι· πότερον οὖν ὁ λόγος ἐστὶν ἡ ψυχή, ἢ μᾶλλον ἕτερόν τι οὖσα ἐγγίνεται τοῖς μέρεσιν; One might at this point question Empedocles. He says that each of these exists in virtue of a proportion. Is this proportion then the soul; or is soul some other thing, thus inborn in the members? § 141
ἔτι δὲ πότερον ἡ φιλία τῆς τυχούσης αἰτία μίξεως ἢ τῆς κατὰ τὸν λόγον, Or further: is concord the cause of any chance combination, or only of one based on some ratio? § 142
καὶ αὕτη πότερον ὁ λόγος ἐστὶν ἢ παρὰ τὸν λόγον ἕτερόν τι; And whether this concord is the ratio of the composition or something else? These are the kinds of problem involved in this, hypothesis. § 143
ταῦτα μὲν οὖν ἔχει τοιαύτας ἀπορίας. εἰ δ' ἐστὶν ἕτερον ἡ ψυχὴ τῆς μίξεως, τί δή ποτε ἅμα τῷ σαρκὶ εἶναι ἀναιρεῖται καὶ τὸ τοῖς ἄλλοις μορίοις τοῦ ζῴου; πρὸς δὲ τούτοις εἴπερ μὴ ἕκαστον τῶν μορίων ψυχὴν ἔχει, εἰ μὴ ἔστιν ἡ ψυχὴ ὁ λόγος τῆς μίξεως, τί ἐστιν ὃ φθείρεται τῆς ψυχῆς ἀπολιπούσης; But if the soul is other than the composition, why does it perish together with the essence of flesh and of other parts of the body? Moreover, granted that each of these parts has a soul, if the soul is not the ratio of the whole composition, what is it that is, corrupted when the soul departs? § 144
ὅτι μὲν οὖν οὔθ' ἁρμονίαν οἷόν τ' εἶναι τὴν ψυχὴν οὔτε κύκλῳ περιφέρεσθαι, δῆλον ἐκ τῶν εἰρημένων. κατὰ συμβεβηκὸς δὲ κινεῖσθαι, καθάπερ εἴπομεν, ἔστι, καὶ κι- νεῖν ἑαυτήν, οἷον κινεῖσθαι μὲν ἐν ᾧ ἐστι, τοῦτο δὲ κινεῖσθαι ὑπὸ τῆς ψυχῆς· ἄλλως δ' οὐχ οἷόν τε κινεῖσθαι κατὰ τόπον αὐτήν. It is evident, then, from what has been said, that the soul cannot be a harmony, or move by revolving. It can, however, be moved and move itself, incidentally, in so far as what it dwells in moves and is moved by the soul. In no other way can it move in place. § 145
ST. THOMAS’S COMMENTARY

LECTIO 9
Postquam philosophus reprobavit opinionem Platonis, hic consequenter reprobat quamdam aliam opinionem conformem opinioni Platonis quantum ad aliquid. Fuerunt enim quidam, qui dixerunt quod anima erat harmonia: et isti concordaverunt cum Platone in hoc, quod Plato dixit quod anima erat composita ex numeris harmonicis, hi vero quod erat harmonia. Sed differebant in hoc, quod Plato dixit quod anima erat harmonia numerorum, hi vero dixerunt, quod harmonia tam compositorum quam mixtorum, vel contrariorum, erat anima. Circa hoc autem tria facit. Primo enim ponit opinionem istorum et rationem opinionis. Secundo disputat contra dictam opinionem, ibi, et quidem harmonia, et cetera. Tertio ostendit quomodo haec opinio est multum probabilis, ibi, si vero alterum anima est, et cetera. 132. After rejecting Plato’s theory the Philosopher goes on to dispose of another opinion rather similar to Plato’s. For certain philosophers thought the soul was a harmony; agreeing so far with Plato’s view that the soul was composed of harmonic numbers; yet differing from him in that, while he spoke only of a numerical harmony, they extended the principle to include harmonies of compounds, mixtures and contrary qualities.
Circa primum duo facit. Primo enim ponit dictam opinionem de anima; dicens, quod quaedam opinio tradita est ab antiquis de anima, quae videbatur habere rectas rationes, et non solum in speciali de anima, sed etiam quantum ad id quod commune est ad omnia principia. Et dicit quantum ad id quod commune est, quia antiqui philosophi nihil tractaverunt de causa formali, sed tantum de materiali. Et inter omnes, illi qui magis visi sunt appropinquare ad causam formalem fuerunt Democritus et Empedocles: qui, scilicet Empedocles, dixit quod omnia constabant ex sex principiis: quorum quatuor posuit materialia, scilicet quatuor elementa: et duo formalia partim activa, et partim materialia, scilicet amicitiam et litem. Et dicebant quod haec principia materialia habebant inter se quamdam proportionem, quae resultabat ex eis, ita quod conveniebant in aliquo uno, quia sine hoc non possent esse simul. Et hanc dicebant formam rerum et harmoniam quamdam esse. Unde sicut de aliis formis, sic dicebant de anima, quod erat harmonia quaedam. 133. First then he tells us, of a tradition handed down from the early philosophers concerning the soul, which seemed to contain some truth, not only about the soul, but about something common to all the principles of things. He says ‘something common’ because the early philosophers said nothing about formal causes treating only of material causes. Democritus and Empedocles were the two who seem to have come nearest to treating of the formal cause. The latter reduced everything to six principles, of which four—the elements—were material and two were formal, namely the part-active and part-passive principles, Concord and Strife. And the material elements were, they said, linked together by a certain proportion, whence they had a certain unity without which they could not exist together. And this proportion they called the form and harmony of things; whence it followed that, the soul was a harmony like other forms.
Secundo cum dicit etenim harmoniam ponit rationem huiusmodi opinionis; dicens, quod harmonia est complexio et proportio et temperamentum contrariorum in compositis et mixtis. Et haec proportio, quae est inter ista contraria, dicitur harmonia, et forma illius compositi. Unde, cum anima sit quaedam forma, dicebant ipsam esse harmoniam. Dicitur autem haec opinio fuisse cuiusdam Dynarchi et Simiatis et Empedoclis. 134. Then, at ‘And they say that harmony,’ he states the ground of this opinion: harmony is the combination and mixing in due proportion of contraries in compounds and mixtures. The proportion itself is called harmony and is the form of the compound; and because the soul is a kind of form it was reckoned a harmony. Such was apparently the view of Dynarchus, Simiates and Empedocles.
Consequenter cum dicit et quidem disputat contra opinionem praedictam. Et circa hoc duo facit. Primo enim disputat generaliter ad positionem dictorum philosophorum. Secundo vero in speciali ad ponentem, scilicet contra Empedoclem, ibi, investigabit autem hoc et cetera. 135. Next, at ‘Yet a harmony’, he begins to criticise it: first in a general way, and then, at ‘One might, etc.,’ with particular reference to Empedocles who formulated it.
Ad positionem autem obiicit quatuor rationibus: quarum prima talis est. Constat quod harmonia proprie dicta est consonantia in sonis: sed isti transumpserunt istud nomen ad omnem debitam proportionem, tam in rebus compositis ex diversis partibus quam in commixtis ex contrariis. Secundum hoc ergo harmonia duo potest dicere: quia vel ipsam compositionem aut commixtionem, vel proportionem illius compositionis seu commixtionis. Sed constat quod neutrum istorum est anima; ergo anima non est harmonia. Quod autem anima non sit compositio sive proportio compositionis, patet. Isti enim accipiunt animam, ut substantiam quamdam; sed illa duo sunt accidentia; non ergo idem sunt. The general theory is attacked with four arguments. The first is as follows. Harmony, strictly speaking, pertains to sounds, but is transferred by these philosophers to mean any due proportion, either in things composed of different parts or in mixtures of contrary elements. On this view, then, harmony is one of two things: either the compound or mixture itself, or the proportion existing in it. But the soul is clearly neither of these; therefore it is not a harmony. The reason why the soul cannot be, for these philosophers, either a compound or the proportion in a compound is that these are both accidental factors, whilst the soul, according to them, is a substance.
Secundam rationem ponit cum dicit amplius autem quae talis est. Constat quod omnes philosophi dicunt quod anima movet: sed harmonia non movet, immo relinquitur ex movente, et sequitur: sicut ex motu chordarum, qui est per musicam, relinquitur harmonia quaedam in sono. Et ex applicatione et contemperatione partium a componente relinquitur proportio quaedam in composito. Ergo si anima est harmonia, et haec relinquitur ex harmonizatore, oportebit ponere aliam animam, quae harmonizet. 136. The second argument begins at ‘Further, movement’. All philosophers agree that the soul moves something. But harmony does not move anything; rather it is a result and trace of movement, just as in music the movement of strings leaves its trace in harmonious sound. Similarly, the putting together and coadaptation of parts by some composing agent results in a certain proportional composition. If then the soul were a harmony resulting from some producer of harmony, we should have to posit another soul in the producer.
Tertiam rationem ponit cum dicit congruit autem quae talis est. Philosophus dicit in quarto physicorum. Quicumque assignat definitionem seu naturam rei, oportet quod illa assignatio, si sufficiens est, conveniat operationibus et passionibus illius rei: tunc enim definitur optime quid est res, quoniam non solum cognoscimus substantiam et naturam ipsius rei, sed etiam passiones et accidentia eius. Si ergo anima est harmonia quaedam, oportet quod per cognitionem harmoniae deveniamus in cognitionem et operationum, et accidentium animae. Sed hoc est valde difficile, ut puta si velimus operationes animae in harmoniam referre. Cuius enim harmoniae erit sentire, et cuius amare aut odire, et intelligere? Sed per cognitionem harmoniae magis congruit venire in cognitionem accidentium corporum; ut si velimus cognoscere sanitatem, dicemus quod est complexio adaequata et contemperata humorum et qualitatum in corpore: et sic de aliis corporeis virtutibus. Et sic harmonia magis esse attribuenda corpori quam animae. 137. The third argument comes at ‘It would be more appropriate’. In the Physics, Book IV, Aristotle had said that, if the definition of anything is to be adequate, it must answer to all that the given thing can do of itself or receive from other things; for the best definition states not only the substance and nature of a thing, but also its accidental qualities and capacities. If then the soul were a harmony, we ought to be able to work out its capacities and accidental qualities from our knowledge of this harmony. But this is extremely difficult; if, for example, we want to derive the operations of the soul from harmony, to what harmony does feeling or love, hating or understanding belong? It would be easier indeed to know the body through harmony. Thus we certainly can define good health as the duly proportioned and equally balanced commingling of the body’s humours; and likewise with other bodily qualities. Thus harmony belongs apparently to the body rather than to the soul.
Quartam rationem ponit cum dicit amplius autem quae talis est. Harmonia invenitur aliquando in compositis et habentibus compositionem et motum; quia quando haec sic invicem simul ponuntur et ordinantur, ut nullum congeneum praetermittatur idest ut nullus defectus eiusdem generis ibi sit, tunc illae partes dicuntur bene harmonizatae, et compositio ipsarum vocatur harmonia, sicut ligna et lapides, et alia corpora naturalia. Sic etiam et chordae, quando bene ordinatae sunt, vel fistulae, ut ex inde consonantia sonorum resultet, dicuntur bene harmonizatae; et huius consonantia dicitur harmonia, et hoc modo proprie dicitur harmonia. Aliquando invenitur in corporibus mixtis ex contrariis. Quando enim aliqua contraria sunt complexa et commixta in aliquo, ita ut nulla repugnantia seu excessus alicuius contrarii sit ibi, utputa calidi aut frigidi, aut humidi aut sicci, tunc illa dicuntur bene harmonizata, et horum ratio idest proportio dicitur harmonia. Si ergo anima est harmonia, secundum aliquem istorum modorum diceretur. Sed constat quod neutro istorum modorum rationabile est animam dici harmoniam; ergo male dicunt animam harmoniam esse. 138. The fourth argument starts at ‘Further, we speak’. Harmony is sometimes found in things composed together and moving, when, that is, such things are so coapted and arranged that ‘nothing becoming to them is missing’, i.e. no defect occurs within the nature of the thing in question. The parts then are said to be well harmonised and the whole composition is called a harmony, e.g. of wood or stones or other natural bodies. In the same way when stringed. instruments or flutes are well-tuned, so that agreeable sounds result, they are said to be well harmonised. This is the proper meaning of the word. Sometimes, again, ‘harmony’ is found in mixtures of contraries; as, when contrary elements are so combined and mixed that no incompatibility remains, nor any excess of any one of them, e.g. of heat or cold or moisture or dryness; then they are said to be harmonised well and their ratio or proportion is called a harmony. So, if the soul is called a harmony it must be in one of these ways. But in fact it cannot rationally be so called in either of these ways. Those philosophers therefore spoke amiss.
Et quod neutro istorum modorum anima dicatur harmonia, patet. Non enim anima potest dici harmonia, secundum quod invenitur in rebus compositis et habentibus compositionem; quod patet. Nam ordo partium compositarum in corpore est valde manifestus: facile enim est scire ordinem ossium ad ossa, et nervorum ad nervos, et brachii ad manum, et carnis ad ossa. Sed ratio ordinis partium animae est nobis immanifesta. Non enim per hoc possumus scire ordinem qui est inter intellectum et sensum et appetitum et huiusmodi. 139. Clearly, the soul should not be called a harmony precisely in the sense in which compounds and compositions are harmonious. For in the body the interrelation of the various parts is quite evident; we can easily tell how the bones or the nerves are interrelated, what the arm is to the hand and the flesh to. the bone. On the other hand the principle according to which the parts of the soul are interrelated is obscure; nor does the correlation of parts in the body reveal to us how the parts of the soul, the understanding, and the senses, and desire, and so forth, are related to each other.
Nec etiam potest dici harmonia secundum proportionem corporum commixtorum ex contrariis. Et hoc duplici ratione. Una ratio est, quia diversa proportio invenitur in diversis partibus corporis: nam commixtio elementorum non habet eamdem rationem, idest proportionem, secundum quam est caro, et secundum quam est os: ergo in diversis partibus erunt diversae animae secundum diversam proportionem et multiplicationem partium animalis. Alia ratio est, quia omnia corpora sunt commixta ex elementis et contrariis: si ergo proportio commixtionis in quolibet corpore est harmonia, et harmonia est anima; ergo in quolibet corpore erit anima: quod est inconveniens. Et sic patet, quod inconvenienter dicunt animam esse harmoniam. 140. Nor can the soul be called a harmony in the same way as the proportion in bodies compounded of a mixture of contrary qualities; and this for two reasons. One reason is that a different proportion is to be found in different parts of the living body; for the elements do not mix in the same ratio or proportion to form flesh as to form bone; and consequently there would be different souls for the different parts of the same living body, according to the proportional diversity and multiplication of its parts. The other reason is that all bodies are compounded of elements and contrary qualities; hence if the proportion of each compound is a harmony, and each harmony is a soul, there will be no body without a soul; which is an awkward thesis to maintain. It is not therefore of much use to call the soul a harmony.
Consequenter cum dicit investigabit autem disputat contra Empedoclem: et ponit contra eum tres rationes quas non deducit. Quarum prima talis est: ipsi ponunt quodlibet corpus consistere ratione, idest proportione quadam, quam dicunt harmoniam, et hanc dicunt animam: quaero ergo, utrum anima sit ipsa ratio, idest proportio commixtionis, aut aliquid aliud a proportione? Si tu dicis quod est ipsa proportio, tunc, cum in uno corpore sint diversae proportiones secundum diversas partes, sequuntur duo inconvenientia: scilicet quod multae animae sunt in uno corpore secundum diversas partes, et quod in quolibet mixto sit anima. Si dicas quod est aliud quam proportio, tunc, cum proportio sit harmonia, anima non erit harmonia. 141. Next, at ‘One might at this point’, Aristotle attacks Empedocles by drawing three unforeseen consequences from his account of the matter. The first is this. If you maintain that every body has a certain ratio or proportion, which you call harmony and identify with the soul, I put the question to you whether the soul itself is this ratio or proportion, or something else. If you answer that it is the proportion itself, then, since in the same body there are different proportions for the different parts, two difficulties arise; there will be many souls in the same body; and there will be a soul for every compound. But if you answer that the soul is not the proportion itself, then, since harmony is proportion, the soul will not be a harmony.
Secundam rationem ponit cum dicit amplius autem quae talis est. Empedocles ponebat quod amicitia esset causa congregationis in rebus, et lis causa disgregationis: sed in congregatione fit aliqua proportio: quaero ergo, utrum amicitia sit causa cuiuslibet congregationis, aut tantum congregationis harmonizatae? Si tu dicas, quod amicitia est causa cuiuslibet congregationis, tunc oportebit ponere aliquid aliud ab amicitia, quod causet huiusmodi proportionem et harmoniam in congregationibus harmonizatis: vel erit dicere, quod huiusmodi harmonizatio est a casu. Si tu dicas, quod est causa solum congregationis harmonizatae, tunc amicitia non erit causa omnis congregationis: quod est contra eum. 142. The second argument begins at ‘Or further’. Empedocles had asserted that the cause of union in things was Concord and the cause of disunion was Strife. Now union implies a certain proportion. I ask you, then, whether Concord is the cause of any and every union or only of such unions as are harmonious. If you answer ‘of every union’, then you must find sole cause other than Concord for the harmony and proportion proper to harmonious unions—unless you say that the latter occur by chance. But if you say that Concord is the cause of harmonious unions, then it is not the cause of all unions.
Tertiam rationem ponit cum dicit et hoc utrum quae talis est. Empedocles dicit quod amicitia est quae facit congregationem in rebus. Quaero ergo utrum amicitia sit idem cum ipsa congregatione harmonizata, aut non? Si dicatur quod est idem, tunc, cum nihil sit causa suiipsius, amicitia non erit causa illius congregationis, sicut Empedocles dicebat. Si vero dicatur quod non est idem, contra. Congregatio harmonizata nihil aliud est, quam convenientia quaedam: amicitia vero videtur esse quaedam convenientia: ergo est idem: et sic idem quod prius. 143. The third argument, at ‘And whether this’, runs as follows. Empedocles says that Concord is what unites things. I ask: is Concord the same as the actual union in harmony, or is it not? If it is the same, then, since nothing causes itself, love cannot be the cause of the union as Empedocles asserted. But suppose it is not the same. Still, harmonious union as such is only a kind of agreement, which seems to be precisely what Concord is too. So they are the same after all; and the preceding argument applies as before.
Consequenter cum dicit si vero ostendit quomodo haec opinio est multum probabilis; dicens, quod ideo videtur haec opinio probabilis, quia posito uno ponitur aliud, et remoto uno removetur alterum; nam recedente ab aliquo corpore harmonia, recedit anima, et permanente harmonia permanet anima. Sed hoc non sequitur; quia proportio huiusmodi non est forma, sicut ipsi credebant, sed est dispositio materiae ad formam. Et si accipiatur proprie harmonia compositionis pro dispositione, bene sequitur, quod manente dispositione materiae ad formam manet forma, et destructa dispositione, removetur forma. Non tamen quod harmonia sit forma, sed dispositio materiae ad formam. 144. Proceeding, Aristotle shows how plausible is the theory in question. Its plausibility, he says, relies on the argument that if you grant one thing another must follow, and if you re move one thing another is removed. Thus when a body loses its harmony it loses its soul, and while its harmony remains the soul too remains. Yet the conclusion does not follow; for this kind of proportion is not, as those philosophers thought, the form itself, but only a disposition of the matter in view of the form. And if the harmony of a composite being is taken in this its proper sense, i.e. to mean a disposition, then the consequence is quite correct, that, so long as the matter’s disposition to the form remains, the form itself remains, and when the disposition goes, the form also goes. Not that the harmony is the form, but that it is a disposition of the matter in view of the form.
Secundo cum dicit quod quidem concludit et epilogat, quod anima non movetur circulariter, sicut Plato dixit. Nec est harmonia, sicut Empedocles asseruit. Movetur autem secundum accidens, sicut diximus supra, et movet seipsam. Et quod moveatur secundum accidens, patet; quia movetur inquantum movetur corpus in quo est, corpus autem movetur ab anima. Alio modo non est moveri ipsam secundum locum nisi per accidens. 145. Finally, where he says ‘It is evident, then’ Aristotle, concluding, summarises his rejection both of Plato’s view that the soul moves in a circle and of Empedocles that it is a harmony. The soul, as has been said, is moved indirectly, and it moves itself. That it is moved indirectly is clear, for it moves when its body moves; but the body itself receives movement from the soul. Only indirectly, and in no other way, does the soul move from place to place.

TEXT
408a34–408b31
BOOK I, CHAPTER, IV, CONTINUED

THEORY OF SOUL AS A SELF-MOVER RECONSIDERED

εὐλογώτερον δ' ἀπορήσειεν ἄν τις περὶ αὐτῆς ὡς 408b κινουμένης, εἰς τὰ τοιαῦτα ἀποβλέψας· φαμὲν γὰρ τὴν ψυχὴν λυπεῖσθαι χαίρειν, θαρρεῖν φοβεῖσθαι, ἔτι δὲ ὀργίζεσθαί τε καὶ αἰσθάνεσθαι καὶ διανοεῖσθαι· ταῦτα δὲ πάντα κινήσεις εἶναι δοκοῦσιν. ὅθεν οἰηθείη τις ἂν αὐτὴν κινεῖσθαι· One might with more reason enquire about the soul as in movement by considering such facts as these: that it is, as we say, sad, pleased, confident, frightened; or again, that it is angry, feels and understands. All these seem to be movements; from which one might suppose that the soul moves. § 146
τὸ δ' οὐκ ἔστιν ἀναγκαῖον. εἰ γὰρ καὶ ὅτι μάλιστα τὸ λυπεῖσθαι ἢ χαίρειν ἢ διανοεῖσθαι κινήσεις εἰσί, καὶ ἕκαστον κινεῖσθαί τι τούτων, τὸ δὲ κινεῖσθαί ἐστιν ὑπὸ τῆς ψυχῆς, οἷον τὸ ὀργίζεσθαι ἢ φοβεῖσθαι τὸ τὴν καρδίαν ὡδὶ κινεῖσθαι, τὸ δὲ διανοεῖσθαι ἤ τι τοιοῦτον ἴσως ἢ ἕτερόν τι, This, however, is not a necessary conclusion. Even if feeling pain or being glad or understanding are in the fullest sense movements, and each of these is a ‘being moved’ (e. a. being angry or fearful occurs by some movement of the heart), this being moved is from the soul. But as for understanding, it is either of such a nature or perhaps something other. §§ 147-50
τούτων δὲ συμβαίνει τὰ μὲν κατὰ φοράν τινων κινουμένων, τὰ δὲ κατ' ἀλλοίωσιν (ποῖα δὲ καὶ πῶς, ἕτερός ἐστι λόγος), τὸ δὴ λέγειν ὀργίζεσθαι τὴν ψυχὴν ὅμοιον κἂν εἴ τις λέγοι τὴν ψυχὴν ὑφαίνειν ἢ οἰκοδομεῖν· βέλτιον γὰρ ἴσως μὴ λέγειν τὴν ψυχὴν ἐλεεῖν ἢ μανθάνειν ἢ διανοεῖσθαι, ἀλλὰ τὸν ἄνθρωπον τῇ ψυχῇ· τοῦτο δὲ μὴ ὡς ἐν ἐκείνῃ τῆς κινήσεως οὔσης, ἀλλ' ὁτὲ μὲν μέχρι ἐκείνης, ὁτὲ δ' ἀπ' ἐκείνης, οἷον ἡ μὲν αἴσθησις ἀπὸ τωνδί, ἡ δ' ἀνάμνησις ἀπ' ἐκείνης ἐπὶ τὰς ἐν τοῖς αἰσθητηρίοις κινήσεις ἢ μονάς. Of these, however, some occur with a change of place in that which moves; others with an alteration,—of what sort or how is another question. To say that the soul is angry is like saying it builds or weaves. For it is perhaps better to say, not that the soul is compassionate, or learns, or understands, but a man by his soul. These modifications occur by movements not so much in the soul as, in some cases, proceeding to it, and in others, proceeding from it, as sensation proceeds from things, whilst remembering proceeds from the soul to the motions or rests which occur in the sensitive organs. §§ 151-62.
408b.18   ὁ δὲ νοῦς ἔοικεν ἐγγίνεσθαι οὐσία τις οὖσα, καὶ οὐ φθείρεσθαι. μάλιστα γὰρ ἐφθείρετ' ἂν ὑπὸ τῆς ἐν τῷ γήρᾳ ἀμαυρώσεως, νῦν δ' ὥσπερ ἐπὶ τῶν αἰσθητηρίων συμβαίνει· εἰ γὰρ λάβοι ὁ πρεσβύτης ὄμμα τοιονδί, βλέποι ἂν ὥσπερ καὶ ὁ νέος. ὥστε τὸ γῆρας οὐ τῷ τὴν ψυχήν τι πεπονθέναι, ἀλλ' ἐν ᾧ, καθάπερ ἐν μέθαις καὶ νόσοις. καὶ τὸ νοεῖν δὴ καὶ τὸ θεωρεῖν μαραίνεται ἄλλου τινὸς ἔσω φθειρομένου, αὐτὸ δὲ ἀπαθές ἐστιν. τὸ δὲ διανοεῖσθαι καὶ φιλεῖν ἢ μισεῖν οὐκ ἔστιν ἐκείνου πάθη, ἀλλὰ τουδὶ τοῦ ἔχοντος ἐκεῖνο, ᾗ ἐκεῖνο ἔχει. διὸ καὶ τούτου φθειρομένου οὔτε μνημονεύει οὔτε φιλεῖ· οὐ γὰρ ἐκείνου ἦν, ἀλλὰ τοῦ κοινοῦ, ὃ ἀπόλωλεν· ὁ δὲ νοῦς ἴσως θειότερόν τι καὶ ἀπαθές ἐστιν. But intellect would seem to be a subsisting essence implanted in the soul, and not to corrupt. For it would corrupt [if it did], principally through the debility accompanying old age. But in fact what happens is similar to the case of the sensitive powers. If an old man could acquire the eye of a young man, I he would see as a young man; hence, senility is not an affliction of the soul, but of that which it inhabits, like drunkenness or disease. Understanding and thinking, then, decay with the decay of something else within. Understanding itself cannot be affected. But reasoning and loving and hating are not affections of the intellect, but of that which has it, precisely in so far as it has it. Wherefore, when this decays, the soul ceases to remember or love. For these proceeded, not from it, but from what was common, which has disintegrated. But perhaps intellect is something more godlike and unalterable.
ὅτι μὲν οὖν οὐχ οἷόν τε κινεῖσθαι τὴν ψυχήν, φανερὸν ἐκ τούτων· εἰ δ' ὅλως μὴ κινεῖται, δῆλον ὡς οὐδ' ὑφ' ἑαυτῆς. Therefore, that the soul cannot be moved is manifest from these arguments. But if it cannot be moved, it is evident that it cannot be self-moving. §§ 163-7
ST. THOMAS’S COMMENTARY

LECTIO 10
Postquam philosophus posuit rationes illorum qui dixerunt animam moveri ex eo quod ipsa movet corpus, et disputavit contra eos, hic consequenter vult ostendere, quod evidentior ratio, quod anima moveatur, potest sumi ex ipsis operationibus animae. Et circa hoc duo facit. Primo enim movet dubitationem illorum, qui dixerunt animam moveri ex operibus animae. Secundo vero solvit dubitationem huiusmodi quantum ad propositum pertinet, ibi, hoc autem non est necesse et cetera. 146. After stating and criticising the arguments of those who thought that, because the soul moves the body, it must itself be in movement, the philosopher is next concerned to show that a stronger support for the assertion that the soul was in movement might be drawn from considering the activities proper to it. Dividing his treatment into two parts, he first states the hypothesis that the soul’s activities are evidence of its movement; and then settles the problem so far as his present purpose requires, this part beginning at ‘This, however’.
Dicit ergo primo, quod licet praedicti philosophi dubitaverint utrum anima moveretur ex eo quod movet corpus, tamen rationabilius, idest probabilius dubitabit aliquis de anima, quod moveatur considerans in huiusmodi quae dicentur, idest in operationibus animae. Ex his enim poterit probabiliter ostendi, quod anima movetur. Nos enim dicimus animam tristari, gaudere, confidere, idest audere et timere. Amplius autem dicimus ipsam irasci, sentire et intelligere. Cum ergo haec omnia sint operationes animae, et sint motus quidam, videtur quod anima moveatur. Haec autem dubitatio videtur magis probabilis quam superior. Nam illa considerat motum animae ex motu corporis. Dicebat enim quod nihil movet, nisi moveatur. Unde, cum anima moveat corpus, manifestum est, quod ipsa movetur. Haec vero opinio considerat motum ipsius animae ex propriis operationibus animae. First, then, he says that whereas the philosophers, of whom he has been speaking, thought that the soul might be in movement from considering the fact that it moved the body, a more rational, i.e. a more plausible, argument might be drawn ‘by considering such facts as these’, i.e. as the activities of the soul itself. For from these one might build up a very plausible argument in favour of the soul’s being in movement. For we say that the soul ‘is sad, pleased, confident (i.e. daring) and frightened’; and we say that it gets angry and senses and understands. And since all these are activities of the soul, and also types of movement, it would seem that the soul moves. And this is a more plausible suggestion than the one already discussed. For the latter argued the soul’s movement from the body’s, according to the principle that every mover is itself moved; so that if soul moves body the soul itself is moved. But the theory now to be considered regards the movement of the soul from the standpoint of the soul’s own activities.
Consequenter cum dicit hoc autem solvit dubitationem. Circa quod sciendum est, quod quando Aristoteles inquirit veritatem aliquam solvendo et obiiciendo, aliquando obiicit et solvit post determinatam veritatem, et tunc obiicit et solvit secundum suam opinionem: aliquando vero ante determinatam veritatem, et tunc obiicit et solvit supponendo opiniones aliorum, et non secundum suam opinionem et veritatem, quam ipse opinatur. Et huius exemplum habemus in tertio physicorum, ubi philosophus disputat contra ponentes infinitum, et utitur contra eos multis rationibus, quae secundum se sunt falsae, licet secundum illos reputentur verae; puta quod omne corpus habet levitatem et gravitatem. Cuius ratio est, quia hoc, scilicet utrum corpus habet levitatem et gravitatem, nondum determinaverat, quod postea determinavit in libro de caelo: et ideo reiteravit ibi quaestionem de infinito. Hunc autem modum obiiciendi et solvendi servat hic Aristoteles; unde et procedit contra eos supponendo illorum opiniones. 147. Next, at ‘This, however,’ he clears up the difficulty. Here we should note that when Aristotle is searching for truth by a process of stating and answering objections, he will sometimes employ this method after having already demonstrated the truth in question; and then his objections and solutions are governed by the opinion he has already formed for himself. But sometimes he does all this before demonstrating the truth, and then he bases his objections and solutions on the views of others and not on his own opinion or on what he believes to be the truth. For example, in Book III of the Physics, where he argues against those who maintained the existence of an infinite, he employs a number of principles false in themselves but considered true by his opponents, e.g. that every body is both light and heavy. For he had not yet decided about the lightness and heaviness of bodies; this he did later on in the De Coelo, where, in consequence, he reopens the question of the infinite. And such is his method here. His criticism rests upon presupposing as true the views of his opponents.
Illi enim, et maxime Platonici, opinati sunt, quod tristari, gaudere, irasci, sentire, et intelligere, et huiusmodi quae dicta sunt, sint motus animae. Et quod quodlibet illorum, etiam intelligere, fiat per organum determinatum, et quantum ad hoc non sit differentia inter sensitivam et intellectivam, et quod omnis anima, non solum intellectiva, sit incorruptibilis. Aristoteles vero omnia ista concedit. Ipse enim supponit quod huiusmodi operationes fiant per determinata organa, etiam intelligere. Et quod omnis anima sit incorruptibilis. Hoc tantum negat, scilicet quod huius operationes, scilicet sentire, gaudere, et huiusmodi, sint motus animae, sed motus coniuncti; et quantum ad hoc disputat contra eos. 148. These latter, especially the Platonists, thought that sorrow, joy, anger, sensation and thought, and so forth, were movements in the soul, and that each of these activities, not excepting thought, had its own particular organ; so that in this respect there was no difference between sensitivity and intelligence; and every kind of soul, not the intellectual soul only, was immortal. All of which Aristotle concedes, presupposing that all such activities, even thinking, are organic, and that all souls are immortal. He only denies that such activities as sensation and joy are movements in the soul, asserting that they belong rather to the compound of body and soul. This alone he makes the point at issue.
Et circa hoc duo facit. Primo enim ostendit, quod huiusmodi operationes non sunt motus animae. Secundo vero probat hoc quodam medio, ibi, intellectus autem et cetera. Dicit ergo, quod isti dicunt duo. Et primo, quod gaudere et tristari et huiusmodi, sunt motus. Secundo, quod haec attribuuntur animae, scilicet quod irascatur, gaudeat, sentiat et huiusmodi; et sic videtur quod anima moveatur. Sed hoc non est necesse; immo utrumque istorum est falsum: scilicet quia neque huiusmodi operationes sunt motus, et neque attribuuntur animae, scilicet quod irascatur, gaudeat, sentiat, et huiusmodi. Sed dato quod sint motus, et loquamur de eis secundum quod sunt motus, nihilominus tamen falsum est quod attribuantur animae, et per consequens quod secundum huiusmodi operationes moveatur. Quod sic patet. 149. And here he does two things. First, he shows that the activities in question are not movements of the soul; secondly, he proves this with a special argument beginning at ‘But intellect’. His opponents, he says, maintain two points: (1) that joy and sorrow and so forth are movements; (2) that these movements are to be attributed to the soul; which therefore moves. But the conclusion does not necessarily follow; and in any case both propositions are false—the activities in question are not movements, nor are such things as anger, joy, sensation, to be attributed to the soul. But even granted, for the sake of argument, that they are movements, they should not be attributed to the soul; nor the soul , in consequence, be held to move in and with them.
Constat enim quod si huiusmodi operationes sunt motus et attribuantur animae, quod non attribuuntur sibi nisi secundum aliquas determinatas partes corporis; sicut sentire non attribuitur animae, nisi in aliqua parte corporis, ut in oculo, sensus qui est per visum, et irasci in corde, et sic de aliis. Similiter manifeste apparet, quod non sunt animae tantum motus, sed coniuncti. Sunt tamen ab anima, ut puta in hoc quod est irasci. Anima enim iudicat aliquid esse dignum ira, cor autem animalis ex hoc movetur, et fervet circa ipsum sanguis. Sic autem se habet ad timores. Nam aliqua particula corporis contrahitur ad terribile et alteratur, et similiter de aliis. Et sic anima non movetur, sed est moveri ab ea in eo quod aliquid, ut cor, quodammodo movet. Et quia ipse determinabit inferius quod intelligere est quaedam operatio animae, in qua non communicat cum corpore, et non est coniuncti; ideo dicit, quod intelligere forsitan est aliquid alterum ab operationibus coniuncti et dicit forsitan, quia non loquitur definiendo, sed supponendo. Quia vero dixit quod huiusmodi motus non sunt animae, sed coniuncti, sunt tamen ab anima. 150. For it is obvious that; even if these activities are movements and are of the soul, they are not of the soul except with respect to certain definite parts of the body: thus sensation only takes place in certain parts of the body, such as the eye, the organ o sight; and anger in the heart; and so with the rest. it is clear that they are movements not of the soul alone, but of soul and body together. Yet they are from the soul; for example, when the soul thinks that anything is worthy of anger, the animal organ called the heart is disturbed and the blood gets heated around it. So also with fear; it makes a definite part of the body contract and change. And likewise with the rest. In these cases, then, the soul in itself does not move, but only moves in the movement of another thing, e.g. the heart. But in view of a point which Aristotle is going to prove later on, namely that understanding is an act of the soul alone, in which the body has no share, he observes here that perhaps understanding should be distinguished from all those activities which occur in the compound of soul and body. He says ‘perhaps’ because he is speaking tentatively. But in asserting that the other activities are of soul and body together he implies that they do arise from the soul.
Ideo cum dicit horum autem vult ostendere quod huiusmodi motus corporis sunt ab anima secundum loci mutationes. Sicut patet in ira, quae fit in anima motis quibusdam particulis ipsius corporis, scilicet moto corde. Ex ira enim sanguis exit ad partes exteriores, motus a fervore cordis. Alia vero est secundum alterationem, sicut patet in timore. Nam cor ad terribile contrahitur et infrigidatur, et alteratur homo et pallescit. Quales autem passiones sint, et quomodo moveantur, alterius rationis est dicere. Sic igitur patet quod huiusmodi motus non sunt animae, sed corporis ab anima, ut dictum est. 151. So, when he says ‘of these, etc.’ he means to show that these movements arise from the soul to the accompaniment of certain local changes; as in the case of anger, which occurs in the soul when parts of the body in and around the heart are moved: the blood heated by the heart is dispelled towards the extremities of the body. There may also be an ‘alteration’ or qualitative movement, as in fear, when the heart contracts and grows cold and one turns pale. What these passions are, and how they come about, is another question; but it is clear that as movements they are not in the soul alone, but in soul and body together.
Sicut ergo animal habet operationes corporales, et huiusmodi non sunt animae, sed corporis, seu coniuncti, ita et huiusmodi operationes, scilicet sentire et gaudere, et huiusmodi, non debent referri ad animam, sed ad coniunctum. Nam si aliquis dicat animam irasci, et secundum huiusmodi operationes moveri, simile est ac si dicat ipsam animam texere vel aedificare, aut cytharizare. Nam et anima est causa horum motuum. Habitus enim aedificativus et textivus, et cytharizandi est in ipsa anima, et huiusmodi ab anima sunt. Sed sicut melius est dicere quod aedificator aedificat, non ars, licet aedificator aedificet per aedificativam artem, sic fortassis melius est dicere quod anima non miseretur neque addiscit, neque intelligit, sed homo per animam. Dicit fortassis intelligere quia loquitur supponendo, ut dictum est. 152. Hence just as any animal’s bodily activities spring not from its soul alone but from its body, or from the compound of soul and body, so too sense-perception and joy and so forth should not be attributed to the soul alone, but to body and soul together. To say that the soul gets angry and is thereby moved is like saying that the soul weaves or builds or plays the harp. The soul indeed is the cause of these activities; for the acquired ability to build or weave or play the harp is in the soul, and the exercise of the ability in each case springs from the soul. But, as it is better to say that the builder, not the art of building, builds, though the builder builds by his art, so perhaps it is better to say that it is not the soul that feels pity or learns or thinks, but the man who does these things with his soul. He says ‘perhaps etc.’ for the reason given above.
Quia vero per hoc, quod dicit quod non movetur anima, sed homo per animam, posset intelligi quod motus existeret in anima sicut in subiecto; ideo removet hoc, dicens, quod cum dico hominem moveri ab anima, non sic dico quod motus in illa, scilicet in anima, existat, sed quasi ab illa. 153. But since the statement that the soul does not move, but man with his soul, might be taken to mean that movement exists in the soul as its subject, to forestall this Aristotle explains that when he says that man moves with his soul he means that movement is derived, as it were, from the soul, not that it is found in the soul itself
Cum enim dico, hoc movetur per hoc, istud potest dupliciter intelligi. Vel quia aliquando ipsa res, qua aliquid movetur, motum sustinet: ut cum dico hominem moveri pede, quia ipse pes movetur. Vel quia ipsa aliquando res non sustinet motum, sed impellit aliquid ad motum. Et hoc modo homo dicitur moveri per animam. 154. For when I say ‘this moves with that’, my statement can be taken in two senses: either that the source of a given movement is itself moving, as when I say that a man moves with his feet, the feet themselves moving; or that something motionless in itself moves another thing; and it is in this latter sense that a man is said to move with his soul.
Et in hoc est duplex motus. Quia aliquando anima est ut terminus motus, quando scilicet motus est ad illam, scilicet ad animam, sicut in apprehensione sensibilium. Nam quando anima apprehendit exteriora sensibilia, tunc virtus sensitiva, quae est in organo, nititur et movetur ad remittendum et reducendum species et intentiones rerum sensibilium usque ad illam, scilicet ad animam. Aliquando vero est ut principium motus, quando scilicet motus operationis initiatus est ab illa, scilicet ab anima, ut est in reminiscentia, a qua intentiones et phantasmata rerum occultata et recondita educuntur ad intelligendum res sensibiles. Sive autem motus aut quietes dicat aliquis, phantasmata huiusmodi sint derelicta interius, non refert quantum ad praesentem materiam. 155. Now this movement is two-fold. Sometimes the soul represents the term, to which the movement tends, as in sensation; for in the act of the soul’s apprehending exterior sense-objects, the sensitive faculty in the bodily organ is aroused and, moving, transmits ‘to it’, i.e. to the soul, images and notions of sensible things. But sometimes the soul behaves as the starting point of movement, as in remembering, when the latent, buried images and notions of things are brought to light, in order that sensible things may be understood through them. Whether the inward storing away of images should itself be called a movement or a resting is not immediately relevant.
Patet igitur quod huiusmodi motus non attribuuntur animae, sed sunt coniuncti, ab ipsa anima tamen, et non sicut motu existente in ipsa anima. 156. Movements of this sort, then, are not to be attributed to the soul, but to the soul and body together; if they spring from the soul, this does not imply movement in the soul.
Notandum tamen quod haec solutio praedictae dubitationis non est distinctiva et definitiva veritatis, sed obviativa. Sciendum enim, quod motus attribuuntur operationibus animae, a diversis diversimode. Nam tripliciter invenitur motus in operationibus animae. In quibusdam enim invenitur motus proprie, in quibusdam minus proprie, in quibusdam vero minime proprie. 157. But observe that this solution of the problem is only provisional; it does not leave us with the truth perfectly defined. For movement is attributed to the soul’s activities in different ways by different people. In fact, three kinds of movement are discernible therein In some of these activities movement in the strict sense is found. In others it is found in a less exact sense of the term. And in others in a still looser sense.
Proprie enim invenitur motus in operationibus animae vegetabilis, et in appetitu sensitivo. In operatione quidem animae vegetabilis, est proprie motus, quando movetur in esse naturae per nutrimentum, et hic est motus augmenti; et secundum hoc anima vegetabilis se habet ut agens, corpus vero ut patiens. In appetitu vero sensitivo proprie invenitur motus, et secundum alterationem et secundum motum localem. Nam ad appetitum alicuius rei, homo statim movetur et alteratur, vel ad iram, sicut in appetitu vindictae, vel ad gaudium sicut in appetitu delectabilis. Item ex hoc movetur etiam sanguis, qui est circa cor, ad partes exteriores, et etiam homo de loco ad locum ad consequendum id quod appetit. 158. For movement proper occurs in the activities of the vegetative soul and in sensuous desire. In vegetative activity the material substance itself moves, in consequence of assimilating food. This movement is growth; wherein the vegetative soul plays the active part, the body a passive one. In sensuous desire also movement proper occurs, both through qualitative alterations and also through changes of place. No sooner does a man desire anything than he is affected by certain changes—becoming angry, as in the desire for revenge, or glad as in the pursuit of pleasure. And, accompanying this, the blood moves outwards from the heart to the extremities of the body; besides the fact that the whole man moves from one place to another in pursuit of what he desires.
Minus vero proprie invenitur motus in operationibus animae sensitivae. In his enim non est motus secundum esse naturae, sed solum secundum esse spirituale, sicut patet in visu cuius operatio non est ad esse naturale, sed spirituale: quia est per species sensibiles secundum esse spirituale receptas in oculo. Sed tamen habet aliquid de mutabilitate, inquantum scilicet subiectum virtutis visivae est corpus. Et secundum hoc habet rationem motus, licet minus propriam. Non enim dicitur motus in operationibus proprie, nisi cum operatio illa est ad esse naturae. 159. In a less strict sense, however, movement occurs in the acts of the sensitive soul. Here there is no movement of the material substance itself, but only a ‘spiritual’ movement of cognition: for example, the act of seeing is not a material modification; it is ‘spiritual’ reception into the eye of sensible forms. Yet it does involve some material change, because the faculty of sight is lodged in the body: and to this extent it involves movement, though it is not movement in the strict sense. Movement in the strict sense is not ascribed to the soul’s activities except when a modification of the material substance is the direct term of the activity.
Minimum autem de proprietate motus, et nihil nisi metaphorice, invenitur in intellectu. Nam in operatione intellectus non est mutatio secundum esse naturale, sicut est in vegetabili, nec subiectum spirituale quod immutetur, sicut est in sensibili. Sed est ibi ipsa operatio, quae quodammodo dicitur motus, inquantum de intelligente in potentia fit intelligens in actu. Differt tamen a motu eius operatio, quia eius operatio est actus perfecti, motus vero est actus imperfecti. 160. Least strictly of all, and indeed only by a metaphor, is movement to be ascribed to the act of the intellect, in which there is no movement of the material substance, as in the case of vegetative activities, nor even any alteration of the subject of ‘spiritual’ operations, as in the case of sense-awareness. There is only an activity which is called movement simply because the mind goes from potency into act. This differs from movement proper; for whereas the latter connotes an imperfection in the moving subject, this activity proceeds from the subject as already perfect and complete.
Et ideo patet quomodo operationes animae vegetabilis et sensitivae, non sunt motus animae, sed coniuncti. Operationes autem intellectus non dicuntur motus nisi metaphorice, et sunt solum animae intellectivae absque aliquo determinato organo. 161. Clearly then the acts of the vegetative and sensitive souls are not exclusively of the soul, but of soul and body together; while those of the intellect are only called movements metaphorically, and are exclusively of the soul, without the use of any particular bodily organ.
Sciendum etiam, quod sicut in sensu invenitur vis appetitiva et apprehensiva, ita et intellectu invenitur vis appetitiva et apprehensiva. Et ideo haec: amor, odium, gaudium et huiusmodi, possunt intelligi, et prout sunt in appetitu sensitivo, et sic habent motum corporalem coniunctum; et prout sunt in intellectu et voluntate tantum absque omni affectione sensitiva, et sic non possunt dici motus, quia non habent motum corporalem coniunctum. Et inveniuntur etiam in substantiis separatis, secundum quod in sequentibus melius patebit. 162. Note too that, as desire and cognition are both found in the sensitive fart, the same division appears in the intellectual part also. Hence love, hatred, delight and so forth can be understood either as sensitive, and in this sense they are accompanied by a bodily movement; or as exclusively intellectual and volitional, without any accompanying sensuous desire; and understood in this sense they are not movements, for they involve no accompanying bodily change. In this latter sense they pertain even to immaterial substances, as will be shown more clearly later.
Consequenter cum dicit intellectus autem vult probare quae ostendit, scilicet quod huiusmodi operationes, etiam si sint motus, sicut ipsi dicebant, non attribuuntur animae, sed corpori et coniuncto. Et hoc probat per quamdam opinionem illorum, quae erat famosa tempore suo, scilicet, quod omnis anima est incorruptibilis; et hoc secundum eos erat de intellectu et de omni anima. Dicit ergo, quod videtur praedictis philosophis quod intellectus sit quaedam substantia, quae est in fieri et nondum completa, et quod non corrumpitur. Cuius ratio est, quia nos videmus quod omnes debilitationes quae fiunt circa intellectum et sensum, non attingunt ad ipsam animam secundum se, sed proveniunt ex debilitate organi. Unde videtur quod intellectus et omnis anima sit incorruptibilis, et quod debilitatio in eius operationibus non sit ex eo quod ipsa corrumpatur, sed ex eo quod debilitantur organa. 163. Then, at ‘But intellect’, Aristotle sets out to prove what has been shown, namely that even if activities of this kind are movements (as the philosophers he is discussing maintained) still they are not movements of the soul alone, but involve the body also. So he takes one of their opinions (famous in his time), namely that not the intellect only, but every kind of soul without exception, is immortal. According to this view the intellect was a substance in the making, still incomplete, and was immortal. For it is a fact of experience that all the weakening and decay that affect the intellect or the senses come from the side of the bodily organ, not from the soul itself. Whence it would seem to follow that the intellect and every other sort of soul was incorruptible; if its activities grow feeble that does not imply its own decay, but the decay of the organs of the body.
Si enim corrumperetur anima, maxime corrumperetur a debilitate quae est in senectute, sicut accidit in organis sensitivis, quae debilitantur ex senectute: tamen anima non debilitatur ex hoc; quia si senex accipiat oculum iuvenis, videbit ut iuvenis. Quare senectus debilitat, non quidem quod ipsa anima patiatur seu virtus sensitiva, sed id in quo est. Sicut in aegritudinibus et in ebrietatibus non debilitatur anima, sed corpus. Sic ergo intelligere, idest simplex apprehensio et considerare, idest operatio intellectus quae est in componendo et dividendo, marcescunt, non quidem quod intellectus corrumpatur et patiatur, sed corrupto quodam alio interius, idest corrupto aliquo, quod est organum intellectus. Ipsum autem intelligere est impassibile. 164. If the soul itself decayed it would decay especially in old age; that is when the organs of sense grow feeble. Yet in fact the soul itself is unaffected by old age; if an old man could be given a young man’s eye he would see just as well as a young man. The decline of old age, then, is not due to a decline in the soul or in the faculties of sense, but to the body; just as in sickness or drunkenness it is the body, not the soul, that is enfeebled. Hence ‘understanding’, i.e. simple apprehension, and thinking,’ i.e. the intellectual activity of combining and distinguishing ideas, grow weak, not through a weakness in the intellect, but through ‘the decay of something else within’, i.e. the intellect’s organ or instrument. Understanding ‘in itself cannot be affected’.
Hoc autem dicit Aristoteles non quod sit huius opinionis, quod credat intellectum habere determinatum organum corporale; sed sicut dictum est, ipse hic loquitur supponendo opiniones istorum philosophorum, qui, sicut dictum est, erant huius opinionis, quod omnes operationes animae, et etiam ipse intellectus, haberent organa determinata. Et ideo secundum hoc assignat quare intelligere marcescat; quia huiusmodi operationes, quae sunt intelligere, amare et odire, sunt passiones illius, scilicet animae (supponendo loquitur), sed huius habentis, scilicet coniuncti seu organi corporalis. Organi dico habentis illud, scilicet intelligere et huiusmodi secundum quod illud habet. Unde corrupto hoc scilicet determinato organo huiusmodi operationis, quae est amare seu intelligere, non rememoratur neque amat, scilicet anima. Cuius ratio est, quia huiusmodi passiones non erant animae tantum sed communis scilicet coniuncti: quod est iam destructum et corruptum. Si ergo omnes huiusmodi motus et operationes debilitantur non propter animam, sed propter debilitatem corporis seu organi, ut dictum est: manifestum est, quod non sunt animae tantum, sed coniuncti; et per consequens, quod anima non movetur, sed coniunctum, licet anima. 165. Now in saying this Aristotle is not giving it as his opinion that the intellect has a special bodily organ, but, in the manner already explained, he is arguing on the supposition that the views of the philosophers whom he is criticising are sound; and it was their view, as we have seen, that each of the soul’s activities, and even intellect itself, had its special bodily organ. Assuming this, therefore, he gives as the reason for the decay of the understanding that it is one of those activities (like hating and loving) which are not of the soul alone, but of ‘that which has it’, i.e. of the compound of body and soul, or the bodily organ—precisely, he adds, in so far as this compound has ‘it’, i.e. understanding, and so forth. Consequently when ‘this’ (i.e. the bodily organ) ‘decays’ its activities, such as loving or understanding, decay likewise, and the soul itself neither remembers nor loves any more. The reason is that such processes did not only involve the soul, but that which was common’, i.e. the whole compound being; which has now decayed and passed away. Clearly, then, if all such movements and activities decay through the body’s decay, not the soul’s. they are not themselves exclusively of the soul, but of the soul and body together; and not the soul, but soul and body together, is what moves.
Quia vero Aristoteles locutus est hic de intellectu, supponendo opiniones aliorum, sicut iam patet; ne credatur quod ipse opinetur intellectum sic esse ut supposuit, ideo removet hoc, dicens, quod fortassis intellectus est aliquid divinius et impassibile, idest aliquid altius et aliqua maior potentia, et per consequens operatio ipsius animae, quam dicatur hic. Dicit autem fortassis quia nondum hoc determinaverat, sed postea hoc in tertio ostendit. Unde patet quod supponendo loquitur. 166. But to remove any impression that he himself believes the intellect to be what the argument he is using supposes it to be, he adds these words, ‘Perhaps intellect is something more godlike and unalterable’, i.e. some sort of nobler power than any we are considering now, whose activity is exclusively of the soul. He says ‘perhaps’ because the question has not been decided yet; it will be cleared up in Book III. So much to show that he is arguing on a supposition.
Consequenter concludit ex omnibus dicens, quod manifestum est ex omnibus his, quae dicta sunt, quod non est possibile animam moveri. Quod si non movetur aliquo modo, manifestum est quod non movetur a seipsa huiusmodi motibus, sicut isti ponebant. 167. Finally, he concludes from all this that it is now clear that the soul itself cannot be the subject of movement. And if so, then the soul is obviously not a self-mover with movements of the kinds here discussed, as the philosophers he is criticising had maintained.

TEXT
408b32–409b18
BOOK I, CHAPTER IV, CONTINUED

SOUL AS A SELF-MOVING NUMBER

πολὺ δὲ τῶν εἰρημένων ἀλογώτατον τὸ λέγειν ἀριθμὸν εἶναι τὴν ψυχὴν κινοῦνθ' ἑαυτόν· ὑπάρχει γὰρ αὐτοῖς ἀδύνατα πρῶτα μὲν τὰ ἐκ τοῦ κινεῖσθαι συμβαίνοντα, ἴδια δ' ἐκ τοῦ 409a λέγειν αὐτὴν ἀριθμόν. πῶς γὰρ χρὴ νοῆσαι μονάδα κινουμένην, καὶ ὑπὸ τίνος, καὶ πῶς, ἀμερῆ καὶ ἀδιάφορον οὖσαν; ᾗ γάρ ἐστι κινητικὴ καὶ κινητή, διαφέρειν δεῖ. Much the most unreasonable thing said about the soul is that it is a number moving itself In this there are several impossibilities. First, what follows upon ‘being moved’, as they say; and then the special difficulties that follow their assertion that it is a number. How is one to conceive a unity, indivisible and undifferentiated in itself, as moving? Or by what? Or in what way? For if it is both moved and mover, there must be some difference in itself. §§ 168-9
ἔτι δ' ἐπεί φασι κινηθεῖσαν γραμμὴν ἐπίπεδον ποιεῖν, στιγμὴν δὲ γραμμήν, καὶ αἱ τῶν μονάδων κινήσεις γραμμαὶ ἔσονται· ἡ γὰρ στιγμὴ μονάς ἐστι θέσιν ἔχουσα, ὁ δ' ἀριθμὸς τῆς ψυχῆς ἤδη πού ἐστι καὶ θέσιν ἔχει. Further, since they say that a line, being moved, makes a plane, and a point, being moved, a line, the movements of the units will be lines. Now a point is unit having position; so that the number of a soul must be in some place and have position. § 170
ἔτι δ' ἀριθμοῦ μὲν ἐὰν ἀφέλῃ τις ἀριθμὸν ἢ μονάδα, λείπεται ἄλλος ἀριθμός· τὰ δὲ φυτὰ καὶ τῶν ζῴων πολλὰ διαιρούμενα ζῇ καὶ δοκεῖ τὴν αὐτὴν ψυχὴν ἔχειν τῷ εἴδει. Further, if one subtracts from a number a number or a unit, another number is left. Plants, however, and many animals, live on after being divided, and seem to retain specifically the same soul. § 171
δόξειε δ' ἂν οὐθὲν διαφέρειν μονάδας λέγειν ἢ σωμάτια μικρά· καὶ γὰρ ἐκ τῶν Δημοκρίτου σφαιρίων ἐὰν γένωνται στιγμαί, μόνον δὲ μένῃ τὸ ποσόν, ἔσται [τι] ἐν αὐτῷ τὸ μὲν κινοῦν τὸ δὲ κινούμενον, ὥσπερ ἐν τῷ συνεχεῖ· οὐ γὰρ διὰ τὸ μεγέθει διαφέρειν ἢ μικρότητι συμβαίνει τὸ λεχθέν, ἀλλ' ὅτι ποσόν· διὸ ἀναγκαῖον εἶναί τι τὸ κινῆσον τὰς μονάδας. εἰ δ' ἐν τῷ ζῴῳ τὸ κινοῦν ἡ ψυχή, καὶ ἐν τῷ ἀριθμῷ, ὥστε οὐ τὸ κινοῦν καὶ κινούμενον ἡ ψυχή, ἀλλὰ τὸ κινοῦν μόνον. It would seem to be a matter of indifference whether one says ‘units’ or ‘small bodies’. For if the spheres of Democritus were to become points, and only quantity remained, there would remain in them a moving and a moved, as in extended matter, For the distinction spoken of is not due to largeness or smallness, but to quantity as such. Hence there must necessarily be something moving the units. But if it is the soul which moves the animal, so also in the case of number: then the soul is not a moving thing, which is also moved, but a mover only. § 172
ἐνδέχεται δὲ δὴ πῶς μονάδα ταύτην εἶναι; δεῖ γὰρ ὑπάρχειν τινὰ αὐτῇ διαφορὰν πρὸς τὰς ἄλλας, στιγμῆς δὲ μοναδικῆς τίς ἂν εἴη διαφορὰ πλὴν θέσις; εἰ μὲν οὖν εἰσὶν ἕτεραι αἱ ἐν τῷ σώματι μονάδες καὶ αἱ στιγμαί, ἐν τῷ αὐτῷ ἔσονται αἱ μονάδες· καθέξει γὰρ <ἑκάστη> χώραν στιγμῆς. καίτοι τί κωλύει ἐν τῷ αὐτῷ εἶναι, εἰ δύο, καὶ ἄπειρα; ὧν γὰρ ὁ τόπος ἀδιαίρετος, καὶ αὐτά. εἰ δ' αἱ ἐν τῷ σώματι στιγμαὶ ὁ ἀριθμὸς ὁ τῆς ψυχῆς, ἢ εἰ ὁ τῶν ἐν τῷ σώματι στιγμῶν ἀριθμὸς ἡ ψυχή, διὰ τί οὐ πάντα ψυχὴν ἔχουσι τὰ σώματα; στιγμαὶ γὰρ ἐν ἅπασι δοκοῦσιν εἶναι καὶ ἄπειροι. Now this would have somehow to be a unit. If so, it must have some principle of differentiation from other units. But how can one isolated point differ from others, but in position? But if there are many different units and points in a body, they will be units in the same subject, and will occupy space as points. But, if there are two in the same place, what is there to prevent an infinity of them together? That of which the place is indivisible is itself such. But if the points in the body are the ‘numbers’ of the soul, or if the ‘number’ of body-points is that of the soul, why are there not souls in all bodies? For in all things there seem to be points, even to infinity. § 173
ἔτι δὲ πῶς οἷόν τε χωρίζεσθαι τὰς στιγμὰς καὶ ἀπολύεσθαι τῶν σωμάτων, εἴ γε μὴ διαιροῦνται αἱ γραμμαὶ εἰς στιγμάς; Furthermore, how is it possible for these points to be separated and released from the body? Since lines cannot be divided up into points? § 174
ΚΕΦΑΛΑΙΟΝ Ε'. CHAPTER V
409a31   1. Συμβαίνει δέ, καθάπερ εἴπομεν, τῇ μὲν ταὐτὸ λέγειν τοῖς σῶμά τι λεπτομερὲς αὐτὴν τιθεῖσι, τῇ δ', ὥσπερ 409b Δημόκριτος κινεῖσθαί φησιν ὑπὸ τῆς ψυχῆς, ἴδιον τὸ ἄτοπον. εἴπερ γάρ ἐστιν ἡ ψυχὴ ἐν παντὶ τῷ αἰσθανομένῳ σώματι, ἀναγκαῖον ἐν τῷ αὐτῷ δύο εἶναι σώματα, εἰ σῶμά τι ἡ ψυχή· τοῖς δ' ἀριθμὸν λέγουσιν, ἐν τῇ μιᾷ στιγμῇ πολλὰς στιγμάς, καὶ πᾶν σῶμα ψυχὴν ἔχειν, εἰ μὴ διαφέρων τις ἀριθμὸς ἐγγίνεται καὶ ἄλλος τις τῶν ὑπαρχουσῶν ἐν τῷ σώματι στιγμῶν· συμβαίνει τε κινεῖσθαι τὸ ζῷον ὑπὸ τοῦ ἀριθμοῦ, καθάπερ καὶ Δημόκριτον αὐτὸ ἔφαμεν κινεῖν· τί γὰρ διαφέρει σφαίρας λέγειν μικρὰς ἢ μονάδας μεγάλας, ἢ ὅλως μονάδας φερομένας; ἀμφοτέρως γὰρ ἀναγκαῖον κινεῖν τὸ ζῷον τῷ κινεῖσθαι ταύτας. This amounts to saying (as we said before), either, under one aspect, the same as those who posit the soul. as a body of very refined elements, or, under another aspect, what Democritus said of the movement of the soul,—a thing intrinsically absurd. For if the soul is in all the body as sentient, there must be two bodies in the same place, if the soul is some sort of body. And for those who say it is a number, there are many points in one point, or else every body has a soul; unless the soul’s ‘number’ be other than that of the points in the body. The animal would then come to be moved by a number, precisely as Democritus said. What difference does it make whether one says small spheres or large units, or, in general, that units are in motion? In any case it must needs be that the animal moves when these are moving. §§ 175-6
τοῖς δὴ συμπλέξασιν εἰς τὸ αὐτὸ κίνησιν καὶ ἀριθμὸν ταῦτά τε συμβαίνει καὶ πολλὰ ἕτερα τοιαῦτα· οὐ γὰρ μόνον ὁρισμὸν ψυχῆς ἀδύνατον τοιοῦτον εἶναι, ἀλλὰ καὶ συμβεβηκός. δῆλον δ' εἴ τις ἐπιχειρήσειεν ἐκ τοῦ λόγου τούτου τὰ πάθη καὶ τὰ ἔργα τῆς ψυχῆς ἀποδιδόναι, οἷον λογισμούς, αἰσθήσεις, ἡδονάς, λύπας, ὅσα ἄλλα τοιαῦτα· ὥσπερ γὰρ εἴπομεν πρότερον, οὐδὲ μαντεύσασθαι ῥᾴδιον ἐξ αὐτῶν. These and many other consequences result for those who would combine number and movement in a single principle. It is impossible for such to be not only a definition of the soul, but even one of its accidents-as is clear if one attempts by this procedure to account for the soul’s activities and modifications, such as pleasure, pain and so forth. As we said before, on these principles it is not easy even to hazard a conjecture. § 177
ST. THOMAS’S COMMENTARY

LECTIO 11
Postquam philosophus improbavit opinionem illorum, qui dixerunt simpliciter animam moveri, hic consequenter arguit contra opinionem Xenocratis, qui supra motum addidit aliquid aliud, scilicet quod anima esset numerus movens seipsum. Et haec opinio est multum irrationabilior opinionibus aliorum philosophorum, quae dictae sunt. Nam his qui dicunt animam esse numerum moventem seipsum, multa impossibilia insunt. Et primo quidem ea quae accidunt eo quod est moveri, id est ex motu, quae etiam accidunt omnibus dicentibus animam moveri; accidunt etiam sic dicentibus, et inconvenientia propria, ex hoc scilicet quod dicunt animam esse numerum. Et propter hoc philosophus improbat definitionem hanc Xenocratis de anima, et non tantum est disputans ad nomen, sed ad ipsam intentionem definientis. Circa hoc autem duo facit. Primo ostendit hanc definitionem esse inconvenientem, quantum ad ipsam animam vel substantiam animae. Secundo vero quantum ad eius accidentia, ibi, complectentibus igitur in unum et cetera. Circa primum duo facit. Primo enim destruit definitionem praedictam de anima per rationes. Secundo vero ostendit quod ad hanc definitionem sequuntur omnia inconvenientia quae sequuntur ad opiniones aliorum philosophorum, ibi, accidit autem sicut diximus et cetera. 168. After refuting those who asserted that the soul was a thing that moved, the Philosopher goes on now to criticise the view of Xenocrates who said, in addition, that soul was a self-moving number; a far less rational opinion than the others already mentioned. For it involves many absurdities. First of course there are those arising from ‘being moved’, the irrationalities, namely into which all who say that the soul itself moves are led; and then, in addition, there are the special difficulties involved in the notion that soul is a number. Therefore in Xenocrates’ definition of soul the Philosopher criticises, not merely the terms employed, but the meaning itself. This critique has two parts. First he shows that the definition does not fit the soul itself or its substance; and then that ‘it does not fit its accidental qualities,—this at ‘These and many other consequences’. The former part subdivides into reasons for (a) rejecting the said definition and (b) for thinking that it involves all the difficulties implicit in the views of the other philosophers already criticised; this part beginning at ‘This amounts to saying’.
Quod autem praedicta definitio sit incongrua, probat sex rationibus. Quarum prima talis est. Tu dicis, animam esse numerum moventem seipsum: numerus autem constat ex unitatibus: ergo dicis animam esse unitates. Si tu dicis animam esse numerum moventem seipsum, ergo et animam unitates moventes seipsas: sed omne movens seipsum habet duas partes, ut probat in octavo physicorum; quarum una est movens et alia mota: ergo oportebit dicere quod unitas seu punctum dividetur in duas partes, quarum una sit movens, et altera mota. Hoc autem est impossibile, ergo impossibile est quod anima sit numerus movens seipsum. Quod autem sit impossibile unitatem habere unam partem moventem et aliam motam, probat: quia nullo modo illud quod est omnino impartibile et indifferens, potest intelligi quod moveatur per se, ita quod habeat partem moventem unam, et aliam motam. Nam in nullo possunt haec duo, scilicet vis motiva vel movens, et mobilis vel mota esse, nisi differant. Cum ergo unitas sit impartibilis et indifferens, non potest huiusmodi partes habere, et sic nec moveri. Ergo anima non est numerus movens seipsum. 169. He shows the unsuitability of the definition by six arguments; the first being as follows. You call the soul a self-moving number; but number is composed of units; the soul then, in your view, consists of units which move themselves. Now in any self-moving thing there are two parts (as is shown in Book VIII of the Physics), one moving, the other moved. Therefore you must mean that each unit or point is composed of two parts, one moving, the other moved. But this is impossible. Therefore the soul is not a self-moving number. To show the impossibility of a unit having a moving part and a moved part: what is wholly indivisible and undifferentiated cannot be thought of as moving itself in such a way that one part moves and another is moved. For the motive or moving factor and the mobile or moved factor cannot exist without differing. Since, then, the unit is indivisible and undifferentiated, it cannot have such parts as these. Therefore the soul is not a self-moving number.
Secundam rationem ponit cum dicit amplius quoniam quae talis est. Tu dicis animam esse numerum: ergo et unitates, ut dictum est. Inter unitatem autem et punctum nulla differentia est, nisi quod punctus habet positionem; est enim punctum unitas positionem habens. Sed si anima est numerus, oportet quod alicubi sit huiusmodi numerus animae, et positionem habens: ergo anima erit unitas positionem habens. Huiusmodi autem sunt puncta: ergo anima erit puncta. Sed secundum quod dicunt Platonici, motus puncti facit lineam, linea autem mota facit superficiem, superficies vero corpus. Sed est anima numerus movens seipsum, ergo eodem modo et unitas; et per consequens est punctum movens seipsum: punctum autem motum non facit nisi lineam: ergo motus animae non facit nisi lineam. Et sic anima motu suo non causat vitam, sed lineam, quod est falsum. Non est igitur anima numerus movens seipsum. 170. The second argument, at ‘Further, since’, runs thus. You say the soul is a number; and therefore composed of units, as has been said. Now the only difference between a unit and a point is that a point has position—it is a unit in position. But if the soul is a number, this number must exist somewhere in position. Therefore the soul is a unit in position, that is to say a point. But according to the Platonists a point in movement makes a line, a line in movement makes a surface, and a surface a body. If then the soul is a self-moving number each of its units is self-moving, and each of these is a self-moving point. But such a point can only make a line; therefore the same is true of the movement of the soul. Hence not life, but a line is the effect of the soul; which is not true. Therefore the soul is not a self-moving number.
Tertiam rationem ponit cum dicit amplius autem quae talis est. Si anima est numerus, ut tu dicis, oportet quod consequatur passiones et naturam numeri: sed constat quod si aliquis auferat a numero unitatem aliquam, seu addat, mutat speciem. Nam si huic numero, scilicet ternario, addas unitatem, mutat speciem. Alia enim species est huius numeri quatuor, et alia eius quod est tria. Si vero ab eodem auferas unitatem, efficitur duo et mutat similiter speciem. Constat autem quod animalia sumunt speciem ab anima, cum unumquodque consequatur per formam speciem suam. Ergo si anima est numerus, ex subtractione vel additione alicuius ab anima, relinquitur alia anima specie: et hoc est falsum. Videmus enim in decisionibus plantarum et animalium annulosorum, quod divisa seu decisa vivunt, et eamdem speciem habent. Non ergo anima est numerus movens seipsum. 171. The third argument, at ‘Further, if’, is the following. if, as you say, the soul is a number, it must have the nature and attributes of number. Now it is evident that whenever a unit is taken from or added to a number, the number is essentially changed. if you add 1 to 3 you alter the number in kind: 4 differs in kind from 3. Similarly if you take 1 from 3, leaving 2. Now it is agreed that living things are specified by their soul; since it is through the form that things are specified. if” then, the soul is a number, any addition to, or subtraction from, it must alter it in kind. But this is not true: for if plants and segmented animals are cut up the divisions go on living, the same in kind as before. Therefore the soul is not a self-moving number.
Quartam rationem ponit cum dicit videbitur autem quae talis est. Tu dicis animam esse numerum: et sicut dictum est; sequitur quod anima sit unitates positionem habentes, et per consequens quod sit puncta. Secundum hoc autem si recte consideremus, videbitur utique quod nihil differt dicere, quod anima sit corpora parva et indivisibilia, sicut dixit Democritus, aut dicere quod sit unitates positionem habentes. Unum enim positionem habens, quantitas est et indivisibilis. 172. The fourth argument, at ‘It would seem to be’ is as follows. You say the soul is a number; whence it follows, as we know, that it consists of units in position, i.e. points. But on this, supposition it is obvious that there is no difference between saying, with Democritus, that the soul consists of small indivisible bodies and saying that it is composed of units in position. For each unit in position is a quantity and indivisible.
Ex hoc ergo sic arguo: anima, secundum positionem tuam, est numerus movens seipsum, et per consequens unitates et puncta moventia seipsa. Ponamus autem quod corpora indivisibilia, quae posuit Democritus, sint puncta, quia non differt, sicut dictum est, et sint quanta, quod necesse est, quia proprie non movetur nisi quantum. Huiusmodi autem puncta movent seipsa, quia anima est numerus seipsum movens. Sed in movente seipso, sicut dictum est, duo sunt: ergo erit in ipso puncto, unum quod est movens, et aliud quod est motum. Nec est curandum utrum sint magna seu parva, dummodo sit quanta; quia in quolibet continuo movente seipsum hoc accidit, scilicet, quod sint duo ibi, unum ut movens, et aliud ut motum. Et sic necesse est quod sit aliquid motivum unitatum. In animali autem, illud quod movet animal, est anima; ergo et in numero, illud quod movet numerum erit anima; ergo anima non est id quod movetur, sed illud quod movet. Et sic mala est definitio animae, quod sit numerus movens seipsum; sed potius quod sit numerus movens numerum motum. Very well then; the soul, in your view, is a self-moving number and, consequently, consists of units and points moving themselves. Let us suppose then that the indivisible bodies of Democritus are points (there is no difference, as we have seen) and are quantities (as they must be, since only quantities, properly speaking, move). Now these points will move themselves if the soul is a self-moving number. But every self-mover, as has been said, is two-fold; hence each point itself is two-fold, having a moving part and a moved part; and this, no matter whether they be large parts or small, provided they have some quantity; for every self-moving continuum contains the two factors; a moving one and a moved one. So there must be a mover of the units. But in living things the mover is the soul; therefore the mover of the number would be the soul; whence it follows that the soul is not a moved but a mover, and thus, the definition of it as a self-moving number is incorrect. It should rather be defined as a number moving another number.
Quintam rationem ponit cum dicit contingit autem quae talis est. Secundum opinionem Xenocratis contingit hanc, scilicet animam, esse unitatem: sed ex hoc contingit ipsam esse puncta; quia si anima est unitas, oportet quod differat ab aliis unitatibus. Non poterit autem differre ab eis nisi per positionem. Quae enim est differentia puncti solitarii id est unitatis intellectae, nisi positio? Nulla unitas autem nisi positionem habens, est punctum: ergo anima non est unitas sed puncta. Sed anima est in corpore, et quodlibet corpus habet puncta sua per se. Quaero ergo, utrum puncta, quae sunt anima, sint eadem cum punctis corporis, aut alia. Si quidem sunt altera, ergo in qualibet parte corporis erunt puncta animae, et sic erunt duo puncta animae in eodem loco simul. Et si duo, propter quid non plura, aut etiam infinita? Nam illa, quorum locus est indivisibilis, et ipsa indivisibilia sunt, unde non indigent ampliori loco. Unde si ponantur duo esse in loco indivisibili, per consequens possunt in eodem loco esse infinita. Si vero dicas, quod sunt eadem puncta quae sunt in corpore cum his punctis, quae sunt anima, sequitur quod cum omne corpus habeat puncta, quod omne corpus habeat animam: sed hoc est falsum: non ergo anima est numerus movens seipsum. 173. The fifth argument begins at ‘Now this would have somehow to be a unit’. In Xenocrates’ opinion the soul is a unity. But if so, then it is a point; for it must, as a unity, differ from other unities and it cannot differ except through position. For what is it that differentiates ‘isolated points’, i.e. unities as here understood, excepting their position? Moreover, only through position are unities points. The soil, then, is not a mere unity, but a point. Yet it exists in the body and every body as such has its own points. Well then, are the soul-points identical with the body-points or not? If they are not, then every part of the body will contain also soul-points, and in every such part there will be two points at the same time in the same place. And if two, why not more than two, ad infinitum? Things whose place is indivisible are themselves indivisible; and require no increase of space if they increase in number; so, that if two can be in an indivisible place, there is no reason why an infinite number should not be there. On the other hand if body-points are identical with soul-points, then every body has a soul, since every body has points. But this is false; therefore the soul is not a self-moving number.
Sextam rationem ponit cum dicit amplius autem et sumitur ex praecedenti. Quae talis est: sicut dictum est, sequitur ex positione Xenocratis, quod anima sit puncta: sed nos videmus quod puncta non separantur, nec absolvuntur a corporibus. Nam lineae non dividuntur a superficiebus, nec puncta a lineis. Anima vero separatur et absolvitur a corpore: ergo non est puncta, neque numerus. Patet ergo quod definitio Xenocratis de anima est incongrua quantum ad ea quae in definitione ponuntur. 174. The sixth argument, at ‘Furthermore, how’, continues the preceding one. It follows from Xenocrates’ theory that the soul is composed of points. Points are obviously inseparable and undetachable from bodies; for lines are not separable from surfaces, nor points from lines. But this is not true of the soul; hence it is not a point or a number. Clearly then, Xenocrates’ definition is intrinsically inappropriate.
Consequenter cum dicit accidit autem dicit definitionem praedictam esse incongruam, quantum ad inconvenientia. Nam ex huiusmodi definitione de anima sequuntur omnia inconvenientia, quae sequuntur ex opinionibus omnium philosophorum de anima. Quidam enim erraverunt circa animam, et dixerunt ipsam esse corpus subtilissimarum partium. Ex quo sequebatur, quod cum anima sit ubicumque est sensus in corpore, et sensus sit ubique per corpus, quod si anima est corpus, quod duo corpora sint simul. Et hoc idem sequetur si anima est puncta, sicut dictum est, scilicet quod duo sint simul et etiam infinita; et hoc si puncta animae sint alia a punctis corporis. Sed si non fiat differens numerus punctorum animae, id est si non differant puncta animae a punctis quae sunt in corpore, sequitur quod in quolibet corpore sit anima. In quolibet enim corpore est invenire puncta. §175. Then, at ‘This amounts to saying,’ he finds this definition objectionable in its consequences. These consequences involve all the objectionable consequences flowing from the theories of all who have philosophised about the soul. For some of these fell into the mistake of saying that the soul was a body made up of extremely fine parts, whence it would follow that two bodies would be together in the same place; for the soul is wherever sensation occurs, and this is everywhere in the body. And the same would follow, as has been said, if the soul were composed of points: two points, or even an infinite number of points, would exist together in the same place at the same time. This would follow if the soul-points differed from body-points. And if ‘the number be other’, i.e. if there is no difference between soul-points and body-points, then every body contains a soul, since it must contain points.
Quidam vero, sicut Democritus, erravit dicens animam moveri, et corpus ex motu animae; et cum ipse diceret componi animam ex indivisibilibus sphaeris, et ex motu ipsarum moveri corpus, sequebatur, quod corpus moveretur ex corporibus indivisibilibus. Et hoc idem inconveniens sequitur ex definitione istorum, scilicet animal moveri ex numero, et per consequens a punctis: et non est differentia, dicere sphaeras parvas, et unitates magnas, aut quascumque unitates moveri. Nam utrobique id est in sphaericis corporibus et unitatibus, necesse est quod anima moveatur, eo quod ipsa, scilicet corpora sphaerica, et puncta seu unitates moventur. 176. Others, like Democritus erred in saying that the soul itself moved, and the body because of the soul. And from Democritus’ statement that the soul was made up of indivisible spheres whose movement caused the body to move it followed that indivisible bodies were the cause of bodily movements. The same difficulty follows from the definition which states that an animal is moved by a number and so by points. It makes no difference what size we give to the moving spheres or units; for ‘in any case’, i.e. with spheres or with units, the origin of the soul’s movement is the movement of bodily spheres and points.
Consequenter cum dicit complectentibus igitur ostendit insufficientiam praedictae definitionis ex parte accidentium. Dicit ergo quod, quandocumque definitio sufficienter assignatur, non solum debet ducere in cognitionem substantiae rei definitae, sed etiam accidentium. Sed si complicemus in unum ista duo, quae posita sunt in definitione animae, scilicet numerum et motum, non solum accidunt nobis inconvenientia quae dicta sunt circa substantiam ipsius animae, sed etiam multa alia; quia haec duo non solum est impossibile esse definitionem, idest substantiam animae, verum etiam est impossibile quod ipsa, scilicet numerus et motus, sint accidentia animae, seu ducant in cognitionem accidentium. Non igitur est congrua definitio, cum non ducat, in cognitionem accidentium. Et quod non ducat in cognitionem accidentium animae, manifestum est si quis ex huiusmodi definitione conabitur passiones et operationes animae assignare, puta ratiocinationes, delectationem, tristitiam, et huiusmodi. Ex ipsis enim, scilicet ex numero et motu, non solum non erit facile devenire in cognitionem accidentium et operationum animae, sed nec divinare poterimus ex eis aliquid de ipsis passionibus et operationibus animae. 177. Next, at ‘These and etc.,’ he shows the weakness of the above definition with respect to accidental qualities. A complete definition, he says, must give knowledge of the accidents as well as of the substance of the thing defined. But if we combine number and movement in our definition of the soul, we shall find ourselves involved in many difficulties besides those that concern the soul’s substance. For these two things, number and movement, not only cannot belong to the substance of the soul, but are not even accidental qualities of it, nor are they means to a knowledge of these qualities. Hence the definition itself is unsuitable; it does not help us to know the accidental qualities of the thing defined. This will be evident to anyone who, relying on this definition, tries to attribute to the soul affections and activities such as reasoning, pleasure, pain and the like. If we started from number and movement, we should not only find it, hard to reach any knowledge of the soul’s accidental qualities and passions and activities, but we could not even begin to hazard any conjecture about them.

TEXT
409b18–411a7
BOOK I, CHAPTER V, CONTINUED

EMPEDOCLES’ THEORY OF COGNITION
SOUL NOT COMPOSED OF THE ELEMENTS

τριῶν δὲ τρόπων παραδεδομένων καθ' οὓς ὁρίζονται τὴν ψυχήν, οἱ μὲν τὸ κινητικώτατον ἀπεφήναντο τῷ κινεῖν ἑαυτό, οἱ δὲ σῶμα τὸ λεπτομερέστατον ἢ τὸ ἀσωματώτατον τῶν ἄλλων. ταῦτα δὲ τίνας ἀπορίας τε καὶ ὑπεναντιώσεις ἔχει, διεληλύθαμεν σχεδόν· λείπεται δ' ἐπισκέψασθαι πῶς λέγεται τὸ ἐκ τῶν στοιχείων αὐτὴν εἶναι. λέγουσι μὲν γάρ, ἵν' αἰσθάνηταί τε τῶν ὄντων καὶ ἕκαστον γνωρίζῃ· ἀναγκαῖον δὲ συμβαίνειν πολλὰ καὶ ἀδύνατα τῷ λόγῳ. τίθενται γὰρ γνωρίζειν τῷ ὁμοίῳ τὸ ὅμοιον, ὥσπερ ἂν εἰ τὴν ψυχὴν τὰ πράγματα τιθέντες. οὐκ ἔστι δὲ μόνα ταῦτα, πολλὰ δὲ καὶ ἕτερα, μᾶλλον δ' ἴσως ἄπειρα τὸν ἀριθμὸν τὰ ἐκ τούτων. There are, then, three ways in which men have defined the soul: some declaring that it is the principal mover, being self-moving; some, that it is the most subtle of bodies, or the least corporeal of things (what contradictions and problems these views entail we have briefly reviewed); so what is left for us to consider is how it is said to be constituted from the elements. They say this is so because the soul perceives things that are and knows each one. But many irrational consequences follow upon this. For they suppose that like is known by like, as if they meant to identify things themselves with the soul. But those [elements] are not the only things; there are many others, perhaps infinite in number, derived from them.
ἐξ ὧν μὲν οὖν ἐστιν ἕκαστον τούτων, ἔστω γινώσκειν τὴν ψυχὴν καὶ αἰσθάνεσθαι· ἀλλὰ τὸ σύνολον τίνι γνωριεῖ ἢ αἰσθήσεται, οἷον τί θεὸς ἢ ἄνθρωπος ἢ σὰρξ ἢ ὀστοῦν; ὁμοίως δὲ καὶ 410a ἄλλο ὁτιοῦν τῶν συνθέτων· οὐ γὰρ ὁπωσοῦν ἔχοντα τὰ στοιχεῖα τούτων ἕκαστον, ἀλλὰ λόγῳ τινὶ καὶ συνθέσει, καθάπερ φησὶ καὶ Ἐμπεδοκλῆς τὸ ὀστοῦν· Granted, then, that the soul knows and perceives the elements of which each of these is formed, yet it will not know or perceive wholes, such as what a divinity is, or a man, or flesh, or bone, or anything else compounded. For the elements of these are not interrelated at random, but by some ratio or principle of composition, as Empedocles said of bone,
         ἡ δὲ χθὼν ἐπίηρος ἐν εὐστέρνοις χοάνοισιν
         τὼ δύο τῶν ὀκτὼ μερέων λάχε νήστιδος αἴγλης,
         τέσσαρα δ' Ἡφαίστοιο· τὰ δ' ὀστέα λευκὰ γένοντο.

The earth all gracious in its ample caverns
Took two parts out of eight of water and light,
But four from the god of fire, and then
White bone was made.

οὐδὲν οὖν ὄφελος ἐνεῖναι τὰ στοιχεῖα ἐν τῇ ψυχῇ, εἰ μὴ καὶ οἱ λόγοι ἐνέσονται καὶ ἡ σύνθεσις· γνωριεῖ γὰρ ἕκαστον τὸ ὅμοιον, τὸ δ' ὀστοῦν ἢ τὸν ἄνθρωπον οὐθέν, εἰ μὴ καὶ ταῦτ' ἐνέσται. τοῦτο δ' ὅτι ἀδύνατον, οὐθὲν δεῖ λέγειν· τίς γὰρ ἂν ἀπορήσειεν εἰ ἔνεστιν ἐν τῇ ψυχῇ λίθος ἢ ἄνθρωπος; ὁμοίως δὲ καὶ τὸ ἀγαθὸν καὶ τὸ μὴ ἀγαθόν· τὸν αὐτὸν δὲ τρόπον καὶ περὶ τῶν ἄλλων. So it is no use supposing elements to be in the soul unless there are in it also principles and co-ordination. Let each know its like, it will not know bone or man unless these be in it. It is hardly necessary to say, however, that this is impossible; who would ever think of enquiring if there is a stone in the soul, or a man? Likewise, the good or the not-good; and similarly with other things. §§ 178-80
410a13   ἔτι δὲ πολλαχῶς λεγομένου τοῦ ὄντος (σημαίνει γὰρ τὸ μὲν τόδε τι, τὸ δὲ ποσὸν ἢ ποιὸν ἢ καί τινα ἄλλην τῶν διαιρεθεισῶν κατηγοριῶν) πότερον ἐξ ἁπάντων ἔσται ἡ ψυχὴ ἢ οὔ; ἀλλ' οὐ δοκεῖ κοινὰ πάντων εἶναι στοιχεῖα. ἆρ' οὖν ὅσα τῶν οὐσιῶν, ἐκ τούτων μόνον; πῶς οὖν γινώσκει καὶ τῶν ἄλλων ἕκαστον; ἢ φήσουσιν ἑκάστου γένους εἶναι στοιχεῖα καὶ ἀρχὰς ἰδίας, ἐξ ὧν τὴν ψυχὴν συνεστάναι; ἔσται ἄρα ποσὸν καὶ ποιὸν καὶ οὐσία. ἀλλ' ἀδύνατον ἐκ τῶν τοῦ ποσοῦ στοιχείων οὐσίαν εἶναι καὶ μὴ ποσόν. τοῖς δὴ λέγουσιν ἐκ πάντων ταῦτά τε καὶ τοιαῦθ' ἕτερα συμβαίνει. Further, ‘that which is’ can be predicated in several ways: in one way, substance, in another, quality, in another, quantity; and in any other way according to the categories that have been distinguished. Will the soul be made up of all these or no? But it does not seem that there are elements common to all these. is it from those of substance only? How then will it know anything of the other kinds? Or is one to say that there are elements and principles proper to each category of which the soul is composed? then there will be quality and quantity and substance in the soul. But it is impossible that of the elements of quantity be derived substance, and not quantity. For those who hold that the soul is composed of all things, these (and other such) difficulties arise. §§ 181-2
ἄτοπον δὲ καὶ τὸ φάναι μὲν ἀπαθὲς εἶναι τὸ ὅμοιον ὑπὸ τοῦ ὁμοίου, αἰσθάνεσθαι δὲ τὸ ὅμοιον τοῦ ὁμοίου καὶ γινώσκειν τῷ ὁμοίῳ τὸ ὅμοιον· τὸ δ' αἰσθάνεσθαι πάσχειν τι καὶ κινεῖσθαι τιθέασιν· ὁμοίως δὲ καὶ τὸ νοεῖν τε καὶ γινώσκειν. It is unreasonable to say that one thing cannot be acted on by its like, and yet that sensation and knowledge is ‘like by like’. For they posit sensation as being moved and affected, and knowing and understanding likewise. § 183
πολλὰς δ' ἀπορίας καὶ δυσχερείας ἔχοντος τοῦ λέγειν, καθάπερ Ἐμπεδοκλῆς, ὡς τοῖς σωματικοῖς στοιχείοις ἕκαστα γνωρίζεται, καί, πρός, τῷ ὁμοίῳ, μαρτυρεῖ τὸ νῦν λεχθέν· ὅσα γάρ ἐστιν ἐν τοῖς τῶν ζῴων σώμασιν ἁπλῶς γῆς, οἷον 410b ὀστᾶ νεῦρα τρίχες, οὐθενὸς αἰσθάνεσθαι δοκεῖ, ὥστ' οὐδὲ τῶν ὁμοίων· καίτοι προσῆκεν. What has now been said witnesses to the many difficulties and doubts to be faced by one who, with Empedocles, says that each thing is known through its corporeal elements and [their relation] to its likeness. For whatever things in the body are obviously earthy (bones, sinews, hair) seem to perceive nothing; nor therefore even their likenesses; and yet they ought [on this hypothesis]. § 184
ἔτι δ' ἑκάστῃ τῶν ἀρχῶν ἄγνοια πλείων ἢ σύνεσις ὑπάρξει· γνώσεται μὲν γὰρ ἓν ἑκάστη, πολλὰ δ' ἀγνοήσει· πάντα γὰρ τἆλλα. Again, each one of the principles will have more ignorance than understanding. For it will know a single principle and be ignorant of many others, indeed of all others. § 185
συμβαίνει δ' Ἐμπεδοκλεῖ γε καὶ ἀφρονέστατον εἶναι τὸν θεόν· μόνος γὰρ τῶν στοιχείων ἓν οὐ γνωριεῖ, τὸ νεῖκος, τὰ δὲ θνητὰ πάντα· ἐκ πάντων γὰρ ἕκαστον. Further, for Empedocles, the Divinity must be the least knowing of all things, for he alone will not know one of the elements, namely Strife; but mortals, all; for every individual is composed of all. § 186
ὅλως τε διὰ τίν' αἰτίαν οὐχ ἅπαντα ψυχὴν ἔχει τὰ ὄντα, ἐπειδὴ πᾶν ἤτοι στοιχεῖον ἢ ἐκ στοιχείου ἑνὸς ἢ πλειόνων ἢ πάντων; ἀναγκαῖον γάρ ἐστιν ἕν τι γινώσκειν ἢ τινὰ ἢ πάντα. In general then, why is it that everything has not a soul? For all things are either elements or are made of one, or of several, or of all. They ought accordingly to know one, or several, or all. § 187
ἀπορήσειε δ' ἄν τις καὶ τί ποτ' ἐστὶ τὸ ἑνοποιοῦν αὐτά· ὕλῃ γὰρ ἔοικε τά γε στοιχεῖα, κυριώτατον δ' ἐκεῖνο τὸ συνέχον, ὅ τί ποτ' ἐστίν· τῆς δὲ ψυχῆς εἶναί τι κρεῖττον καὶ ἄρχον ἀδύνατον· ἀδυνατώτερον δ' ἔτι τοῦ νοῦ· εὔλογον γὰρ τοῦτον εἶναι προγενέστατον καὶ κύριον κατὰ φύσιν, τὰ δὲ στοιχεῖά φασι πρῶτα τῶν ὄντων εἶναι. One might wonder what gives unity to them. For the elements are comparable to matter, and that which holds them together, whatever it is, is the most essential principle. That it should have a higher function or be more excellent than the soul is impossible; still more impossible that it be higher than intellect. For that this is the primordial and most exalted and godlike thing by nature is in full accord with reason. Yet these men say that the elements have priority among beings. § 188
πάντες δὲ καὶ οἱ διὰ τὸ γνωρίζειν καὶ αἰσθάνεσθαι τὰ ὄντα τὴν ψυχὴν ἐκ τῶν στοιχείων λέγοντες αὐτήν, καὶ οἱ τὸ κινητικώτατον, οὐ περὶ πάσης λέγουσι ψυχῆς. οὔτε γὰρ τὰ αἰσθανόμενα πάντα κινητικά (φαίνεται γὰρ εἶναί τινα μόνιμα τῶν ζῴων κατὰ τόπον· καίτοι δοκεῖ γε ταύτην μόνην τῶν κινήσεων κινεῖν ἡ ψυχὴ τὸ ζῷον)· ὁμοίως δὲ καὶ ὅσοι τὸν νοῦν καὶ τὸ αἰσθητικὸν ἐκ τῶν στοιχείων ποιοῦσιν. φαίνεται γὰρ τά τε φυτὰ ζῆν οὐ μετέχοντα [φορᾶς οὐδ'] αἰσθήσεως, καὶ τῶν ζῴων <τὰ> πολλὰ διάνοιαν οὐκ ἔχειν. εἰ δέ τις καὶ ταῦτα παραχωρήσειε καὶ θείη τὸν νοῦν μέρος τι τῆς ψυχῆς, ὁμοίως δὲ καὶ τὸ αἰσθητικόν, οὐδ' ἂν οὕτω λέγοιεν καθόλου περὶ πάσης ψυχῆς οὐδὲ περὶ ὅλης οὐδεμιᾶς. 15. τοῦτο δὲ πέπονθε καὶ ὁ ἐν τοῖς Ὀρφικοῖς καλουμένοις ἔπεσι λόγος· φησὶ γὰρ τὴν ψυχὴν ἐκ τοῦ ὅλου εἰσιέναι ἀναπνεόντων, φερομένην ὑπὸ τῶν ἀνέμων, οὐχ οἷόν τε δὲ τοῖς φυτοῖς τοῦτο συμβαίνειν οὐδὲ 411a τῶν ζῴων ἐνίοις, εἴπερ μὴ πάντα ἀναπνέουσιν· τοῦτο δὲ λέληθε τοὺς οὕτως ὑπειληφότας. Not one of those who maintain that the soul is constituted from elements because it perceives and knows realities, and that it is primary among moving forces, considers every kind of soul. For not all sentient beings move; for certain species of animals are observed to remain in one place, although it would seem that the soul moved the animal with this one motion only [i.e. locally]. Likewise with those who would make of elements the sensitive and intellectual powers; for plants seem to live, but are not endowed with local motion or perception; and many animals lack intelligence. Even setting this fact on one side, and admitting that intellect is a part of the soul, and the sensitive power likewise, they would not be speaking of every soul, nor of the whole of any soul, nor of one [entire soul]. The same objection tells against a notion expressed in the Orphic hymns, where it is said, ‘The soul enters from the universe, breathed in by the winds.’ This cannot occur in the case of plants and certain animals: unless, indeed, all use respiration; a fact overlooked by those who put forward this view. §§ 189-90
16. (εἰ δὲ δεῖ τὴν ψυχὴν ἐκ τῶν στοιχείων ποιεῖν, οὐθὲν δεῖ ἐξ ἁπάντων· ἱκανὸν γὰρ θάτερον μέρος τῆς ἐναντιώσεως ἑαυτό τε κρίνειν καὶ τὸ ἀντικείμενον. καὶ γὰρ τῷ εὐθεῖ καὶ αὐτὸ καὶ τὸ καμπύλον γινώσκομεν· κριτὴς γὰρ ἀμφοῖν ὁ κανών, τὸ δὲ καμπύλον οὔθ' ἑαυτοῦ οὔτε τοῦ εὐθέος.) But if one must constitute the soul from the elements, there is no need to use them all; for one term of contraries suffices for the discernment of itself and its opposite; thus by the straight line we know both itself and the oblique; the criterion of both is the rule, but the curved is a criterion neither of itself nor of the straight.
ST. THOMAS COMMENTARY

LECTIO 12
Postquam philosophus ostendit supra, quomodo antiqui naturales in cognitionem animae venerunt per tria, scilicet per motum et cognitionem, et per esse incorporalissimum, et disputavit contra illos qui venerunt in cognitionem animae per motum, et contra illos qui dixerunt animam esse quid incorporalissimum et maxime simplex, hic consequenter disputat contra illos qui dicebant animam omnia cognoscere, quia composita erat ex omnibus. 178. Having in the preceding sections explained that the early philosophers pursued their enquiry into the soul by three ways, that of movement, of knowledge and of incorporeal being, and having pressed certain objections against those who took the way of movement, and against those who identified soul with something bodiless and entirely simple, the Philosopher now turns to criticise the upholders of the principle that the soul knows everything because everything is included in itself.
Quorum positio fuit quod anima cognosceret res omnes, quia cognitio fit per assimilationem, quasi hoc a longe divinantes, dicebant animam, ad hoc quod omnia cognosceret, esse compositam ex omnibus; et quod similitudo rerum omnium esset in anima secundum proprium modum essendi, scilicet corporalem. Unde, cum res constent ex elementis, dicebant, quod anima erat composita ex omnibus elementis, ut sentiat et cognoscat omnia quae sunt. Et quia principalis in hac positione fuit Empedocles, cum poneret animam compositam ex pluribus elementis quam aliquis aliorum, ideo philosophus principaliter hic reprobat opinionem suam, et disputat contra eam. Et circa hoc duo facit. Primo enim improbat opinionem Empedoclis. Secundo vero quamdam aliam, ibi, in toto autem quidem ipsam et cetera. 179. With their theory that all knowledge takes place by means of assimilation these philosophers had caught, as it were, a far-off glimpse of the truth; but they expressed this by saying that the reason why the soul knew all things was that all things entered into its composition, and that the soul possessed the likeness of all things according to the mode of existence, i.e. a corporeal one, which things have in themselves outside it. Hence, if things consist of elements, the same is true, they said, of the soul; and that is the cause of sensation and knowledge. The chief upholder of this view was Empedocles, who posited more elements in the soul than anyone else; and therefore the Philosopher is more concerned here to refute him than anyone else. So he first attacks the opinion of Empedocles, and only then, at ‘And some say’ that of certain others.
Improbat autem opinionem Empedoclis decem rationibus: quarum prima talis est. Empedocles dicit, quod quia cognitio fit per similitudinem, cum anima cognoscat omnia, oportet animam compositam esse ex omnibus. Sed patet quod huic rationi est necessarium accidere multa inconvenientia et impossibilia. Constat enim, quod in qualibet re non sunt haec sola, scilicet elementa, sed multa alia ab elementis, sicut est proportio commixtionis et ratio uniuscuiusque, et forte sunt infinita numero, quae accidunt rebus compositis ex his, scilicet elementis, sicut patet in osse. Nam non solum oportet cognoscere illa ex quibus componitur os, sed etiam proportionem, quae est inter illa ex quibus componitur et rationem ossis: quia omnia quae sunt composita, non consistunt, quocumque modo se habeant elementa, sed quadam ratione et compositione, scilicet ut sint proportionata adinvicem. Nam os, cum habeat octo partes, secundum quod dicit Empedocles, unumquodque compositum os haberet octo partes quae non aequaliter attribuuntur omnibus elementis, sed terra habet ibi duas partes. Aer habet ibi unam, aqua similiter unam, sed ignis quatuor: et ideo ex maiori participatione ignis dicit ossa esse facta alba, et ex terra sicca. Sic ergo in rebus compositis non solum sunt ipsa elementa, sed proportio et ratio uniuscuiusque. Inde sic. Aut ergo istae proportiones sunt in anima cum elementis, aut non. Si sunt in anima; ergo in anima sunt ossa, et carnes, et huiusmodi, et per consequens homo et lapis, et corpora, et contraria: unde nullus dubitat quod haec non sunt in anima. Si vero dicas, quod non sunt ibi huiusmodi proportiones et rationes, sed solum elementa, tunc anima non cognoscet proportionem rerum, nec ipsa composita: quomodo enim poterit cognoscere Deum, scilicet totum caelum, aut hominem, aut lapidem seu os? Nullo modo cognoscet, sed elementa tantum. 180. Against Empedocles he brings ten arguments. The first is as follows. Empedocles argues that the soul must be composed of all the objects of its knowledge because knowledge takes place by means of similitude. But this involves many difficulties and absurdities. For clearly the elements are not all that any given thing contains; it includes much else besides, such as the proportion in which its elements are combined and the formulable essence of each one in particular, and there may even be an infinity of accidents belonging to things made up of elements. Take, for example, bones. To understand bones we need to know, not only the elements of which they are composed, but also how these elements combine in them, and the functional pattern of bones; for the order of elements in compound things is not a random one, it involves a certain definite proportional arrangement. If bone, as Empedocles says, is composed of eight parts, each bone has eight parts into which the various elements enter in unequal measure: for earth, he says, contributes two parts, air and water one each, and fire four—to which predominance of fire is due the whiteness of bone, while from earth comes its dryness. Thus in compound things there are, besides the elements, certain proportions and patterns. Well then, either these proportions are in the soul together with the elements, or not. If they are in the soul, then bones and flesh and so forth, and therefore men and stones and bodies and things quite contrary to one another, are all in the soul; and this nobody dreams of conceding. But if only the elements are in the soul, then it does not in fact know the proportion in things nor compound things as such; and how can it know God (i.e. the Heavens as a whole) or man or stone or bone? It cannot possibly know these things; it knows only the elements which compose them, according to this view.
Secundam rationem ponit cum dicit amplius autem quae talis est. Tu dicis, quod anima est composita ex principiis: sed diversorum generum diversa sunt principia: cum ergo id quod est, dicatur multipliciter, idest secundum diversa genera, sicut substantiae, qualitatis, quantitatis, et aliorum praedicamentorum: ergo erunt diversa principia. Quaero ergo, utrum anima sit composita tantum ex principiis substantiae, aut ex principiis omnium generum. Si tantum ex principiis substantiae, tunc anima non cognoscet nisi substantias, et ipsi ponunt eam cognoscere omnia. Si vero componitur ex principiis omnium generum, tunc, cum quicquid est ex principiis substantiae sit substantia, et ex principiis quantitatis sit quantitas, et sic de singulis, anima erit substantia, quantitas, qualitas, relatio, et huiusmodi. 181. The second argument, starting at ‘Further, that which is’, runs thus. You say the soul is made up of elementary principles. But these differ according to the different categories of things, such as substance, quality, quantity and the rest. Is then the soul made up of the elementary principles of substance alone, or does it include those of the other categories? If the first alternative is right, then the soul only knows substance; yet the supposition is that it knows everything. But if it includes the elements of all the categories, then, since whatever has the elementary principles of substance is a substance, and whatever has those of quantity is a quantity, and so on likewise with the rest, it follows that the soul is at once both a substance, and a quality, and a relation, and so on and so forth.
Posset autem responderi contra hanc rationem Aristotelis quod principia substantiae sunt etiam quantitatis et qualitatis, et aliorum, cum omnia fundentur supra substantiam; et ideo non oportet quod sint in anima aliqua alia principia quam principia substantiae, et nihilominus cognoscet omnia. Ad hoc dicendum, quod quaelibet res habet principia proxima et remota, et cognitio oportet quod sit per principia proxima. Principia autem substantiae, licet sint principia aliorum, sunt tamen remota et non proxima, et ideo per ea non potest haberi cognitio nisi de substantia. 182. It might be answered that the elementary principles of substance are also those of quantity, quality, etc., since everything is grounded in substance; hence the soul need only possess the principles of substance to know everything. But I say that things have both remote and proximate principles, and should be known by means of the latter. The principles of substance may be the remote, but they are not the proximate, principles of the other categories; hence they cannot give knowledge of anything except substance.
Tertiam rationem ponit cum dicit inconveniens autem quae talis est. Ratio quare anima sit composita ex omnibus elementis, est, quia anima cognoscit omnia, et cognitio est per similitudinem. Contra. Constat enim quod sentire et cognoscere est pati aliquid. Sed inconveniens est dicere quod simile patiatur a simili, sed a contrario; ergo et inconveniens est dicere quod sentire seu cognoscere sit simile simili. 183. The third argument, starting at ‘It is unreasonable’, is this. The reason why the soul is said to be composed of all the elements is that it knows all things and knowledge is by similarity. Against this is the admitted fact that sensation and knowledge are a sort of being acted upon; and it seems unreasonable to say that like is acted upon by like, and not rather by its contrary; and consequently, to say that sensation or knowledge are by similarity.
Quartam rationem ponit cum dicit multas autem quae talis est. Ex hoc quod dictum est superius, testatur quod dictum Empedoclis, scilicet quod simile simili cognoscatur, habet multas dubitationes et difficultates. Sed adhuc etiam magis apparet difficile et improprie dictum. Nam si anima cognosceret simile simili, sicut Empedocles dicit, tunc sequitur quod elementum aeris cognoscat aera, et sic de aliis. Sed nos videmus quod multae partes terrae sunt in animali, quae nihil sentiunt, sicut pili, et ossa, et nervi: et tamen conveniret quod sentirent secundum positionem eorum; ergo non cognoscitur simile simili, vel etiam non est composita ex omnibus elementis. 184. The fourth argument, at ‘What has now’, is this. What has been said already is enough to show that Empedocles’ theory is highly questionable and his manner of expressing it slipshod. But there is a yet stronger objection. If the soul, as he says, knows by similarity, then the element air Will know air, and so on for the other elements. But we know that animals’ bodies have many earthy parts which lack sensation, such as hair, bones and nerves; yet they ought to have sensation according to this theory. Therefore knowledge is not by similarity nor the soul composed of the elements.
Quintam rationem ponit cum dicit amplius autem quae talis est. Adhuc ex positione Empedoclis, quod simile cognoscatur simili, sequitur aliud inconveniens, scilicet quod principium habet plus de ignorantia quam de intelligentia. Si enim cognitio est per simile tantum, et principium quodlibet sit simplex et non habet alicuius similitudinem in se nisi suam, non cognosceret nisi seipsum, et ignorabit multa, omnia scilicet quae sunt alia ab eo. 185. The fifth argument’s at ‘Again etc.’, runs thus. Another objection to this view is that it implies that principles as such are more ignorant than percipient. For if knowledge is only by similarity, and if every principle is quite simple, having no likeness to anything but itself, it follows that each principle only knows itself and is ignorant of everything else.
Sextam rationem ponit cum dicit accidet autem quae talis est. Adhuc etiam ex dicta positione, scilicet quod simile cognoscatur simili, accidet aliud inconveniens Empedocli: hoc videlicet, quod Deus sit insipientissimus omnium animalium. Quod ex hoc sequitur. Sciendum enim quod sicut dictum est, Empedocles posuit ista omnia inferiora composita esse ex quatuor elementis, et ex lite et amicitia; et quod generatio et corruptio provenit in rebus ex istis duobus, scilicet lite et amicitia. Caelum vero dixit esse Deum, et dixit quod erat compositus ex quatuor elementis, et amicitia, sed non ex lite, et ideo est incorruptibile. Si ergo simile cognoscitur simili, cum Deus non sit compositus ex lite, non cognoscet litem, et sic erit simpliciter insipientior ceteris animalibus quae cognoscunt litem cum sint composita ex ea. 186. The sixth argument comes at ‘Further’. This theory also implies the doubtful consequence that God is the most ignorant of all living beings. For, as we have seen, Empedocles thought that everything on this earth could be reduced to the four elements together with Strife and Friendship, these last being the causes of coming-to-be and passing-away. But the sky he called God and said it was composed of the four elements and Friendship, but not of Strife; and was therefore incorruptible. If then knowledge is by similarity, God cannot know Strife, since it does not form part of him, and God is therefore less percipient, strictly speaking, than other living beings which know Strife because they include it.
Septimam rationem ponit cum dicit omnino autem quae talis est. Si anima est composita ex omnibus elementis, sequitur quod omnia quae sunt habent animam: omne enim quod est, aut est ex omnibus elementis, aut ex aliquibus: sed omne quod est compositum ex elementis, aut ex elementis, est corpus: ergo omnia corpora habent animam et omnia quae sunt, quod falsum est. 187. The seventh argument’ comes at ‘In general, why’. If the soul is made of all the elements, then all things have souls; for all things are made of either all or some elements. Now whatever is made up of elements or of compounds of elements is a body. Hence all bodies, indeed all beings, have souls; which is false.
Octavam rationem ponit cum dicit dubitabit autem quae talis est. Elementa sunt plura et contraria. Ubicumque autem aliqua contraria conveniunt et componuntur, oportet quod sit aliquid aliud quod contineat et faciat ipsa unum. Si ergo anima est composita ex omnibus elementis, oportet quod sit aliquid aliud continens illa. Sed hoc est valde dubium quid sit, quia sic esset nobilius et prius anima, quod est impossibile, et ad minus de intellectu; quia valde rationabile est quod intellectus sit nobilissimus omnium et divinus secundum naturam. Item sequeretur quod illud esset prius quam elementa: quod est falsum: quia Empedocles et alii dicunt elementa esse prima inter omnia entia. Non est ergo anima composita ex elementis. 188. The eighth argument’ begins at ‘One might wonder’. The elements are many and contrary; but whenever contrary things come together in a composition there must be some other thing which includes and unifies them. Hence if the soul is made up of the elements there must be something in it which unifies them. But it is extremely doubtful what this can be; for it must be something in the soul nobler than the soul, which is an impossibility, at least as regards that, which it is reasonable to consider the supremely noble and divine thing, namely the mind. Besides, this other thing would have to be prior to the elements, whereas Empedocles and the rest have asserted that the elements were the first of all beings. Therefore the soul is not made up of elements.
Nonam rationem ponit cum dicit omnes autem et ostendit defectum et insufficientiam positionis Empedoclis et aliorum omnium qui considerant animam ex motu seu sensu. Quae talis est. Apparet etiam quod omnes et quicumque dixerunt animam esse aliquid motivum secundum locum, insufficienter dixerint. Nam multa animata sunt quae non moventur secundum locum, sed manent, sicut plantae et alia huiusmodi. Similiter autem et illi qui dixerunt animam esse quid intellectivum et sensitivum, insufficienter dixerunt. Nam multa sunt animata quae neque sentiunt neque intelligunt. Si vero aliquis hoc segregaverit, scilicet intellectivum, sensitivum, et motivum, et dicat intellectivum unam partem animae et similiter sensitivum, non tamen propter hoc dicet de omni anima, cum non omnes animae sint intellectivae. Neque de tota, cum intellectivum et sensitivum sunt partes animae. Neque de una, quia sic non diceret omnes proprietates animae cuiuscumque, cum in anima sint aliae proprietates, quam sint intelligere et sentire. 189. He begins the ninth argument at ‘Not one of those’, showing the weakness of Empedocles’ view and that of all the others who have enquired about the soul, whether by way of movement or by way of sense-perception. For (1) there is a gap in the arguments of all who defined the soul in terms of local movement. Many living beings, such as plants and things resembling plants, do not move locally at all but are fixed in one place. And (2) there is a like inadequacy in the definition of the soul in terms of intellect or sensation; for plenty of living things neither sense nor think. And if local motion, intellect and sensation are taken separately and regarded as distinct parts of the one soul, this will not apply to soul in general, since not all souls are intellectual; nor to the whole of any one soul, since only parts of it will be intellectual and sensitive; nor to any one single soul, since this description does not enumerate all the characteristics of any given soul; for in any soul there are other things besides understanding and sensation.
Et quia quidam philosophus qui vocatus est Orpheus, defective etiam de anima locutus est quasi in similem defectum incidit: ideo hic adiungit eius defectum. Sciendum est quod Orpheus iste fuit unus de primis philosophis qui erant quasi poetae theologi, loquentes metrice de philosophia et de Deo, et fuerunt tantum tres, Samius, Orpheus, et quidam alius. Et iste Orpheus primo induxit homines ad habitandum simul et fuit pulcherrimus concionator, ita quod homines bestiales et solitarios reduceret ad civilitatem. Et propter hoc dicitur de eo, quod fuit optimus cytharaedus, in tantum quod fecit vel faceret lapides saltare, id est, ita fuit pulchre concionator, quod homines lapideos emollivit. Post hos vero tres, fuerunt septem sapientes, quorum unus fuit Thales. Hic ergo Orpheus volebat quod totus aer animatus esset et anima quaedam; et quod anima corporum viventium nihil aliud esset, nisi illud quod attrahit animal de aere animato per respirationem; et hoc dicebat metrice. Et ideo dicit philosophus quod ratio Orphei quae est in metricis carminibus de anima, sustinuit eumdem defectum quem sustinuerunt rationes praecedentium, quia, sicut dictum est, ipse voluit quod illud esset anima, quod attrahitur per respirationem animalium. Sed hoc insufficienter dictum est: quia multa animalium sunt quae non respirant: hoc autem, scilicet quod animalia multa non respirant, latuit illos qui fuerunt praedictae opinionis. Et sic patet quod isti reprehenduntur de insufficientia. 190. And a certain philosopher named Orpheus having fallen into a rather similar error in what he said about the soul, he too is mentioned here. Orpheus was one of those three early thinkers who were, so to say, poet-theologians; for they wrote in verse on philosophy and about God. The other two were Museus and a certain Linus. Orpheus, a wonderful orator whose words had power to civilise wild and brutish folk, was the first man to induce his fellows to five together in society. For this reason it is said of him that he could make rocks dance to the sweet sounds of his harp, which really means that his eloquence could melt the hardest hearts. And after these three poet-philosophers came the seven sages, of whom Thales was one. Now this Orpheus thought that the whole air was alive, was indeed a sort of living soul, and that the so-called souls of living bodies were really nothing but the air these bodies breathed; and this idea he expressed in verse. But the Philosopher objects to the Orphic theory, saying that it is just as inadequate as the others he has criticised; for there are many animals that do not breathe at all, ‘a fact’, he says, ‘which was overlooked’ by those who held this opinion. The criticism touches the inadequacy of the theory.
Decimam rationem ponit cum dicit si vero et arguit eos de superfluitate: quae talis est. Dicunt enim isti quod ad hoc quod anima cognoscat, oportet quod sit composita ex elementis. Sed cum nos videamus quod cognitio omnis rei possit haberi per pauciora; ergo etsi concedatur animam componi ex elementis, non tamen debet dici composita ex elementis omnibus, sed ad plus, ex duobus. Et quod cognitio habeatur per pauciora, patet; quia cum compositum constet ex aliquo perfecto et imperfecto, ratio cognoscendi imperfectum, est perfectum; et cum contraria reducantur in privationem et habitum, sufficiens est altera pars, scilicet illa quae se habet per modum habitus et perfecti, ad cognoscendum seipsam et alteram partem, quae est per modum privationis et imperfecti. Nam per rectum diiudicamus et cognoscimus ipsum rectum, et etiam obliquum. Canon enim idest regula est illud per quod habetur iudicium de utroque. Per obliquum vero nec ipsum cognoscimus, nec rectum. Non ergo fuit necesse animam facere, idest eam componere ex omnibus elementis, sed ex duobus tantum, scilicet ex igne et terra, et per hoc cognosceret et seipsam et contraria; sicut per ignem cognosceret calida et frigida, et per terram, sicca et humida. 191. At ‘But if one’ comes the tenth argument; which convicts the Empedoclean theory of unnecessary complication. The soul’s capacity for knowledge is explained by its composition from elements. Now it is a matter of experience that knowledge of anything rests on few, rather than many, principles-, hence even if we grant that the soul is composed of elements we ought not to suppose that these are all the elements, but at the most two. And that knowledge rests on few rather than many principles is clear if we consider that in composite things, consisting of two principles, one of perfection, the other of imperfection, it is in the light of the former that we know the latter; and that in contraries, which can be reduced to a quality and its privation, it suffices to understand the term denoting quality and perfection in order to understand also the other term denoting privation and imperfection. Thus by, the idea of straight line we know and for in judgements about both straight and crooked lines; for ‘the rule’, i.e. the measure, is the means of knowing both; but the crooked line is the means of knowing neither itself nor the straight. Hence there was no need to regard the soul as made up of all the elements; enough to adduce two only, fire and earth, as its means of knowing both itself and contrary things. Through fire it could know both cold and hot objects, and through earth the dry and the moist.

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BOOK I, CHAPTER V, CONTINUED

THE ELEMENTS HAVE NO SOUL

17. καὶ ἐν τῷ ὅλῳ δή τινες αὐτὴν μεμῖχθαί φασιν, ὅθεν ἴσως καὶ Θαλῆς ᾠήθη πάντα πλήρη θεῶν εἶναι. And some say that the soul is intermingled generally with the Universe. That is perhaps why Thales thought that the whole world was full of divinities. § 192
18. τοῦτο δ' ἔχει τινὰς ἀπορίας· διὰ τίνα γὰρ αἰτίαν ἐν μὲν τῷ ἀέρι ἢ τῷ πυρὶ οὖσα ἡ ψυχὴ οὐ ποιεῖ ζῷον, ἐν δὲ τοῖς μικτοῖς, καὶ ταῦτα βελτίων ἐν τούτοις εἶναι δοκοῦσα; 19. (ἐπιζητήσειε δ' ἄν τις καὶ διὰ τίν' αἰτίαν ἡ ἐν τῷ ἀέρι ψυχὴ τῆς ἐν τοῖς ζῴοις βελτίων ἐστὶ καὶ ἀθανατωτέρα.) 20. συμβαίνει δ' ἀμφοτέρως ἄτοπον καὶ παράλογον· καὶ γὰρ τὸ λέγειν ζῷον τὸ πῦρ ἢ τὸν ἀέρα τῶν παραλογωτέρων ἐστί, καὶ τὸ μὴ λέγειν ζῷα ψυχῆς ἐνούσης ἄτοπον. This, however, involves several difficulties. For why does the soul in fire and air not result in an animated being, whereas it does so in composite beings?—and that, even though it is thought to be more excellent in the former. (And one might well query why the soul in the air should be nobler and more enduring than that in animals.) On either count the theory is absurd and unreasonable. To say that air or fire is an animal is among the most wanton of absurdities; and if there is a soul in them, it is inconsistent not to call them animals. §§ 193-5
21. ὑπολαβεῖν δ' ἐοίκασιν εἶναι τὴν ψυχὴν ἐν τούτοις ὅτι τὸ ὅλον τοῖς μορίοις ὁμοειδές· ὥστ' ἀναγκαῖον αὐτοῖς λέγειν καὶ τὴν ψυχὴν ὁμοειδῆ τοῖς μορίοις εἶναι, εἰ τῷ ἀπολαμβάνεσθαί τι τοῦ περιέχοντος ἐν τοῖς ζῴοις ἔμψυχα τὰ ζῷα γίνεται. They seem to have held that there was a soul in these on the ground that the Universe is made up of homogeneous parts; so that if animals become animate by partaking of the containing element, they must say that the soul [of the Whole] is homogeneous with its parts. § 196
εἰ δ' ὁ μὲν ἀὴρ διασπώμενος ὁμοειδής, ἡ δὲ ψυχὴ ἀνομοιομερής, τὸ μέν τι αὐτῆς ὑπάρξει δῆλον ὅτι, τὸ δ' οὐχ ὑπάρξει. ἀναγκαῖον οὖν αὐτὴν ἢ ὁμοιομερῆ εἶναι ἢ μὴ ἐνυπάρχειν ἐν ὁτῳοῦν μορίῳ τοῦ παντός. If then the air, divided off thus, be homogeneous, but the soul be composed of heterogeneous parts, something of it [the soul] will exist and something not. It is necessary then, either that it be of homogeneous parts, or that it be not in any and every part of the whole. § 197
22. φανερὸν οὖν ἐκ τῶν εἰρημένων ὡς οὔτε τὸ γινώσκειν ὑπάρχει τῇ ψυχῇ διὰ τὸ ἐκ τῶν στοιχείων εἶναι, οὔτε τὸ κινεῖσθαι αὐτὴν καλῶς οὐδ' ἀληθῶς λέγεται. It is evident then, from what has been said, that the cause of knowledge being in the soul is not that soul is made up of the elements; and that it is neither true nor apposite to say that it is in motion. § 198
ST. THOMAS’S COMMENTARY

LECTIO 13
Postquam philosophus posuit opiniones ponentium animam esse ex elementis, et rationes ipsorum, et improbavit eas, hic ex incidenti ponit opinionem quorumdam dicentium animam esse in elementis. Et circa hoc duo facit. Primo enim ponit opinionem. Secundo vero rationem opinionis, ibi opinari autem. Circa primum duo facit. Primo ponit opinionem. Secundo improbat eam, ibi, hoc autem et cetera. 192. Having stated and rejected the theories and arguments of those who maintained that the soul was composed of elements, the Philosopher is now led, by the same train of thought, to discuss the notion, upheld by some, according to which a soul is intermingled with the elements. First, then, he states this opinion, and then, at ‘They seemed to have held’, the argument used to support it. And the opinion itself is first stated and then, at ‘This, however,’ attacked.
Dicit ergo quod sunt quidam, qui dicunt animam misceri in toto universo, ponentes eam tam in elementis quam in elementatis. Unde quidam philosophus nomine Thales, fortassis motus ab hac opinione, opinatus est omnia plena esse diis. Volebat enim quod totum universum esset animatum, et eius anima esset Deus. Unde, sicut anima est in qualibet parte animalis, et tota, ita volebat quod in qualibet parte universi esset Deus, et sic omnia essent plena diis: et forte ex hoc provenit idolatria. There are, he says, some who see a soul intermingled with everything, whether simple elements or things composed of these. This perhaps is what Thales meant when he said that everything was full of gods; perhaps he thought that the entire Universe was alive and its life was divine; that just as soul exists everywhere in each living thing so a god was everywhere in the Universe and everything therefore was ‘full of divinities’. And perhaps this was the notion that underlay idolatry.
Consequenter cum dicit hoc autem improbat hanc opinionem; dicens, quod hoc, scilicet quod anima sit in elementis et in elementatis, habet quasdam dubitationes et oppositiones: quarum una est, quia si anima est in aere et in igne, in istis enim duobus dicebant maxime eam esse, difficile erit eis dicere propter quam causam anima in eis non facit animal, id est quare ista non sunt animalia: cum in mixtis anima facit animal, id est mixta animata sunt animalia; praecipue, cum putandum sit quod haec, scilicet anima, sit melior in elementis simplicibus, quam in elementatis. 193, At ‘This, however,’ he points out, against this opinion, that it presents certain difficulties. For instance, if a soul exists in air and in fire (and of these two especially this was asserted) it is hard to see why it does not make ‘animated beings’ of them, i.e. why air and fire are not animals. Things composed of several elements are animals precisely because they contain a soul; and one would expect the soul to be all the more powerful where the element is pure and simple.
Alia dubitatio est, quia quaeret aliquis ex his utique motus, quare anima quae secundum ipsos est in elementis, est melior et immortalior quam anima quae est in elementatis, cum haec quae est in elementatis, constituat animal et cognoscens et sentiens: illa vero quae est in elementis, non constituat. 194. Again, one might ask, he says, why the soul which they place in the elements should be considered higher and more immortal than the soul of things composed of elements. For the latter constitute knowing, sentient animals; not so the former.
Ex his autem dubitationibus quaecumque ponatur, accidit inconveniens et irrationabile; quia dicere quod ignis sive aer sit animal, ut primo dubitatur, est maxime inconveniens, et ad sensum apparet falsum, et est dictum non habentium rationem. Et non dicere ea in quibus est anima, esse animalia, valde inconveniens est. Nam secundum hoc in nullo differt, inter esse animam in aliquo corpore, et non esse. 195. But, however the objections are put, the result is damaging to this theory. To say that fire or air is a living body is most improbable in itself; it is contradicted by experience; and is unsupported by any good reason. And to deny that things which have souls need be living bodies is most unreasonable; for it would follow that there was no difference between souls that exist in bodies and those that do not.
Consequenter cum dicit opinari autem ponit rationem praemissae opinionis; et circa hoc duo facit. Primo ponit rationem, et improbat eam. Secundo concludit quid manifestum sit ex omnibus quae dicta sunt, ibi, manifestum igitur et cetera. Circa primum duo facit. Primo enim ponit rationem opinionis; dicens, quod ratio quare dicti philosophi opinari videntur animam esse in his, id est in omnibus elementis, est quia ipsi volebant quod totum et partes in elementis, cum sint simplicia, quod essent similis speciei. Unde, cum viderent et opinarentur quod pars continentis, id est aeris, intercepta in corporibus animalium per inspirationem et respirationem, sit causa quare animalia fiant animata, et sit anima, necesse erat eis dicere animam esse similis speciei partibus, id est totum continens esse animatum. 196. Then, at ‘They seem to have held’, he states the reason used in support of this theory and refutes it; after which, at ‘It is... evident’ he draws a general conclusion from all the foregoing discussions. The reason, he says, why some philosophers seem to have thought that a soul existed in ‘these’, i.e. in all the elements, was that they thought that the whole and the parts in elements were of the same nature, since the elements are simple. Observing that that part of ‘the containing element’, i.e. the air, which came into contact with the bodies of animals through their breathing, was the cause and principle of animal life, they thought it necessary to conclude that the soul of the whole was ‘of the same specific nature as the parts’, that is to say, that all the containing air was alive.
Secundo vero cum dicit si autem improbat dictam rationem; dicens, quod quia aer discerptus et attractus est similis speciei toti aeri, sequetur quod anima animalis sit similis partis animae totius aeris. Sed constat quod anima animalis cuiuslibet est dissimilis partis animae aeris, quia una ipsius, scilicet anima aeris existet, id est immortalis est secundum eos, utpote quae semper vivificat et semper vivificavit omnia viva: aliud autem, scilicet anima huius vel illius animalis non existet, idest, est mortalis secundum eos. Necesse est ergo alterum duorum inconvenientium sequi ex hoc; videlicet quod si aer sit similis partis, scilicet ille qui est intra, et ille qui est extra, et anima etiam: quod improbatum est. Aut si ipsa anima est dissimilis partis, et aer similium, tunc sequitur quod anima non sit in qualibet parte omnis idest totius aeris: quod est contra eos qui totum aerem animatum ponebant. 197. At ‘If then’ he refutes this argument. The assumption is that, because the portion of the air removed and inhaled by an animal is of a like nature to the air as a whole, the soul of the animal itself is, as it were, a portion of the soul of the whole air. But on their own principle this is clearly false; for, according to them, the soul of air ‘exists’, i.e. is immortal, as that which has never ceased from vivifying animate beings, whereas the soul of this or that particular animal ‘does not exist’, i.e. is not immortal. Therefore either of two awkward consequences flow from this theory. If all the parts of air, those outside and those breathed in, are homogeneous, then the same is true of the soul; but this has been disproved. But if the soul’s parts are heterogeneous while the air’s are homogeneous, then the soul is not in every part ‘of the whole’, i.e. of the whole air; which is against those who said that all the air had a soul.
Consequenter cum dicit manifestum igitur concludit ex omnibus quae dicta sunt de opinionibus antiquorum, quod neutrum illorum quod ipsi attribuebant animae, sit verum, nec bene dictum, eo modo quo ipsi dixerunt, scilicet quod neque cognoscere inest animae ex eo quod ex elementis, sicut ipsi ponebant, neque etiam motus seu moveri inest ei, ex hoc quod ex dictis elementis constabat secundum eos: et hoc satis aperte et clare patet inspicienti ad supradicta. 198. Then at ‘It is evident’ Aristotle concludes this part of the discussion of earlier opinions. Neither of these two predications made’ by the ancients was, he says, either true or well-expressed; namely that knowledge in the soul is a consequence of its being composed of elements, and that movement is in it for the same reason. So much should be clear to anyone who has followed the discussion up to the present.

TEXT
411a26–41lb30
BOOK I, CHAPTER V, CONTINUED

THE UNITY OF THE SOUL

23. ἐπεὶ δὲ τὸ γινώσκειν τῆς ψυχῆς ἐστὶ καὶ τὸ αἰσθάνεσθαί τε καὶ τὸ δοξάζειν, ἔτι δὲ τὸ ἐπιθυμεῖν καὶ βούλεσθαι καὶ ὅλως αἱ ὀρέξεις, γίνεται δὲ καὶ ἡ κατὰ τόπον κίνησις τοῖς ζῴοις ὑπὸ τῆς ψυχῆς, ἔτι δ' αὔξη τε καὶ ἀκμὴ καὶ φθίσις, πότερον ὅλῃ 411b τῇ ψυχῇ τούτων ἕκαστον ὑπάρχει, καὶ πάσῃ νοοῦμέν τε καὶ αἰσθανόμεθα καὶ κινούμεθα καὶ τῶν ἄλλων ἕκαστον ποιοῦμέν τε καὶ πάσχομεν, ἢ μορίοις ἑτέροις ἕτερα; καὶ τὸ ζῆν δὴ πότερον ἔν τινι τούτων ἐστὶν ἑνὶ ἢ καὶ ἐν πλείοσιν ἢ πᾶσιν, ἢ καὶ ἄλλο τι αἴτιον; Since knowledge pertains to the soul, and sensation, and thinking, as well as desiring and deliberating—in a word, all appetition; and as in animate beings there also occur local motion, and growth, and preservation, and decay, all from the soul, is each of these in the whole soul, and do we understand and perceive and do and undergo every particular experience, with the whole soul? Or does each require a different part? And is life itself in any one of these? Or in several? Or in all? Or is it from some quite distinct cause? §§ 199-203
24. λέγουσι δή τινες μεριστὴν αὐτήν, καὶ ἄλλῳ μὲν νοεῖν ἄλλῳ δὲ ἐπιθυμεῖν. Some say the soul is divisible, understanding by one part and desiring by another. §§ 204-5
τί οὖν δή ποτε συνέχει τὴν ψυχήν, εἰ μεριστὴ πέφυκεν; οὐ γὰρ δὴ τό γε σῶμα· δοκεῖ γὰρ τοὐναντίον μᾶλλον ἡ ψυχὴ τὸ σῶμα συνέχειν· ἐξελθούσης γοῦν διαπνεῖται καὶ σήπεται. εἰ οὖν ἕτερόν τι μίαν αὐτὴν ποιεῖ, ἐκεῖνο μάλιστ' ἂν εἴη ψυχή. δεήσει δὲ πάλιν κἀκεῖνο ζητεῖν πότερον ἓν ἢ πολυμερές. εἰ μὲν γὰρ ἕν, διὰ τί οὐκ εὐθέως καὶ ἡ ψυχὴ ἕν; εἰ δὲ μεριστόν, πάλιν ὁ λόγος ζητήσει τί τὸ συνέχον ἐκεῖνο, καὶ οὕτω δὴ πρόεισιν ἐπὶ τὸ ἄπειρον. If then the soul is of its very nature divisible, what holds it together? Not the body, certainly: much rather the contrary seems to be true, that the soul holds the body together; for when it departs, the body expires and decomposes. If there is some other thing which makes it one, this other is rather the soul. One would then have to ask, concerning this other, whether it be one or of many parts. If it is one, why not call it the soul straightway? But if it is divisible, reason again demands, what it is that holds this together? And so on ad infinitum. § 206
411b14   25. ἀπορήσειε δ' ἄν τις καὶ περὶ τῶν μορίων αὐτῆς, τίν' ἔχει δύναμιν ἕκαστον ἐν τῷ σώματι. εἰ γὰρ ἡ ὅλη ψυχὴ πᾶν τὸ σῶμα συνέχει, προσήκει καὶ τῶν μορίων ἕκαστον συνέχειν τι τοῦ σώματος. τοῦτο δ' ἔοικεν ἀδυνάτῳ· ποῖον γὰρ μόριον ἢ πῶς ὁ νοῦς συνέξει, χαλεπὸν καὶ πλάσαι. A further query arises about the soul’s parts: what power has each in the body? if the whole soul holds together the whole body, it would be fitting if each of the parts controlled some part of the body. But this looks like an impossibility. It is difficult even to imagine what part the intellect would hold together, or how. § 207
26. φαίνεται δὲ καὶ τὰ φυτὰ διαιρούμενα ζῆν καὶ τῶν ζῴων ἔνια τῶν ἐντόμων, ὡς τὴν αὐτὴν ἔχοντα ψυχὴν τῷ εἴδει, εἰ καὶ μὴ ἀριθμῷ· ἑκάτερον γὰρ τῶν μορίων αἴσθησιν ἔχει καὶ κινεῖται κατὰ τόπον ἐπί τινα χρόνον. εἰ δὲ μὴ διατελοῦσιν, οὐθὲν ἄτοπον· ὄργανα γὰρ οὐκ ἔχουσιν ὥστε σώζειν τὴν φύσιν. ἀλλ' οὐδὲν ἧττον ἐν ἑκατέρῳ τῶν μορίων ἅπαντ' ἐνυπάρχει τὰ μόρια τῆς ψυχῆς, καὶ ὁμοειδῆ ἐστιν ἀλλήλοις καὶ τῇ ὅλῃ, ἀλλήλοις μὲν ὡς οὐ χωριστὰ ὄντα, τῇ δ' ὅλῃ ψυχῇ ὡς οὐ διαιρετῇ οὔσῃ. It is also held that plants live after being divided, and certain divided animals also; as if they had a soul specifically one, but not numerically. For each of these parts is endowed with sensation and moves locally for a certain time. If they are not long-lived, that is no objection: they have not the organs. requisite for the preservation of their natures. Nevertheless, in each of the parts are to be found all the parts of the soul; and those separated parts are specifically the same as each other and as the whole; as each other, as if they were not separable; as the whole, as having an indivisible unity. § 208
27. ἔοικε δὲ καὶ ἡ ἐν τοῖς φυτοῖς ἀρχὴ ψυχή τις εἶναι· μόνης γὰρ ταύτης κοινωνεῖ καὶ ζῷα καὶ φυτά, καὶ αὕτη μὲν χωρίζεται τῆς αἰσθητικῆς ἀρχῆς, αἴσθησιν δ' οὐθὲν ἄνευ ταύτης ἔχει. It would seem that the principle in plants is some sort of soul. Plants have only this in common with animals, and while this is independent of the sensitive principle, nothing has sensation without having this. §§ 209-10
ST. THOMAS’S COMMENTARY

LECTIO 14
Positis opinionibus antiquorum de anima et improbatis, consequenter philosophus movet quasdam dubitationes. Et circa hoc duo facit. Primo enim movet ipsas quaestiones. Secundo vero solvit eas, ibi, dicunt itaque et cetera. Sciendum est autem, quod operationes animae scilicet sentire, intelligere, appetere, moveri secundum locum, et augeri, possunt dupliciter accipi: quia vel secundum modum operandi, et sic sunt tres potentiae animae, et his attribuuntur huiusmodi actiones; potentiae videlicet vegetabili, sensibili et intellectuali. 199. Having reviewed and criticised earlier opinions on the soul the Philosopher proceeds now to put certain questions of his own; which at ‘Some say’ he begins to answer. But first we have to realise that the activities, of the soul, such as sensation, understanding, desire, movement in space, and growth, can be considered in two distinct ways. We can consider the mode of these activities; and from this point of view we can distinguish, underlying these activities, three powers of the soul: the vegetative, the sensitive and the intellectual.
Quae quidem differunt. Nam nutritiva sive vegetabilis agit mediantibus qualitatibus activis et passivis, ut calidum, frigidum et huiusmodi. Sensitiva vero seu sensus, licet non indigeat qualitatibus sensibilibus ad sentiendum, indiget tamen organo corporali. Intellectus vero neutro istorum indiget, quia nec qualitatibus, nec per organum corporale aliquid intelligit, sed perficitur in operatione sua absque aliquo organo. 200. And these powers differ. For whilst the vegetative or nutritive power acts through active and passive qualities of matter, such as heat and cold and the like, the sensitive power requires no such sensible qualities for its sentient activity, though it does depend on corporeal organs; while the intellectual power acts through neither sensible qualities nor a corporeal organ, for it functions in an entirely incorporeal way.
Si autem accipiamus huiusmodi actiones secundum genera actionum, sic sunt quinque potentiae; scilicet nutritivum, sensitivum, motivum secundum locum, appetitivum, et intellectivum; et actiones horum sunt sentire, nutrire, movere, et appetere et intelligere. 201. But if we consider the kinds of activities within the soul’s range, then we distinguish five powers with five corresponding activities: the nutritive, sensitive, locomotive, appetitive and intellectual powers.
Et ideo cum philosophus de anima secundum suam totalitatem secundum opiniones antiquorum supra tractasset, et reprobasset eas, hic inquirit de partibus et operationibus ipsarum partium, et movet duas quaestiones. Quarum prima talis est: utrum operationes animae, quae sunt cognoscere et sentire quantum ad sensum, et opinari quantum ad intellectum, adhuc concupiscere quantum ad concupiscibilem, deliberare quantum ad rationalem, et etiam appetitus, quod est in plus, quia concludit cum his duobus irascibilem, et moveri secundum locum, et augeri, et stare, et diminui, conveniant toti animae, ut scilicet unumquodque eorum sit in omni parte animae, id est secundum quamlibet partem animae intelligamus, sentiamus, moveamur, appetamus et nutriamur. Aut singulum istorum habeat singulam partem animae determinatam, ut scilicet alio intelligamus et alio sentiamus, et sic de aliis. 202. Having then discussed and criticised earlier opinions on the soul in general, Aristotle begins now an enquiry into the parts and particular activities of the soul. And he proposes two problems. The first is whether activities like sensing, rational judgement, desiring, deliberating, and also appetition (which he related to special parts of the soul in a more general way than these, placing the irascible urge in both the sensitive and the rational parts), together with local motion and rest, growth and decline, whether all these pertain to the whole soul in such a way that each one occurs in every part of the soul, so that with each part we both understand and sense and move and desire and assimilate food; or whether the truth is not rather that each activity has its own special part, that is to Say, that with one part we understand, with another we sense, and so on
Secunda quaestio est, quia dato quod quaelibet operatio animae habeat specialem partem, item erit quaestio, utrum hoc, quod est vivere, conveniat alicui partium, ita quod sit in aliquo uno, aut in pluribus partibus, aut in omnibus. Et si non in his, utrum sit in aliquo alio. 203. The second problem is this. Granted that each activity has its special part of the soul, is this true of the activity of simply being alive? Is this activity proper to any one of these parts? Or to many? Or to all at once? Or does it perhaps belong to some other part?
Consequenter cum dicit dicunt itaque respondet ad quaestiones positas. Et primo ad primam. Secundo vero ad secundam, ibi, videtur autem et quae et cetera. Respondens autem primae quaestioni, primo ponit opinionem quorumdam philosophorum ad hoc. Secundo improbat eam, ibi, quid igitur continetur et cetera. Quidam enim dicunt quod huiusmodi operationes non conveniunt toti animae, sed partibus. Dicunt enim animam esse partibilem, et quod alio intelligit, et alio concupiscit; sicut qui ponebant sensitivam in cerebro, vivificativam in corde, et huiusmodi. 204. Then at ‘Some say’ he answers these questions in order. As to the first one, he states and then rejects a view of certain philosophers that the activities in question spring severally from the soul’s parts, life from the soul in general; that the soul is so divided into parts that it understands with one and desires with another, just as some people hold that the sensitive power is in the brain and the vital power in the heart, and so on.
Sed huiusmodi opinio est quodammodo vera, et quodammodo falsa: quia si in anima intelligas diversas partes potentiales, sic est verum quod anima habet diversas partes et vires, et alia intelligit, et alia sentit. Anima enim est quoddam totum potentiale, et pars accipitur ibi potentialis respectu totius potestativi. Si vero intelligatur quod anima sit quaedam magnitudo, seu quantitas, et dividatur in diversas partes quantitativas, sic est falsa. Isti vero philosophi intelligebant animam esse partibilem secundum hunc modum. Et addebant plus, quod huiusmodi potentiae animae erant diversae animae. 205. Now this is partly true and partly false. if you take it to mean that the soul has different parts potentially, it is quite true that its parts and powers are distinct and that one of them understands and another senses. The soul is a whole in the sense that it has a total capacity with partial capacities subordinate to the whole. But if you take it quantitatively, as though the soul were of a certain size with parts of certain sizes, then this opinion is false. And this was how the philosophers in question thought of the soul—even to the extent that they made out the soul’s different powers to be different souls.
Consequenter cum dicit quid igitur improbat philosophus opinionem praedictam per tres rationes: quarum prima talis est. Diversa non possunt uni convenire, nisi ab aliquo uniantur: si igitur sunt diversae animae in corpore, oportet quod ab aliquo contineantur et uniantur: sed nihil est quod uniat eas et contineat: ergo non sunt diversae. Et quod nihil sit continens et uniens animam, sic patet. Quia aut est corpus in quo est, aut aliquid aliud sed corpus non unit eam et continet, immo magis anima continet corpus. Videmus enim quod egrediente anima a corpore, corpus deficit et marcescit. Si autem aliquid aliud continet eam, tunc illud erit maxime anima, quia animae est continere et regere. Et si illud erit anima, tunc iterum oportebit quaerere utrum sit una, aut multipartium. Et si dicatur quod multipartium est, iterum erit quaestio quid uniat illud, et sic in infinitum. Si vero dicatur quod est unum, quare non dicunt mox id est ab ipso principio, quod anima sit unum? Non igitur anima est divisibilis in partes quantitativas, sicut ipsi dicunt. 206. Next, at ‘If then the soul’, Aristotle attacks this last hypothesis, with three arguments. The, first is this. Different things cannot be unified except by something else that unites them. If the one body contained several souls, these would have to be joined together and contained by something else. But there is nothing else that can do this; therefore the hypothesis is groundless. That there is no other unifying principle is shown thus. Whatever contains and unifies the soul will be either the body or some other thing. Now it is not the body. Rather, the body is contained and unified by its soul and falls to pieces when the soul leaves it. Then it is something else; but this must be a soul if it pertains especially the soul to unify and control. Is then this unifying soul itself intrinsically one, or made of several parts? If of several parts, then what unites them? And so on ad infinitum. But if this unifying soul is intrinsically one, then ‘why not call it the soul straight away’, i.e. why not concede at the beginning that the soul is intrinsically one? The soul, then, is not, as they thought, quantitatively divisible.
Secundam rationem ponit cum dicit dubitabit autem quia si diversae partes animae sunt in diversis partibus corporis, sequitur quod cuilibet operationi animae sit determinata pars corporis, seu organum corporale. Sed hoc est impossibile, quia intellectus non habet determinatam partem seu organum in corpore. Non igitur anima habet diversas partes, sicut ipsi dicunt. 207. The second argument comes at ‘A further query’. If the different parts of the soul are in different parts of the body, then each soul-activity has its own corporeal part or organ. But the intellect has no special corporeal organ. Hence their conception of the soul’s parts is false.
Tertiam rationem ponit cum dicit dicuntur autem quia si diversae operationes animae sunt in diversis partibus, tunc non erit invenire partem in qua sint plures operationes simul, nec erunt partes animalis similis speciei: sed nos invenimus partes aliquorum animatorum, quae habent plures operationes, et quorum anima est eiusdem speciei in toto et in partibus; sicut est in plantis et in quibusdam animalibus, quae decisa vivunt, sicut est in animalibus anulosis, quorum quaelibet pars decisa sentit et movetur in quoddam tempus. Et si dicatur quod non diu vivunt, non refert; quia non habent instrumenta, quibus salvent suam ipsorum naturam: nihilominus tamen existunt in partibus diversis plures operationes animae, et sunt similis speciei adinvicem, et etiam toti. Non ergo sunt diversae partes animae in diversis partibus corporis. 208. The third argument starts at ‘It is also held’. If each of the various activities of soul is proper to a special part of the body, then no one part is the organ of several distinct activities, nor are there several parts ‘in an animal’ body the same in kind. But experience proves that certain living things have parts with several activities each, and a soul that is identical in kind in the whole and in all the parts; e.g. in plants and in certain (segmented) animals ‘ which go on living after being cut up, the cut off parts retaining their feelings and movement for some time. It does not matter if these parts live for only a short time through lack of the organs of self-preservation. The point is that several soul-activities exist in several distinct corporeal parts at once, and the latter are specifically similar to each other and to the whole. Therefore the soul is not divided according to the different parts of the body.
Ratio autem, quare decisa vivunt, est, quia quanto anima est perfectior, tanto exercet plures perfectas operationes et diversas. Et ideo ad exercendum huiusmodi operationes, necessaria sunt ei plura et diversa organa vel instrumenta corporalia in corpore in quo est. Quia vero anima rationalis, quanto nobilior et perfectior est, tanto exigit maiorem diversitatem organorum; anima autem quae est in animalibus anulosis et in plantis, quia parum habet de perfectione, nec exercet diversas operationes, ideo requirit corpus magis simile et uniforme, et salvatur in qualibet parte. The reason why such animals go on living after being divided is that the number and diversity of activities complete in themselves varies in direct proportion to the perfection of the soul in living things. The higher the soul, the wider is the range of its activities; and the wider its active range the more, and the more distinctly diversified, organs or bodily instruments are required by it. So the relatively greater nobility of the rational soul calls for a greater diversity of its bodily organs, whilst the far lower soul of a segmented animal or a plant has only a narrow field of activity and therefore needs a body that is more uniform and less articulated, and in any part of which, taken separately, it can maintain its being.
Consequenter cum dicit videtur autem solvit secundam quaestionem. Circa quod sciendum est quod vivere proprie est eorum quae habent motum et operationem ex seipsis, sine hoc quod moveantur ab aliis. Unde et vivere dupliciter accipitur. Uno modo accipitur vivere, quod est esse viventis, sicut dicit philosophus, quod vivere est esse viventibus. Alio modo vivere est operatio. 209. Then, at ‘It would seem’, he answers the second question; concerning which we must realise that life belongs, properly speaking, to things that move and act of themselves and are not caused to do so by others. So ‘to live’ has two meanings. It can mean the being of a living thing, and in this sense Aristotle says that living is the being of living things. And also it can mean activity.
Dicendum ergo quod anima quae est in plantis, scilicet vegetabilis, videtur esse quasi quoddam principium, quod manifestat vitam in rebus inferioribus, quia sine hac nihil vivit, et in hac sola communicant omnia quae vivunt, in aliis autem non omnia. Animalia enim et plantae in vegetabili conveniunt solummodo. Item vegetabile potest esse sine sensibili et intelligibili, sed haec non possunt esse sine vegetabili. Nullum enim animal habet sensum seu intellectum sine hoc scilicet vegetabili. Ergo sic vivere attribuitur isti principio, scilicet vegetabili, sicut sentire tactui. Non tamen quod animal per solam vegetabilem vivat, sed quia est primum principium in quo manifestatur vita. 210. Now the soul of plants, the vegetative soul, seems to be a sort of primary manifestation of life among things here on earth; for nothing lives without it and all living things share in it, though in other ways their modes of life differ. Animals and plants have only this in common. It can exist without sense or intelligence, but not sense or intelligence without it; no animal has sense or reason except it first have vegetative life. Thus it bears the same relation to life as touch to sensation. Not that living things only live by this principle, but it is the point where life first appears.

ΒΙΒΛΙΟΝ ΔΕΥΤΕΡΟΝ
Liber 2
BOOK TWO

TEXT
412a1–412b9
BOOK II, CHAPTER I
ΚΕΦΑΛΑΙΟΝ Α'

THE DEFINITION OF THE SOUL

412a   1. Τὰ μὲν δὴ ὑπὸ τῶν πρότερον παραδεδομένα περὶ ψυχῆς εἰρήσθω· πάλιν δ' ὥσπερ ἐξ ὑπαρχῆς ἐπανίωμεν, πειρώμενοι διορίσαι τί ἐστι ψυχὴ καὶ τίς ἂν εἴη κοινότατος λόγος αὐτῆς. Hitherto we have spoken of what our predecessors handed down to us about the soul. But let us now re-open the enquiry from the beginning and endeavour to determine what the soul is and what is its most comprehensive definition. § 211
2. λέγομεν δὴ γένος ἕν τι τῶν ὄντων τὴν οὐσίαν, ταύτης δὲ τὸ μέν, ὡς ὕλην, ὃ καθ' αὑτὸ οὐκ ἔστι τόδε τι, ἕτερον δὲ μορφὴν καὶ εἶδος, καθ' ἣν ἤδη λέγεται τόδε τι, καὶ τρίτον τὸ ἐκ τούτων. ἔστι δ' ἡ μὲν ὕλη δύναμις, τὸ δ' εἶδος ἐντελέχεια, καὶ τοῦτο διχῶς, τὸ μὲν ὡς ἐπιστήμη, τὸ δ' ὡς τὸ θεωρεῖν. Now, we say that one of the kinds of things that are is substance. Of this, there is one element, matter, which of itself is no particular thing; another, the form or species according to which it is called ‘this particular thing’; and a third, that which is from both of these. Matter is, indeed, potency, and the form, act; and this latter has two modes of being, one, like knowledge possessed, the other, like the act of knowing. §§ 212-16
412a.11     3. οὐσίαι δὲ μάλιστ' εἶναι δοκοῦσι τὰ σώματα, καὶ τούτων τὰ φυσικά· ταῦτα γὰρ τῶν ἄλλων ἀρχαί. τῶν δὲ φυσικῶν τὰ μὲν ἔχει ζωήν, τὰ δ' οὐκ ἔχει· ζωὴν δὲ λέγομεν τὴν δι' αὑτοῦ τροφήν τε καὶ αὔξησιν καὶ φθίσιν. Bodies especially seem to be substances; and, among these, natural bodies, for these are the principle’s of the others. Of natural bodies, some possess vitality, others do not. We mean by ‘possessing vitality’, that a thing can nourish itself and grow and decay. §§ 217-19
ὥστε πᾶν σῶμα φυσικὸν μετέχον ζωῆς οὐσία ἂν εἴη, οὐσία δ' οὕτως ὡς συνθέτη. 4. ἐπεὶ δ' ἐστὶ καὶ σῶμα καὶ τοιόνδε, ζωὴν γὰρ ἔχον, οὐκ ἂν εἴη σῶμα ἡ ψυχή· οὐ γάρ ἐστι τῶν καθ' ὑποκειμένου τὸ σῶμα, μᾶλλον δ' ὡς ὑποκείμενον καὶ ὕλη. ἀναγκαῖον ἄρα τὴν ψυχὴν οὐσίαν εἶναι ὡς εἶδος σώματος φυσικοῦ δυνάμει ζωὴν ἔχοντος. ἡ δ' οὐσία ἐντελέχεια· τοιούτου ἄρα σώματος ἐντελέχεια. Therefore every natural body sharing in life will be a substance, and this substance will be in some way composite. Since, however, it is a body of such and such a nature, i.e. having vitality, the soul will not itself be the body. For the body is not one of the factors existing in the subject; rather, it is as the subject and the matter. It is necessary, then, that the soul be a substance in the sense of the specifying principle of a physical body potentially alive. Now, substance [in this sense] is act; it will therefore be the act of a body of this sort. §§ 220-6
5. αὕτη δὲ λέγεται διχῶς, ἡ μὲν ὡς ἐπιστήμη, ἡ δ' ὡς τὸ θεωρεῖν. φανερὸν οὖν ὅτι ὡς ἐπιστήμη· ἐν γὰρ τῷ ὑπάρχειν τὴν ψυχὴν καὶ ὕπνος καὶ ἐγρήγορσίς ἐστιν, ἀνάλογον δ' ἡ μὲν ἐγρήγορσις τῷ θεωρεῖν, ὁ δ' ὕπνος τῷ ἔχειν καὶ μὴ ἐνεργεῖν· προτέρα δὲ τῇ γενέσει ἐπὶ τοῦ αὐτοῦ ἡ ἐπιστήμη. διὸ ἡ ψυχή ἐστιν ἐντελέχεια ἡ πρώτη σώματος φυσικοῦ δυνάμει ζωὴν ἔχοντος. 412b Now this can mean one of two things: one, as is the possession of knowledge; another, as is the act of knowing. It is plain that it is like knowledge possessed. For the soul remains in the body whether one is asleep or awake. Being awake is comparable to the act of knowing, sleep to possession without use. Now knowledge possessed is prior in the order of generation, in one and the same thing. The soul, therefore, is the primary act of a physical body capable of life. §§ 227-9
6. τοιοῦτον δὲ ὃ ἂν ᾖ ὀργανικόν. (ὄργανα δὲ καὶ τὰ τῶν φυτῶν μέρη, ἀλλὰ παντελῶς ἁπλᾶ, οἷον τὸ φύλλον περικαρπίου σκέπασμα, τὸ δὲ περικάρπιον καρποῦ· αἱ δὲ ῥίζαι τῷ στόματι ἀνάλογον· ἄμφω γὰρ ἕλκει τὴν τροφήν.) Such a body will be organic. Parts of plants, indeed, are organs, though very elementary—the leaf is the covering of the pericarp and the pericarp of the fruit: roots, too, are like mouths, for both draw in nourishment. §§ 230-2
εἰ δή τι κοινὸν ἐπὶ πάσης ψυχῆς δεῖ λέγειν, εἴη ἂν ἐντελέχεια ἡ πρώτη σώματος φυσικοῦ ὀργανικοῦ. If then there is anyone generalisation to be made for any and every soul, the soul will be the primary act of a physical bodily organism. § 233
7. διὸ καὶ οὐ δεῖ ζητεῖν εἰ ἓν ἡ ψυχὴ καὶ τὸ σῶμα, ὥσπερ οὐδὲ τὸν κηρὸν καὶ τὸ σχῆμα, οὐδ' ὅλως τὴν ἑκάστου ὕλην καὶ τὸ οὗ ἡ ὕλη· τὸ γὰρ ἓν καὶ τὸ εἶναι ἐπεὶ πλεοναχῶς λέγεται, τὸ κυρίως ἡ ἐντελέχειά ἐστιν. Hence it is unnecessary to enquire whether the soul and body be one, any more than whether the wax and an impression made in it are one; or in general, the matter of anything whatever, and that of which it is the matter. For while one and being are predicated in many ways, that which is properly so is actuality, § 234
ST. THOMAS’S COMMENTARY

LECTIO 1
Postquam Aristoteles posuit opinionem aliorum de anima in primo libro, in secundo accedit ad determinandum de anima secundum propriam opinionem et veritatem. Et circa hoc duo facit. Primo dicit de quo est intentio sua, continuans se ad praecedentia. Secundo prosequitur suam intentionem, ibi, dicimus itaque quoddam et cetera. Dicit ergo primo, quod in primo libro dicta sunt ea quae tradita sunt a prioribus de anima. Sed oportet iterum quasi redeundo a principio determinare veritatem. Quod quidem propter suam difficultatem magis oportet tentare, quam securitatem de veritate invenienda praesumere. Et cum supra in prooemio quaesitum fuerit, utrum prius de anima ipsa determinandum sit, aut de partibus eius, quasi hanc quaestionem determinans, dicit, quod in principio dicendum est, quid est anima, in quo notificatur ipsa animae essentia. Postea autem determinabitur de partibus sive potentiis ipsius. Et quasi huiusmodi rationem assignans, subiungit, et quae utique erit communissima ratio ipsius. Cum enim ostenditur quid est anima, traditur id quod est commune. Cum autem determinatur de unaquaque partium aut potentiarum ipsius, traditur id quod est speciale circa animam. Hic est autem ordo doctrinae, ut a communibus ad minus communia procedatur, sicut ostendit philosophus in principio physicorum. 211. Having reviewed, in Book One, other men’s opinions on the soul, Aristotle now begins Book Two of his Treatise, in which he sets out what he himself holds on the matter. First, then, linking up with what has gone before, he states his general aim; I and secondly, at ‘Now we say that one’, he starts to carry it out. He begins by saying that despite all the previous accounts of the soul it is necessary to go into the whole matter again from the beginning. The subject is so difficult that it is wiser to assume that the truth about it has not yet been discovered. And in answer to the question raised in the Introduction to Book One, whether one should first define the soul, and afterwards its parts, he decides now to define the essence of the soul before coming to conclusions about its parts. As though explaining this decision, he adds that we shall thus have acquired the most comprehensive idea of soul. For the definition of the soul itself comprises what is most common or general, whereas that of each of its parts or potencies comprises only some special aspect of it. And as he explains at the beginning of the Physics, the right way to teach is to begin with what is most general and end with precisions in detail.
Deinde cum dicit dicimus itaque prosequitur suam intentionem quam proposuerat. Et dividitur in partes duas. In prima ostendit quid est anima. In secunda determinat de partibus sive potentiis eius, ibi, potentiarum autem animae et cetera. Prima dividitur in duas. In prima ponit definitionem animae, quae est quasi demonstrationis conclusio. In secunda ponit definitionem animae quae est quasi demonstrationis principium, ibi, quoniam autem ex incertis quidem et cetera. Sciendum est enim quod, sicut dicitur in primo posteriorum, omnis definitio aut est conclusio demonstrationis, sicut haec, tonitruum est continuus sonus in nubibus, aut est demonstrationis principium, sicut haec, tonitruum est extinctio ignis in nube, aut est demonstratio positione, idest ordine differens: sicut haec, tonitruum est continuus sonus in nubibus, propter extinctionem ignis in nube. In hac enim ponitur et demonstrationis conclusio, et principium, etsi non secundum ordinem syllogismi. 212. Beginning then at ‘Now we say’, his treatment divides into two parts, in the first of which he-shows what soul in general is, and in the second, starting at ‘Of the soul’s powers’, what are its parts or powers. The first part subdivides into (a) a definition that concludes, and (b) one that introduces, a demonstrative argument;—this latter part comes at ‘Since it is from the less clear’. Note in passing that any definition, as he says in Book I of the Posterior Analytics, is either the conclusion of a demonstration, e.g. ‘Thunder is a continuous noise in the clouds’, or it is the demonstration’s starting point, e.g. ‘Thunder is the extinction of fire in the clouds’, or it is the demonstration itself, but thrown into a different order, e.g. ‘Thunder is a continuous noise etc., caused by the extinction of fire etc.’ in which the conclusion and the starting point both appear, though not in syllogistic order.
Prima autem pars dividitur in duas. In prima ponit definitionem primam animae. In secunda manifestat eam, ibi universaliter igitur dictum et cetera. Prima dividitur in duas. In prima praemittit quasdam divisiones, ex quibus habetur via ad investigandum definitionem animae. In secunda investigat animae definitionem, ibi, quare omne corpus et cetera. As to (a), it includes first a definition of the soul, and then, at ‘It has been stated then’, an explanation of the definition. And to clear the ground before the defining proper begins (at ‘Therefore every natural body’), he makes some preliminary distinctions.
Sciendum autem est, quod sicut docet philosophus in septimo metaphysicae, haec est differentia inter definitionem substantiae et accidentis, quod in definitione substantiae nihil ponitur quod sit extra substantiam definiti: definitur enim unaquaeque substantia per sua principia materialia vel formalia. In definitione autem accidentis ponitur aliquid quod est extra essentiam definiti, scilicet subiectum; oportet enim subiectum poni in definitione accidentis. Sicut cum dicitur simitas est curvitas nasi. Et hoc ideo est, quia definitio significat quod quid est res; substantia autem est quid completum in suo esse et in sua specie; accidens autem non habet esse completum, sed dependens a substantia. Similiter etiam nulla forma est quid completum in specie, sed complementum speciei competit substantiae compositae. Unde substantia composita sic definitur, quod in eius definitione non ponitur aliquid quod sit extra essentiam eius. In omni autem definitione formae ponitur aliquid, quod est extra essentiam formae, scilicet proprium subiectum eius sive materia. Unde, cum anima sit forma, oportet quod in definitione eius ponatur materia sive subiectum eius. 213. It should be noted here that, according to the teaching of Book VII of the Metaphysics, there is this difference between defining substance and defining accidents that in the former case nothing extrinsic is included: every substance is defined in terms merely of its material and formal principles; but in the latter case something extrinsic to the thing defined is referred to, i.e. the subject of the accidents in question—as when one defines snubness as ‘curvature of the nose’. The reason is that a definition must express what a thing is, and while substance is something complete in its being and kind, accidents have being only in relation to a substance. In the same way no form as such is complete in kind; completeness in this sense belongs only to the substance composed of form and matter; so that the latter’s definition is complete without reference to anything else, whilst that of the form has to include d, reference to its proper subject which is matter. Hence, if the soul is a form its definition will not be complete without reference to its subject or matter.
Et ideo in prima parte ponit duas divisiones; quarum prima necessaria est ad investigandum id quod in definitione animae ponitur ad exprimendam essentiam eius. Alia quae est necessaria ad investigandum id quod ponitur in definitione animae ad exprimendum subiectum ipsius, ibi, substantiae autem maxime et cetera. Circa primum innuit tres divisiones: quarum prima est secundum quod ens dividitur in decem praedicamenta. Et hanc innuit per hoc quod dicit, quod substantia dicitur esse unum genus entium. 214. So, in the first part of this section, he makes certain distinctions, first in view of the work of defining the soul’s essence, and then, at ‘Bodies especially seem to be substances,’ in view of defining its subject. As regards the former point he alludes to three distinctions, of which the first is that of being into the ten categories; this he hints at when he says that substance is reckoned to be ‘one of the kinds of things that are’.
Secunda divisio est secundum quod substantia dividitur in materiam et formam et compositum. Materia quidem est, quae secundum se non est hoc aliquid, sed in potentia tantum ut sit hoc aliquid. Forma autem est, secundum quam iam est hoc aliquid in actu. Substantia vero composita est, quae est hoc aliquid. Dicitur enim esse hoc aliquid, id est aliquid demonstratum quod est completum in esse et specie; et hoc convenit soli substantiae compositae in rebus materialibus. Nam substantiae separatae, quamvis non sint compositae ex materia et forma, sunt tamen hoc aliquid, cum sint subsistens in actu et completae in natura sua. Anima autem rationalis, quantum ad aliquid potest dici hoc aliquid, secundum hoc quod potest esse per se subsistens. Sed quia non habet speciem completam, sed magis est pars speciei, non omnino convenit ei quod sit hoc aliquid. 215. The second distinction alluded to is that of substance into matter, form and the compound of both. Matter is that which is not as such a ‘particular thing’ but is in mere potency to become a ‘particular thing’. Form is that by which a ‘particular thing’ actually exists. And the compound is ‘the particular thing’ itself; for that is said to be a ‘particular thing’ (i.e. something you can point to) which is complete in being and in kind; and among material things only the compound is such. For although immaterial substances are not compounds of matter and form, still they are particular things, having actual existence in themselves, and being complete in their own nature. Not so the rational soul; for though it has the existence in itself which belongs to a ‘particular thing’, it is not a complete nature by itself; it is rather a part of a specific nature. Hence it is not in all respects a ‘particular thing’.
Est ergo differentia inter materiam et formam, quod materia est ens in potentia, forma autem est endelechia, id est actus, quo scilicet materia fit actu, unde ipsum compositum est ens actu. Matter, then, differs from form in this, that it is potential being; form is the ‘entelechy’ or actuality that renders matter actual; and the compound is the resulting actual being.
Tertia divisio est quod actus dicitur dupliciter. Uno modo sicut scientia est actus. Alio modo sicut considerare est actus. Et differentia horum actuum ex potentiis perpendi potest. Dicitur enim aliquis in potentia grammaticus, antequam acquirat habitum grammaticae, discendo vel inveniendo: quae quidem potentia in actum reducitur, quando iam aliquis habet habitum scientiae. Sed tunc est iterum in potentia ad usum habitus, cum non considerat in actu; et haec potentia in actum reducitur cum actu considerat. Sic igitur et scientia est actus, et consideratio est actus. 216. Thirdly, he distinguishes two senses of the term ‘act’. In one sense knowledge is an act, in the other thinking is an act; and the difference can be understood by relating these acts to their potencies. Before one acquires the grammatical habit and becomes a grammarian, whether self-taught or led by another, one is only potentially so; and this potency is actualised by the habit. But once the habit is acquired one is still in potency to the use of it, so long as one is not actually thinking about grammar; and this thinking is a further actualisation. In this sense, then, knowledge is one act and thinking another.
Deinde cum dicit substantiae autem ponit divisiones, ex quibus investigatur id quod ponitur in definitione animae, pertinens ad eius subiectum. Et innuit tres divisiones. Quarum prima est, quod substantiarum quaedam sunt corpora, quaedam non sunt corpora. Inter quas substantias maxime sunt manifestae corporales substantiae. Nam substantiae incorporeae, quaecumque sint, immanifestae sunt, eo quod sunt a sensibus remotae et sola ratione investigabiles. Hoc est ergo quod dicit, quod corpora maxime videntur esse substantiae. 217. Then at ‘Bodies especially’ he alludes to three distinctions which are presupposed by his enquiry into the meaning of the definition of the soul, so far as the subject endowed with soul is concerned. The first is the distinction between corporeal and incorporeal substances. Now the former are the most evident to us: for, whatever the latter may be in themselves, they do not impinge on our senses, but are only discoverable by an exercise of the reason. Hence he says that ‘bodies especially seem to be substances’.
Secunda divisio est, quod corporum, quaedam sunt corpora physica, id est naturalia; quaedam non naturalia, sed artificialia. Homo enim et lignum et lapis sunt naturalia corpora, domus et securis sunt artificialia. Magis autem videntur substantiae corpora naturalia quam artificialia, quia corpora naturalia sunt principia artificialium. Ars enim operatur ex materia quam natura ministrat; forma autem quae per artem inducitur, est forma accidentalis, sicut figura vel aliquid huiusmodi. Unde corpora artificialia non sunt in genere substantiae per suam formam, sed solum per suam materiam, quae est naturalis. Habent ergo a corporibus naturalibus quod sint substantiae. Unde corpora naturalia sunt magis substantiae quam corpora artificialia: sunt enim substantiae non solum ex parte materiae, sed etiam ex parte formae. 218. The next distinction, is between physical or natural bodies and artificial bodies. Man and wood and stone are natural bodies, but a house or a saw is artificial. And of these the natural bodies seem to be the more properly called substances, since artificial bodies are made out of them. Art works upon materials furnished by nature, giving these, moreover, a merely accidental form, such as a new shape and so forth; so that it is only in virtue of their matter, not their form, that artificial bodies are substances at all; they are substances because natural bodies are such. Natural bodies therefore are the more properly called substances, being such through their form as well as through their matter.
Tertia divisio est, quod corporum naturalium, quaedam habent vitam, et quaedam non habent. Illud autem dicitur habere vitam, quod per seipsum habet alimentum, augmentum et decrementum. Sciendum autem est, quod haec explanatio magis est per modum exempli, quam per modum definitionis. Non enim ex hoc solo quod aliquid habet augmentum et decrementum, vivit, sed etiam ex hoc quod sentit et intelligit, et alia opera vitae exercere potest. Unde in substantiis separatis est vita ex hoc quod habent intellectum et voluntatem, ut patet in undecimo metaphysicae, licet non sit in eis augmentum et alimentum. Sed quia in istis generabilibus et corruptibilibus anima, quae est in plantis, ad quam pertinent alimentum et augmentum, ut in fine primi dictum est, principium est vitae, ideo hic quasi exemplariter exposuit habens vitam, id quod habet alimentum et augmentum. Propria autem ratio vitae est ex hoc, quod aliquid est natum movere seipsum, large accipiendo motum, prout etiam intellectualis operatio motus quidam dicitur. Ea enim sine vita esse dicimus, quae ab exteriori tantum principio moveri possunt. 219. Thirdly, he distinguishes between living and non-living natural bodies; and the living are those which of themselves take nutriment and grow and decay. Note here that this is said by way of example rather than definition. For, besides growth and decay, living things may exhibit sensation and intellectual knowledge and other vital activities. Immaterial substances, as is proved in the Metaphysics, Book XI, have the life of intellect and volition, though they cannot grow and do not take food. But because, in the sphere of things that are born and die, the plant-soul (the principle of nutrition and growth) marks the point where life begins, this soul is here taken as the type of all living things. However, life is essentially that by which anything has power to move itself, taking movement in its wide sense so as to include the ‘movement’ or activity of the intellect. For we call those things inanimate which are moved only from outside.
Deinde cum dicit quare omne investigat animae definitionem, suppositis praemissis divisionibus. Et circa hoc tria facit. Primo investigat partes definitionis. Secundo ponit definitionem, ibi, si autem aliquod commune et cetera. Tertio ex definitione data, excludit quamdam dubitationem, ibi, unde non oportet quaerere et cetera. Circa primum duo facit. Primo investigat particulas definitionis, quae pertinent ad essentiam animae. Secundo ea quae pertinent ad essentiam subiecti. Tale autem quodcumque organicum. Circa primum duo facit. Primo investigat hanc particulam, quod anima est actus. Secundo hanc, quod est actus primus, ibi, hic autem dicitur dupliciter. 220. After this, at ‘Therefore every natural body” he begins to define the soul, presupposing the distinctions already made. And his enquiry here has three parts: (a) he enquires into the elements of the definition taken separately; (b) at, ‘If, then, there is any one generalisation’, he states his definition; and (c) at ‘Hence it is unnecessary’, he uses it to refute an objection. As to (a) he first deals with the elements that refer to the soul’s essence, and then to those that refer to its subject, at ‘Such a body will be organic’, and in the part that concerns the essence he considers first the statement that the soul is an ‘act’, and then, at ‘Now this can mean one of two things’. that it is a ‘primary act’.
Concludit ergo primo ex praedictis, quod cum corpora physica maxime videantur esse substantiae, et omne corpus habens vitam, sit corpus physicum, necesse est dicere quod omne corpus habens vitam sit substantia. Et cum sit ens actu, necesse est quod sit substantia composita. Quia vero, cum dico, corpus habens vitam, duo dico, scilicet quod est corpus et quod est huiusmodi corpus, scilicet habens vitam, non potest dici quod illa pars corporis habentis vitam, quae dicitur corpus, sit anima. Per animam enim intelligimus id, quo habens vitam vivit: unde oportet quod intelligatur sicut aliquid in subiecto existens; ut accipiatur hic large subiectum, non solum prout subiectum dicitur aliquid ens actu, per quem modum accidens dicitur esse in subiecto; sed etiam secundum quod materia prima, quae est ens in potentia, dicitur subiectum. Corpus autem, quod recipit vitam, magis est sicut subiectum et materia quam sicut aliquid in subiecto existens. Aristotle’s first conclusion, then, in line with what has been said already, is that if physical bodies are substances in the fullest sense, all living bodies are substances too, for they are physical bodies. And as each living body is an actual being, it must be a compound substance. But just because to say ‘living body’ is to imply two things, the body itself and that modification of body by which it is alive, it cannot be said that the element in the composition referred to by the term body is itself the principle of life or the ‘soul’. By ‘soul’ we understand that by which a living thing is alive; it is understood, therefore, as existing in a subject, taking ‘subject’ in a broad sense to include not only those actual beings which are subjects of their accidental modifications, but also bare matter or potential being. On the other hand the body that receives life is more like a subject and a matter than a modification existing in a subject.
Sic igitur, cum sit triplex substantia, scilicet compositum, materia, et forma, et anima non est ipsum compositum, quod est corpus habens vitam: neque est materia, quae est corpus subiectum vitae: relinquitur, per locum a divisione, quod anima sit substantia, sicut forma vel species talis corporis, scilicet corporis physici habentis in potentia vitam. 221. Since, then, there are three sorts of substance: the compound; matter; and form; and since the soul is neither the compound-the living body itself; nor its matter—the body as the subject that receives life; we have no choice but to say that the soul is a substance in the manner of a form that determines or characterises a particular sort of body, i.e. a physical body potentially alive.
Dixit autem habentis vitam potentia et non simpliciter habentis vitam. Nam corpus habens vitam intelligitur substantia composita vivens. Compositum autem non ponitur in definitione formae. Materia autem corporis vivi est id quod comparatur ad vitam sicut potentia ad actum: et hoc est anima, actus, secundum quem corpus vivit. Sicut si dicerem quod figura est actus, non quidem corporis figurati in actu, hoc enim est compositum ex figura et corpore, sed corporis quod est subiectum figurae, quod comparatur ad figuram sicut potentia ad actum. 222. Note that he does not say simply ‘alive’, but ‘potentially alive’. For by a body actually alive is understood a living compound; and no compound as such can enter into the definition of a form. On the other hand the matter of a living body stands to the body’s life as a potency to its act; and the soul is precisely the actuality whereby the body has life. It is as though we were to say that shape is an actuality; it is not exactly the actuality of an actually shaped body—i.e. the compound of body and shape—but rather of the body as able to receive a shape, of the body as in potency to an actual shape.
Et ne aliquis crederet quod anima sic esset actus sicut aliqua forma accidentalis actus est, ad hoc removendum, subdit quod anima est sic actus, sicut substantia est actus, id est sicut forma. Et quia omnis forma est in determinata materia, sequitur quod sit forma talis corporis, quale dictum est. §.223. But lest it be thought that soul is an actuality in the manner of any merely accidental form, he adds that it is a substantial actuality or form. And since every form has the matter proper to it, the soul must actualise just this special sort of body.
Sciendum autem est quod haec est differentia formae substantialis ad formam accidentalem, quod forma accidentalis non facit ens actu simpliciter, sed ens actu tale vel tantum, utputa magnum vel album vel aliquid aliud huiusmodi. Forma autem substantialis facit esse actu simpliciter. Unde forma accidentalis advenit subiecto iam praeexistenti actu. Forma autem substantialis non advenit subiecto iam praeexistenti in actu, sed existenti in potentia tantum, scilicet materiae primae. Ex quo patet, quod impossibile est unius rei esse plures formas substantiales; quia prima faceret ens actu simpliciter, et omnes aliae advenirent subiecto iam existenti in actu, unde accidentaliter advenirent subiecto iam existenti in actu, non enim facerent ens actu simpliciter sed secundum quid. 224. The difference between accidental form and substantial form is that whereas the former does not make a thing simply be, but only makes it be in this or that mode—e.g. as quantified, or white— the substantial form gives it simple being. Hence the accidental form presupposes an already existing subject; but the substantial form presupposes only potentiality to existence, i.e. bare matter. That is why there cannot be more than one substantial form in any one thing; the first makes the thing an actual being; and if others are added, they confer only accidental modifications, since they presuppose the subject already in act of being.
Per quod tollitur positio Avicebron in libro fontis vitae, qui posuit quod secundum ordinem generum et specierum est ordo plurium formarum substantialium in una et eadem re; ut puta quod in hoc individuo hominis est una forma, per quam est substantia: et alia, per quam est corpus: et tertia, per quam est animatum corpus, et sic de aliis. Oportet enim secundum praemissa dicere, quod una et eadem forma substantialis sit, per quam hoc individuum est hoc aliquid, sive substantia, et per quam est corpus et animatum corpus, et sic de aliis. Forma enim perfectior dat materiae hoc quod dat forma minus perfecta, et adhuc amplius. Unde anima non solum facit esse substantiam et corpus, quod etiam facit forma lapidis, sed etiam facit esse animatum corpus. Non ergo sic est intelligendum quod anima sit actus corporis, et quod corpus sit eius materia et subiectum, quasi corpus sit constitutum per unam formam, quae faciat ipsum esse corpus, et superveniat ei anima faciens ipsum esse corpus vivum; sed quia ab anima est, et quod sit, et quod sit corpus vivum. Sed hoc quod est esse corpus, quod est imperfectius, est quid materiale respectu vitae. 225. We can therefore reject the view of Avicebron (in the Book called Fons Vitae) that according to the way in which any given thing can be divided into genera and species so it can be divided into substantial forms. Thus an individual man would have one form that made him a substance, another that gave him a body, another that gave him life, and so on. But what our premises compel us to say is that it is one and the same substantial form that makes a man a particular thing or substance, and a bodily thing, and a living thing, and so on. For the higher form can give to its matter all that a lower form gives, and more; the soul gives not only substance and body (as a stone’s form does) but life also. We must not think, therefore, of the soul and body as though the body had its own form making it a body, to which a soul is superadded, making it a living body; but rather that the body gets both its being and its life from the soul. This is not to deny, however, that bodily being as such is, in its imperfection, material with respect to life.
Et inde est quod recedente anima, non remanet idem corpus specie; nam oculus et caro in mortuo non dicuntur nisi aequivoce, ut patet per philosophum in septimo metaphysicorum. Recedente enim anima, succedit alia forma substantialis quae dat aliud esse specificum, cum corruptio unius non sit sine generatione alterius. 226. Therefore, when life departs the body is not left specifically the same; the eyes and flesh of a dead man, as is shown in the Metaphysics, Book VII, are only improperly called eyes and flesh. When the soul leaves the body another substantial form takes its place; for a passing-away always involves a concomitant coming-to-be.
Deinde cum dicit hic autem venatur secundam particulam definitionis: et dicit quod actus dicitur dupliciter: alius, sicut scientia, et alius sicut considerare, ut supra expositum est. Et manifestum est, quod anima est actus sicut scientia, quia in hoc quod anima inest animali et somnus et vigilia. Et vigilia quidem assimilatur considerationi; quia sicut consideratio est usus scientiae, ita vigilia est usus sensuum; sed somnus assimilatur habitui scientiae, quando aliquis secundum ipsum non operatur, in somno enim quiescunt virtutes animales. 227. Then, at ‘Now this can mean’, he examines the second term in the definition. He observes that there are two kinds of actuality, as we explained above, the kind that is like knowledge and the kind like thinking. And clearly the soul is of the former kind; for it is due to the soul that an animal is able to be both awake and asleep; and while waking is similar to thinking (for it is a use of the exterior senses just as thinking is a use of knowledge already possessed), sleep is more like the knowledge which lies dormant in the mind so long as it is not actually being used; for in sleep an animal’s faculties are quiescent.
Horum autem duorum actuum, scientia est prior generatione, in eodem. Comparatur enim consideratio ad scientiam, sicut actus ad potentiam. Actus autem, ut habetur in nono metaphysicae, natura est prior potentia. Est enim finis et complementum potentiae. Sed ordine generationis et temporis, universaliter loquendo actus est prior potentia. Nam id quod est in potentia, reducitur in actum per aliquid ens actu. Sed in uno et eodem potentia est prior actu. Nam aliquid est primo in potentia, et postea actus fit. Et propter hoc dicit quod scientia est prior generatione, in eodem, quam consideratio. 228. Now, of these two actualities, knowledge comes first in the order of coming-to-be in the same person; for it stands to thinking as potency to act. But in the order of nature or essence act is prior to potency (see the Metaphysics, Book IX) as the end and complete perfection of potency. And even in the temporal order of coming-to-be, act, in a quite general sense, is prior; for the potential is actualised only by something already in act. But in this or that particular thing considered in itself potentiality may come first; the thing may be actualised by degrees. Hence his remark that ‘knowledge... is prior (i.e. to thinking) in the order of generation in one and the same thing’.
Unde concludit quod cum anima sit actus sicut scientia, quod sit actus primus corporis physici potentia vitam habentis. Sciendum autem quod philosophus dicit animam esse actum primum, non solum ut distinguat animam ab actu qui est operatio, sed etiam ut distinguat eam a formis elementorum, quae semper habent suam actionem, nisi impediantur. 229. So he concludes that soul is the primary act of a physical body potentially alive, where act means the same sort of actuality as knowledge. He says primary act, not only to distinguish soul from its subsequent activities, but also to distinguish it from the forms of the elements; for these retain their own proper activities, unless impeded.
Deinde cum dicit tale autem venatur particulam, quae est ex parte subiecti: et quia dixerat, quod anima est actus corporis physici habentis vitam in potentia, etiam dicit, quod tale est omne corpus organicum. Et dicitur corpus organicum, quod habet diversitatem organorum. Diversitas autem organorum necessaria est in corpore suscipiente vitam propter diversas operationes animae. Anima enim, cum sit forma perfectissima inter formas rerum corporalium, est principium diversarum operationum; et ideo requirit diversitatem organorum in suo perfectibili. Formae vero rerum inanimatarum, propter sui imperfectionem sunt principia paucarum operationum: unde non exigunt diversitatem organorum in suis perfectionibus. 230. Next, at ‘Such a body’ he examines that part of the definition which has to do with the soul’s subject, observing that the ‘physical body’ referred to is any organic body, i.e. any body equipped with the various organs required by a living body in consequence of the life-principle’s various vital activities. For from this principle (the soul) which is the richest of embodied forms, spring many different activities, so that it requires, in the matter informed by it, a full equipment of different organs. Not so the less perfect forms of inanimate things.
Inter animas autem anima plantarum imperfectior invenitur: unde in plantis minor est diversitas organorum quam in animalibus. Et ideo ad ostendendum, quod omne corpus suscipiens vitam est organicum, accipit argumentum ex plantis in quibus est minor diversitas organorum. Et hoc est quod dicit, quod etiam plantarum partes sunt diversa organa. Sed partes plantarum sunt penitus simplices, idest consimiles; non enim est in eis tanta diversitas, sicut in partibus animalium. Pes enim animalis ex diversis partibus compositus est, scilicet carne, nervo, osse, et huiusmodi. Sed partes organicae plantarum non habent talem diversitatem partium, ex quibus componantur. 231. Now plants, the least perfect of animate things, exhibit less organic diversity than animals. That is why Aristotle chooses plants to illustrate his assertion that every animate body is organic, saying that even plants have organically diversified parts. But these parts are very simple, i.e. like to one another; they lack the differentiation that we find in animals. Thus the foot of an animal is made up of different parts, flesh, nerves, bones and so forth, but the organs of plants are composed of less diverse sets of parts.
Et quod partes plantarum sint organicae, manifestat per hoc, quod diversae partes sunt ad diversas operationes. Sicut folium est ad cooperimentum corticis vel fructiferi, id est illius partis in qua fructus nascitur. Cortex autem vel fructiferum, ad cooperimentum fructus. Radices autem in plantis sunt proportionabiles ori animalium, quia utraque attrahunt alimentum, scilicet radix in plantis, et os in animalibus. 232. The organic character of the parts of plants is displayed in their diverse functions. Thus a leaf functions as a covering for the pericarp, or fruit-bearing part, i.e. for the part in which the fruit is born. The pericarp, again, protects the fruit itself. So too the roots have a function in a plant similar to that of the mouth in an animal; they draw in nourishment.
Deinde cum dicit si autem colligit ex omnibus praedictis definitionem animae; et dicit, quod si aliqua definitio communis debeat assignari, quae conveniat omni animae, erit haec, anima est actus primus corporis physici organici. Non autem oportet addere, potentia vitam habentis. Loco enim huius ponitur organicum, ut ex dictis patet. 233. Next, at ‘if, then,’ he gathers all these observations into one definition, saying that if any definition covers all types of ‘soul’ it will be this: the soul is the primary actuality of a physical bodily organism. He does not need to add ‘having life potentially’; for this is implied in ‘organism’.
Deinde cum dicit unde non ex definitione data, solvit quamdam dubitationem. Fuit enim a multis dubitatum, quomodo ex anima et corpore fieret unum. Et quidam ponebant aliqua media esse, quibus anima corpori uniretur, et quodammodo colligaretur. Sed haec dubitatio iam locum non habet, cum ostensum sit, quod anima sit forma corporis. Et hoc est quod dicit quod non oportet quaerere si ex anima et corpore fit unum, sicut nec dubitatur circa ceram et figuram, neque omnino circa aliquam materiam et formam, cuius est materia. Ostensum est enim in octavo metaphysicae quod forma per se unitur materiae, sicut actus eius; et idem est materiam uniri formae, quod materiam esse in actu. Et hoc est etiam quod hic dicit, quod cum unum et ens multipliciter dicatur, scilicet de ente in potentia, et de ente in actu, id quod proprie est ens et unum est actus. Nam sicut ens in potentia non est ens simpliciter, sed secundum quid, ita non est unum simpliciter sed secundum quid: sic enim dicitur aliquid unum sicut et ens. Et ideo sicut corpus habet esse per animam, sicut per formam, ita et unitur animae immediate, inquantum anima est forma corporis. Sed inquantum est motor, nihil prohibet aliquid esse medium, prout una pars movetur ab anima, mediante alia. 234. Then at ‘Hence it is’ he applies this definition to solve a difficulty. There had been much uncertainty about the way the soul and body are conjoined. Some had supposed a sort of medium connecting the two together by a sort of bond. But the difficulty can be set aside now that it has been shown that the soul is the form of the body. As he says, there is no more reason to ask whether soul and body together make one thing than to ask the same about wax and the impression sealed on it, or about any other matter and its form. For, as is shown in the Metaphysics, Book VIII, form is directly related to matter as the actuality of matter; once matter actually is it is informed. Moreover, although, as he goes on to say, being and unity are variously predicated (in one way of potential, and in another way of actual, being), that is primarily and properly a being and a unity which has actuality. just as potential being is only a being under a certain aspect, so it is only a unity under a certain aspect; for unity follows being. Therefore, just as the body gets its being from the soul, as from its form, so too it makes a unity with this soul to which it is immediately related. If, on the other hand, we regard the soul in its function as the mover of the body, then there is no reason why it should not move by means of a medium, moving one part of the body by means of another.

TEXT
412b10–413a10
BOOK II, CHAPTER I, CONTINUED

THE DEFINITION EXPLAINED
SOUL AND BODY

8. καθόλου μὲν οὖν εἴρηται τί ἐστιν ἡ ψυχή· οὐσία γὰρ ἡ κατὰ τὸν λόγον. τοῦτο δὲ τὸ τί ἦν εἶναι τῷ τοιῳδὶ σώματι, καθάπερ εἴ τι τῶν ὀργάνων φυσικὸν ἦν σῶμα, οἷον πέλεκυς· ἦν μὲν γὰρ ἂν τὸ πελέκει εἶναι ἡ οὐσία αὐτοῦ, καὶ ἡ ψυχὴ τοῦτο· χωρισθείσης δὲ ταύτης οὐκ ἂν ἔτι πέλεκυς ἦν, ἀλλ' ἢ ὁμωνύμως, νῦν δ' ἔστι πέλεκυς. οὐ γὰρ τοιούτου σώματος τὸ τί ἦν εἶναι καὶ ὁ λόγος ἡ ψυχή, ἀλλὰ φυσικοῦ τοιουδί, ἔχοντος ἀρχὴν κινήσεως καὶ στάσεως ἐν ἑαυτῷ. It has been stated, then, what the soul in general is. It is ‘substance’ as definable form; and this means what is the essence of such a kind of body. If some utensil, for example an axe, were a natural body, then ‘being an-axe’ [axeishness] would be its substance, and this would be its soul. Apart from this, it would no longer be an axe, save equivocally. As it is, it is really an axe. And the soul is not the essence or ‘what-it-is’ of such a body as this, but of a natural body, such as has in itself the principle of motion and rest. §§235-8
9. θεωρεῖν δὲ καὶ ἐπὶ τῶν μερῶν δεῖ τὸ λεχθέν. εἰ γὰρ ἦν ὁ ὀφθαλμὸς ζῷον, ψυχὴ ἂν ἦν αὐτοῦ ἡ ὄψις· αὕτη γὰρ οὐσία ὀφθαλμοῦ ἡ κατὰ τὸν λόγον (ὁ δ' ὀφθαλμὸς ὕλη ὄψεως), ἧς ἀπολειπούσης οὐκέτ' ὀφθαλμός, πλὴν ὁμωνύμως, καθάπερ ὁ λίθινος καὶ ὁ γεγραμμένος. δεῖ δὴ λαβεῖν τὸ ἐπὶ μέρους ἐφ' ὅλου τοῦ ζῶντος σώματος· ἀνάλογον γὰρ ἔχει ὡς τὸ μέρος πρὸς τὸ μέρος, οὕτως ἡ ὅλη αἴσθησις πρὸς τὸ ὅλον σῶμα τὸ αἰσθητικόν, ᾗ τοιοῦτον. Now what has been said should be considered with respect to parts. For if the eye were an animal, sight would be its soul. For this is the substance, in the sense of the definable form, of the eye. The eye is the matter of sight, and apart from this it is an eye no longer save equivocally, as with a painted or stone eye. What, therefore, holds of a part, we ought to apply to the whole living body: for the relation of a part [of the soul] to part [of the body] corresponds to that of sensitivity as a whole to the whole sensitive body, considered as such. §239
10. ἔστι δὲ οὐ τὸ ἀποβεβληκὸς τὴν ψυχὴν τὸ δυνάμει ὂν ὥστε ζῆν, ἀλλὰ τὸ ἔχον· τὸ δὲ σπέρμα καὶ ὁ καρπὸς τὸ δυνάμει τοιονδὶ σῶμα. ὡς μὲν οὖν ἡ τμῆσις καὶ ἡ ὅρασις, οὕτω καὶ ἡ ἐγρήγορσις ἐντελέχεια, [413a] ὡς δ' ἡ ὄψις καὶ ἡ δύναμις τοῦ ὀργάνου, ἡ ψυχή· τὸ δὲ σῶμα τὸ δυνάμει ὄν· ἀλλ' ὥσπερ ὀφθαλμὸς ἡ κόρη καὶ ἡ ὄψις, κἀκεῖ ἡ ψυχὴ καὶ τὸ σῶμα ζῷον. Not that which has cast off its soul is ‘capable of life’, but that which possesses it. But seed and fruit are only in potency such a body. As cutting or seeing is act, so is consciousness. The soul is like sight and the capacity of a tool; the body, like the thing in potency. But as an eye is a pupil together with the power of sight, so is there a living thing where there are both body and soul. §§ 240-1
11. ὅτι μὲν οὖν οὐκ ἔστιν ἡ ψυχὴ χωριστὴ τοῦ σώματος, ἢ μέρη τινὰ αὐτῆς, εἰ μεριστὴ πέφυκεν, οὐκ ἄδηλον· ἐνίων γὰρ ἡ ἐντελέχεια τῶν μερῶν ἐστὶν αὐτῶν. οὐ μὴν ἀλλ' ἔνιά γε οὐθὲν κωλύει, διὰ τὸ μηθενὸς εἶναι σώματος ἐντελεχείας. 12. ἔτι δὲ ἄδηλον εἰ οὕτως ἐντελέχεια τοῦ σώματος ἡ ψυχὴ <ἢ> ὥσπερ πλωτὴρ πλοίου. τύπῳ μὲν οὖν ταύτῃ διωρίσθω καὶ ὑπογεγράφθω περὶ ψυχῆς. Therefore it is evident enough that the soul is inseparable from the body—or certain parts of it, if it naturally has parts; for it is of certain bodily parts themselves that it is the act. But with respect to certain of its parts there is nothing to prevent its being separated, because these are acts of nothing bodily. Furthermore, it is not clear that the soul is not the ‘act’ of the body in the way that a sailor is of his ship. Let these remarks serve to describe and define the soul, in outline. §§ 242-4

ST. THOMAS’S COMMENTARY
LECTIO 2
Posita definitione animae, philosophus hic eam manifestat. Et circa hoc duo facit. Primo manifestat definitionem praemissam. Secundo ex definitione manifestata, quamdam veritatem concludit, ibi, quod quidem igitur non sit anima et cetera. Circa primum duo facit. Primo manifestat definitionem animae, quantum ad id quod in definitione praedicta ponitur ex parte ipsius animae. Secundo quantum ad id quod ibi ponitur ex parte subiecti, ibi, est autem non abiiciens animam et cetera. Circa primum duo facit. Primo manifestat definitionem animae ex similitudine rerum artificialium. Secundo ex partibus eius, ibi, considerare autem in partibus oportet et cetera. 235. The Philosopher now begins to explain the definition of the soul given in Lectio 1; after which, at ‘Therefore it is evident’, he draws a conclusion from it. The explanation has two parts, in the first of which he is concerned directly with the soul itself, while in the second, where he says ‘Not that which has cast off’ he explains that part of the definition which refers to the subject which has a soul. With regard to the soul itself, he begins by illustrating the definition by a comparison with artificial things; and then goes on, at ‘Now what has.’ to explain it by considering the parts of the soul separately.
Quia enim formae artificiales accidentia sunt, quae sunt magis nota, quoad nos, quam formae substantiales, utpote sensui propinquiora: ideo convenienter rationem animae, quae est forma substantialis, per comparationem ad formas accidentales manifestat. Similiter etiam partes animae sive potentiae eius manifestiores sunt quoad nos, quam ipsa anima: procedimus enim in cognitione animae, ab obiectis in actus, ab actibus in potentias, per quas anima ipsa nobis innotescit; unde convenienter etiam per partes ratio manifestatur. In artificial things, made by human skiff, the forms imposed on the material are accidental forms; and since these are easier for us to perceive than is substantial form, as being more accessible to the senses, it is obviously reasonable to approach the soul, which is a substantial form, through a comparison with accidental forms. And again, the soul’s parts or potencies are more readily perceptible to us than its essence; for all our enquiry into the soul has to start from the objective terms of its activities and then proceed from these activities to their potencies, and thence to an understanding of the soul in its essence; that is why a study of the soul’s parts can throw light on the definition of it.
Dicit ergo primo, quod dictum est in universali quid sit anima, cum praedicta definitio omni animae conveniat. Dictum est enim quod anima est substantia, quae est forma, a qua accipitur ratio rei. Est autem differentia inter formam quae est substantia, et formam quae non est substantia. Nam forma accidentalis, quae non est in genere substantiae, non pertinet ad essentiam sive quidditatem subiecti: non enim albedo est de essentia corporis albi. Sed forma substantialis est de essentia, sive de quidditate subiecti. Sic igitur anima dicitur forma substantialis, quia est de essentia sive de quidditate corporis animati. Et hoc est quod subdit, haec autem, scilicet substantia quae est secundum rationem est quod quid erat esse huic corpori, id est corpori constituto in specie per talem formam. Ipsa enim forma pertinet ad essentiam rei, quae significatur per definitionem significantem de re quid est. 236. First, then, he observes that the definition given above is ‘general’, i.e. it applies to any soul. It posits the soul as a substance, which is a form; and this means that it presents to us the idea of the essence of something. For there is this difference between a form that is substance and one that is not, that the latter sort are not strictly of the essence or ‘whatness’ of a thing: whiteness is not of the essence of a white body; whereas substantial form is essential and quidditative. To call the soul a substantial form, therefore, is to imply that it is of the essence and ‘whatness’ of the body it animates. Hence he says ‘this’, i.e. this quidditative substance, ‘is the essence of this body’, i.e. of the body that is what it is precisely through having this particular form. For this form is essential to the thing, and is denoted by the definition of what the thing is.
Et quia formae substantiales, cuiusmodi sunt formae corporum naturalium, sunt latentes, manifestat hoc per formas artificiales, quae sunt accidentales. Et hoc est quod subdit: sicut si aliquid organorum, id est artificialium instrumentorum, ut puta dolabra esset corpus physicum, idest naturale, forma sua hoc modo se haberet ad ipsum sicut dictum est. Et ideo subdit. Erat quidem dolabrae esse substantia ipsis, idest forma dolabrae, secundum quam accipitur ratio dolabrae: quam quidem rationem nominat esse dolabrae, eo quod secundum eam dolabra dicitur esse dolabra, haec inquam forma est substantia dolabrae. Et hoc ideo dicit, quia formae corporum naturalium sunt in genere substantiae. Et ulterius si dolabra non esset solum corpus physicum, sed etiam corpus animatum, forma dolabrae esset anima, et ea separata, non esset amplius dolabra nisi aequivoce, sicut separata anima, non est caro nec oculus, nisi aequivoce. Nunc autem, quia dolabra non est corpus naturale, nec eius forma est quod quid erat esse tali corpori, remota forma dolabrae adhuc est dolabra, id est substantia dolabrae. Substantia enim corporum artificialium est materia eorum, quae remanet sublata forma artificiali, licet non remaneat ipsum corpus artificiale in actu. 237. And because substantial forms, including the forms of natural bodies, are not evident to us, Aristotle makes his meaning clear with an example taken from the forms (accidental) of artificial. things. ‘If’, he says, ‘some utensil (i.e. an artificial instrument) for example an axe, were a physical (i.e. a natural) body,’ it would possess a form in the manner already explained. So he continues: ‘Then being-an-axe would be its substance,’ i.e. would be the substantial form of the axe, which is that to which we refer our idea of axe as such. This idea of axe as such he identifies with the essence of the axe, with what causes it to be an axe; and this essential form he identifies with the substance of the axe. He says ‘substance’ because the forms of natural bodies are substantial forms. Furthermore, if the axe were not merely a natural, but also an animate, body, its form would be a soul; and if it lost this soul it would no longer be an axe, except in name; just as when the soul leaves the body there is no longer an eye or flesh, except in name. Of course the axe, not being in fact a natural body, has no axe-form which is of the essence of the body that it is; so that if it lost the form of axe, the axe would still exist substantially, because the substance of artificial things is their matter which remains when the artificial form and, with this artificial form, the actuality of the artificial body as such, is removed.
Et quia dixerat quod aliter nunc est in dolabra, et aliter esset si esset corpus physicum animatum, assignat rationem huius, dicens, quod hoc ideo est, quia anima non est quod quid est esse et ratio, id est forma huiusmodi corporis, scilicet artificialis sed corporis physici huiuscemodi scilicet habentis vitam. Et ut manifestet quid sit esse physicum corpus, subiungit habentis in seipso principium motus et status. Naturalia enim sunt, quae in seipsis principium motus et status habent. Huiusmodi enim principium, natura dicitur, uti habes in libro physicorum secundo. 238. Then he explains why he has distinguished between the axe as it actually is and as it would be were it a physical (that is, a natural) living body: for the soul is not the essence and idea, i.e. the form, of an artificial body like an axe, but ‘of such a physical body’, i.e. of a body that is alive. To make this clearer he adds ‘as has in itself the principle of movement and rest’—which is characteristic of natural things. For Nature is this sort of principle, as he says in the Physics, Book II.
Deinde cum dicit considerare autem manifestat definitionem animae ex partibus, dicens, quod id quod dictum est de tota anima et de toto corpore vivente, oportet considerare in partibus utriusque; quia, si oculus esset animal, oporteret quod visus esset anima eius, quia visus est substantialis forma oculi, et oculus est materia visus, sicut corpus organicum materia animae. Deficiente autem visu, non remanet oculus nisi aequivoce, sicut oculus lapideus aut depictus aequivoce dicitur oculus. Et hoc ideo est, quia aequivoca sunt, quorum nomen solum commune est et ratio substantiae diversa: et ideo sublata forma a qua est ratio substantiae oculi, non remanet nisi nomen oculi aequivoce dictum. Quod ergo invenitur in parte viventis corporis, oportet accipere in toto vivente corpore, scilicet quod sicut visus est forma substantialis oculi, et eo remoto non remanet oculus nisi aequivoce, ita anima est forma substantialis viventis corporis, et ea remota non remanet corpus vivum nisi aequivoce. Sicut enim se habet una pars animae sensitivae ad unam partem corporis sensitivi, sic se habet totus sensus ad totum corpus sensitivum inquantum huiusmodi. 239. Then at ‘Now what has been said’ he applies what has been concluded about the soul as a whole, and the animate body as a whole, to the parts of each. if, he says, the eye were a whole animal, its soul would be sight; for sight is the essential form of the eye; which in itself is the material condition of sight; in the same way as an organic body is the material condition of a soul. Once sight is lost, the eye, is no longer an eye, except in the sense that a stone or painted eye may be called an eye equivocally (this term is used when the same name is given to essentially different things). Remove, then, what makes an eye really an eye, and there is left only the name. And the same argument applies to the animate body as a whole: what makes it an animate body is its form, the soul. This removed, you have a living body only equivocally. For as one part of the sensitive soul is to one part of the sensitive body, so the faculty of sense as a whole is to the whole sensitive body as such.
Deinde cum dicit est autem exponit praemissam definitionem de anima quantum ad hoc quod dixerat, quod est actus corporis habentis vitam in potentia. Dicitur enim aliquid esse in potentia dupliciter. Uno modo, cum non habet principium operationis. Alio modo cum habet quidem, sed non operatur secundum ipsum. Corpus autem, cuius actus est anima, est habens vitam in potentia, non quidem primo modo, sed secundo. Et hoc est quod dicit corpus potentia ens ut vivat, id est habens vitam in potentia, cuius est actus anima, non sic dicitur esse in potentia ad vitam, quod sit abiiciens animam, id est carens principio vitae, quod est anima, sed quod est habens huiusmodi principium. Sed verum est quod semen et fructus, in quo conservatur semen plantae, est in potentia ad huiusmodi corpus vivum, quod habet animam: nondum enim semen habet animam. Unde sic est in potentia, sicut abiiciens animam. 240. Next, at ‘Not that which has cast off’, he explains what was meant by defining the soul as the ‘act of a potentially animate body’. Now ‘potentially’ may be said about a thing in either of two senses: (a) as lacking the power to act; (b) as possessed of this power but not acting by it. And the body, whose act is the soul, is potentially animate in the second sense only. So, when he calls the body a thing potentially alive he does not mean that it has lost the soul it had and now lacks a life-principle altogether; he is speaking of what still has such a principle. On the other hand, seeds and the fruits that contain them are only potentially living bodies with souls; for a seed as yet lacks a soul. It is ‘potential’ therefore like that which has lost its soul.
Et ut ostendat quomodo est in potentia ad vitam corpus cuius actus est anima, subiungit quod ita vigilantia est actus animae sensitivae, sicut incisio est actus cultelli, et visio est actus oculi. Quodlibet enim istorum est operatio et usus principii habiti. Sed anima est actus primus, sicut visus et quaecumque potentia organi; quodlibet enim horum est principium operationis. Sed corpus quod est perfectum per animam, est potentia habens quidem actum primum, sed aliquando carens actu secundo. Sed sicut oculus est aliquid compositum ex pupilla sicut materia, et visu sicut forma, ita animal est compositum ex anima sicut forma et ex corpore sicut materia. 241. And to show just how the body is potential to the actuality that comes from its soul he adds that being awake is the actuality of the sensitive soul in the same way as cutting is the actuality of a knife and seeing is that of an eye; for each of these acts is the activity and use of a principle already there. But the soul is the first and underlying actuality; like the faculty of sight itself or the capacity of any tool; for each of these is the operative principle itself. So the body, complete with its soul, is potentially animate in the sense that, though it has its first actuality, it may lack the second. And as the eye is a thing composed of a pupil as its matter and the faculty of sight as its form, so an animal is a thing composed of soul as its form and body as its matter.
Deinde cum dicit quod quidem concludit quamdam veritatem ex praemissis: quia enim ostensum est quod anima est actus totius corporis, et partes sunt actus partium, actus autem et forma non separantur ab eo cuius est actus vel forma: manifestum est quod anima non potest separari a corpore, vel ipsa tota, vel aliquae partes eius, si nata est aliquo modo habere partes. Manifestum est enim quod aliquae partes animae sunt actus aliquarum partium corporis, sicut dictum est quod visus est actus oculi. Sed secundum quasdam partes nihil prohibet animam separari, quia quaedam partes animae nullius corporis actus sunt, sicut infra probabitur de his quae sunt circa intellectum. 242. Then, at ‘Therefore it is evident’, he deduces a truth from the foregoing. Having shown that the soul is the whole body’s actuality, its ‘parts’ being the actualities of the body’s parts, and granted that an actuality or form cannot be separated from that which is actual and has form, we can certainly conclude that no soul can be separated from its body,—at least certain parts of the soul ‘cannot be separated, if the soul can be said to have parts. For obviously some ‘parts’ of the soul are nothing but actualities of parts of the body; as we have seen in the case of sight, that it is the eye’s actuality. On the other hand, certain parts of the soul may well be separable from the body, since they are not the actuality of any corporeal part, as will be proved when we come to treat of the intellect.
Et quia Plato ponebat quod anima est actus corporis non sicut forma, sed sicut motor, subiungit quod hoc nondum est manifestum, si anima sic sit actus corporis sicut nauta est actus navis, scilicet ut motor tantum. 243. As to Plato’s opinion that the soul is the act of the body not as its form but as its mover, he adds that it is not yet clear whether the soul is the act of the body as a sailor of a ship, i.e. as its mover only.
Deinde epilogando colligit quae dicta sunt; et dicit quod secundum praedicta determinatum est de anima, et posita est animae descriptio figuraliter quasi extrinsece et superficialiter et incomplete. Complebitur enim determinatio de anima quando pertinget usque ad intima ut determinetur natura uniuscuiusque partis ipsius animae. 244. Finally, recapitulating, he says that the foregoing is an ‘outline’ description of the soul, meaning that it is extrinsic, as it were, and superficial and incomplete. It will be completed when he comes to define the innermost nature of the soul and the nature of each of its parts.


TEXT
413a11–413b13
BOOK II, CHAPTER II
ΚΕΦΑΛΑΙΟΝ Β'

THE DEFINITION JUSTIFIED
MODES OF LIFE

413a11   1. Ἐπεὶ δ' ἐκ τῶν ἀσαφῶν μὲν φανερωτέρων δὲ γίνεται τὸ σαφὲς καὶ κατὰ τὸν λόγον γνωριμώτερον, πειρατέον πάλιν οὕτω γ' ἐπελθεῖν περὶ αὐτῆς· Since it is from the less clear, though more obvious, facts that what is certain and more evident to thought emerges, let us attempt to approach the matter afresh. § 245
οὐ γὰρ μόνον τὸ ὅτι δεῖ τὸν ὁριστικὸν λόγον δηλοῦν, ὥσπερ οἱ πλεῖστοι τῶν ὅρων λέγουσιν, ἀλλὰ καὶ τὴν αἰτίαν ἐνυπάρχειν καὶ ἐμφαίνεσθαι. νῦν δ' ὥσπερ συμπεράσμαθ' οἱ λόγοι τῶν ὅρων εἰσίν· οἷον τί ἐστιν ὁ τετραγωνισμός; τὸ ἴσον ἑτερομήκει ὀρθογώνιον εἶναι ἰσόπλευρον. ὁ δὲ τοιοῦτος ὅρος λόγος τοῦ συμπεράσματος· ὁ δὲ λέγων ὅτι ἐστὶν ὁ τετραγωνισμὸς μέσης εὕρεσις τοῦ πράγματος λέγει τὸ αἴτιον. For it is not enough that a defining principle should merely show a fact, as do most formulae, but also there should be contained and made plain the causes involved. Usually the constituent terms are like conclusions: for instance, what is a square that is equal to an oblong? An equilateral orthogon. Such a term is of the nature of a conclusion. But to say that a square is the discovery of a mean line states the reason why. §§ 246-52
2. λέγομεν οὖν, ἀρχὴν λαβόντες τῆς σκέψεως, διωρίσθαι τὸ ἔμψυχον τοῦ ἀψύχου τῷ ζῆν. Going back, then, to the beginning of our enquiry, let us say that the animate is distinguished from the inanimate by being alive.
πλεοναχῶς δὲ τοῦ ζῆν λεγομένου, κἂν ἕν τι τούτων ἐνυπάρχῃ μόνον, ζῆν αὐτό φαμεν, οἷον νοῦς, αἴσθησις, κίνησις καὶ στάσις ἡ κατὰ τόπον, ἔτι κίνησις ἡ κατὰ τροφὴν καὶ φθίσις τε καὶ αὔξησις. To live, however, is predicated in several ways; and even if one only of these is present, we say there is life; as, for example, intellection, sensation, or movement and rest in place; as well as the movement and rest involved in nourishment, and growth and decay. §§ 253-5
3. διὸ καὶ τὰ φυόμενα πάντα δοκεῖ ζῆν· φαίνεται γὰρ ἐν αὑτοῖς ἔχοντα δύναμιν καὶ ἀρχὴν τοιαύτην, δι' ἧς αὔξησίν τε καὶ φθίσιν λαμβάνουσι κατὰ τοὺς ἐναντίους τόπους· οὐ γὰρ ἄνω μὲν αὔξεται, κάτω δ' οὔ, ἀλλ' ὁμοίως ἐπ' ἄμφω καὶ πάντῃ, ὅσα ἀεὶ τρέφεταί τε καὶ ζῇ διὰ τέλους, ἕως ἂν δύνηται λαμβάνειν τροφήν. Hence all plants seem to live. They appear to have in themselves a power and principle of this kind, by which they increase or decay in various directions—that is to say, they do not grow up but not down, but alike either way; and in all their parts they are continually nourished, and they live so long as they can take nourishment. §§ 256-7
4. χωρίζεσθαι δὲ τοῦτο μὲν τῶν ἄλλων δυνατόν, τὰ δ' ἄλλα τούτου ἀδύνατον ἐν τοῖς θνητοῖς. φανερὸν δ' ἐπὶ τῶν φυομένων· οὐδεμία γὰρ αὐτοῖς ὑπάρχει δύναμις ἄλλη 413b ψυχῆς. τὸ μὲν οὖν ζῆν διὰ τὴν ἀρχὴν ταύτην ὑπάρχει τοῖς ζῶσι, It is possible for this power to exist apart from the others; but for the others to exist apart from it is impossible, at least in mortal beings. This is evident in plants; for there is in them no other soul-power. To live by this principle, then, is common to all living things. § 258
τὸ δὲ ζῷον διὰ τὴν αἴσθησιν πρώτως· καὶ γὰρ τὰ μὴ κινούμενα μηδ' ἀλλάττοντα τόπον, ἔχοντα δ' αἴσθησιν, ζῷα λέγομεν καὶ οὐ ζῆν μόνον. But an animal is such primarily by sensation. For we also call animals things that do not move or change their place, provided they have sensation, and do not merely live. There seem to be many of this sort: by nature they stay in one place, but they have one of the senses. § 259
αἰσθήσεως δὲ πρῶτον ὑπάρχει πᾶσιν ἁφή· ὥσπερ δὲ τὸ θρεπτικὸν δύναται χωρίζεσθαι τῆς ἁφῆς καὶ πάσης αἰσθήσεως, οὕτως ἡ ἁφὴ τῶν ἄλλων αἰσθήσεων (θρεπτικὸν δὲ λέγομεν τὸ τοιοῦτον μόριον τῆς ψυχῆς οὗ καὶ τὰ φυόμενα μετέχει), τὰ δὲ ζῷα πάντα φαίνεται τὴν ἁπτικὴν αἴσθησιν ἔχοντα· Touch is in all, primarily. As the vegetative powers can be separated from touch and all sensation as a whole, so can touch from the other senses. (We give the name ‘vegetative’ to that part of the soul in which plants participate). All animals are seen to possess the sense of touch. § 260
δι' ἣν δ' αἰτίαν ἑκάτερον τούτων συμβέβηκεν, ὕστερον ἐροῦμεν. 5. νῦν δ' ἐπὶ τοσοῦτον εἰρήσθω μόνον, ὅτι ἐστὶν ἡ ψυχὴ τῶν εἰρημένων τούτων ἀρχὴ καὶ τούτοις ὥρισται, θρεπτικῷ, αἰσθητικῷ, διανοητικῷ, κινήσει. For what cause each of these facts is so we shall say later on. At present only this need be said: that soul is the principle of the qualities we have discussed, and is characterised by the vegetative, sensitive, intellective and motive powers. § 261
ST. THOMAS’S COMMENTARY

LECTIO 3
Postquam philosophus posuit definitionem animae, hic intendit demonstrare ipsam. Et primo dicit de quo est intentio. Secundo prosequitur intentum, ibi, dicamus igitur principium et cetera. Circa primum duo facit. Primo determinat modum demonstrationis, quo uti intendit in demonstrando. Secundo manifestat quomodo quaedam definitiones sunt demonstrabiles, ibi, non enim solum quodque et cetera. Circa primum sciendum est, quod cum ex notis oporteat in cognitionem ignotorum devenire: omnis autem demonstratio adducitur causa notificandi aliud, necesse est, quod omnis demonstratio procedat ex notioribus quo ad nos, quibus per demonstrationem fit aliquid notum. In quibusdam autem eadem sunt notiora quo ad nos et secundum naturam, sicut in mathematicis, quae sunt a materia abstracta; et in his demonstratio procedit ex notioribus simpliciter et notioribus secundum naturam, scilicet ex causis in effectus: unde dicitur demonstratio propter quid. In quibusdam vero non sunt eadem magis nota simpliciter et quo ad nos, scilicet in naturalibus, in quibus plerumque effectus sensibiles sunt magis noti suis causis; et ideo in naturalibus, ut in pluribus proceditur ab his quae sunt minus nota secundum naturam et magis nota quo ad nos, ut dicitur in primo physicorum. 245. Having defined the soul the Philosopher now sets out to prove his definition. First he says what he intends to do, and then, at ‘Going back, then,’ proceeds to do it. As to the former point, he first determines the method of demonstration that he intends to use; after which, at ‘For it is not enough’ he explains how certain types of definition can be proved. With regard to the method to be used we should note that, since we can only come to know the unknown if we start from what we know, and since the purpose of demonstration is precisely to cause knowledge, it follows that every demonstration must begin from something more knowable to us than the thing to be made known by it. Now in certain subjects, such as mathematics, which abstract from matter, what is the more knowable is such both in itself and relatively to us; hence in these subjects, demonstration can start from what is absolutely and of its nature more knowable, and therefore can deduce effects from their causes; whence the name given it of a priori demonstration. But in the quite different sphere of the natural sciences, what is more knowable is not the same thing in itself and relatively to us; for sensible effects are generally more evident than their causes. Hence in these sciences we generally have to begin from what is, indeed, absolutely speaking less knowable, but is more evident relatively to us (see the Physics, Book 1).
Et hoc modo demonstrationis intendit hic uti. Et hoc est quod dicit, quod quia illud quod est certum secundum naturam, et quod est secundum rationem notius, fit certius quo ad nos ex his quae sunt incerta secundum naturam, certiora autem quo ad nos, per istum modum tentandum est iterum aggredi de anima, demonstrando definitionem eius supra positam. 246. And this is the kind of demonstration which will be used here. So he says that what is of its nature more certain, and is more evident to thought, becomes certain to us by means of things less certain in nature but more certain to us; and that this shows us the method to use in enquiring once more into the soul and showing the grounds of the definition given above.
Deinde cum dicit non enim assignat rationem praedictae intentionis; ostendendo quod aliquae definitiones sunt demonstrabiles. Et hoc est quod dicit, quod ideo oportet iterum aggredi de anima, quia oportet quod ratio definitiva non solum dicat hoc quod est quia, sicut plures terminorum idest definitionum dicunt; sed oportet etiam quod in definitione tangatur causa, et quod per definitionem dicentem propter quid, demonstretur definitio quae dicit solum quia. Inveniuntur autem multae rationes terminorum, idest definitiones, quae sunt sicut conclusiones. Et ponit exemplum in geometricalibus. 247. Then, at ‘For it is not enough’, he tells us why the question must be taken up again. Certain definitions can, he says, be demonstrated, and in these cases it is not enough for the defining formula to express, as most ‘formulae’, i.e. definitions, do, the mere fact; it should also give the cause of the fact; and this being given, one can then proceed to deduce the definition which states the mere fact. At present many definitions are given in the form of conclusions; and he gives an example from geometry.
Ad cuius intelligentiam sciendum est, quod figurarum quadrilaterarum, quaedam habent omnes angulos rectos, et vocantur orthogonia, idest superficies rectorum angulorum; quaedam autem non habent angulos rectos, et vocantur rhomboydes. Sciendum est autem, quod orthogoniorum quoddam consistit ex omnibus lateribus aequalibus, et vocatur quadratum sive tetragonismus; quoddam autem non habet omnia latera aequalia, in quo tamen quaelibet duo latera sibi opposita sunt aequalia: et vocatur huiusmodi orthogonium altera parte longius, sicut patet in sequentibus figuris. (Figura). 248. To understand which we must note that there are two kinds of four-sided figure: those whose angles are all right angles, and these are called rectangles; and the kind with no right angles, and these are called rhomboids. Of the rectangles, again, there is one with four equal sides—the square or tetragon; and another which, without having all four sides equal, has two pairs of equal and opposite sides—the oblong. Thus:

deanima1.jpg square


oblong


rhomboid
Item sciendum est, quod in qualibet superficie rectorum angulorum duae rectae lineae, quae angulum rectum concludunt, dicuntur totam superficiem continere, quia cum alia duo latera sint aequalia eis, unumquodque suo opposito, necesse est, quod una praedictarum linearum rectum angulum concludentium mensuret longitudinem superficiei rectangulae; et alia latitudinem; unde tota superficies rectangula consurgit ex ductu unius in aliam. Unde si imaginaremur, quod una earum moveretur per aliam, consurgeret talis superficies. 249. Note further, that in any rectangular surface the two straight lines enclosing the right angle are said to contain the whole figure; because, the other two sides being equal to these two, each equal to its opposite, it follows that one of the enclosing lines measures the length of the whole figure, and the other its breadth: so that the whole figure is given in the contact of the two lines. If we imagine one of these lines moving along the other we see the whole figure form itself
Item sciendum est, quod cum in orthogonio quod est altera parte longius, duae lineae continentes ipsum, sint inaequales, si accipiatur inter eas linea media in proportione, et ducatur in seipsam, fiet quadratum aequale altera parte longiori. Et quia haec demonstrationibus geometricis diffusum esset ostendere, sufficiat hoc ad praesens manifestare in numeris. Sit igitur orthogonium altera parte longius, cuius maius latus sit novem palmorum, minus vero quatuor. Accipiatur autem linea media in proportione inter ea, quae scilicet sunt sex palmorum. Quia sicut se habent sex ad novem, ita quatuor ad sex. Quadratum autem huius lineae erit aequale praedicto orthogonio altera parte longiori. Quod etiam in numeris patet. Nam quater novem sunt triginta sex. Similiter etiam sexies sex sunt triginta sex. 250. Note also that if, between the two unequal sides that contain the oblong, one takes the proportional mean and squares it, one gets a quadrilateral equal to the oblong. This would take too long to prove geometrically, so let a numerical argument do for the present. Let our oblong then have its longer side 9 feet and its shorter side 4 feet. Then the proportional mean line will be 6 feet; for as 6 is to 9, so 4 is to 6. Now the square of this line must equal the oblong; which is obvious numerically: 4 x 9 = 36, 6 x 6 = 36.
Hoc est ergo quod dicit, quod si quaeratur quid est tetragonismus, idest quadratum, quod est aequale altera parte longiori, assignabitur talis definitio, ut dicatur esse orthogonium, idest superficies rectorum angulorum aequilaterale, idest habens omnia latera aequalia, et cetera. Talis autem terminus, idest talis definitio est ratio conclusionis, idest per demonstrationem conclusa. Si autem aliquis sic definiat, dicens quod quadratum est inventio mediae, scilicet lineae mediae in proportione inter duo latera inaequalia orthogonii altera parte longioris, idest orthogonium constitutum ex tali linea inventa, qui inquam sic definit dicit causam rei. 2,51. Now it is thus, he says,’ that the question, What is a square (i.e. the quadrilateral equal to an oblong)? is answered; it is said ‘to be an orthogon’, i.e. a right-angled plane figure, which is ‘equilateral’, i.e. having all its sides equal, and so on. ‘Such a term’, i.e. a definition of this sort, is really ‘of the nature of a conclusion’, namely of a presupposed demonstration; whereas if one were to say that a square is ‘the discovery of a mean line’, i.e. of the proportional mean between the two unequal sides of the oblong, meaning that a square is what is constructed from this line, then at last the definition would disclose the ‘reason why’ of the thing defined.
Attendendum est autem, quod hoc exemplum quod hic inducitur, est simile ei quod intendit circa animam, quantum ad aliquid, scilicet quantum ad hoc quod demonstretur definitio animae, non autem quantum ad hoc quod demonstretur demonstratione dicente propter quid. 252. Note, however, that this example is only relevant to the definition of the soul in so far as this definition is simply to be demonstrated; it must not be taken to imply that our demonstration can proceed a priori from causes to effects.
Deinde cum dicit dicamus igitur incipit demonstrare definitionem animae superius positam, modo praedicto, scilicet per effectum. Et utitur tali demonstratione. Illud quod est primum principium vivendi est viventium corporum actus et forma: sed anima est primum principium vivendi his quae vivunt: ergo est corporis viventis actus et forma. Manifestum est autem, quod haec demonstratio est ex posteriori. Ex eo enim quod anima est forma corporis viventis, est principium operum vitae, et non e converso. Circa hoc ergo duo facit. Primo ostendit, quod anima est principium vivendi. Secundo, quod primum principium vivendi est forma corporis viventis, ibi, quoniam autem quo vivimus et sentimus. Circa primum tria facit. Primo distinguit modos viventium. Secundo ostendit, quod anima est vivendi principium, ibi, unde et vegetabilia omnia, et cetera. Tertio manifestat quomodo se habeant partes animae, abinvicem, secundum quas est principium operum vitae, ibi, utrum autem unumquodque horum. 253. Next, at ‘Going back then’, he begins to prove the definition of the soul given above; and this in the way indicated, i.e. from effects to causes. This is how he sets about it: the first principle of fife in things is the actuality and form of living bodies; but soul is the first principle of life in living things; therefore it is actuality and form of living bodies. Now this argument is clearly a posteriori; for in reality the soul is the source of vital activities because it is the form of a living body, not e converso. So he has to do two things here; first, to show that soul is the source or principle of vitality, and secondly, to show that the first principle of vitality is the form of living bodies (this comes at ‘Since that whereby etc.’). With regard to the first point he does three things: (a) he distinguishes modes of life, (b) he shows that the soul is the principle of living activities—at ‘Hence all plants’; and (c) he explains how these parts of the soul are interrelated, by means of which it originates vital activities. This is at ‘We now ask whether each of these’.
Dicit ergo primo, quod ad prosequendum nostram intentionem, qua intendimus demonstrare definitionem animae, oportet hoc quasi principium accipere, quod animatum distinguitur ab inanimato in vivendo. Animata enim vivunt, sed inanimata non vivunt. Sed cum multiplex sit modus vivendi, si unus tantum eorum insit alicui, dicitur illud vivens et animatum. 254. He starts then by saying that to carry put our intention of proving the definition of the soul, we must assume as a kind of principle that things with souls differ from those without souls in being alive. Life is the test; and as life shows itself in several ways, if a thing has life in only one of these ways it is still said to be alive and to possess a soul.
Ponit autem quatuor modos vivendi: quorum unus est per intellectum, secundus per sensum, tertius per motum et statum localem, quartus per motum alimenti, et decrementi et augmenti. Ideo autem quatuor tantum modos ponit vivendi, cum supra quinque genera operationum animae posuerit, quia hic intendit distinguere modos vivendi, secundum gradus viventium; qui distinguuntur secundum haec quatuor. In quibusdam enim viventium inveniuntur tantum alimentum, augmentum et decrementum, scilicet in plantis. In quibusdam autem, cum his invenitur sensus sine motu locali, sicut in animalibus imperfectis, sicut sunt ostreae. In quibusdam autem, ulterius invenitur motus secundum locum, sicut in animalibus perfectis, quae moventur motu progressivo, ut bos et equus. In quibusdam autem, cum his ulterius invenitur intellectus, scilicet in hominibus. Appetitivum autem, quod est quintum praeter haec quatuor, non facit aliquam diversitatem in gradibus viventium. Nam ubicumque est sensus, ibi est et appetitus. 255. Life, he says, shows itself in four modes: (1) as intellectual; (2) as sensitive; (3) as the cause of motion or rest in space; (4) as cause of the motions of taking nourishment, decay and growth. He distinguishes only these four modes, although he has already distinguished five main types of vital activity, and this because he is thinking here and now of the degrees of animate being. There are four such degrees, distinguished in the same way as the four modes in which life is manifested: for some living things, i.e. plants, only take nourishment and grow and decay; some have also sensation, but are always fixed to one place—such are the inferior animals like shell-fish; some again, i.e. the complete animals like oxen and horses, have, along with sensation, the power to move from place to place; and finally some, i.e. men, have, in addition, mind. The appetitive power, which makes a fifth type of vitality, does not, however, imply a distinct degree of living being; for it always accompanies sensation.
Deinde cum dicit unde et vegetabilia manifestat, quod anima est principium vivendi secundum omnes modos praedictos. Et circa hoc tria facit. Primo ostendit, quomodo anima est principium vivendi in plantis. Secundo in animalibus, ibi, animal autem propter sensum, et cetera. Tertio ostendit quid dictum sit, et quid restat dicendum, ibi, propter unam autem causam, et cetera. Circa primum duo facit. Primo ostendit, quod anima est principium vivendi in plantis; et dicit, quod cum dictum sit, quod quibuscumque inest unum quatuor praedictorum modorum viventium, dicuntur vivere, sequitur quod omnia vegetabilia vivant. Omnia enim in seipsis habent potentiam quamdam, et principium, quo suscipiunt motum augmenti et decrementi. 256. Next, at ‘Hence all plants’, he shows that a soul is involved in all these modes of life. He does this with regard (1) to plants, and (2) to animals, at ‘But an animal is such, primarily’. Then (3), he summarises, at ‘For what cause”, what has been said and remains to be said. As to (1) he does two things. First he shows that the life-principle in plants is a soul. We have remarked, he says, that whatever evinces one of the four modes of life mentioned above can be said to live. Therefore plants are alive; for they all possess some intrinsic power or principle of growth and decay.
Et quod hoc principium non sit natura sed anima, manifestum est. Nam natura non movet ad contraria loca: motus autem augmenti et decrementi est secundum contraria loca. Augentur enim vegetabilia omnia, non solum sursum et deorsum, sed utroque modo. Manifestum est ergo, quod principium horum motuum non est natura sed anima. Nec solum vegetabilia vivunt, dum augentur et decrescunt, sed quaecumque nutriuntur tamdiu vivunt, quamdiu possunt accipere nutrimentum per quod fit augmentum. 257. Now this principle is not mere nature. Nature does not move in opposite directions, but growth and decay are in opposite directions; for all plants grow not only upwards or downwards, but in both directions. Hence a soul, not nature, is clearly at work in them. Nor do plants live only when actually growing or decaying, but, as things that take nourishment, they live so long as they can assimilate the food that induces growth.
Secundo ibi separari autem ostendit quod praedictum vivendi principium, est primum et separabile ab aliis. Et dicit quod hoc, scilicet principium augmenti et alimenti, potest separari ab aliis principiis vivendi, sed alia non possunt separari ab eo in rebus mortalibus. Quod ideo dicit, quia in rebus immortalibus, sicut sunt substantiae separatae, et corpora caelestia, si tamen sunt animata, invenitur intellectivum sine nutritivo. Quod autem hoc principium sit separabile ab aliis, manifestum est in his quae vegetantur, idest, in plantis, in quibus nulla alia potentia animae inest, nisi huiusmodi. Ex quo manifestum est, quod illud propter quod primum invenitur vita in rebus mortalibus, est principium augmenti et alimenti, quod vocatur anima vegetabilis. 258. Next, at ‘It is possible’, he shows that this principle of feeding and growing can exist apart from other life-principles, but these cannot exist apart from it, at least in things subject to death. He adds this last clause because of immortal beings like immaterial substances or heavenly bodies; because, if these have a soul, it is intellectual; it is not a capacity to take nourishment. And the separability of this life principle from others is clearly evident in plants which have, in fact, no other one but this. it follows that what first of all causes life in mortal things is this principle of growth and nourishment, the so-called vegetative soul.
Deinde cum dicit animal autem manifestat quomodo anima est principium vivendi in animalibus. Et circa hoc duo facit. Primo dicit, quod primum dicitur aliquid esse animal propter sensum, licet animalia quaedam et sentiant et moveantur. Ea enim dicimus esse animalia, et non solum vivere, quae licet non mutent locum, tamen habent sensum. Sunt enim multa animalium talia, quae naturaliter manent in eodem loco, et tamen habent sensum, sicut ostreae, quae non moventur motu progressivo. 259. Then, at ‘But an animal is such primarily’ he shows that a soul is the source of living in animals. And here he does two things. First he observes that what primarily distinguishes animals is sensation, though there are animals which have local movement as well; for we call those things animals (not just living beings) which have sensation, even if they are fixed to one place. For there are many such animals whose nature restricts them to one place, but which have the power of sense, e.g. shell-fish, which cannot move from place to place.
Secundo ibi sensuum autem ostendit quod inter alios sensus primo inest tactus animalibus. Quod probat ex hoc, quod sicut vegetativum potest separari a tactu et ab omni sensu, sic tactus potest separari ab aliis sensibus. Multa enim sunt animalia, quae solum sensum tactus habent, sicut animalia imperfecta. Omnia autem animalia habent sensum tactus. Vegetativum autem principium dicimus illam partem animae, qua etiam vegetabilia, idest plantae, participant. Sic igitur ex praedictis patent tres gradus viventium. Primus est plantarum. Secundus animalium imperfectorum immobilium, quae habent solum sensum tactus. Tertius est animalium perfectorum, quae moventur motu progressivo, quae etiam habent alios sensus. Manifestum est autem, quod quartus gradus est eorum, quae habent cum his etiam intellectum. 260. Then at ‘Touch is’ he shows that touch is the primary sense in animals. For just as the vegetative soul, he says, is separable from all the senses including touch, so touch is separable from all the other senses. For many inferior animals have only the sense of touch; but there are no animals without this sense. Now that degree of soul in which even plants participate we call the vegetative. Hence we can distinguish three degrees of living beings: first, plants; secondly, the inferior animals fixed to one place and with no sense but touch; and, thirdly, the higher, complete animals which have the other senses and also the power to move from place to place. And a fourth degree consists, evidently, of beings which have all this and mind as well.
Deinde cum dicit propter quam ostendit quid dictum sit, et quid restat dicendum. Et dicit, quod posterius dicendum est, propter quam causam utrumque horum accidat, scilicet quod vegetativum potest esse sine sensu, et quod tactus sine aliis sensibus. Hoc enim dicet in fine libri. Nunc autem sufficiet intantum dictum esse, quod anima est principium vivendi secundum praedictos modos, et quod distincta est istis quatuor, scilicet vegetativo, quod est in plantis et in omnibus viventibus, et sensitivo, quod est in omnibus animalibus, et intellectivo, quod est in omnibus hominibus, et motu progressivo, qui est in omnibus animalibus perfectis sensu vel intellectu. 261. Finally, at ‘For what cause’ summarising what has been said and remains to be said, he remarks that the cause of both these phenomena, namely the separability of the vegetative principle from sensation and of touch from the other senses, will be -given later on. He does this at the end of the whole Treatise. For the present it suffices to say that ‘soul’ is the one principle underlying the four distinct modes in which life is manifested, namely the vegetative mode which belongs to plants and to all living things; the sensitive mode in all animals; the intellectual mode in all men; and fourthly, the mode that is a power to move from place to place, which exists in all the higher animals, both those with senses only and those with intellect as well.

TEXT
413b13–44a28
BOOK II, CHAPTER II, CONTINUED

DIFFERENT KINDS OF SOUL

πότερον δὲ τούτων ἕκαστόν ἐστι ψυχὴ ἢ μόριον ψυχῆς, καὶ εἰ μόριον, πότερον οὕτως ὥστ' εἶναι χωριστὸν λόγῳ μόνον ἢ καὶ τόπῳ, We now ask whether each of these [powers] is a soul, or a part of a soul: and if a part, whether it is separable only in thought or has also a distinct place. § 262
περὶ μὲν τινῶν τούτων οὐ χαλεπὸν ἰδεῖν, ἔνια δὲ ἀπορίαν ἔχει. 6. ὥσπερ γὰρ ἐπὶ τῶν φυτῶν ἔνια διαιρούμενα φαίνεται ζῶντα καὶ χωριζόμενα ἀπ' ἀλλήλων, ὡς οὔσης τῆς ἐν αὐτοῖς ψυχῆς ἐντελεχείᾳ μὲν μιᾶς ἐν ἑκάστῳ φυτῷ, δυνάμει δὲ πλειόνων, οὕτως ὁρῶμεν καὶ περὶ ἑτέρας διαφορὰς τῆς ψυχῆς συμβαῖνον ἐπὶ τῶν ἐντόμων ἐν τοῖς διατεμνομένοις· καὶ γὰρ αἴσθησιν ἑκάτερον τῶν μερῶν ἔχει καὶ κίνησιν τὴν κατὰ τόπον, εἰ δ' αἴσθησιν, καὶ φαντασίαν καὶ ὄρεξιν· ὅπου μὲν γὰρ αἴσθησις, καὶ λύπη τε καὶ ἡδονή, ὅπου δὲ ταῦτα, ἐξ ἀνάγκης καὶ ἐπιθυμία. Concerning some of these powers it is not difficult to see [the answers to our questions]; others, however, give rise to doubts. For, as in the case of plants some, on being divided, seem to go on living in separation from one another, as if there were in each plant one soul in act, but several in potency; so we find it happens in the case of other differentiations of soul, for instance in divided animals each division has sensation and local motion; and if sensation, phantasm and appetition; for where there is sensation there is pleasure, and pain, and where these are there must necessarily be appetition. §§ 263-7
7. περὶ δὲ τοῦ νοῦ καὶ τῆς θεωρητικῆς δυνάμεως οὐδέν πω φανερόν, ἀλλ' ἔοικε ψυχῆς γένος ἕτερον εἶναι, καὶ τοῦτο μόνον ἐνδέχεσθαι χωρίζεσθαι, καθάπερ τὸ ἀΐδιον τοῦ φθαρτοῦ. 8. τὰ δὲ λοιπὰ μόρια τῆς ψυχῆς φανερὸν ἐκ τούτων ὅτι οὐκ ἔστι χωριστά, καθάπερ τινές φασιν· But as regards intellect and the speculative faculty, nothing has so far been demonstrated; but it would seem to be another kind of soul, and alone capable of being separated, as the eternal from the perishable. It is evident, however, from the foregoing, that the other parts of the soul are not separable, as some have said. § 268
τῷ δὲ λόγῳ ὅτι ἕτερα, φανερόν· αἰσθητικῷ γὰρ εἶναι καὶ δοξαστικῷ ἕτερον, εἴπερ καὶ τὸ αἰσθάνεσθαι τοῦ δοξάζειν, ὁμοίως δὲ καὶ τῶν ἄλλων ἕκαστον τῶν εἰρημένων. By definition, however, they are obviously distinct. For if feeling is other than opining, the sense-faculty will differ from the capacity to form opinions. Likewise with each of the other powers mentioned. § 269
9. ἔτι δ' ἐνίοις μὲν τῶν ζῴων ἅπανθ' ὑπάρχει ταῦτα, τισὶ δὲ τινὰ τούτων, ἑτέροις δὲ ἓν μόνον (τοῦτο δὲ ποιεῖ δια- 414a φορὰν τῶν ζῴων)· διὰ τίνα δ' αἰτίαν, ὕστερον ἐπισκεπτέον. παραπλήσιον δὲ καὶ περὶ τὰς αἰσθήσεις συμβέβηκεν· τὰ μὲν γὰρ ἔχει πάσας, τὰ δὲ τινάς, τὰ δὲ μίαν τὴν ἀναγκαιοτάτην, ἁφήν. Further, all these powers are in some animals; in others, some only; in yet others, only one. This makes the varieties of animal. Why this should be so will be considered later. The same obtains with regard to the senses: certain species of animal have all; certain others, some; yet others have only the one most necessary, touch. § 270
10. ἐπεὶ δὲ ᾧ ζῶμεν καὶ αἰσθανόμεθα διχῶς λέγεται, καθάπερ ᾧ ἐπιστάμεθα (λέγομεν δὲ τὸ μὲν ἐπιστήμην τὸ δὲ ψυχήν, ἑκατέρῳ γὰρ τούτων φαμὲν ἐπίστασθαι), ὁμοίως δὲ καὶ [ᾧ] ὑγιαίνομεν τὸ μὲν ὑγιείᾳ τὸ δὲ μορίῳ τινὶ τοῦ σώματος ἢ καὶ ὅλῳ, τούτων δ' ἡ μὲν ἐπιστήμη τε καὶ ὑγίεια μορφὴ καὶ εἶδός τι καὶ λόγος καὶ οἷον ἐνέργεια τοῦ δεκτικοῦ, ἡ μὲν τοῦ ἐπιστημονικοῦ, ἡ δὲ τοῦ ὑγιαστοῦ (δοκεῖ γὰρ ἐν τῷ πάσχοντι καὶ διατιθεμένῳ ἡ τῶν ποιητικῶν ὑπάρχειν ἐνέργεια), ἡ ψυχὴ δὲ τοῦτο ᾧ ζῶμεν καὶ αἰσθανόμεθα καὶ διανοούμεθα πρώτως-ὥστε λόγος τις ἂν εἴη καὶ εἶδος, ἀλλ' οὐχ ὕλη καὶ τὸ ὑποκείμενον. 11. τριχῶς γὰρ λεγομένης τῆς οὐσίας, καθάπερ εἴπομεν, ὧν τὸ μὲν εἶδος, τὸ δὲ ὕλη, τὸ δὲ ἐξ ἀμφοῖν, τούτων δ' ἡ μὲν ὕλη δύναμις, τὸ δὲ εἶδος ἐντελέχεια, ἐπεὶ τὸ ἐξ ἀμφοῖν ἔμψυχον, οὐ τὸ σῶμά ἐστιν ἐντελέχεια ψυχῆς, ἀλλ' αὕτη σώματός τινος. Since ‘that whereby we live and perceive’ can mean two things,—like ‘that by which we know’. for we name one thing knowledge, and another, the soul, though we are said to know by both of these; and likewise as ‘that by which we are healthy’; for health is one thing, while a part of the body (or the whole of it) is another; and in these cases knowledge, or health, is the form and specific essence or ratio, and, as it were, the act of such as can receive knowledge in the one case and health in the other (for the action of an agent seems to exist in the recipient or disposed material)—and soul being that by which we primarily live and perceive and move and understand it follows that the soul will be a sort of species or ratio; not, as it were, a matter or substratum. Substance is predicated in three ways, as we have said: in one way as the form; in another as the matter; and in another as what is from both. Of these, matter is the potency, form the act; hence if what is from both is the animate being, the body is not the act of the soul, but the soul of the body. §§ 271-5.
καὶ διὰ τοῦτο καλῶς ὑπολαμβάνουσιν οἷς δοκεῖ μήτ' ἄνευ σώματος εἶναι μήτε σῶμά τι ἡ ψυχή· σῶμα μὲν γὰρ οὐκ ἔστι, σώματος δέ τι, 12. καὶ διὰ τοῦτο ἐν σώματι ὑπάρχει, καὶ ἐν σώματι τοιούτῳ, καὶ οὐχ ὥσπερ οἱ πρότερον εἰς σῶμα ἐνήρμοζον αὐτήν, οὐθὲν προσδιορίζοντες ἐν τίνι καὶ ποίῳ, καίπερ οὐδὲ φαινομένου τοῦ τυχόντος δέχεσθαι τὸ τυχόν. 13. οὕτω δὲ γίνεται καὶ κατὰ λόγον· ἑκάστου γὰρ ἡ ἐντελέχεια ἐν τῷ δυνάμει ὑπάρχοντι καὶ τῇ οἰκείᾳ ὕλῃ πέφυκεν ἐγγίνεσθαι. ὅτι μὲν οὖν ἐντελέχειά τίς ἐστι καὶ λόγος τοῦ δύναμιν ἔχοντος εἶναι τοιούτου, φανερὸν ἐκ τούτων. And on this account they were right who thought that the soul is neither apart from the body nor the same as the body; for it is not, indeed, the body; yet is something of the body. And therefore it is in a body, and a body of a definite kind; and not as some earlier thinkers made out, who related it to a body without defining at all the nature and quality of that body; despite the fact that it is apparent that not any subject whatever can receive any form at random. And that such is the case is confirmed by reason: the act of any one thing is of that which is in potency to it, and it occurs naturally and fittingly in matter appropriate to it. That the soul, then, is an actuality and formal principle of a thing in potency to exist accordingly, is evident from these considerations. §§ 276-8
ST. THOMAS’S COMMENTARY

LECTIO 4
Ostendit superius philosophus, quod anima est principium vivendi, secundum diversa genera vitae. Et ideo nunc inquirit, qualiter principia vivendi secundum diversa genera vitae se habent ad animam et adinvicem. Et circa hoc duo facit. Primo movet quaestiones duas. Quarum prima est. Cum anima, quae est principium vivendi, sit determinata vegetativo, sensitivo, motivo secundum locum, et intellectivo, utrum quodlibet eorum sit anima per se, aut sit pars animae. Et manifestum est, quod in his quae tantum augentur et nutriuntur, sicut in plantis, vegetativum est anima. In his autem quae vegetantur et sentiunt, est pars animae, et similiter est de aliis. Secunda quaestio est. Si unumquodque praedictorum est pars animae, puta cum omnia inveniantur in una anima sicut in humana, utrum hoc modo sint partes, quod separentur adinvicem solum secundum rationem, ut scilicet sint diversae potentiae, aut etiam separentur loco et subiecto, utpote quod in una parte corporis sit sensitivum, in alia appetitivum, in alia motivum, et sic de aliis, sicut quibusdam visum fuit. 262. After showing that ‘soul’ is the one principle common to the several types of vitality, the Philosopher now enquires into the various principles of the latter, asking how they are related both to the soul and to each other. And he does two things here. First, he put two questions (a) If the soul, the life-principle, is realised actually as a vegetative, sensitive, locomotive or intellectual principle, is each of these principles to be identified with the soul proper, or is each no more than apart of the soul? Now obviously, where the thing’s vitality consists entirely in growing and taking nourishment (as in plants) the vegetative principle is simply the soul or life-principle itself. But where the thing also has sensation, this vegetative principle is only a part of the soul. And the same reasoning applies to other cases. (b) If each of these principles is a part of the life-principle, as in the human soul which contains all of them, are they parts in the sense that they are merely diverse powers of the one soul, existing in one thing though they can be thought of apart from one another, or are they distinct beings having each its distinct locality, so that the sense-power is in one part of the body, appetition. in another, locomotion in another, and so on; as some indeed have thought.
Secundo cum dicit de quibusdam solvit propositas quaestiones. Et primo secundam. Secundo primam, ibi, ad haec quibusdam animalium. Circa primum duo facit. Primo solvit secundam quaestionem quantum ad secundam partem, ostendens, utrum partes animae sint separabiles loco. Secundo, quantum ad primam, utrum scilicet sint separabiles ratione, ibi, ratione autem, quod alterae et cetera. Dicit ergo primo, quod de quibusdam partibus animae, non est difficile videre utrum sint separabiles loco, idest subiecto; sed de quibusdam dubium est. 263. Secondly, when he says ‘Concerning some of these’, he answers the above questions: first the second one; then, at ‘Further, all these powers’, the first. The second question is answered in two parts: (a) with respect to the local separability of the parts of the soul, and (b) at ‘By definition’ concerning their separability in the mind. As to (a) he says that some parts of the soul raise no difficulties, but that others do.
Et ad ostendendum quod in quibusdam hoc facile est videre, praemittit similitudinem de plantis, ibi, sicut enim in plantis: dicens quod quaedam partes divisae ab eis, et separatae ab aliis partibus, videntur vivere. Et hoc manifestatur per hoc, quod ramusculi abscissi inseruntur vel plantantur, et coalescunt; quod non esset nisi remaneret in eis vita, et per consequens anima, quae est principium vivendi: quod contingit tamquam in unaquaque planta, anima sit una in actu, et multiplex in potentia. Sicut enim accidere videtur in formis corporum naturalium inanimatorum, ita in eis quae propter sui imperfectionem non requirunt diversitatem in partibus, quod in aliquo uno toto anima est in actu una et plures in potentia, sicut et ipsum corpus est unum in actu, et plura in potentia. Potest enim dividi unumquodque eorum in diversas partes similes specie, sicut patet in aere, aqua et in corporibus mineralibus. Unde oportet, quod si partes sunt similes specie adinvicem et toti, quod forma specifica post divisionem sit in utraque partium. Et eadem ratione, quia anima plantae imperfecta est in ordine animarum, non requirit magnam diversitatem in partibus, unde anima totius potius potest salvari in aliqua partium. 264. And he illustrates this by a comparison with plant-life. Certain parts, he says, of plants can be cut off and yet seem to go on living; for the cuttings, grafted or replanted, unite with a new stem or with the soil. In these cases the life-principle appears to be actually single but potentially many. The same sort of thing is observable in the forms of inanimate physical bodies; as each such body is actually one and potentially many, so in the lower animate bodies whose parts are still undifferentiated, the soul exists as one whole actually, but as many potentially. For inanimate bodies can be divided into parts which each retain the same specific nature (e.g. air, water, minerals) and this nature was also the nature of the whole body; and it is somewhat the same with plants, the lowest order of animate beings; they require very little differentiation in their parts, and the life-principle of the whole survives, as such, in some of the separated parts.
Et sic etiam videmus in aliis differentiis animae, sicut in entomis decisis, idest in animalibus quae decisa vivunt, quia utraque partium habet sensum. Quod patet ex hoc, quod retrahit se, si pungitur. Et etiam habet motum secundum locum, ut ad sensum apparet. Sic ergo in una et eadem parte apparet et sensitivum et motivum principium. Et si est ibi sensus, necesse est, quod sit ibi phantasia. Phantasia autem nihil aliud est, quam motus factus a sensu secundum actum, ut infra dicetur. Et similiter si habeat sensum pars decisa, necesse est, quod habeat appetitum; ad sensum enim de necessitate sequitur laetitia et tristitia, sive delectatio et dolor. Necesse est enim, si sensibile perceptum est conveniens, quod sit delectabile: si autem est nocivum, quod sit dolorosum. Ubi autem est dolor et delectatio, oportet quod sit desiderium et appetitus; unde necesse est, quod si pars decisa sentit, quod etiam habeat appetitum. 265. So also with those animals which remain alive after being cut up. Each division still has a sensitive soul: it will shrink back if you prick it. And obviously it can move about. So the same part retains, evidently, the principle of sensation and local movement. And if sensation, then it must also have imagination which is simply a certain motion derived from actual sensation, as we shall see later. Again, it must also have appetition, since sensation necessarily involves satisfaction or dissatisfaction, i.e. pleasure or pain, because it involves a contact with the congenial or the uncongenial. And pleasure and pain involve desire and appetition. So the divided parts of such animals are able to desire.
Sic ergo manifestum est, quod vegetativum, sensitivum, appetitivum et motivum inveniuntur in una parte decisa: ex quo patet, quod non distinguuntur loco in corpore animalis. Sed de quibusdam potentiis particularibus, manifestum est quod distinguuntur loco. Visus enim manifeste non est nisi in oculo, auditus in aure, olfactus in naribus, gustus in lingua et palato. Sed primus sensus qui est tactus, et necessarius animali, est in toto. 266. Now if each such divided part contains the vegetative, sensitive, appetitive and locomotive principles all together, it is clear that these principles are not to be located in any special parts of the animal’s body. Yet certain powers are obviously so located: seeing is only in the eye, hearing in the ear, smelling in the nostrils, taste on the tongue and palate. But the fundamental and most necessary sense of touch is found over the whole body.
Sed quod dicit quod phantasia est in parte decisa, videtur esse dubium. Nam a quibusdam phantasiae attribuitur determinatum organum in corpore. Sed sciendum est, quod phantasia invenitur indeterminata in animalibus imperfectis, in animalibus vero perfectis determinata, sicut infra in tertio dicetur. Organum ergo aliquod determinatum phantasiae attribuitur, ad maiorem perfectionem et determinationem sui actus, sine quo phantasiae actus nullo modo esse posset, sicut actus visus nullo modo potest esse sine oculo. Sic igitur manifestavit quod in quibusdam potentiis animae, non est difficile videre utrum sunt separabiles loco. 267. A doubt may occur about imagination; for some assign to it a special organ of the body. But note that imagination (as will be shown later) in the lower animals is indefinite; it is definite only in the higher animals. Hence if we assign a special organ to imagination, this is because the special completeness and definiteness of its activities call for a special organ of the body, just as seeing requires an eye. But as to some powers of the soul it is not difficult to decide whether they are located in distinct parts of the body.
Deinde cum dicit de intellectu ostendit in qua parte animae circa hoc possit esse dubium. Et dicit, quod de intellectu, quocumque nomine vocetur perspectiva potentia, idest speculativa, nihil est adhuc manifestum. Nondum enim per ea quae dicta sunt, apparet utrum habeat aliquod organum in corpore distinctum loco ab aliis organis, vel non distinctum. Sed tamen quantum in superficie apparet, videtur quod sit alterum genus animae ab aliis partibus animae, idest alterius naturae, et alio modo se habens; et quod hoc solum genus animae possit separari ab aliis partibus animae, vel etiam quod sit separatum ab organo corporeo, sicut perpetuum a corruptibili. Sed quod reliquae partes animae non sint separabiles loco adinvicem, manifestum est ex praedictis. 268. Then, at ‘But as regards intellect’, he points to one part of the soul over which doubts may arise. About the intellect, or whatever we call the percipient or speculative faculty, we are still, he says, uncertain. No proof has yet been given of its location in any special or particular organ of the body. Yet even at first sight it would seem to be of a different nature from the other parts of the soul, and to exist ‘in a different way; and that it alone is separarable from the rest of the soul (and may even exist apart from any organ of the body) as what is immortal from what is mortal. That the other parts of the soul are not locally separated is now clear.
Deinde cum dicit ratione autem ostendit quod sint separabiles ratione. Cuiuslibet enim potentiae ratio est secundum ordinem ad actum: unde necesse est, si actus sint diversi secundum speciem, quod potentiae habeant diversam rationem speciei. Et hoc est quod dicit, quod alterum est esse sensitivo et opinativo, id est intellectivo: idest altera est ratio utriusque potentiae, si sentire est alterum ab opinari: et similiter est de praedictis aliis potentiis. 269. Then at ‘By definition” he shows that they are mentally separable from one another. For we distinguish potencies by their relation to acts; if the acts are specifically distinct, then so are the potencies. Hence he says here that the sensitive and opining, i.e. intellectual, principles are diverse; meaning that,, as sensing is other than forming opinions, the faculties implied have distinct definitions. And the same is true of the other principles already mentioned.
Deinde cum dicit ad haec quibusdam solvit primam quaestionem: et dicit, quod hic facit differentiam in animalibus, quod quibusdam animalium insunt omnia praedicta, quibusdam vero quaedam horum, aliis vero unum solum. Quibuscumque autem inest unum solum praedictorum, oportet quod illud sit anima. In quibus vero insunt plura, quodlibet est pars animae; sed illa anima denominatur a principaliori, vel sensitiva, vel intellectiva. Quare autem hoc sit, quod quaedam habent unum, quaedam plura, quaedam omnia, posterius dicetur. Et sicut accidit circa potentias animae, ita accidit circa sensus. Quaedam enim habent omnes sensus, sicut animalia perfecta: quaedam vero habent quosdam sensus, sed non omnes, ut talpa: quaedam vero habent unum maxime necessarium, scilicet tactum, ut animalia imperfecta. 270. Then, at ‘Further, all these powers’, he answers the first of the two questions proposed above, observing that animals differ in this, that in some are found all the four vital principles mentioned above, in others only some of them, and in some only one. And where one only of these principles is found it is the soul itself; but where several are found together each is a part of the soul and the soul itself is named after the principal part, whether sensitive or intellectual as the case may be (the reason why animals differ in this way will be shown later). And as with the powers of the soul, so with the particular senses; for some animals, (the higher) have all the senses; some (e.g. moles) have some, but not all; while some (die lowest animals) have only the most necessary one, touch.
Potest autem et haec particula ad alium sensum referri, ut dicatur quod quia superius ostenderat philosophus, quod partes animae non sunt separabiles abinvicem loco, vel subiecto, in animali in quo sunt, quod propter hoc etiam non separentur in diversis animalibus, sed cuicumque inest unum, inessent omnia. Et ideo removet hoc in hac particula. This passage might also be understood as referring to the statement, made a few lines earlier, that the parts of the soul which coexist ‘in any one animal are not distinct beings nor in different places. For from this one might argue that they are not separable as between one animal and another; which error this passage removes.
Deinde cum dicit quoniam autem ostenso quod anima est primum vivendi principium, concludit ex hoc definitionem prius assignatam. Et circa hoc duo facit. Primo demonstrat propositum. Secundo ex veritate demonstrata, quasdam conclusiones ulterius inducit, ibi, propter hoc bene opinantur et cetera. Circa primum ponit talem demonstrationem. Duorum, quorum utroque dicimur esse aliquid aut operari, unum, scilicet quod primum est, est quasi forma, et aliud quasi materia. Sed anima est primum quo vivimus, cum tamen vivamus anima et corpore: ergo anima est forma corporis viventis. Et haec est definitio superius de anima posita, quod anima est actus primus physici corporis potentia vitam habentis. Manifestum est autem, quod medium huius demonstrationis est quaedam definitio animae, scilicet anima est quo vivimus primum. 271. Next, at ‘Since etc.’, he concludes, from the fact, that the soul is the first principle of life, to the definition of it already given; first proving this definition, and then, at ‘And on this account’, drawing some further conclusions. The proof runs thus. Granted that there are two principles of our being and activity, one (the form) will be prior to the other (the matter). Now both body and soul are principles of life in us, but the soul comes first in this respect. The soul then is the form of the living body; which agrees with the definition already given: the soul is the primary actuality of a physical body capable of life. Clearly, the middle term of this argument is the definition of the soul as the primary principle of life.
Circa hanc autem demonstrationem quatuor facit. Primo ponit maiorem; dicens, quod quo vivimus et sentimus dicitur dupliciter: scilicet altero, sicut forma, et altero sicut materia. Sicut et quo scimus dicitur dupliciter. Duobus enim dicimur scire: quorum unum est scientia, et aliud est anima. Et similiter quo sanamur dicitur de duobus: quorum unum est sanitas, et aliud est aliqua pars corporis, vel etiam totum corpus. Utrobique autem unum est quasi forma, et aliud quasi materia. Nam scientia et sanitas sunt formae et quasi actus susceptivorum: scientia quidem forma scientifici, idest partis animae, in qua est scientia; sanitas vero est forma corporis sanabilis. Ideo autem dicit sanabile et scientificum, ut ostendat aptitudinem in subiecto ad tales formas. Semper enim activorum actus, idest formae, quae inducuntur ab agentibus in materia, videntur esse in patiente et disposito, idest in eo quod est natum pati actiones agentis a tali agente, et quod est dispositum ad consequendum finem passionis, scilicet formam ad quam patiendo perducitur. 272. The argument itself he sets out in four parts. (1) Explaining the major, he observes that we can speak of the principle of life and sensation from two points of view, formally or materially, just as we speak of the act of knowing as proceeding either from knowledge itself or from the soul; or as we speak of becoming healthy either with respect to health itself, or with respect to some part of the body, or to the whole of it. In both these cases, one of the principles is formal and the other material. For knowledge and health are forms or actualities of certain subjects: knowledge is a form of the part of the soul that knows, health of the body capable of health. Thus he says ‘capable of knowing’ and ‘capable of health’ in order to indicate the, particular subject’s aptitude to its particular form. For the actuality of an active principle, such as the form transmitted to matter by an agent, always appears to exist in what receives it and is adapted to it, i.e. in the subject, whose nature it. is to receive from some one particular active principle, and which is adapted to attain the final term of the receiving-process, namely the form in question.
Secundo ibi, anima autem hoc, ponit minorem propositionem: et dicit, quod anima est primum quo et vivimus, et sentimus, et movemur, et intelligimus. Et referuntur haec quatuor ad quatuor genera vitae de quibus superius fecerat mentionem. Vivere enim refert ad principium vegetativum, quia superius dixerat, quod vivere propter hoc principium inest omnibus viventibus. Sciendum est autem, quod quamvis sanitate et corpore dicamur esse sani, tamen sanitas est primum quo sani dicimur esse. Non enim dicimur esse sani corpore nisi inquantum habet sanitatem. Et similiter scientia est primum quo dicimur esse scientes, quia anima non dicimur esse scientes nisi inquantum habet scientiam. Similiter etiam et corpore non dicimur esse viventes, nisi inquantum habet animam: et propter hoc, hic dicitur, quod anima est primum quo vivimus, sentimus, et cetera. 273. (2) At ‘and soul being that by which’, he states the minor, saying that the soul is the primary principle of our life and feeling and movement and understanding—these being the four chief manifestations of vitality already mentioned (for by ‘life’ here is meant the vegetative principle which, as has been said, is common to all living things). Now though it is in the body that we enjoy health, health itself is that by which we are called healthy primarily. Only in so far as the body has health are we said to be healthy. So too our souls are not said to know except in so far as they have knowledge; thus knowledge itself is that by which, primarily, the soul is said to be in the state of knowing. And the same is true of our body and its life; we are not said to live by the body except in so far as the body has a soul. Therefore he calls the ‘soul’ here the first principle of life and feeling, etc.
Tertio ibi, quare ratio quaedam, ponit conclusionem, et pendet hucusque constructio ab illo loco quoniam autem quo vivimus et cetera. Concludit ergo ex praedictis, quod anima se habet ut ratio et species, et non sicut materia et subiectum. 274. (3) He concludes at ‘it follows that the soul’, linking this phrase with the previous one, that the soul is a sort of nature or specific form; not the material for, or mere subject of, anything.
Quarto ibi, tripliciter enim dicta substantia, etc., ostendit conclusionem sequi ex praemissis. Non enim videbatur magis sequi de anima, quod sit forma, quam de corpore, cum utroque vivere dicamur: unde ad perfectionem dictae demonstrationis, subiungit, quod cum substantia dicatur tripliciter, ut supra dictum est, scilicet de materia, forma, et composito ex utrisque, quorum materia est potentia, et species sive forma est actus, et compositum ex utrisque est animatum, manifestum est, quod corpus non est actus animae, sed magis anima est actus corporis alicuius: corpus enim est in potentia respectu animae. Et ideo cum consequatur ex praedicta demonstratione, quod vel corpus vel anima sit species: et corpus, ut dictum est, non sit species animae, sequitur quod anima sit species corporis. 275. (4) Then at ‘Substance is predicated’, I he shows how this conclusion follows from the premises. For it might have seemed to follow that the body no less than the soul was a form, since we call the body also a principle of life. So, to clinch the argument, he adds that if, as we have said, the term ‘substance’ can refer to three things, to matter, to form, and to the complex of both (the matter being the potential element; the form the actuality; and the complex the thing that is alive in this way) the body is clearly not the soul’s actuality, but rather the soul is the body’s; for the body is potential with respect to the soul. And if the foregoing argument has led us to the alternative that the specifying principle is either the soul or the body, we can now conclude that it is the soul; for it is now dear that the body is not the form of the soul.
Deinde cum dicit et propter hoc bene inducit quasdam conclusiones ex praemissis: quarum prima est, quod bene opinati sunt, quibus visum est, quod anima non sit sine corpore, neque sit corpus. Non enim est corpus, quia non est materia; sed est aliquid corporis, quia est actus corporis. Et quia omnis actus est in eo cuius est actus, infert consequenter ibi et propter hoc, in corpore. 276. Then at ‘And on this account’, he deduces from the foregoing: (a) that they were right who thought that the soul required the body and yet was essentially distinct from it. It is not the body, for it is not matter; but it is essentially involved with the body, because it is its actuality; whence too it follows, as he says here, that it exists in that body whose actuality it is.
Secundam conclusionem, scilicet quod anima est in corpore, et tali corpore, scilicet physico, organico, et hoc non est per modum quo priores physici loquebantur de anima et unione eius ad corpus, nihil determinantes in quo vel quali corpore esset. Et vere hoc est, sicut nunc dicimus, quod anima est in determinato corpore, cum non videatur anima accipere quodcumque corpus contingat, sed determinatum. Et hoc rationabiliter accidit; quia unusquisque actus natus est fieri in propria et determinata materia: unde et anima oportet, quod in determinato corpore recipiatur. 277. (b) Being then in the body, and in a special kind of body, namely physical and organic, it is not, however, in it as the old natural philosophers fancied when they spoke of it. For they did not specify the kind of body that it has. Yet it does in fact have only one kind of body. And this we should expect a priori, it being natural to any act to be realised in some definite and appropriate material. So also, then, with the soul.
Ultimo autem epilogando concludit, quod anima est actus quidam et ratio habentis esse huiusmodi, scilicet potentia viventis. 278. Summarising, he concludes that the soul is a certain actuality and formal principle of that which exists accordingly, namely as potentially animate.

TEXT
414a28–414b31
BOOK II, CHAPTER III
ΚΕΦΑΛΑΙΟΝ Γ'

THE SOUL’S POWERS IN GENERAL

414a27   1. Τῶν δὲ δυνάμεων τῆς ψυχῆς αἱ λεχθεῖσαι τοῖς μὲν ὑπάρχουσι πᾶσαι, καθάπερ εἴπομεν, τοῖς δὲ τινὲς αὐτῶν, ἐνίοις δὲ μία μόνη. δυνάμεις δ' εἴπομεν θρεπτικόν, αἰσθητικόν, ὀρεκτικόν, κινητικὸν κατὰ τόπον, διανοητικόν. Of the soul's powers already spoken of all are present in some, certain only are present in others, and one only in yet others. By the powers of the soul we mean the vegetative, the sensitive, the appetitive, the locomotive and the intellectual. §§ 279-87
2. ὑπάρχει δὲ τοῖς μὲν φυτοῖς τὸ θρεπτικὸν μόνον, ἑτέροις δὲ 414b τοῦτό τε καὶ τὸ αἰσθητικόν. εἰ δὲ τὸ αἰσθητικόν, καὶ τὸ ὀρεκτικόν· ὄρεξις μὲν γὰρ ἐπιθυμία καὶ θυμὸς καὶ βούλησις, τὰ δὲ ζῷα πάντ' ἔχουσι μίαν γε τῶν αἰσθήσεων, τὴν ἁφήν· ᾧ δ' αἴσθησις ὑπάρχει, τούτῳ ἡδονή τε καὶ λύπη καὶ τὸ ἡδύ τε καὶ λυπηρόν, οἷς δὲ ταῦτα, καὶ ἐπιθυμία· τοῦ γὰρ ἡδέος ὄρεξις αὕτη. In plants there is only the vegetative; in other living things, this and the sensitive; but if the sensitive is present, so must the appetitive be. For appetition means desire, and anger and will. Now all animals have the sense of touch; and where sensation is found there is pleasure and pain, the pleasant and the repugnant. What has these has appetite, this being desire for a pleasurable object. §§ 288-9
3. ἔτι δὲ τῆς τροφῆς αἴσθησιν ἔχουσιν· ἡ γὰρ ἁφὴ τῆς τροφῆς αἴσθησις· ξηροῖς γὰρ καὶ ὑγροῖς καὶ θερμοῖς καὶ ψυχροῖς τρέφεται τὰ ζῶντα πάντα, τούτων δ' αἴσθησις ἁφή, τῶν δ' ἄλλων αἰσθητῶν κατὰ συμβεβηκός. οὐθὲν γὰρ εἰς τροφὴν συμβάλλεται ψόφος οὐδὲ χρῶμα οὐδὲ ὀσμή, ὁ δὲ χυμὸς ἕν τι τῶν ἁπτῶν ἐστιν. πεῖνα δὲ καὶ δίψα ἐπιθυμία, καὶ ἡ μὲν πεῖνα ξηροῦ καὶ θερμοῦ, ἡ δὲ δίψα ὑγροῦ καὶ ψυχροῦ· ὁ δὲ χυμὸς οἷον ἥδυσμά τι τούτων ἐστίν. διασαφητέον δὲ περὶ αὐτῶν ὕστερον, νῦν δ' ἐπὶ τοσοῦτον εἰρήσθω, ὅτι τῶν ζώντων τοῖς ἔχουσιν ἁφὴν καὶ ὄρεξις ὑπάρχει. περὶ δὲ φαντασίας ἄδηλον, ὕστερον δ' ἐπισκεπτέον. 4. ἐνίοις δὲ πρὸς τούτοις ὑπάρχει καὶ τὸ κατὰ τόπον κινητικόν, ἑτέροις δὲ καὶ τὸ διανοητικόν τε καὶ νοῦς, οἷον ἀνθρώποις καὶ εἴ τι τοιοῦτον ἕτερον ἔστιν ἢ τιμιώτερον. Further; all have a sense of nutriment, inasmuch as touch is this sense. For all living beings are nourished by things dry and wet or hot and cold; and the sense of touch is of these. But they are nourished by the other sense-objects only indirectly. Sound, colour and smell contribute nothing to nutrition; and as for savour, it is found in objects of touch. Hunger and thirst being appetites, hunger for the hot and dry and thirst for the cold and liquid, savour is as it were the delectable in these. We must settle these questions later; for the present let us only say that animals endowed with touch have appetition also. The case of imagination is not clear and must be examined later. Some animals, again, have local motion; some intellect and mind—such as men and whatever other beings there are of a like nature, or of one even more excellent. §§ 290-4
5. δῆλον οὖν ὅτι τὸν αὐτὸν τρόπον εἷς ἂν εἴη λόγος ψυχῆς τε καὶ σχήματος· οὔτε γὰρ ἐκεῖ σχῆμα παρὰ τὸ τρίγωνον ἔστι καὶ τὰ ἐφεξῆς, οὔτ' ἐνταῦθα ψυχὴ παρὰ τὰς εἰρημένας. γένοιτο δ' ἂν καὶ ἐπὶ τῶν σχημάτων λόγος κοινός, ὃς ἐφαρμόσει μὲν πᾶσιν, ἴδιος δ' οὐδενὸς ἔσται σχήματος. ὁμοίως δὲ καὶ ἐπὶ ταῖς εἰρημέναις ψυχαῖς. διὸ γελοῖον ζητεῖν τὸν κοινὸν λόγον καὶ ἐπὶ τούτων καὶ ἐφ' ἑτέρων, ὃς οὐδενὸς ἔσται τῶν ὄντων ἴδιος λόγος, οὐδὲ κατὰ τὸ οἰκεῖον καὶ ἄτομον εἶδος, ἀφέντας τὸν τοιοῦτον. 6. (παραπλησίως δ' ἔχει τῷ περὶ τῶν σχημάτων καὶ τὰ κατὰ ψυχήν· ἀεὶ γὰρ ἐν τῷ ἐφεξῆς ὑπάρχει δυνάμει τὸ πρότερον ἐπί τε τῶν σχημάτων καὶ ἐπὶ τῶν ἐμψύχων, οἷον ἐν τετραγώνῳ μὲν τρίγωνον, ἐν αἰσθητικῷ δὲ τὸ θρεπτικόν.) It is therefore clear that the idea of soul must be one in the same way as that of figure: for as there is no figure other than the triangle and those that derive from it, so there is no soul apart from the aforesaid. There will be, however, in the case of figures a general idea applicable to all figures, yet proper to none. Likewise with these souls just mentioned. Hence it is absurd to seek a common definition in this matter (or in any other) which will be that of no existing thing, and on the other hand, to seek to define in terms of the individual species without taking into account such a common definition. There is indeed an analogy between what holds of figures and what holds of the soul. For in that which is consequent there is always potential that which is primary, both in figures and in animate beings. As the triangle is contained in the square, so is the vegetative in the sensitive. §§ 295-8
ST. THOMAS’S COMMENTARY

LECTIO 5
Postquam Aristoteles definivit animam in communi, nunc accedit ad determinandum de partibus eius. Non autem habet aliter anima partes, nisi, secundum quod eius potentiae partes eius dicuntur, prout alicuius potentis multa, partes dici possunt potestates ad singulas. Unde determinare de partibus eius est determinare de singulis potentiis eius. Dividitur autem haec pars in duas. In prima determinat de potentiis animae in communi, distinguendo eas abinvicem. In secunda determinat de singulis earum, ibi, quare primum de alimento et generatione et cetera. Prima autem pars dividitur in duas. In prima distinguit potentias animae abinvicem. In secunda ostendit quid de potentiis animae, et quomodo, et quo ordine determinandum sit, ibi, quare et secundum unumquodque quaerendum, et cetera. Circa primum duo facit. Primo distinguit potentias animae abinvicem. Secundo ostendit quomodo ratio communis animae se habet ad partes praedictas, ibi manifestum igitur est quoniam eodem et cetera. Circa primum duo facit. Primo enumerat potentias animae. Secundo ostendit quomodo seinvicem consequantur, ibi, inest autem plantis, et cetera. Dicit ergo primo, quod de potentiis animae, quae supra nominatae sunt, quibusdam insunt omnes, sicut hominibus, quibusdam quaedam harum, sicut aliis animalibus: quibusdam una tantum, sicut plantis. Et quia superius non nominaverat eas potentias, sed partes animae; ideo manifestat, quod per potentias idem intelligit, quod supra per partes. Quarum quidem sunt quinque genera; scilicet vegetativum, sensitivum, appetitivum, motivum secundum locum, intellectivum. 279. After defining the soul in general Aristotle comes to treat of its ‘parts’. Now the soul has no parts except in the sense that its potentialities are parts of it; in that one subject, being in potency to many activities, its power with respect to each in particular can be called a part of it. To treat of its parts then is to treat of its various potencies. This he does here in two main sections: the first treats of the soul’s powers in general and their distinction from one another; the second, at ‘Hence we must speak first’, takes them one by one. The former subdivides into (a) a division of the powers of the soul; and (b) at ‘So we must enquire” a discussion of what has to be proved about them, and how and in what order. The division itself of the powers (at ‘it is therefore clear’) necessitates showing how the soul as a whole is related to its parts; but before we come to this, the powers enumerated have to be related to each other, which he does at ‘In plants there is etc.’ First of all, then, he observes that, of the powers already enumerated, all are in some beings (men); some are in some beings (the other animals); and one only is in some others (plants). And having previously called them, not ‘powers’, but ‘parts’ of the soul, he clearly implies that the two terms mean the same. Now of these parts or powers there are five main types: the vegetative, sensitive, appetitive, locomotive and intellectual.
Oportet autem haec duo videre. Primo quidem quare ponuntur hic quinque genera potentiarum animae; praecipue cum consuetum sit dici triplicem esse animam, vegetabilem, sensibilem et rationalem. Secundo considerare oportet quare hic ponit quinque cum superius posuerit tantum quatuor. 280. Regarding this five-fold division two things must be made clear: (1) why the usual threefold division of potencies into vegetative, sensitive and intellectual is set aside; and (2) why he has already made a fourfold division.
Sciendum autem circa primum, quod cum omnis potentia dicatur ad actum proprium, potentia operativa dicitur ad actum qui est operatio. Potentiae autem animae sunt operativae, talis enim est potentia formae; unde necesse est secundum diversas operationes animae, accipi diversitatem potentiarum. Operatio autem animae, est operatio rei viventis. Cum igitur unicuique rei competat propria operatio, secundum quod habet esse, eo quod unumquodque operatur inquantum est ens: oportet operationes animae considerare, secundum quod invenitur in viventibus. 281. As to (1) we should note that all potencies are defined by their proper acts, and operative potencies by activities. The soul, being a form, has operative potencies; hence by differences between its activities we have to differentiate between its potencies. Now, as the activity of anything is consequent upon and corresponds to its being, we have to study vital activities precisely in the living beings which display them.
Huiusmodi autem viventia inferiora, quorum actus est anima, de qua nunc agitur, habent duplex esse. Unum quidem materiale, in quo conveniunt cum aliis rebus materialibus. Aliud autem immateriale, in quo communicant cum substantiis superioribus aliqualiter. 282. The being of things whose actuality is ‘soul’, i.e. of the animate beings that exist on this earth and are the subject of the present discussion, this being includes two factors: one, material, in which it resembles the being of all other material things; and the other, immaterial, by which it has something in common with the world of the higher substances.
Est autem differentia inter utrumque esse: quia secundum esse materiale, quod est per materiam contractum, unaquaeque res est hoc solum quod est, sicut hic lapis, non est aliud quam hic lapis: secundum vero esse immateriale, quod est amplum, et quodammodo infinitum, inquantum non est per materiam terminatum, res non solum est id quod est, sed etiam est quodammodo alia. Unde in substantiis superioribus immaterialibus sunt quodammodo omnia, sicut in universalibus causis. 283. Now there is this difference between these two divisions of being, that in so far as a thing is material, it is restricted by its matter to being this particular thing and nothing else, e.g. a stone; whilst in so far as it is unmaterial, a thing is free from the restriction of matter and has a certain width and infinity, so that it is not merely this particular subject but, in a certain sense, it is other things as well. That is why everything pre-exists, somehow, in the higher immaterial substances, as in universal causes.
Huiusmodi autem immateriale esse, habet duos gradus in istis inferioribus. Nam quoddam est penitus immateriale, scilicet esse intelligibile. In intellectu enim res habent esse, et sine materia, et sine conditionibus materialibus individuantibus, et etiam absque organo corporali. Esse autem sensibile est medium inter utrumque. Nam in sensu res habet esse sine materia, non tamen absque conditionibus materialibus individuantibus, neque absque organo corporali. Est enim sensus particularium, intellectus vero universalium. Et quantum ad hoc duplex esse, dicit philosophus in tertio huius, quod anima est quodammodo omnia. 284. But in the lower terrestrial natures there are two degrees of immateriality. There is the perfect immateriality of intelligible being; for in the intellect things exist not only without matter, but even without their individuating material conditions, and also apart from any material organ. Then there is the half-way state of sensible being. For as things exist in sensation they are free indeed from matter, but are not without their individuating material conditions, nor apart from a bodily organ. For sensation is of objects in the particular, but intellection of objects universally. It is with reference to these two modes of existence that the philosopher will say, in Book III, that the soul is somehow all things.
Operationes igitur, quae competunt viventi secundum esse materiale, sunt operationes quae attribuuntur animae vegetabili: quae tamen licet ad id ordinentur, ad quod etiam ordinantur actiones in rebus inanimatis, scilicet ad consequendum esse et conservandum, tamen in viventibus hoc fit per altiorem et nobiliorem modum. Corpora enim inanimata generantur et conservantur in esse a principio motivo extrinseco; animata vero generantur a principio intrinseco, quod est in semine, conservantur vero a principio nutritivo intrinseco. Hoc enim videtur esse viventium proprium, quod operentur tamquam ex seipsis mota. Operationes autem, quae attribuuntur rebus viventibus secundum esse penitus immateriale, pertinent ad partem animae intellectivam; quae vero attribuuntur eis secundum esse medium, pertinent ad partem animae sensitivam. Et secundum hoc triplex esse distinguitur communiter triplex anima: scilicet vegetabilis, sensibilis et rationalis. 285. The activities, therefore, appropriate to living things in their material being are those we attribute to the vegetative soul. They fulfil the same purpose as the actions of inanimate beings, i.e. to attain and maintain existence; but they do this in a higher or nobler way. Inanimate bodies are brought into being and maintained by an exterior moving principle, whereas animate beings are generated by an intrinsic principle, i.e. seed, and are kept in existence by an intrinsic nutritive principle. It seems characteristic of living things that their activities should thus proceed from within themselves. But the purely immaterial activities of living things we identify with the intellectual part of the soul; while those in between belong to its sensitive part. Hence it is usual to distinguish three kinds of soul: vegetative, sensitive, intellectual.
Sed quia omne esse est secundum aliquam formam, oportet, quod esse sensibile sit secundum formam sensibilem, et esse intelligibile secundum formam intelligibilem. Ex unaquaque autem forma sequitur aliqua inclinatio, et ex inclinatione operatio; sicut ex forma naturali ignis, sequitur inclinatio ad locum qui est sursum, secundum quam ignis dicitur levis; et ex hac inclinatione sequitur operatio, scilicet motus qui est sursum. Ad formam igitur tam sensibilem quam intelligibilem sequitur inclinatio quaedam quae dicitur appetitus sensibilis vel intellectualis; sicut inclinatio consequens formam naturalem, dicitur appetitus naturalis. Ex appetitu autem sequitur operatio, quae est motus localis. Haec igitur est ratio, quare oportet esse quinque genera potentiarum animae, quod primo quaerebatur. 286. But since everything exists as formed in a certain way, the being of the sensible must have a sensible form, and the being of the intelligible an intelligible form. Now every form has by nature a certain trend or tendency whence proceed its activities or operations. Thus the form of fire tends naturally upwards (giving to fire its lightness) whence follows fire’s activity which is the movement upwards. Now the trend that proceeds from a sensible or intellectual form is called sensitive or intellectual desire; as that of any form in nature is called a natural desire. And from this desire follows the activity of local movement. Here then is the explanation we required of the five-fold division of the powers of soul.
Circa secundum sciendum est, quod supra Aristoteles intendens ostendere quod anima est principium vivendi in omnibus viventibus, distinxit ipsum vivere secundum gradus viventium, et non secundum operationes vitae secundum quas distinguuntur haec genera potentiarum. Appetitivum autem non constituit aliquem diversum gradum in viventibus; quia omnia quae habent sensum, habent appetitum; et sic remanent tantum quatuor gradus viventium, ut supra ostensum est. 287. And as to the second point, note that when Aristotle wished to show that soul was the life-principle in things that five, he divided these into grades; which are not the same as those different kinds of vital activity whence we get our division of the powers of the soul. For, since all things that sense also desire, desire or appetition does not constitute a distinct grade of animate being; so we are left with only four such grades.
Deinde cum dicit inest autem ostendit, quomodo praedictae potentiae consequuntur se invicem: manifestans quod supra dixerat, quod potentiarum quibusdam insunt omnes, quibusdam quaedam, quibusdam una sola. Ubi considerandum est, quod ad hoc quod universum sit perfectum, nullus gradus perfectionis in rebus intermittitur, sed paulatim natura de imperfectis ad perfecta procedit. Propter quod etiam Aristoteles, in octavo metaphysicae, assimilat species rerum numeris, qui paulatim in augmentum proficiunt. Unde in viventibus quaedam habent unum tantum praedictorum, scilicet plantae, in quibus est solum vegetativum, quod necesse est in omnibus viventibus materialibus esse, quia huic potentiae attribuuntur operationes pertinentes ad esse materiale. Aliis autem, scilicet animalibus, inest vegetativum et sensitivum. Si autem est ibi sensitivum, oportet quod adsit tertium, scilicet appetitivum. Quod quidem dividitur in tria: scilicet desiderium, quod est secundum vim concupiscibilem; et iram, quae est secundum vim irascibilem: qui duo appetitus pertinent ad partem sensitivam: sequuntur enim apprehensionem sensus. Tertium autem est voluntas, quod est appetitus intellectivus, consequens scilicet apprehensionem intellectus. 288. Then, at ‘In plants there is only’, he shows the interconnection of the powers of the soul, thus explaining what he said previously, that all these powers are in some things, some of them in tome, and only one in some others. Here we have to consider that the completeness of the Universe requires that there should be no gaps in its order, that in Nature there should everywhere be a gradual development from the less to the more perfect. Hence, in the Metaphysics, Book VIII, Aristotle likens the nature of things to numbers; which increase by tiny degrees, one by one. Thus among living things there are some, i.e. plants, which have only the vegetative capacity,—which, indeed, they must have because no living being could maintain an existence in matter without the vegetative activities. Next are the animals, with sensitivity as well as vegetative life; and sensitivity implies a third power, appetition, which itself divides into three: into desire, in the stricter sense, which springs from the concupiscible appetite; anger, corresponding to the irascible appetite—both of these being in the sensitive part and following sense-knowledge; and finally will, which is the intellectual appetite and follows intellectual apprehension.
Quod autem appetitivum insit omnibus animalibus, probat duplici ratione. Quarum prima est, quod omnia animalia habent ad minus unum sensum, scilicet tactum; quibus autem inest sensus, inest laetitia et tristitia, delectatio et dolor. Laetitia enim et tristitia magis videntur sequi apprehensionem interiorem. Sed delectatio et dolor consequuntur apprehensionem sensus, et praecipue sensus tactus. Et si est laetitia et tristitia, necesse est quod sit aliquid triste et dulce, idest delectabile et dolorosum; oportet enim, omne quod sentitur secundum tactum, esse, vel conveniens, et sic est delectabile: vel nocivum, et sic est dolorosum. Quibuscumque autem inest aliquid delectabile et triste, his inest et concupiscentia, quae est appetitus delectabilis; ergo de primo ad ultimum omnibus animalibus, quibus inest sensus tactus, inest appetitus. 289. That appetition exists in all animals he demonstrates in two ways. (1) All animals have at least one sense, touch; but where there is any sensation there is pleasure and pain, joy and sorrow. Now while joy and sorrow seem to spring from inward apprehension, pain and pleasure come from external sensations, especially from touch. But joy and sorrow necessarily imply some sweet or disagreeable object, i.e. something pleasant or painful. For everything touched is either congenial to the one touching, and then it gives pleasure; or uncongenial, and then it gives pain. But whatever can feel pleasure and pain can desire the pleasant. Since then all animals, without exception, have a sense of touch, all can desire.
Secundam rationem ad idem ostendendum ponit ibi adhuc autem quae talis est. Omnia animalia habent sensum, quo cognoscunt suum alimentum; scilicet sensum tactus, qui est sensus alimenti. Et quia necessarium est omnibus animalibus uti alimento, ut dictum est; ideo necessarium est, quod habeant sensum tactus quo percipiant alimentum sibi conveniens. Quod autem tactus sit sensus alimenti, manifestum est: sicuti enim corpora viventia constant ex calidis, et humidis, et frigidis, et siccis, ita ex his nutriuntur: tactus autem est sensus discretivus horum. Sed aliis sensibilibus, idest aliis sensibilibus non nutriuntur viventia nisi secundum accidens, inquantum videlicet coniunguntur tangibilibus. Sonus enim et odor et color nihil conferunt in alimentum inquantum huiusmodi, sed solum inquantum contingit colorata et odorata et sonantia esse calida vel frigida, humida vel sicca: humor autem, idest sapor, est quoddam de numero tangibilium qualitatum, sicut et gustus est quidam tactus. Sic igitur patet, quod omnia animalia habent sensum alimenti. 290. (2) This second argument begins at ‘Further, all have’ and runs thus. All animals have the sense that is aware of food; and this is touch; which is as necessary therefore to every animal as eating the food that agrees with it. The fact that it is touch that perceives food is clear if we consider that, as living bodies are made up of warm, moist, cold and dry elements it is of these that their food must consist; and these elements are just what touch is aware of. But other sense-objects’, he says, do not, save indirectly, nourish living bodies; they do so only so far as they are involved in the objects of touch. Sound, colour, smell have nothing to do with food as such; they occur in food only in so far as things that sound or are coloured or odorous, are also hot, or cold, moist or dry. Savour, however, is reckoned a tangible quality—so that tasting is a sort of touch. Clearly, then, all animals have a sense-awareness of food.
Quibuscumque autem inest sensus alimenti, his inest esuries et sitis: quorum utrumque est concupiscentia alimenti: esuries quidem est concupiscentia calidi et sicci, quod habet rationem cibi: sitis autem frigidi et humidi, quod habet rationem potus. Sapor autem est quoddam horum delectamentum: sapor enim delectabilis indicat convenientem proportionem calidi et frigidi, humidi et sicci in alimento. Unde magis pertinet ad delectationem alimenti, quam ad necessitatem. Sic igitur ubicumque est sensus tactus, est etiam appetitus. 291. But whatever has this awareness can feel the two desires of nourishment, hunger and thirst. Hunger is desire for the hot and the dry elements, i.e. food; thirst for the cold and the moist, i.e. drink. Savour is a certain delectability in food and drink indicating a proper balance of the hot and cold, the moist and dry elements. It is more of a pleasure added to eating than a necessity. Desire, then, always accompanies touch.
Quomodo autem phantasia se habet ad appetitivum et sensitivum, posterius dicetur. 292. What imagination has to do with desire and sensitivity will be shown later.
Quibusdam autem animalibus, supra haec tria, scilicet vegetativum, sensitivum et appetitivum, inest etiam motivum secundum locum. Aliis vero supra haec quatuor inest etiam intellectivum et intellectus ipse, scilicet hominibus, et si aliquod aliud genus rerum est simile hominibus, aut etiam honorabilius hominibus. Invenitur autem aliquid honorabilius hominibus, quibus inest intellectus; est enim in substantiis separatis, et in corporibus caelestibus, si tamen sunt animata: licet in viventibus mortalibus non est aliquod genus viventium habentium intellectivum, nisi in specie humana. 293. Now besides these three powers, the vegetative, the sensitive and the appetitive, some animals also have the capacity to move from one place to another. Some, too, i.e. human beings and any other kind of beings, if such exist, resembling or even perhaps excelling mankind, have, in addition to these four capacities, the power of understanding or intellect. The beings ‘more excellent’ are the immaterial substances and the heavenly bodies, the latter, however, only if they are alive. Among living corruptible beings the human race alone is endowed with intellect.
Cum enim intellectus non habeat organum corporale, non possunt diversificari habentia intellectum secundum diversam complexionem organorum, sicut diversificantur species sensitivorum secundum diversas complexiones, quibus diversimode se habent ad operationes sensus. 294. For as intellect has no bodily organ, intelligent beings cannot be differentiated according to a physical diversity in the constitution of their bodily organs, as are the different species of animals (whose different constitutions cause them to sense in different ways).
Deinde cum dicit manifestum igitur ostendit qualiter se habet praedicta definitio animae ad partes enumeratas. Et ad huius intellectum, sciendum est, quod Plato posuit universalia esse separata secundum esse; tamen in illis, quae se habent consequenter, non posuit unam ideam communem, sicut in numeris et figuris: non enim posuit unam ideam numeri praeter omnes numeros, sicut posuit unam ideam hominis praeter omnes homines, eo quod numerorum species naturali ordine consequenter se habent. Et sic prima earum, scilicet dualitas, est causa omnium consequentium. Unde non oportet ponere aliquam ideam communem numeris, ad causandum speciem numerorum. Et similis ratio est de figuris. Nam eius species consequenter se habent, sicut et species numerorum: trigonum enim est ante tetragonum, et tetragonum ante pentagonum. 295. Then at ‘It is therefore clear’ he shows how his definition of soul is related to the ‘parts’ that we have enumerated. To understand him here we must remember what Plato said about universal ideas, that they had a separate existence of their own. He did not say, however, that objects which follow successively from each other, such as numbers and geometrical figures, had a universal idea, i.e. he did not posit a universal idea of Number apart from particular numbers—as, for him, there was a universal idea of Man in addition to all existing men; and this because the classes of number are, of their nature, derived successively from each other, so that the first of these, duality, is the cause of all the rest. There is no need to posit a general idea of Number as the cause of the numerical species. The same argument applies to geometrical figures. They follow each other in the same way as numbers: from the triangle comes the tetragon, and from the latter the pentagon.
Dicit ergo manifestum esse, quod eodem modo una est ratio animae, sicut una est ratio figurae. Sicuti enim inter figuras non est aliqua figura quae sit praeter triangulum et alias species consequentes, utpote quae sit communis omnium figurarum, ita nec in proposito est aliqua anima, quasi separata existens praeter omnes praedictas partes. 296. Aristotle, then, says that the idea of Soul is one in the same way as that of geometrical figure is one. just as there is no figure existing apart from the triangle and the rest, as their common idea, so it is with the soul. There exists’ no soul apart from the parts which have been enumerated.
Sed quamvis non sit una figura separata in esse praeter omnes figuras, etiam secundum Platonicos, qui ponunt species communes separatas; tamen invenitur una ratio communis, quae convenit omnibus figuris, et non est propria alicuius earum; ita est et in animalibus. Et ideo ridiculum est, quod homo quaerat unam rationem communem, tam in animalibus, quam in aliis rebus, quae non conveniat alicui animarum quae sunt in rerum natura particulariter. Neque etiam est conveniens, quod homo quaerat definitionem animae, secundum unamquamque speciem animae, et dimittat definitionem communem omnibus. Ergo neque definitio communis animae praetermittenda fuit; neque sic est assignanda definitio communis animae quod non conveniat singulis animabus. 297. But while, there is (even for the Platonists), no figure existing apart from all figures, nevertheless one common definition can be found which answers to all figures, without being proper to any particular one. And the same is true of living beings. It would be ludicrous therefore to seek a common definition, whether of animals or anything else, which did not fit any particular living thing actually existing. On the other hand it will not do to look for a definition that will fit only one sort of soul, ignoring what all have in common. We need a common definition which must, however, be applicable to souls in particular.
Et quia dixerat, quod eodem modo se habet ratio animae sicut ratio figurae, ostendit convenientiam inter utrumque: et dicit quod similiter se habent figurae et animae adinvicem: in utrisque enim illud quod est prius, est in potentia in eo quod est consequenter. Manifestum est enim in figuris, quod trigonum, quod est prius, est potentia in tetragono. Potest enim tetragonum dividi in duos trigonos. Et similiter in anima sensitiva, vegetativa est quasi quaedam potentia eius, et quasi anima per se. Et similiter est de aliis figuris, et aliis partibus animae. 298. He goes on now to show the resemblance between the two definitions, namely of soul and of geometrical figure. In both cases what comes first is potentially in what follows. In figures the three-sided figure exists potentially in the square; for the square is divisible into two triangles. Likewise the sensitive life-principle contains the vegetative, both as potential, as it were, with respect to sensitivity, and also as a certain life-principle in itself. The same holds good with the other figures and the other divisions of soul.

TEXT
414b32–415a22
BOOK II, CHAPTER III, CONTINUED

THE SOUL’S POWERS CONTINUED
THEIR INTERRELATION
HOW TO DEFINE EACH

ὥστε καθ' ἕκαστον ζητητέον, τίς ἑκάστου ψυχή, οἷον τίς φυτοῦ καὶ τίς ἀνθρώπου ἢ θηρίου. So We must enquire in each particular case what the soul is of each: of plant, of man, of beast § 299
7. διὰ τίνα δ' αἰτίαν τῷ 415a ἐφεξῆς οὕτως ἔχουσι, σκεπτέον. ἄνευ μὲν γὰρ τοῦ θρεπτικοῦ τὸ αἰσθητικὸν οὐκ ἔστιν· τοῦ δ' αἰσθητικοῦ χωρίζεται τὸ θρεπτικὸν ἐν τοῖς φυτοῖς. πάλιν δ' ἄνευ μὲν τοῦ ἁπτικοῦ τῶν ἄλλων αἰσθήσεων οὐδεμία ὑπάρχει, ἁφὴ δ' ἄνευ τῶν ἄλλων ὑπάρχει· πολλὰ γὰρ τῶν ζῴων οὔτ' ὄψιν οὔτ' ἀκοὴν ἔχουσιν οὔτ' ὀσμῆς αἴσθησιν. καὶ τῶν αἰσθητικῶν δὲ τὰ μὲν ἔχει τὸ κατὰ τόπον κινητικόν, τὰ δ' οὐκ ἔχει· τελευταῖον δὲ καὶ ἐλάχιστα λογισμὸν καὶ διάνοιαν· οἷς μὲν γὰρ ὑπάρχει λογισμὸς τῶν φθαρτῶν, τούτοις καὶ τὰ λοιπὰ πάντα, οἷς δ' ἐκείνων ἕκαστον, οὐ πᾶσι λογισμός, ἀλλὰ τοῖς μὲν οὐδὲ φαντασία, τὰ δὲ ταύτῃ μόνῃ ζῶσιν. περὶ δὲ τοῦ θεωρητικοῦ νοῦ ἕτερος λόγος. It must be considered why they stand in this order: for there is no sensitive soul without the vegetative, yet in plants the vegetative exists apart from the sensitive. Again, there can be no sense apart from that of touch, but touch exists without the others; for many animals have no sight or hearing or sense of smell. Again, among sentient beings, some. have local motion, others not. Last and least extensive of all [the species] that reasons and understands (as man and any other such). For mortal beings which possess reason have also all the other [powers], but reason is not found in all that have any one of the latter; some indeed have not even imagination, others live by this alone. The speculative intellect is another issue.
ὅτι μὲν οὖν ὁ περὶ τούτων ἑκάστου λόγος, οὗτος οἰκειότατος καὶ περὶ ψυχῆς, δῆλον. Clearly then, whatever is the most precise definition with respect to each of the above will be that also of the soul. §§ 300-2
ΚΕΦΑΛΑΙΟΝ Δ' CHAPTER IV
415a13   1. Ἀναγκαῖον δὲ τὸν μέλλοντα περὶ τούτων σκέψιν ποιεῖσθαι λαβεῖν ἕκαστον αὐτῶν τί ἐστιν, εἶθ' οὕτως περὶ τῶν ἐχομένων καὶ περὶ τῶν ἄλλων ἐπιζητεῖν. It is necessary for the student of these [parts of the soul] to discover what is the nature of each, and only then to investigate habits and other matters. § 303
εἰ δὲ χρὴ λέγειν τί ἕκαστον αὐτῶν, οἷον τί τὸ νοητικὸν ἢ τὸ αἰσθητικὸν ἢ τὸ θρεπτικόν, πρότερον ἔτι λεκτέον τί τὸ νοεῖν καὶ τί τὸ αἰσθάνεσθαι· πρότεραι γάρ εἰσι τῶν δυνάμεων αἱ ἐνέργειαι καὶ αἱ πράξεις κατὰ τὸν λόγον. εἰ δ' οὕτως, τούτων δ' ἔτι πρότερα τὰ ἀντικείμενα δεῖ τεθεωρηκέναι, περὶ ἐκείνων πρῶτον ἂν δέοι διορίσαι διὰ τὴν αὐτὴν αἰτίαν, οἷον περὶ τροφῆς καὶ αἰσθητοῦ καὶ νοητοῦ. But if one is to say what each of them is (namely the intellectual power or the sensitive or the vegetative) one must first say what it is to understand or perceive by sense; for actions and operations are prior to faculties in the order of thought. And if this is so, one ought first to consider the appropriate objects; which are prior even to the operations, and correspond to them; and thus to determine, in the first place, what these objects are—for instance, food and the sense-object and the intelligible. §§ 304-8
ST. THOMAS’S COMMENTARY

LECTIO 6
Postquam philosophus enumeravit genera potentiarum animae, et quomodo se habet definitio communis animae supra posita ad partes eius, hic ostendit quid aliud modo determinandum sit, et quo ordine. Et dividitur in partes duas. In prima ostendit quid determinandum restat de anima. Secundo ostendit quo ordine determinare oporteat, ibi, necessarium autem est debentem. Circa primum ostendit duo restare ad determinandum: quorum unum concludit ex praedictis. Dictum est supra, quod sicut non est quaerenda talis definitio communis animae, quae nulli animae partium conveniat, ita non debemus esse contenti definitione communi, sed oportet propriam definitionem cuiuslibet partis animae inquirere. Et ex hoc concludit, quod hoc, secundum unumquodque animatum quaerendum est, quae sit uniuscuiusque anima; ut scilicet sciatur quid est anima plantae, et quid anima hominis, et quid anima bestiae: et hoc est scire de unaquaque parte animae, quid sit. 299. After enumerating the powers of the soul and showing how the general definition given above is related to the particular divisions. of soul, the Philosopher now explains what remains to be cleared up and in what order. There are, he says, still two points to be made clear, one of which links up with the argument just given. For we have seen that, just as we must not be satisfied with a completely general definition of soul, such as will not express any of its particular realisations, so too we cannot rest content even with a definition which does answer in some way to these latter; we must pursue our enquiry until we shall have defined precisely what is proper to each of these divisions of soul in particular. Whence it follows that we have to ask about each particular type of living being—plant or man or animal—what is its own particular life-principle; thus applying and particularising our common notion of soul.
Secundo ibi propter quam ponit aliud, quod restat ad determinandum. Dictum est enim supra, quod partes animae consequenter se habent adinvicem, sicut species figurae. Sed considerandum est propter quam causam partes animae hoc modo se habeant consequenter. Huiusmodi enim causam in fine libri assignabit. Exponit autem qualiter se habeant consequenter: quia sensitivum non potest esse sine vegetativo, sed vegetativum separatur a sensitivo in plantis. Nec est mirum; quia supradictum est; quod opera vegetativi ordinantur ad adipiscendum et conservandum esse, quod subiacet quasi fundamentum. Iterum etiam consequentia quaedam invenitur in ipsis sensibus; quia sine sensu tactus, nullus aliorum sensuum esse potest; tactus autem invenitur sine aliis sensibus. Multa enim animalium, neque visum habent, neque auditum, neque sensum odoratus, sed solum tactum. Et hoc etiam rationabiliter accidit. Nam tactus est sensus perceptivus eorum quae pertinent ad consistentiam animalis, ex quibus scilicet animal constat et nutritur. Alia vero sensibilia non conferunt ad hoc nisi per accidens. Unde alii sensus non sunt de necessitate animalis, et propter hoc non inveniuntur in omnibus animalibus, sed in perfectis. 300. Then at ‘It must be considered’, he states the next point to be decided. He has already said that the parts of the soul follow each other in a series like the kinds of geometrical figure; and it remains to consider the reason for this. This reason will be given at the end of the Treatise; here he only shows how the parts of soul follow one from the other successively. The sensitive part, he says, cannot exist without the vegetative, but the latter can, in plants, exist without the sensitive. And this is not surprising; for, as we have seen, the purpose of the vegetative activities is to attain and retain existence itself, which is the ground of all the rest, as it were. And the senses display a like sequence; there. are no senses at an unless there is touch; but touch itself can exist without the others. Many animals neither see, nor hear, nor smell, but only touch. And this will appear quite reasonable if we consider that by touch an animal is aware of the elements of which its substance consists (what it consists of and is nourished by), with which elements the other senses are only indirectly concerned. Hence the latter are not necessary for all animals, and in fact are found only in the higher animals.
Est etiam consideranda consequentia sensitivi et motivi. Nam motivum non potest esse sine sensitivo: sensitivum autem potest esse sine motivo: aliqua enim habentium sensum, habent etiam motum secundum locum, sed aliqua non habent. Sed intelligendum est de motu progressivo animalium secundum quod animalia moventur de loco ad locum. Hic enim motus non inest omnibus animalibus. Sed quae carent hoc motu, habent aliquem motum localem, scilicet dilatationis et constrictionis, sicut apparet in ostreis. 301. Again, there is the connection between sensitive and motive powers. Motive power cannot exist without sensitive, but the converse is not true. Some sentient beings move from place to place, but not all. We are speaking of the progressive movement of animals from one place to another; which is not found in all ,animals; though such as lack it show certain local movements of expansion and contraction—for instance, shellfish.
Illud autem, quod est ultimum inter omnes partes animae et minimum, quia non dividitur in diversa secundum speciem, est, quod habet rationem et intellectum, quia quibuscumque de numero corruptibilium inest ratio, his insunt et omnia alia praedicta. Hoc autem dicit, ut praeservet se a substantiis separatis, et a corporibus caelestibus si sunt animata: quia cum sint sine generatione et corruptione, non indigent vegetativo. Iterum, eorum intellectus per se speculatur ea quae sunt secundum se intelligibilia: unde non indigent sensibus ad cognitionem intellectivam consequendam. Sed in mortalibus habentibus intellectum, necesse est omnia alia praeexistere, sicut quaedam instrumenta, et praeparatoria ad intellectum, qui est ultima perfectio intenta in operatione naturae. Non autem omnibus quibus inest aliquod praedictorum, inest et ratio. Et quia imaginatio videtur habere quamdam affinitatem ad intellectum, cum supra dictum sit, quod intellectus, vel est phantasia quaedam, vel non sine phantasia; addit de imaginatione; et dicit quod quibusdam animalibus non solum non inest intellectus, sed non etiam imaginatio. The ultimate division of soul—and the least extensive since it is not subdivided into different species—is that which has the power of reason and understanding; because where reason exists in mortal beings, there also are found all the other aforesaid powers. He says ‘mortal’ to exclude immaterial substances and the heavenly bodies (if these are alive) which, as neither being born nor dying, do not need the vegetative power; and as being able to understand by a direct intuition of the intelligible object, do not require sense-knowledge as a preliminary condition of understanding; whereas in corruptible natures all the sub-intellectual powers are presupposed as instruments preparing the way for intellect, which is the final perfection of Nature. But these sub-intellectual powers do not necessarily imply reason in the subjects that possess them. And in view of the affinity between intellect and imagination (as he said above, intellect either is, or is accompanied by, imagination), he adds that some animals lack not only intellect but also imagination.
Videtur tamen hoc esse contrarium ei quod supra dixerat: quia si pars decisa habet sensum et appetitum, habet etiam phantasiam; si tamen phantasia est idem cum imaginatione, ut videtur. Dicendum est igitur, quod animalia imperfecta, ut in tertio dicetur, habent quidem phantasiam, sed indeterminatam, quia scilicet motus phantasiae non remanet in eis post apprehensionem sensus: in animalibus autem perfectis remanet motus phantasiae, etiam abeuntibus sensibilibus. Et secundum hoc, dicitur hic quod imaginatio non est eadem omnibus animalibus. Sed quaedam animalia sunt, quae hac sola vivunt, carentia scilicet intellectu, et directa in suis operationibus per imaginationem, sicut nos dirigimur per intellectum. Et licet non omnibus animalibus insit imaginatio, sicut nec intellectus, tamen de intellectu speculativo est alia ratio quam de imaginatione. Differunt enim adinvicem, ut infra patebit. 302. Now this might seem to contradict a previous remark of his, that if a part cut from an animal retains sensation and desire, it retains also images—if the latter imply imagination, as seems likely. We must therefore say that (as will be shown in Book III)3 the lower animals have indeed a sort of imagination but indeterminately: i.e. the activity of imagining does not, in them, outlast actual sense-apprehension, as it does in the higher animals which retain images of things sensed after these have been removed. Thus, as he says here, imagination varies in different animals. Some animals, lacking reason, live only by imagination, being led by it as we are led by reason. And though certain other animals lack both imagination and speculative intelligence, these two powers are not the same, as we shall see.
Manifestum est igitur quod de unaquaque parte animae propriissime dicitur haec definitio, quae assignata est de anima. Clearly, then, the definition of the soul which has been given applies very precisely to each part of the soul.
Deinde cum dicit necessarium autem ostendit quo ordine determinandum sit de partibus animae. Et assignat ordinem, quantum ad duo. Primo quantum ad hoc, quod ille qui debet de partibus animae perscrutari, primo debet accipere unumquodque horum, quid est: et postea debet considerare de habitis, idest consequentibus partibus, et de aliis quae sunt consideranda circa partes animae et circa ipsa animata, sicut de organis, et de aliis huiusmodi. Et iste ordo necessarius est; quia si simul de omnibus determinaretur, esset confusa doctrina. 303. Then, at ‘It is necessary’, he shows the order to be followed in examining the parts of soul. From one point of view, he explains, the first thing to do is to define the nature of each of these parts; and then consider ‘habits’, i.e. whatever other parts of soul derive from them, and anything else pertaining to them and to whatever they animate, such as the organs of the body and things of that kind. This procedure is necessary to avoid confusion.
Secundum tangit ibi si autem dicens, quod si oportet de aliqua parte animae dicere quid est, scilicet quid est intellectivum, aut sensitivum, aut vegetativum, prius oportet dicere de actibus, scilicet quid sit intelligere, et quid sentire. Et hoc ideo, quia secundum rationem definitivam, actus et operationes sunt priores potentiis. Potentia enim, secundum hoc ipsum quod est, importat habitudinem quamdam ad actum: est enim principium quoddam agendi vel patiendi: unde oportet, quod actus ponantur in definitionibus potentiarum. Et si ita se habet circa ordinem actus et potentiae, et actibus adhuc sunt priora opposita, idest obiecta. 304. Then, at ‘But if etc.’, he observes that, from another point of view, our definition of any part of the soul—intellect or sensitivity or vegetativity—must begin from the act of the part in question, e.g. understanding or actual sensation; because in idea acts and operations precede potentialities. Potentiality is nothing but a capacity to act or be acted upon; it essentially involves a relation to actuality and can only be defined in such terms. And if this is the case with acts and potencies, acts in their turn connote something prior to themselves, i.e. their objects.
Species enim actuum et operationum sumuntur secundum ordinem ad obiecta. Omnis enim animae operatio, vel est actus potentiae activae, vel passivae. Obiecta quidem potentiarum passivarum comparantur ad operationes earum ut activa, quia reducunt potentias in actum, sicut visibile visum, et omne sensibile sensum. Obiecta vero potentiarum activarum comparantur ad operationes ipsarum ut fines. Obiecta enim potentiarum activarum, sunt operata ipsarum. Manifestum est autem, quod in quibuscumque praeter operationes sunt aliqua operata, quod operata sunt fines operationum, ut dicitur in primo Ethic.: sicut domus quae aedificatur, est finis aedificationis. Manifestum est igitur, quod omne obiectum comparatur ad operationem animae, vel ut activum, vel ut finis. Ex utroque autem specificatur operatio. 305. For the type of every act or operation is determined by an object. Every operation of the soul is the act of a potentiality—either active or passive. Now the objects of passive potentialities stand to these as the causal agents which bring each potentiality into its proper activity; and it is thus that visible objects, and indeed all sensible things, are related to sight and to the other senses. But the objects of the active capacities are related to these as the final terms attained by their activities; for in this case the object is what each of these activities effectively realises. It is obvious that whenever an activity effectively realises anything besides the activity itself, the thing thus realised is the final term of the activity (cf. the Ethics, Book I); for example a house is the final term of building. Hence all the objects of the soul’s activities are either causal agents or final terms; and in both respects they specify those activities.
Manifestum est enim, quod diversa activa secundum speciem, habent operationes specie differentes, sicut calefactio est a calore, et infrigidatio a frigore. Similiter etiam ex termino et fine specificatur operatio; sicut sanatio et aegrotatio differunt specie, secundum differentiam sanitatis et aegritudinis. Sic igitur obiecta sunt priora operationibus animae in via definiendi. For, obviously, specifically diverse causal agents do specifically diverse things—as heat heats and cold chills. And so also with the final term of activity: becoming well or becoming ill differ as ‘doings’, because health differs from illness. Thus in the work of seeking definitions we have to consider the objects of the soul’s operations before these operations themselves.
Unde et prius oportebit determinare de obiectis quam de actibus, propter eamdem causam, propter quam et de actibus prius determinatur quam de potentiis. Obiecta autem sunt sicut alimentum respectu vegetativi, et sensibile respectu sensus, et intelligibile respectu intellectus. 306. We ought, therefore, to reach conclusions about objects before activities for the same reason as leads us to define activities before potencies. The ‘objects’ in question are such things as food and sensible being and intelligible being, with respect to the vegetative, sensitive and intellectual faculties respectively.
Sed sciendum est, quod ex obiectis diversis non diversificantur actus et potentiae animae, nisi quando fuerit differentia obiectorum inquantum sunt obiecta, id est secundum rationem formalem obiecti, sicut visibile ab audibili. Si autem servetur eadem ratio obiecti, quaecumque alia diversitas non inducit diversitatem actuum secundum speciem et potentiae. Eiusdem enim potentiae est videre hominem coloratum et lapidem coloratum; quia haec diversitas per accidens se habet in obiecto inquantum est obiectum. 307. But note that the activities and powers of soul are not distinguished with respect to distinct objects except precisely in so far as these are objects. For instance, visible being differs from audible being precisely as object. But if there is no difference as object, then it does not matter what other differences there may be; they win not essentially affect the kind of activity or potentiality. Thus by the same faculty we see a coloured man and a coloured stone; the difference is merely incidental to the object of the faculty.
Sciendum est etiam, quod intellectus noster possibilis est in potentia tantum in ordine intelligibilium: fit autem actu per formam a phantasmatibus abstractam. Nihil autem cognoscitur nisi secundum quod est actu: unde intellectus possibilis noster cognoscit seipsum per speciem intelligibilem, ut in tertio habetur, non autem intuendo essentiam suam directe. Et ideo oportet, quod in cognitionem animae procedamus ab his quae sunt magis extrinseca, a quibus abstrahuntur species intelligibiles, per quas intellectus intelligit seipsum; ut scilicet per obiecta cognoscamus actus, et per actus potentias, et per potentias essentiam animae. Si autem directe essentiam suam cognosceret anima per seipsam, esset contrarius ordo servandus in animae cognitione; quia quanto aliquid esset propinquius essentiae animae, tanto prius cognosceretur ab ea. 308. Note too that our intellectual potency is, as such, only potentially intelligible; in order to be understood it must be actualised through an idea drawn from sensible images. A thing is knowable only in the degree that it is actual; hence our intellectual potency attains to self-knowledge only through possessing an intelligible object in a concept (as will be explained in Book III), and not by directly intuiting its own essence. This is why the process of self-knowledge has to start from the exterior things whence the mind draws the intelligible concepts in which it perceives itself; so we proceed from objects to acts, from acts to faculties, and from faculties to essence. But if the soul could know its essence in itself and directly it would be better to follow the reverse procedure; for in that case the closer anything was to the soul’s essence, the more directly could it be known by the soul.

TEXT
415a23–415b28
BOOK II, CHAPTER, IV, CONTINUED

THE VEGETATIVE PRINCIPLE
HOW SOUL CAUSES BODY

2. ὥστε πρῶτον περὶ τροφῆς καὶ γεννήσεως λεκτέον· ἡ γὰρ θρεπτικὴ ψυχὴ καὶ τοῖς ἄλλοις ὑπάρχει, καὶ πρώτη καὶ κοινοτάτη δύναμίς ἐστι ψυχῆς, καθ' ἣν ὑπάρχει τὸ ζῆν ἅπασιν. We must first speak of nutrition and generation. For the vegetative soul is present in others, and is primary, and is that most general power of the soul by which life is present in anything: its operations being reproduction and the use of nutriment. §§ 309-10
ἧς ἐστὶν ἔργα γεννῆσαι καὶ τροφῇ χρῆσθαι· φυσικώτατον γὰρ τῶν ἔργων τοῖς ζῶσιν, ὅσα τέλεια καὶ μὴ πηρώματα ἢ τὴν γένεσιν αὐτομάτην ἔχει, τὸ ποιῆσαι ἕτερον οἷον αὐτό, ζῷον μὲν ζῷον, φυτὸν δὲ φυτόν, ἵνα τοῦ ἀεὶ καὶ τοῦ θείου μετέχωσιν ᾗ 415b δύνανται· πάντα γὰρ ἐκείνου ὀρέγεται, καὶ ἐκείνου ἕνεκα πράττει ὅσα πράττει κατὰ φύσιν (τὸ δ' οὗ ἕνεκα διττόν, τὸ μὲν οὗ, τὸ δὲ ᾧ). ἐπεὶ οὖν κοινωνεῖν ἀδυνατεῖ τοῦ ἀεὶ καὶ τοῦ θείου τῇ συνεχείᾳ, διὰ τὸ μηδὲν ἐνδέχεσθαι τῶν φθαρτῶν ταὐτὸ καὶ ἓν ἀριθμῷ διαμένειν, ᾗ δύναται μετέχειν ἕκαστον, κοινωνεῖ ταύτῃ, τὸ μὲν μᾶλλον τὸ δ' ἧττον, καὶ διαμένει οὐκ αὐτὸ ἀλλ' οἷον αὐτό, ἀριθμῷ μὲν οὐχ ἕν, εἴδει δ' ἕν. For the most natural of the operations of such living beings as are mature, and not defective nor spontaneously generated, is to produce others like themselves: an animal an animal, and a plant a plant. To this extent do they participate, as far as they are able, in the imperishable and the divine. For this all things seek after, doing all that they do by nature for the sake of this. Now ‘that for the sake of which’ anything takes place, is twofold, one, the end ‘for which’, the other the end ‘in which’. Since then they cannot share by a continuous being, in the divine and everlasting (since nothing corruptible remains for ever numerically one and the same) each shares in this as far as it is able, one, however, more, and another less. And thus it endures, not the same, but as if the same; one indeed, but in species, not numerically. §§311-17
3. ἔστι δὲ ἡ ψυχὴ τοῦ ζῶντος σώματος αἰτία καὶ ἀρχή. ταῦτα δὲ πολλαχῶς λέγεται, ὁμοίως δ' ἡ ψυχὴ κατὰ τοὺς διωρισμένους τρόπους τρεῖς αἰτία· καὶ γὰρ ὅθεν ἡ κίνησις καὶ οὗ ἕνεκα καὶ ὡς ἡ οὐσία τῶν ἐμψύχων σωμάτων ἡ ψυχὴ αἰτία. The soul is the cause and principle of the living body. Now these words can be used in many ways. The soul, however, is a cause in three established senses: for it is that whence comes movement; that ‘for the sake of which’; and as the essence of living bodies. § 318
ὅτι μὲν οὖν ὡς οὐσία, δῆλον· τὸ γὰρ αἴτιον τοῦ εἶναι πᾶσιν ἡ οὐσία, τὸ δὲ ζῆν τοῖς ζῶσι τὸ εἶναί ἐστιν, αἰτία δὲ καὶ ἀρχὴ τούτου ἡ ψυχή. That it is as the essence is evident. For in all things, the essence is the cause of existence. In things that live, to live is to be; and the cause and principle of this is the soul. § 319
ἔτι τοῦ δυνάμει ὄντος λόγος ἡ ἐντελέχεια. Further: of that which is in potency, the act is the [immanent] idea. § 320
5. φανερὸν δ' ὡς καὶ οὗ ἕνεκεν ἡ ψυχὴ αἰτία· ὥσπερ γὰρ ὁ νοῦς ἕνεκά του ποιεῖ, τὸν αὐτὸν τρόπον καὶ ἡ φύσις, καὶ τοῦτ' ἔστιν αὐτῆς τέλος. τοιοῦτον δ' ἐν τοῖς ζῴοις ἡ ψυχὴ κατὰ φύσιν· πάντα γὰρ τὰ φυσικὰ σώματα τῆς ψυχῆς ὄργανα, καθάπερ τὰ τῶν ζῴων, οὕτω καὶ τὰ τῶν φυτῶν, ὡς ἕνεκα τῆς ψυχῆς ὄντα· διττῶς δὲ τὸ οὗ ἕνεκα, τό τε οὗ καὶ τὸ ᾧ. It is manifest that the soul is also a cause ‘for the sake of which’. For Nature operates for a purpose, in the same way as, as mind; and this is its end. Such is the soul in living thin according to Nature. For all natural bodies are instruments of the soul: whether of animals or of plants, they exist as for the sake of the soul. ‘For the sake of’ is a phrase used in two ways, as ‘that for which’, and ‘that in which’. §§ 321-2
6. ἀλλὰ μὴν καὶ ὅθεν πρῶτον ἡ κατὰ τόπον κίνησις, ψυχή· οὐ πᾶσι δ' ὑπάρχει τοῖς ζῶσιν ἡ δύναμις αὕτη. ἔστι δὲ καὶ ἀλλοίωσις καὶ αὔξησις κατὰ ψυχήν· ἡ μὲν γὰρ αἴσθησις ἀλλοίωσίς τις εἶναι δοκεῖ, αἰσθάνεται δ' οὐθὲν ὃ μὴ μετέχει ψυχῆς, ὁμοίως δὲ καὶ περὶ αὐξήσεώς τε καὶ φθίσεως ἔχει· οὐδὲν γὰρ φθίνει οὐδ' αὔξεται φυσικῶς μὴ τρεφόμενον, τρέφεται δ' οὐθὲν ὃ μὴ κοινωνεῖ ζωῆς. But also the soul is the principle whence comes local motion. Yet this power is not present in all living things. Change and growth are, however, due to a soul, while sensation seems to be a kind of alteration, and nothing senses unless it has a soul. The same holds good of growth and decay; for nothing undergoes growth or decay physically, unless it is nourished; and nothing is nourished which does not share in life. § 323
ST. THOMAS’S COMMENTARY

LECTIO 7
Postquam philosophus distinxit potentias animae abinvicem, et ostendit quid et quo ordine de eis tractandum sit, hic secundum praetaxatum ordinem de eis determinat. Et dividitur in partes duas. In prima determinat de singulis partibus animae, quid sit unaquaeque. In secunda assignat causam, quare talem consequentiam habent adinvicem, ibi, vegetabilem igitur habent animam etc., in penultimo capitulo libri. 309. Having distinguished the capacities of ‘soul’ from one another, and explained how and in what order he means to discuss them, the Philosopher now treats of them in the order indicated. This he does in two stages. First, he examines one by one the divisions into which he has analysed soul, coming to certain conclusions about all of them. After that, in the penultimate chapter of this book, where he says, ‘All living things have the vegetative soul’, he explains the interrelation of these ‘parts’ of soul.
Prima dividitur in partes quatuor.
  1. In prima determinat de vegetativo.
  2. In secunda de sensitivo, ibi, determinatis autem his, dicamus communiter de omni sensu, et cetera.
  3. In tertia de intellectivo, ibi, de parte autem animae, qua cognoscit, et cetera.
  4. In quarta de motivo secundum locum, ibi, de movente autem, quod forte animae sit, et cetera.
The former section divides into four treatises:
  1. On the vegetative principle.
  2. Starting at ‘These questions being settled’ [II, 10: §350] on the sensitive principle.
  3. At ‘As to the part of the soul by which it knows’ [III, 7: §671], on the intellect.
  4. At ‘We must now consider’ [III, 14: §795], on the principle of local movement.
De appetitivo autem non facit specialem tractatum, quia appetitivum non constituit aliquem specialem gradum viventium, et quia simul cum motivo de eo determinatur in tertia. To the appetitive principle is assigned no special treatise, because it does not of itself constitute any special grade of animate being. It is treated, along with motion, in Book III.
Prima autem pars dividitur in duas. In prima praemittit quaedam, quae sunt necessaria ad cognitionem partis vegetativae. In secunda determinat de parte vegetativa, ibi, quoniam autem eadem potentia animae vegetativae et generativae, et cetera. Prima dividitur in duas. In prima dicit de quo est intentio. In secunda manifestat quaedam, quae praeexiguntur ad cognitionem partis vegetativae, ibi, naturalissimum enim operum et cetera. Treatise (1) divides into two parts: the first part contains certain preliminaries to the study of the vegetative principle; the second, beginning at ‘Since the vegetative and generative’ [II, 9: §333], contains Aristotle’s conclusions on this matter. The former section again divides into (a) a statement of his aim, and (b) at ‘For the most natural’ [§311] an exposition of certain things which an understanding of the vegetative principle presupposes.
Concludit ergo primo ex praedictis, quod cum dicendum sit primo de obiectis et actibus, quam de potentiis: et primo de prima potentia, quam de consequentibus; sequitur quod primo dicendum est de alimento, quod est obiectum animae vegetativae, et de generatione, quae est actus eius. Ideo primo dicendum est de obiecto et actu huiusmodi partis, quam aliarum: quia ista pars est prima inter alias partes animae in subiectis in quibus invenitur cum aliis: est enim quasi fundamentum aliarum, sicut esse naturale ad quod pertinent operationes eius, est fundamentum esse sensibilis et intelligibilis. Et alia ratio est, quare prius de ea dicendum est; quia ipsa est communis omnibus viventibus: ipsa enim separatur ab aliis, sed aliae non separantur ab ea, et de communibus prius est agendum. Huiusmodi autem partis opera sunt: generare, et alimento uti; et ideo de istis primo agendum est. 310. (a) First of all, then, he remarks that if, as we saw in the last chapter, objects and acts have to be defined before potencies, and the fundamental potency before those which follow from it, we ought in consequence to begin by discussing nourishment, the object with which the vegetative principle deals, and generation, which is this principle’s activity. Now this principle should be discussed first; because, whenever it coexists in one subject with the other parts. of ‘soul’, it is as it were their foundation; for through its activities the physical reality, underlying both sensitivity and intelligence, is maintained. Besides, this part of ‘soul’ is common to all living things, and while it can exist apart from the others, they cannot exist without it; and it is always best to start with the more general datum. Its activities, then, being reproduction and taking nourishment, it is with these that we begin.
Deinde cum dicit naturalissimum enim determinat quaedam quae praeexiguntur ad cognitionem partis vegetativae. Et dividitur in duas partes. In prima ostendit, quod generare pertinet ad partem vegetativam: quod ideo necessarium fuit quia supra huic parti non attribuit generationem, sed solum augmentum et decrementum. In secunda ostendit, quod opera potentiae vegetativae sint ab anima: quod ideo necessarium fuit, quia cum his operibus deserviant qualitates activae vel passivae, posset alicui videri, quod essent a natura, et non ab anima; et praecipue quia in plantis est vita occulta et latens, et hoc ibi, est autem anima viventis corporis, et cetera. 3 11. (b) Next, when he says ‘For the most natural’ he settles a few preliminary questions; and this in two stages. First, he shows that to generate one’s kind is an act of the vegetative principle. This he had not yet shown, having spoken so far only of growth and decay in this connection. Next, at ‘The soul is cause’, he proves that a soul is the principle of all vegetative activities (for indeed these activities might have seemed to come from mere nature, and not from a life-principle, since it is of their essence that they make use of the active and passive physical and corporeal qualities; and still more, because life in plants is hard to discern and latent).
Primum ostendit tali ratione. Omnis operatio, quae naturaliter invenitur in omnibus viventibus, pertinet ad potentiam vegetativam, secundum quam primo vivere inest omnibus, ut dictum est: sed generare naturaliter inest omnibus viventibus: ergo pertinet ad potentiam vegetativam. Dicit ergo, quod ideo generare est opus animae vegetativae, quia inter alia opera est magis naturale omnibus viventibus. Et dicitur naturalissimum, quia in hoc convenit etiam cum aliis rebus inanimatis, quae generationem habent, licet alio modo: habent enim inanimata generationem ab extrinseco generante; sed viventia a principio intrinseco, inquantum generantur ex semine, quod proficit in rem vivam. 312. The first point is proved thus. All activities found to be natural to all living things spring, as we have seen, from the vegetative principle as the fundamental condition of there being any life at all; and reproduction being one such activity, it must spring from the vegetative principle. Indeed, he relates reproduction to this principle because it is, as he says, the activity most natural to all living things; and this because in a certain way the process of generation is common to all beings, even to inanimate things. Of course the latter are generated differently; still, they are generated. But with them the generating principle is something quite exterior to the thing that comes into being, whereas animate things proceed from an, interior principle inasmuch as they spring from the seed with its potentiality for new life.
Sed ab ista generalitate viventium excipiuntur tria, quibus hoc opus non competit. Primo illa quae sunt imperfecta, sicut pueri non generant. Quod enim potest alterum facere tale quale ipsum est, in unoquoque genere, perfectum est. Secundo excipit illa quae patiuntur aliquem defectum alicuius principii naturalis, sicut sunt spadones et frigidi. Tertio animalia et plantae quae generantur sine semine ex putrefactione. In his enim, propter sui imperfectionem sufficit ad eorum productionem agens universale, scilicet virtus corporis caelestis, et materia disposita. In animalibus autem perfectis plura requiruntur principia; non enim agens universale sufficit, sed requiritur agens proprium univocum. 313. There are, however, three exceptions to the general rule that living things reproduce their kind. First, the immature; for children do not beget. Secondly, those defective in some essential requirement, such as the impotent and eunuchs. Thirdly, the case of spontaneous generation from putrefying matter. In this last case the life resulting is of a type so inferior that the general environment suffices to cause it, i.e. the influence of the heavenly bodies and the right material conditions. But these causes alone are not sufficient to generate the higher animals: this requires also the activity of particular causes of the same species as the animals generated.
Dicit ergo, quod viventia possunt facere alterum quale ipsa sunt quaecumque sunt perfecta ad excludendum pueros: et non orbata: ad excludendum eunuchos, et habentes similes defectus: aut quaecumque non habent generationem spontaneam: ad excludendum ea quae generantur ex putrefactione, quae dicuntur quasi sponte nasci, quia producuntur ex terra sine semine, per illam similitudinem, qua dicitur aliquis sponte facere illud, ad quod extrinseco non inducitur. Sic autem intelligitur, quod res viva facit alterum quale ipsum est, quia animal facit animal, et planta plantam. Et ulterius secundum speciem tale animal facit tale animal, ut homo generat hominem, et oliva olivam. Ideo autem est naturale viventibus facere alterum tale quale ipsum est, ut semper participent, secundum quod possunt, divino et immortali, id est ut assimilentur ei secundum posse. 314. Hence he says that any living thing can reproduce its kind provided that it is ‘mature’ (excluding children) and not ‘defective’ (excluding eunuchs and such like) and that the effect generated is not ‘spontaneously generated’ (excluding things produced by putrefaction, which are said to come to be ‘spontaneously’ because they spring up without seed, which is something like the way things are done, as we say, spontaneously, i.e. not under exterior compulsion). And what he means by living things producing their like is that animals produce animals and plants plants; and more precisely that each species produces its like, men producing men and olive-trees olive-trees. And the reason why living things produce their like is that they may continuously participate, so far as they can, in what is divine and immortal, i.e. that they may become as like to the divine as possible.
Considerandum est enim, quod sicut sunt diversi gradus perfectionis in aliquo uno et eodem, quod exit de potentia in actum, ita etiam sunt diversi gradus perfectionis in diversis entibus: unde quanto aliquid fuerit magis perfectum, tanto perfectioribus magis assimilatur. Sicut igitur unumquodque quando fuerit exiens de potentia in actum, cum fuerit in potentia, ordinatur ad actum, et appetit ipsum naturaliter, et cum fuerit in actu minus perfecte desiderat actum perfectiorem: ita unumquodque, quod est in inferiori gradu rerum, desiderat assimilari superioribus, quantum potest. Et hoc est quod subiungit, quod omnia appetunt illud, scilicet assimilari divino et immortali, et illius causa agunt, quaecumque naturaliter agunt. 315. For just as there are degrees of perfection in one and the same being, inasmuch as it develops from potentiality into act, so there are more and less perfect beings; and therefore the more perfect a given thing is in itself, the more does it resemble the more perfect beings. Hence just as, while a thing is moving from potency to actuality, and as long as it is still in potency, it has a natural relation and inclination towards actuality, and when it attains incomplete actuality it still desires a more complete actuality, so, in the same way, everything in a lower form of existence is inclined to the maximum possible assimilation to the higher form. Hence Aristotle adds that ‘all things seek this’, i.e. an assimilation to what is divine and imperishable, and this is that ‘for the sake of which they do all that they do by nature’.
Sed intelligendum est, quod id cuius causa agitur, dicitur dupliciter. Uno modo id cuius causa agitur directe, sicut sanitatis causa agit medicus: alio modo sicut quo. Quod potest intelligi dupliciter. Uno modo, ut intelligamus, quod finis dicitur, et subiectum habens id cuius causa agitur, ut si dicamus, quod finis medicinae est, non tantum sanitas, sed etiam corpus habens sanitatem; alio modo ut dicamus, quod finis est, non tantum principale intentum, sed etiam illud quo illud adipiscimur, ut si dicamus, quod finis medicinae est calefacere corpus, quia a calore habetur aequalitas complexionis, quae est sanitas. Sic igitur et hoc potest dici, quod ipsum esse perpetuum est cuius causa agitur, vel res habens perpetuitatem, cui naturalia intendunt assimilari per generationem, in quo scilicet est perpetuitas, vel etiam ipsa generatio, qua perpetuitatem adipiscuntur. 316. Now ‘that for the sake of which’ something is done can mean two things: (a) the end aimed at directly by an activity, as health is the direct aim of doctoring; and (b) as the end aimed at indirectly; and this again may be taken in two ways. For we might take the ‘end’ to include also that subject in which the activity’s direct aim is realised, and in this sense the end of doctoring would be not health merely, but a healthy body. Alternately, we could mean by ‘end’ not only what is principally intended, but also the means to be employed; we might say, e.g. that the end of doctoring was to keep the body warm, because warmth preserves that harmony of elements in the body which is health. So then, when it is said here that perpetuity of being is the reason for the activity in question, we are referring either to some imperishable nature which material things strive, by reproducing their kind, to resemble, or to the reproductive process itself, which is the means to this end.
Quia igitur non possunt communicare inferiora viventia ipsi esse sempiterno et divino, per modum continuationis, idest ut maneant eadem numero, propter hoc quod nihil corruptibilium contingit unum et idem numero permanere semper, et cum necessitas corruptionis sit necessitas absoluta, utpote proveniens ex ipsa materia, non ex fine, sequitur, quod unumquodque communicet perpetuitate secundum quod potest: hoc quidem magis, quod est diuturnius: illud vero minus, quod est minus diuturnum, et tamen permanet semper per generationem, non idem simpliciter, sed ut idem, id est in simili secundum speciem. Unde exponens quod dixerat, subdit quod non permanet unum numero, quod est esse unum simpliciter; sed permanet idem specie, quia unumquodque generat sibi simile secundum speciem. 317. Because, then, the lower forms of life are unable to share in the perpetual, divine being by way of continuity of their individual identity—since it is absolutely and intrinsically necessary (not merely a necessity imposed from without) that all corruptible things should individually pass away since they are intrinsically material—it follows that they can only share in it so far as their nature allows; the more lasting natures more, the less lasting less; but all sharing in it continuously by way of reproduction; each remaining one and the same, not indeed literally, but ‘as if the same’ in the sense that one and the same species remains. Hence he adds that it does not remain one thing numerically, i.e. in the strict sense of the terms, but only specifically; and this because each individual reproduces its like according to species.
Deinde cum dicit est autem ostendit quod opera, quae attribuuntur potentiae vegetativae, sunt ab anima. Et circa hoc duo facit. Primo ostendit veritatem. Secundo excludit errorem, ibi, Empedocles autem non bene dixit, et cetera. Circa primum duo facit. Primo proponit quod intendit: et dicit, quod anima est principium et causa viventis corporis. Et cum principium et causa dicatur multipliciter, anima dicitur tribus modis principium et causa viventis corporis. Uno modo, sicut unde est principium motus. Alio modo, sicut cuius causa, idest finis. Tertio, sicut substantia, id est forma corporum animatorum. 318. Then, at ‘The soul is the cause’, he shows the connection between the activities attributed to the vegetative principle and the soul. And he does two things here: first, he establishes a truth; secondly, at ‘Empedocles’, he points out an error. The proof of the truth, again, has two stages. First, he states his aim, asserting that the soul is principle and cause of the living body; and since these terms are ambiguous, going on to distinguish three senses in which this proposition is to be taken. Soul, he says, is cause of the living body, (a) as the source of its movements, (b) as ‘that for the sake of which’, or end, and (c) as its ‘essence’ or form.
Secundo ibi quod igitur probat quod supposuerat. Et primo, quod anima sit causa viventis corporis, ut forma: et hoc duplici ratione: quarum prima talis est. Illud est causa alicuius ut substantia, idest, ut forma, quod est causa essendi. Nam per formam unumquodque est actu. Sed anima viventibus est causa essendi; per animam enim vivunt, et ipsum vivere est esse eorum: ergo anima est causa viventis corporis, ut forma. 319. in the second place, at ‘That it is’, he proves his proposition; and first with regard to soul being the cause of the living body as its form. Here he uses two arguments: first, the cause of anything as its ‘essence’, i.e. form, is the same as the cause of its being, for everything has actual existence through its form. Now it is the soul that gives being to living things; for their being is precisely their life, which they have from the soul. Hence the soul causes the body as its form.
Secundam rationem ponit ibi amplius autem quae talis est. Id quod est actus alicuius, est ratio et forma eius quod est in potentia: sed anima est actus corporis viventis, ut ex superioribus patet: ergo anima est ratio et forma viventis corporis. 320. Then the second argument, at ‘Further’: the actuality of anything is the immanent idea and form of the thing as in potency. Now the soul, as we have seen, is the living body’s actuality. Therefore it is the form and immanent idea of the living body.
Secundo ibi manifestum autem ostendit quod anima est causa, ut finis. Et quod sit causa, ut finis, viventium corporum, sic ostendit. Sicut enim intellectus operatur propter finem, ita et natura, ut probatur in secundo physicorum. Sed intellectus in his quae fiunt per artem, materiam ordinat et disponit propter formam: ergo et natura. Cum igitur anima sit forma viventis corporis, sequitur quod sit finis eius. 321. Next, at ‘It is manifest’, he shows that the soul is a final cause of living bodies. For Nature, like mind, acts for a purpose, as was shown in Book II of the Physics. But the mind, in its constructions, always orders and arranges materials in view of some form. So also, then, does Nature. If then the soul is the living body’s form, it must also be its final cause.
Et ulterius non solum anima est finis viventium corporum, sed etiam omnium naturalium corporum in istis inferioribus: quod sic probat. Videmus enim quod omnia naturalia corpora sunt quasi instrumenta animae, non solum in animalibus, sed etiam in plantis. Videmus enim quod homines utuntur ad sui utilitatem animalibus, et rebus inanimatis: animalia vero plantis et rebus inanimatis; plantae autem rebus inanimatis, inquantum scilicet alimentum et iuvamentum ab eis accipiunt. Secundum autem, quod agitur unumquodque in rerum natura, ita natum est agi. Unde videtur quod omnia corpora inanimata, sint instrumenta animatorum, et sint propter ipsa. Et etiam animata minus perfecta, sint propter animata magis perfecta. Et consequenter distinguit id cuius causa est, sicut et supra. 322. Moreover the soul is the end not only of living bodies, but also of all sublunary natural bodies. For it is evident that all such bodies are, as it were, instruments of ‘soul’—not only of animals’ souls but of the plant soul as well. Thus men turn to their own, purposes both animals and inanimate things; animals make use of plants and inanimate things; and plants of the inanimate things which support and feed them. If then the action of things is an index to their nature it seems that all inanimate bodies are naturally instruments of animate things and exist for their sake. And, incidentally, the lower animate things exist for the higher. After this he distinguishes ‘for the sake of’ into the two aspects which have already been explained.
Tertio ibi at vero ostendit quod anima est principium moventis corporis, sicut unde motus: et utitur quasi tali ratione. Omnis forma corporis naturalis est principium motus proprii illius corporis, sicut forma ignis est principium motus eius. Sed quidam motus sunt proprii rebus viventibus: scilicet motus localis, quo animalia movent seipsa motu processivo secundum locum, licet hoc non insit omnibus viventibus: et similiter sentire est alteratio quaedam: et hoc non inest nisi habentibus animam. Item motus augmenti et decrementi non inest nisi illis quae aluntur, et nihil alitur nisi habens animam: ergo oportet, quod anima sit principium omnium istorum motuum. 323. Thirdly, at ‘But also the soul’, he shows that the soul is the source of movement in the body. The form of every natural body, he explains, is the principle of the characteristic movement of that particular kind of body—e.g. the form of fire is cause of fire’s movement. Now certain movements are characteristic of living bodies; such, for instance, as that by which animals move themselves about from place to place, though this, to be sure, is not found in all living things. Similarly sensation involves a certain alteration of the body not found except in beings that have soul. So too with growth and decay; these movements imply the use of food and therefore also a soul. The soul, then, is the principle of all these movements.

TEXT
415b28–416a18
BOOK II, CHAPTER IV, CONTINUED

THE VEGETATIVE PRINCIPLE CONTINUED
TWO ERRORS REFUTED

416a          7. Ἐμπεδοκλῆς δ' οὐ καλῶς εἴρηκε τοῦτο προστιθείς, τὴν αὔξησιν συμβαίνειν τοῖς φυτοῖς κάτω μὲν συρριζουμένοις διὰ τὸ τὴν γῆν οὕτω φέρεσθαι κατὰ φύσιν, ἄνω δὲ διὰ τὸ <τὸ> πῦρ ὡσαύτως. Empedocles is mistaken here, adding that growth occurs in plants by their sending a root downwards, because earth is by nature below, and also upwards because of fire. § 324
οὔτε γὰρ τὸ ἄνω καὶ κάτω καλῶς λαμβάνει (οὐ γὰρ ταὐτὸ πᾶσι τὸ ἄνω καὶ κάτω καὶ τῷ παντί, ἀλλ' ὡς ἡ κεφαλὴ τῶν ζῴων, οὕτως αἱ ῥίζαι τῶν φυτῶν, εἰ χρὴ τὰ ὄργανα λέγειν ἕτερα καὶ ταὐτὰ τοῖς ἔργοις). Nor did he understand aright ‘up’ and ‘down’; for these are not for all things the same as for the Universe; but roots of plants correspond to the head, in animals, if it is permissible to identify organs by their functions. For we reckon those organs to be the same which perform the same operations. §§ 325-7
πρὸς δὲ τούτοις τί τὸ συνέχον εἰς τἀναντία φερόμενα τὸ πῦρ καὶ τὴν γῆν; διασπασθήσεται γάρ, εἰ μή τι ἔσται τὸ κωλύον· εἰ δ' ἔσται, τοῦτ' ἔστιν ἡ ψυχή, καὶ τὸ αἴτιον τοῦ αὐ- ξάνεσθαι καὶ τρέφεσθαι. Besides, what holds fire and earth together if they tend in contrary directions? They must come apart if there is nothing to prevent this. But if there is such a thing, it must be the soul; and be also the cause of growth and nourishment. § 328
8. δοκεῖ δέ τισιν ἡ τοῦ πυρὸς φύσις ἁπλῶς αἰτία τῆς τροφῆς καὶ τῆς αὐξήσεως εἶναι· καὶ γὰρ αὐτὸ φαίνεται μόνον τῶν σωμάτων [ἢ τῶν στοιχείων] τρεφόμενον καὶ αὐξόμενον, διὸ καὶ ἐν τοῖς φυτοῖς καὶ ἐν τοῖς ζῴοις ὑπολάβοι τις ἂν τοῦτο εἶναι τὸ ἐργαζόμενον. Now it seems to some that the nature of fire is the sole cause of growth and nutrition; for it certainly seems to be the only one of the bodies and elements that is self-nourishing and self-increasing. Whence the notion that it is this that is operative in plants and animals. §§ 329-30
τὸ δὲ συναίτιον μέν πώς ἐστιν, οὐ μὴν ἁπλῶς γε αἴτιον, ἀλλὰ μᾶλλον ἡ ψυχή· ἡ μὲν γὰρ τοῦ πυρὸς αὔξησις εἰς ἄπειρον, ἕως ἂν ᾖ τὸ καυστόν, τῶν δὲ φύσει συνισταμένων πάντων ἔστι πέρας καὶ λόγος μεγέθους τε καὶ αὐξήσεως· ταῦτα δὲ ψυχῆς, ἀλλ' οὐ πυρός, καὶ λόγου μᾶλλον ἢ ὕλης. It is indeed a concomitant cause, but the cause absolutely is not fire, but rather the soul. For the increase of fire is infinite so long as there is anything combustible. But there are limitations to all things that subsist naturally, and some definite principle governs their dimensions and growth. And this belongs to the soul, not to fire, and to a specific principle rather than to matter. §§ 331-2
ST. THOMAS’S COMMENTARY

LECTIO 8
Superius ostendit philosophus, quod opera quae attribuuntur potentiae vegetativae, sunt ab anima. Nunc excludit quosdam errores, contra determinatam veritatem. Et dividitur in partes duas, secundum duos errores, quos removet. Secunda pars incipit, ibi, videtur autem quibusdam. Circa primum duo facit. Primo ponit errorem. Secundo improbat ipsum, ibi, neque enim sursum et deorsum. Sciendum est igitur circa primum, quod sicut Empedocles alias utilitates, quae in rebus viventibus proveniunt, non dixit procedere ex intentione naturae, sed ex necessitate materiae, puta quod pedes animalium sic sunt dispositi, non ut sint utiles ad gressum, sed quia sic contingit materiam dispositam fuisse circa pedes; ita etiam et augmentum viventium non attribuit animae, sed motui gravium et levium. Videbat enim quod viventia augentur in diversas partes, puta sursum et deorsum; quod apparet manifeste in plantis, quae radices in deorsum mittunt, et rami in sursum elevantur. Dicebat igitur, quod augmentum plantarum in deorsum, causatur ex motu terrae, quae est in compositione plantae, et naturaliter deorsum fertur, propter sui gravitatem. Augmentum autem in sursum causatur ex motu ignis, qui propter sui levitatem naturaliter sursum fertur. 324. The Philosopher has just shown that the activities we call vegetative have their origin in the soul. He now proceeds to refute two errors on this subject, which he deals with respectively in two sections; the second of which begins at ‘Now it seems to some that the nature of fire’. In the first section he begins by stating the error, and then, at ‘Nor did he understand’ attacks it. Regarding the error itself, we should note that just as Empedocles refused to explain other cases of purposeful arrangement in Nature by any natural finality—for example he said that animals had the sort of feet they have, not in order to help them to walk, but simply because the matter of that part of their bodies happened to be arranged in that sort of way; so also the growth of living things he ascribed merely to the motion of light and heavy bodies. Observing that living things increase their size in different directions, e.g. up and down—as is evident in plants, which thrust their roots down and their branches up—he said that the downward growth of plants was due to the earth in their composition, which is heavy and therefore necessarily tends downwards; whilst their upward growth was due to fire which, being light, must tend upwards.
Deinde cum dicit neque enim reprobat praedictam opinionem dupliciter. Et primo quidem per hoc quod non bene accipit sursum et deorsum. Ad cuius evidentiam sciendum est, quod sursum et deorsum, et aliae positionum differentiae, scilicet ante et retro, dextrum et sinistrum, in quibusdam quidem distinguuntur secundum naturam, in quibusdam vero solum positione quoad nos. In quibus enim sunt determinatae partes, quae sunt naturaliter principia aliquorum motuum, in his distinguuntur praedictae positionum differentiae secundum naturam; sicut in universo, ad cuius medium naturaliter feruntur gravia, ad circumferentiam feruntur naturaliter levia. Unde in universo sursum et deorsum naturaliter distinguuntur. Et sursum dicitur locus ad quem feruntur levia: et deorsum sive medium, ad quem feruntur naturaliter gravia. In viventibus etiam et mortalibus, secundum motum augmenti et decrementi, determinantur sursum et deorsum. Nam sursum dicitur illa pars, unde viventia alimentum accipiunt; deorsum autem pars opposita, unde superfluitates emittuntur. 325. Aristotle, then, at ‘Nor did he’, brings two arguments against this opinion of Empedocles. First, he says that Empedocles misunderstood ‘up and down’. To see what he means here we should note that ‘up and down’, and the other differences of position (before and behind, right and left) are differentiated in some objects naturally, whilst in others they are merely relative to ourselves. In things which have definite parts as the natural principle of their various movements, these positions are based on Nature itself Thus the Cosmos as a whole has a mid-point to which heavy things naturally tend, and a circumference to which light things naturally rise; which makes a natural cosmic difference between up and down, according to the natural resting places of the light and the heavy. Again, in living things and mortal beings up and down follow growth and decay: the upper is that part which takes in food, and the lower the opposite part which ejects superfluities.
Ante vero et retro determinatur in quibusdam animalibus vel viventibus secundum sensum: dextrum et sinistrum secundum motum localem. In his vero in quibus non est aliqua determinata pars, principium aut terminus alicuius motus, in eis non determinantur positionum differentiae secundum naturam, sed solum positione quoad nos, sicut in rebus inanimatis. Unde eadem columna dicitur sinistra et dextra, secundum quod est homini dextra vel sinistra. In quibusdam autem viventium, in quibus determinatur sursum et deorsum secundum naturam, eodem modo determinantur sicut in universo; ut in homine, cuius superior pars, idest caput, est versus sursum universi, inferior autem est versus deorsum ipsius. In plantis autem est e converso; nam radices plantarum sunt proportionabiles capiti; ad eumdem enim actum ordinantur: nam sicut animalia cibum accipiunt ore, quod est in capite, ita plantae radicibus. Instrumenta autem dicuntur eadem et altera, sive similia et dissimilia, ex operibus, quae sunt fines eorum; unde radices plantarum sunt similes capitibus animalium, et tamen sunt versus deorsum. Unde modo contrario se habet sursum et deorsum in plantis, et in universo. In brutis autem animalibus non eodem modo se habet; quia eorum capita non se habent versus sursum universi, neque deorsum ipsius. Hoc est ergo quod dicit, quod sursum et deorsum non est idem omnibus, scilicet viventibus, et omni, idest universo. 326. Again, in some animals before and behind are determined in relation to their senses, and the right and the left by their movements in space. But things, no part of which is a special source or term of movement, have no natural differences of position in themselves; these are fixed simply by the thing’s position relative to us. So is it with inanimate objects: the same pillar is said to be on the right or the left according as it is to the right or left of a man. Now in certain living things the natural upper and lower parts are fixed in the same way as in the Cosmos as a whole. It is so in man whose head is turned towards the top of the Cosmos and his feet to its bottom. But the reverse is found in plants, whose roots correspond to the head in man, since they function (as the part which takes in food) in the same way as the head in man. For we reckon that instruments are similar or dissimilar if their functions are so; hence the likeness between a plant’s roots and the head of an animal, although they point downwards. Up and down, then, mean opposite things in plants and in the Cosmos as a whole. But brute animals are different; their heads are turned neither up nor down in relation to the Cosmos as a whole. This is what he means when he says that up and down are not for all things (i.e. living things) what they are for the Cosmos.
Sed Empedocles sic accipit sursum et deorsum, ac si eodem modo esset in omnibus viventibus et in universo. Si enim motus augmenti, secundum quem determinatur sursum et deorsum in viventibus, sit secundum motum gravium et levium secundum quem determinatur sursum et deorsum in universo, sequetur quod eodem modo sit sursum et deorsum in omnibus viventibus et in universo. Et ideo etiam ipse in plantis augmentum radicum dicit esse deorsum. 327. But Empedocles took up and down to be the same for all living things and for the Cosmos. And. indeed, if the movement of growth, by which we fix the upper and lower in living beings, followed the movements of the heavy and the light, by which the same relations are fixed for the Cosmos as a whole, then up and down would mean the same in all living beings and in the Cosmos. This is what led Empedocles to say that the roots of plants grew downwards.
Secundo ibi adhuc autem reprobat praedictam positionem alio modo. Ad cuius evidentiam sciendum est, quod cum elementa non sint actu in mixto, sed in virtute, non habet in eo quodlibet elementum seorsum proprium motum, sed totum mixtum movetur motu elementi praedominantis in ipso. Si autem quodlibet elementum haberet proprium motum, ut Empedocles ponere videbatur; cum naturalis motus elementorum sit ad contraria loca, sequeretur, quod totaliter abinvicem separarentur, nisi esset aliquid continens elementa, quod non sineret totaliter abscedere elementa abinvicem. Illud autem quod continet elementa, ne totaliter abinvicem segregentur, maxime videtur esse causa augmenti. Sed augmentum secundum diversas partes contingit ex diversis motibus elementorum. Non enim posset imaginari, qualiter esset augmentum, elementis in contraria motis, nisi per hoc quod manent adinvicem coniuncta; quia si totaliter separarentur, esset divisio, non augmentum. Illud igitur principaliter est causa augmenti, quod continet elementa, ne totaliter abinvicem separentur: hoc autem est anima in rebus viventibus: anima igitur est principium augmenti. 328. The second argument against Empedocles begins at ‘Besides, what holds’. To understand it, we should note that each element in a mixture is present not equally but virtually, and, therefore lacking the movement proper to itself. The whole mixture moves with the movement of the element that predominates. If each, as, Empedocles seems to have thought, retained its own movement, then, since the elements have natural movements in contrary directions, it follows that they would become quite separate from one another, unless some containing force held them together. Now it is just this container of the element which seems to be the chief cause of growth. For though, to be sure, the increase of the body in its various parts is due to diverse motions of the elements, yet,’ given the contrariety of elemental motion, growth is inconceivable unless the elements remain conjoined; otherwise there would be division, not growth. But in living things the soul is what holds the elements together; it is also, therefore, the’ source of their growth.
Deinde cum dicit videtur autem ponit aliam positionem. Et circa hoc duo facit. Primo ponit eam. Secundo improbat, ibi, hoc autem concausa, et cetera. Sciendum est autem, quod haec opinio differt in hoc a prima, quod prima attribuebat causam augmenti et alimenti diversis elementis, scilicet igni et terrae: haec autem attribuit eorum causam igni tantum. 329. Next, at ‘Now it seems to some’, he states another theory; which, at ‘It is indeed’ he then disproves. Unlike the theory. of Empedocles, which put the causes of growth and nutrition in both earth and fire, this theory ascribes them only to fire.
Et movebantur ad hoc hac ratione. Quia illud videtur esse principium alicuius passionis vel motus in aliquo, secundum quod se habet illam passionem vel motum: sicut ignis, qui secundum se calidus est, est causa caloris in rebus mixtis; et terra, quae secundum se est gravis, est causa gravitatis in eis. Inter autem elementa videtur solus ignis nutriri et augeri, si superficialiter de nutrimento et augmento loquamur. Solus igitur ignis videtur esse faciens augmentum et alimentum in plantis et animalibus. Utrum vero ignis nutriatur et augeatur, inferius erit manifestum. 330. The reason given is that the cause of anything’s modifications or motion would appear to be whatever had such modifications or motions essentially—e.g. fire, being essentially hot, is the cause of heat in things that contain other elements as well; and in the same way earth is the cause of heaviness. Now of the elements fire alone seems to ‘feed’ itself and to ‘grow’ ; if we take these terms in a superficial sense. Therefore fire alone would seem to cause growth and nutrition in plants and animals. But whether fire really feeds itself and grows will be made clear later.
Deinde cum dicit hoc autem improbat praedictam positionem. Sciendum tamen est, quod praedicta positio aliquid habet veritatis. Necesse est enim omne alimentum decoqui: quod quidem fit per ignem: unde ignis aliquo modo operatur ad alimentum, et per consequens ad augmentum: non quidem sicut agens principale, hoc enim est animae; sed sicut agens secundarium et instrumentale. Et ideo dicere, quod ignis quodammodo concausa est augmenti et alimenti, sicut instrumentum concausa est principalis agentis, verum est; non tamen est principaliter causa ut principale agens, sed hoc modo causa est anima: quod sic probat. 331. Then he attacks the above opinion. But note its grain of truth. All food has to be cooked, and this is done by fire, so that fire does play a part in nutrition, and consequently in growth also; not indeed as the principal agent (which is the soul) but as a secondary, instrumental agent. To say then that fire is a sort of concurrent or instrumental cause of growth and nutrition is true. But it cannot be the principal cause or agent, as he goes on to show.
Illud est principale in qualibet actione a quo imponitur terminus et ratio ei quod fit; sicut patet in artificialibus, quod terminus vel ratio arcae vel domui non imponitur ab instrumentis, sed ab ipsa arte. Nam instrumenta se habent differenter ut cooperentur ad hanc formam vel quantitatem, vel aliam. Serra enim quantum est de se, apta est ad secandum lignum, secundum quod competit et ostio, et scamno, et domui, et in quacumque quantitate; sed quod sic secetur lignum, quod sit aptum ad talem formam et ad talem quantitatem, est ex virtute artis. Manifestum est autem, quod in omnibus quae sunt secundum naturam, est certus terminus, et determinata ratio magnitudinis et augmenti: sicut enim cuilibet speciei debentur aliqua accidentia propria, ita et propria quantitas, licet cum aliqua latitudine propter diversitatem materiae, et alias causas individuales; non enim omnes homines sunt unius quantitatis. Sed tamen est aliqua quantitas tam magna, ultra quam species humana non porrigitur; et alia quantitas tam parva, ultra quam homo non invenitur. Illud igitur quod est causa determinationis magnitudinis et augmenti est principalis causa augmenti. Hoc autem non est ignis. Manifestum est enim, quod ignis augmentum non est usque ad determinatam quantitatem, sed in infinitum extenditur, si in infinitum materia combustibilis inveniatur. Manifestum est igitur, quod ignis non est principale agens in augmento et alimento, sed magis anima. Et hoc rationabiliter accidit; quia determinatio quantitatis in rebus naturalibus est ex forma, quae est principium speciei, magis quam ex materia. Anima autem comparatur ad elementa, quae sunt in corpore vivente, sicut forma ad materiam. Magis igitur terminus et ratio magnitudinis et augmenti est ab anima, quam ab igne. 332. The principal agent in any action is that which imposes the term or natural limit upon what is done; thus in artificial things like boxes or houses the limit or term is fixed, not by the instruments used in the work, but by the art itself. The instruments, as such, are quite indifferent as to whether they are used to produce a thing of this shape and quantity or of that. A saw, as such, can be used to cut wood for a door or a bench or a house, and in any quantity you please; and if it cuts wood in this or that particular shape and quantity, this is due to the man who uses it. Now in Nature each thing obviously has certain limits to its size and its increase; each thing grows to a certain fixed pattern. For as each species of thing requires its own accidental modifications, so it needs its own measure of quantity, though some margin must be left to material differences and other individual factors. Men are nor all equal in size. But there is a limit both to their largeness and their littleness; and whatever determines this limit is the true principal cause of growth. But this cannot be fire, because the growth of fire has no naturally fixed limits; it would spread to infinity if an infinite amount of fuel were supplied to it. Clearly, then, fire is not the chief cause of growth and nutrition, but rather the soul. And this is reasonable enough, for the quantitative limits of material things are fixed by form—the specific principle—rather than matter. Now the soul of a living being is to the elements it contains as form is to matter; the soul, then, rather than fire, sets the term and natural limit to size and growth.

TEXT
416a19–416b31
BOOK II, CHAPTER IV, CONTINUED

THE VEGETATIVE PRINCIPLE CONTINUED
NUTRITION

9. ἐπεὶ δ' ἡ αὐτὴ δύναμις τῆς ψυχῆς θρεπτικὴ καὶ γεννητική, περὶ τροφῆς ἀναγκαῖον διωρίσθαι πρῶτον· ἀφορίζεται γὰρ πρὸς τὰς ἄλλας δυνάμεις τῷ ἔργῳ τούτῳ. Since the vegetative and generative faculties of the soul are a single power, it is first necessary to fix the nature of nutrition. For it is by this operation that [this power] is distinguished from the others. § 333
δοκεῖ δ' εἶναι ἡ τροφὴ τὸ ἐναντίον τῷ ἐναντίῳ, οὐ πᾶν δὲ παντί, ἀλλ' ὅσα τῶν ἐναντίων μὴ μόνον γένεσιν ἐξ ἀλλήλων ἔχουσιν ἀλλὰ καὶ αὔξησιν· γίνεται γὰρ πολλὰ ἐξ ἀλλήλων, ἀλλ' οὐ πάντα ποσά, οἷον ὑγιὲς ἐκ κάμνοντος. φαίνεται δ' οὐδ' ἐκεῖνα τὸν αὐτὸν τρόπον ἀλλήλοις εἶναι τροφή, ἀλλὰ τὸ μὲν ὕδωρ τῷ πυρὶ τροφή, τὸ δὲ πῦρ οὐ τρέφει τὸ ὕδωρ. ἐν μὲν οὖν τοῖς ἁπλοῖς σώμασι ταῦτ' εἶναι δοκεῖ μάλιστα τὸ μὲν τροφὴ τὸ δὲ τρεφόμενον. It would appear that food is a contrary to that which is fed: yet not every contrariety [involves feeding]; but only such contraries as find their increase as well as their origin in each other. For there are many things which originate from opposites: but not all derive their increase thus; (for instance, health coming from sickness). Nor, it seems, do all that do so nourish one another in the same way. For water is a food to fire, but fire does not feed water. And with uncompounded bodies this seems especially to be the case; that which feeds is one thing and that which is fed another. §§ 334-5
10. ἀπορίαν δ' ἔχει· φασὶ γὰρ οἱ μὲν τὸ ὅμοιον τῷ ὁμοίῳ τρέφεσθαι, καθάπερ καὶ αὐξάνεσθαι, τοῖς δ' ὥσπερ εἴπομεν τοὔμπαλιν δοκεῖ, τὸ ἐναντίον τῷ ἐναντίῳ, ὡς ἀπαθοῦς ὄντος τοῦ ὁμοίου ὑπὸ τοῦ ὁμοίου, τὴν δὲ τροφὴν δεῖν μεταβάλλειν καὶ πέττεσθαι· ἡ δὲ μεταβολὴ πᾶσιν εἰς τὸ ἀντικείμενον ἢ τὸ μεταξύ. ἔτι πάσχει τι ἡ τροφὴ ὑπὸ τοῦ τρεφομένου, ἀλλ' οὐ τοῦτο ὑπὸ τῆς 416b 11. τροφῆς, ὥσπερ οὐδ' ὁ τέκτων ὑπὸ τῆς ὕλης, ἀλλ' ὑπ' ἐκεί- νου αὕτη· ὁ δὲ τέκτων μεταβάλλει μόνον εἰς ἐνέργειαν ἐξ ἀργίας. But a difficulty arises here. For some say that anything is nourished by what is similar to it; just as it is increased thus. But to others, as we have said, it seems, on the contrary, that a thing is nourished by its opposite,—as though it were impossible that like [should be altered] by, like; whilst food is altered and digested. Change in all things is either [to] an opposite or to a mean state. Moreover nutriment is acted upon by that which is nourished: not the latter by the nourishment; any more than a craftsman by his material; but this is acted on by him—the craftsman changing only from repose to activity.
πότερον δ' ἐστὶν ἡ τροφὴ τὸ τελευταῖον προσγινόμενον ἢ τὸ πρῶτον, ἔχει διαφοράν. εἰ δ' ἄμφω, ἀλλ' ἡ μὲν ἄπεπτος ἡ δὲ πεπεμμένη, ἀμφοτέρως ἂν ἐνδέχοιτο τὴν τροφὴν λέγειν· ᾗ μὲν γὰρ ἄπεπτος, τὸ ἐναντίον τῷ ἐναντίῳ τρέφεται, ᾗ δὲ πεπεμμένη, τὸ ὅμοιον τῷ ὁμοίῳ. ὥστε φανερὸν ὅτι λέγουσί τινα τρόπον ἀμφότεροι καὶ ὀρθῶς καὶ οὐκ ὀρθῶς. It makes all the difference indeed whether food is considered as what it is at first or as what it becomes finally. But if as both, in the one sense as undigested, in the other as digested, then certainly both the [above] theories of food can be upheld: for as it is undigested, one of two contraries is nourished by the other: but in so far as it is digested, one of two similars is nourished by the other. Whence it is clear that both parties speak in one way rightly, and in another way wrongly. § 339
12. ἐπεὶ δ' οὐθὲν τρέφεται μὴ μετέχον ζωῆς, τὸ ἔμψυχον ἂν εἴη σῶμα τὸ τρεφόμενον, ᾗ ἔμψυχον, ὥστε καὶ ἡ τροφὴ πρὸς ἔμψυχόν ἐστι, καὶ οὐ κατὰ συμβεβηκός. Since only what is alive is nourished, what is nourished is the animate body as such. Wherefore nutriment means something related to what is animate, and this not incidentally only. §§ 340-2
ἔστι δ' ἕτερον τροφῇ καὶ αὐξητικῷ εἶναι· ᾗ μὲν γὰρ ποσόν τι τὸ ἔμψυχον, αὐξητικόν, ᾗ δὲ τόδε τι καὶ οὐσία, τροφή (σώζει γὰρ τὴν οὐσίαν, καὶ μέχρι τούτου ἔστιν ἕως ἂν τρέφηται), To be nutritive and to be active are two distinct things. In so far as the living being is quantitative, food is active; but in so far as it is substantial, food is nutritive. It preserves the substance, and this just so long as it is fed. § 343
καὶ γενέσεως ποιητικόν, οὐ τοῦ τρεφομένου, ἀλλ' οἷον τὸ τρεφόμενον· ἤδη γὰρ ἔστιν αὐτοῦ ἡ οὐσία, γεννᾷ δ' οὐθὲν αὐτὸ ἑαυτό, ἀλλὰ σώζει. And it is productive of generation, not of the one nourished, but of such a one as the one nourished—for this latter is already a substance; and nothing generates itself, it only maintains itself in being. § 344
ὥσθ' ἡ μὲν τοιαύτη τῆς ψυχῆς ἀρχὴ δύναμίς ἐστιν οἵα σώζειν τὸ ἔχον αὐτὴν ᾗ τοιοῦτον, ἡ δὲ τροφὴ παρασκευάζει ἐνεργεῖν· διὸ στερηθὲν τροφῆς οὐ δύναται εἶναι. Wherefore, this soul-principle is a power able to preserve what possesses it as a thing of such a kind; and food is preparatory to the operation; hence the being cannot continue, deprived of food. § 345
13. [ἐπεὶ δ' ἔστι τρία, τὸ τρεφόμενον καὶ ᾧ τρέφεται καὶ τὸ τρέφον, τὸ μὲν τρέφον ἐστὶν ἡ πρώτη ψυχή, τὸ δὲ τρεφόμενον τὸ ἔχον ταύτην σῶμα, ᾧ δὲ τρέφεται, ἡ τροφή.] Since there are three factors: what is nourished; that by which it is nourished; and that which nourishes; what nourishes is the primary soul, that which is nourished is the body containing it, and that by which it is nourished is food. § 346
ἐπεὶ δὲ ἀπὸ τοῦ τέλους ἅπαντα προσαγορεύειν δίκαιον, τέλος δὲ τὸ γεννῆσαι οἷον αὐτό, εἴη ἂν ἡ πρώτη ψυχὴ γεννητικὴ οἷον αὐτό. Since all things are rightly named from their end and the end [of this soul] is to have generated another being like itself, then the primary soul is generative of what is like itself. § 347
ἔστι δὲ ᾧ 416b26 τρέφει διττόν, ὥσπερ καὶ ᾧ κυβερνᾷ καὶ ἡ χεὶρ καὶ τὸ πηδάλιον, τὸ μὲν κινοῦν καὶ κινούμενον, τὸ δὲ κινούμενον μόνον. πᾶσαν δ' ἀναγκαῖον τροφὴν δύνασθαι πέττεσθαι, ἐργάζεται δὲ τὴν πέψιν τὸ θερμόν· διὸ πᾶν ἔμψυχον ἔχει θερμότητα. ‘That by which’ in nourishment is twofold, as ‘that by which’ in steering is the hand or the rudder: the one moving and moved, the other moving only. Now of necessity all food must be such that it can be digested, and what effects digestion is heat. Hence every animate being has heat.
τύπῳ μὲν οὖν ἡ τροφὴ τί ἐστιν εἴρηται· διασαφητέον δ' ἐστὶν ὕστερον περὶ αὐτῆς ἐν τοῖς οἰκείοις λόγοις. In outline, then, we have stated what nutriment is: the subject must be further examined later in a special discussion. §§ 348-9
ST. THOMAS’S COMMENTARY

LECTIO 9
Postquam philosophus ostendit, quod anima est principium operationum quae attribuuntur potentiae vegetativae, hic intendit de his determinare. Et circa hoc tria facit. Primo determinat de obiecto secundum se, scilicet de alimento. Secundo determinat de eo secundum quod congruit operationibus animae vegetativae, ibi, quoniam autem non alitur. Tertio potentias definit, quae sunt principia harum operationum, ibi, quare huiusmodi animae, et cetera. Circa primum tria facit. Primo dicit de quo est intentio. Secundo proponit id quod primo aspectu apparet de alimento, ibi, videtur autem esse alimentum, et cetera. Tertio movet circa hoc dubitationem, ibi, dubitationem autem habet. 333. After showing that the activities called vegetative originate in the soul, the Philosopher proceeds to examine these activities. And first he examines their subject-matter, which is food. Next he shows how the activities and their subject-matter correspond—this at ‘Since only what is alive’. Thirdly, at ‘Wherefore this soul-principle’, he defines the faculties brought into play in these activities. As regards the first point he does three things: (a) he states the plan of the present argument; (b) at ‘It would appear that food’, he says what at first sight appears true about nutrition; to which (c) at ‘But a difficulty’ he brings an objection.
Dicit ergo primo, quod cum vegetativa et generativa ab eadem communi potentia animae contineatur, licet vegetativa, idest nutritiva sit quaedam specialis potentia distincta a generativa, oportet primum determinare de alimento, quod est obiectum generativae, sive nutritivae. Hoc enim opere, scilicet nutritione, distinguitur haec pars animae ab aliis, scilicet intellectivo, sensitivo, et cetera. Nam aliae operationes huius partis, idest animae, hanc praesupponunt. In the first place, then, (a) he observes that, as the vegetative and reproductive powers are included in the same general vegetative power (‘vegetative’ as a special power being really the nutritive power), we should discuss food first of all in relation to this power as a whole. For it is taking food that characterises this part of the soul as distinct from the intellectual or sensitive parts. For the other vegetative activities all presuppose taking food.
Deinde cum dicit videtur autem proponit illud, quod primo aspectu de alimento apparet; et proponit tria: quorum primum est, quod alimentum videtur esse contrarium ei quod alitur; et hoc ideo, quia nutrimentum convertitur in id quod nutritur: generationes autem fiunt ex contrariis. Secundum autem est quod non videtur quodcumque contrarium sufficere ad rationem alimenti, sed oportet quod sit de illis contrariis, quae habent generationem ex se invicem. Nutrimentum enim convertitur in substantiam nutriti; unde quaecumque contraria insunt in substantia, secundum quae fiunt alterationes adinvicem, et non generationes, non pertinent ad rationem alimenti. Non enim dicimus quod infirmum sit nutrimentum sani, vel album nigri, aut aliquid huiusmodi. Quomodo autem in substantiis sit aliqua contrarietas, alia quaestio est. 334. Then (b) he states in three points what appears at first sight with regard to nourishment. First, food would always seem to be the contrary of the subject fed; and this because it has to become the latter, and becoming is from one thing to its contrary. Secondly, however, it seems to be clear that not any contraries will do; they must be such as can change into one another. Food is changed into the being of the one fed; hence all contraries which alternate in a subject without the one ever actually changing into the other have nothing to do with food. Thus sickness is not the food of health, nor white of black. But how substances come to contain contraries is another question.
Tertio oportet, quod sit de illis contrariis, quae augmentum suscipiunt ex invicem, quia alimentum videtur sequi augmentum. Unde licet ex igne generetur aqua, sicut e converso, non tamen dicitur quod ex igne nutriatur aqua: sed quod ex aqua nutriatur ignis, inquantum liquores humidi cedunt in ignis nutrimentum: quia scilicet dum ignis in aquam convertitur, non apparet nova aquae generatio; sed ignis praeexistens, ad sui conservationem et augmentum videtur in se humorem convertere. Et ideo in elementis videtur solus ignis nutriri, et sola aqua esse eius nutrimentum, secundum quod ad aquam pertinent omnes humores et liquores. 335. (c) Again, since increase of bulk seems to follow nutrition, the contraries involved must be such as affect each other in this way. Water may be generated by fire and e converso, but we do not say that water is fed by fire. Yet we can say that fire is fed by water, inasmuch as watery vapour nourishes fire. When water comes from fire there is no new coming-to-be of water; but fire can make use of and grow by means of watery vapours. Among the elements, therefore, only fire seems to be fed and only water seems to be food, taking water to include all vapours and liquids.
Deinde cum dicit dubitationem autem movet quamdam dubitationem circa praedeterminata. Et primo obiicit ad utramque partem. Secundo solvit eam, ibi, utrum autem sit alimentum, et cetera. Oritur autem dubitatio circa hoc quod supra dictum est, quod alimentum oportet esse contrarium. Quibusdam autem videtur quod alimentum oportet esse simile ei quod alitur. Alimentum enim est causa augmenti: oportet autem quod simile simili augeatur. Si enim aliquid diversum apponeretur alicui, non esset eiusdem augmentum, sed naturae extraneae adiunctio. Videtur igitur quod oporteat simile simili ali. 336. Then at ‘But a difficulty” Aristotle brings an objection against what he has just said. The difficulty concerns the statement that food is a ‘contrary’. For some maintain that food should resemble the subject fed. Food causes growth, and a thing grows by what it resembles; otherwise the growth would be a mere addition of something extrinsic. Therefore like, it seems, is fed by like.
Aliis autem videtur, quod alimentum oportet esse contrarium ei quod alitur, secundum id quod supra dictum est. Et ad hoc inducuntur duplici ratione: quarum prima est, quia alimentum decoquitur et mutatur in id quod nutritur. Nihil autem mutatur nisi in contrarium aut medium; sicut album mutatur in nigrum aut pallidum. Medium autem est quodammodo contrarium. Pallidum enim albo comparatum, est nigrum: nigro vero comparatum, est album; est enim compositum ex utroque. Ergo nutrimentum est contrarium ei quod alitur, et in quod mutatur. 337. To others, however, it seems that food must, as we have said, be contrary to what is fed. And they are moved by two reasons. (a) Food, being cooked, is transformed into the subject fed. But all transformation is either into a contrary or into an intermediate, as white into either black or grey. And the intermediate is a sort of contrary: grey compared with white, is black; and compared with black, is white; for it combines both. Therefore food is contrary to the subject into which it is transformed.
Secunda ratio est, quia agens est contrarium patienti; non enim simile a simili patitur. Alimentum autem patitur ab eo quod alitur; alteratur enim ab eo, et digeritur. Id autem quod alitur, non patitur ab alimento, sicut neque artifex patitur a materia, sed e converso: materia enim mutatur, non autem artifex, nisi forte per accidens, secundum quod exit de potentia in actum. Videtur igitur, quod alimentum sit contrarium ei quod alitur. Prima igitur harum rationum sumitur ex contrarietate quam oportet esse inter terminos mutationis. Secunda vero ex contrarietate, quam oportet esse inter agens et patiens. Id enim quod alitur, et agit in alimentum, est terminus, in quem alimentum mutatur. 338. (b) Again, every agent is contrary to that on which it acts; like is not passive to like. But food is passive to what is fed: it is transformed and digested. What is fed is not passive to its food, any more than an artist to his material (for it is the material that is altered, not the artist, except indirectly, in so far as he moves from potency to act). It would seem, then, that food is contrary to what is fed. Now the first of these two reasons is drawn from the contrariety between the two terns of a change; and the second from the contrariety between agent and patient. That which is fed, and itself acts upon the food, is the term into which the food is transformed.
Deinde cum dicit utrum autem solvit propositam dubitationem; dicens, quod differt quantum ad propositam quaestionem, utrum alimentum dicatur id quod ultimo advenit, scilicet post decoctionem et digestionem, an illud quod primo assumitur, scilicet antequam digeratur et decoquatur. Et si dici possit utrumque horum, alimentum: unum horum quasi alimentum decoctum, aliud vero quasi non decoctum, secundum utramque partem quaestionis poterit iudicari de alimento. Quia inquantum alimentum dicitur non decoctum, sic contrarium contrario alitur, hoc enim est quod patitur et mutatur. Inquantum vero est coctum, sic alitur simile simili; agens enim assimilat sibi patiens; unde in fine passionis oportet passum esse simile agenti, et per hunc modum potest augere id quod alitur. Et sic patet quod utrique praedictorum opinantium, aliquo modo dicunt recte, et aliquo modo non dicunt recte. 339. Then at ‘It makes all the difference’, he solves the problem, saying that the answer depends on whether by ‘food’ we mean what remains at the end of the process of heating and digesting, or what is received at first before this process begins. If food can be taken in both these senses—namely as the finished and as the raw product—then the two answers are both admissible. If it is taken in the latter sense, then subjects are fed by their contrary, which itself is acted upon and transformed; but if in the former sense, then like is fed by like; for the active agent assimilates what it acts upon, which is ultimately made like the agent and, as such, can increase the agent’s bulk. Thus both the above opinions were in one way true and another way false.
Deinde cum dicit quoniam autem determinat de alimento secundum quod convenit operationibus animae vegetativae. Et primo secundum quod congruit nutritioni. Secundo secundum quod congruit augmento, ibi, est autem alterum alimento, et cetera. Tertio secundum quod congruit generationi, ibi, et generationis autem factivum, et cetera. 340. Next, at ‘Since only’, he shows how food is related to the activities of the vegetative principle: to taking nourishment; to growth (at ‘To be nutritive’) ; and to reproduction (at ‘And it is productive’).
Dicit ergo primo, quod nihil nutritur, quod non participet vitam: omne autem participans vitam est animatum: sequitur ergo quod corpus quod alitur sit animatum. Alimentum autem est in potentia ad id quod alitur, convertitur enim in ipsum: relinquitur ergo quod alimentum, inquantum est nutritionis obiectum, sit aliquid existens in potentia ad animatum per se, et non secundum accidens. First, then, he observes that nothing is fed except what has life and soul; hence the besouled body is what is fed. Now food is potential with respect to the subject fed; for it is changed into this subject. It follows that, inasmuch as food is the material of feeding, it is essentially, not accidentally, related to the besouled body as in potency to this body.
Considerandum est autem, quod nihil proprie nutritur nisi animatum: ignis autem videtur quidem per quamdam similitudinem nutriri, non autem proprie nutritur: quod sic patet. Id proprie nutriri dicimus, quod in seipso aliquid recipit ad suiipsius conservationem: hoc autem in igne videtur quidem accidere, sed tamen non accidit. Cum enim igne accenso aliqua materia combustibilis additur, in illa materia combustibili novus ignis generatur, non autem ita, quod illud combustibile additum cedat in conservationem ignis, in alia materia prius accensi. Puta, si aliquod lignum de novo ignitur, per hanc ignitionem non conservatur ignitio alterius ligni prius igniti: totus enim ignis qui est ex congregatione multorum ignitorum, non est unus simpliciter, sed videtur unus aggregatione, sicuti acervus lapidum est unus: et propter talem unitatem, est ibi quaedam similitudo nutritionis. 341. Nothing then is, properly speaking, fed excepting what has a soul. Fire might seem to resemble in some way things that are fed, but it is not fed, strictly speaking. For that is properly said to be fed which absorbs something else in order to maintain its own being; and though this appears to happen with fire, it does not really happen. Once a fire has started, if you add fresh fuel, a new fire starts in the new fuel; but not in such a way that the new fuel maintains the fire already started before it was added. By starting a fire in fresh wood you do not maintain the flame in the other wood already burning. For the one flame made up of many flames is not one in the simple sense of the term; it is only one by the aggregation of many units, like a heap of stones. And it is this sort of unity that gives to burning a certain likeness to taking food.
Sed corpora animata vere nutriuntur, quia per alimentum conservatur vita in illa parte eadem, quae prius fuit. Et propter hoc etiam sola animata vere augentur, quia quaelibet pars eorum nutritur et augetur; quod non convenit rebus inanimatis, quae videntur per additionem crescere. Non enim crescit id quod prius fuit, sed ex additione alterius constituitur quoddam aliud totum maius. 342. Living bodies, on the other hand, are really fed; food maintains life precisely where it already existed. This also is why only living bodies, properly speaking, grow; for each and every part in them is fed and increases; whereas inanimate things increase only by addition of part to part; what existed already does not increase, it is merely made into a new whole together with some other thing added to it.
Ideo autem similitudo augmenti et nutrimenti praecipue apparet in igne, quia ignis habet plus de forma, quam alia elementa, et est potentior in virtute activa: unde propter hoc quod manifeste alia convertit in se, videtur nutriri et augeri. But if fire has a special likeness to living and growing things, this is because the formal principle in fire is stronger than in the other elements, and its active power greater. It seems, therefore, to feed and grow because it so obviously seizes and subdues to itself other things.
Deinde cum dicit est autem ostendit quomodo alimentum congruit augmento. Et dicit quod licet idem sit subiecto, quod est obiectum nutritionis, prout dicitur alimentum, et quod est obiectum augmenti, prout dicitur augmentativum, tamen differt ratione. Dictum est enim quod alimentum est in potentia ad corpus animatum. Corpus autem animatum, et est quoddam quantum, et est hoc aliquid et substantia. Secundum igitur quod est quoddam quantum, secundum hoc alimentum adveniens ei, quod etiam et ipsum quantum est facit augmentum, et dicitur augmentativum: in quantum autem corpus animatum, hoc aliquid et substantia est, sic habet rationem alimenti. Hoc enim est de ratione alimenti, quod conservat substantiam eius quod alitur. Quae quidem conservatio necessaria est propter continuam consumptionem humidi a calido naturali; et ideo tamdiu durat substantia eius quod nutritur, quamdiu nutriatur. 343. Then, at ‘To be nutritive’, he relates taking food to growth, observing that whilst the objective terms of feeding as feeding and of growing as growing are one and the same thing, they differ in idea. Food, we have seen, is in potency to the living body; which itself is both a quantum and a definite particular thing or substance. As a quantum it receives its food (which itself is a quantum) as a cause of growth; but as a particular sort of substance it receives food precisely as food. For it is of the nature of food to maintain the substance of what is fed; which is required by the continuous using up of natural warmth and moisture. Hence the substance of the thing fed lasts just so long as it is fed.
Deinde cum dicit et generationis ostendit quomodo alimentum congruat generationi. Et dicit, quod etiam alimentum est factivum generationis. Semen enim quod est generationis principium, est superfluum alimenti. Non tamen alimentum est principium generationis eius quod alitur, sed alterius quod est tale secundum speciem, quale est quod alitur: quia substantia quae alitur, iam est, et quod est, non generatur, et nihil generat seipsum; quia quod generat, iam est, quod generatur nondum est. Sed aliquid potest agere ad sui conservationem. 344. Then at ‘And it is productive’ he relates nutrition to generation, as the latter’s cause. For seed, the generative principle, is the residue of food. And food is an agent in generating, not the subject fed, but other subjects of the same kind; for the subject fed already exists and cannot be generated afresh. Nothing generates itself; only what does not yet exist is generated. This is not to say, however, that things cannot maintain themselves.
Deinde cum dicit quare tale ex praemissis accipit definitionem potentiarum animae vegetabilis. Et primo potentiae nutritivae. Secundo totius animae vegetabilis, ibi, quoniam autem a fine, et cetera. Circa primum, primo ex praemissis concludit definitionem potentiae nutritivae: et dicit, quod cum dictum sit, quod nutrimentum inquantum huiusmodi salvat nutritum, manifestum est quod hoc principium animae, quod scilicet est principium nutritionis, nihil est aliud quam potentia potens salvare suum susceptivum, inquantum huiusmodi. Alimentum vero est, quod praeparat operationem huiusmodi potentiae, inquantum talis potentia mediante alimento salvat suum susceptivum. Et propter hoc, illud quod privatur alimento, non potest conservari. 345. Next, at ‘Wherefore, this soul-principle’ he concludes with a definition of the powers of the vegetative soul: first, of the nutritive power, and then, at ‘Since all things’, of the whole vegetative principle. As to the nutritive power, he observes that it is simply that faculty by which a living being is able to maintain itself as such; while food is the condition of this faculty’s activity, that by means of which it maintains its subject. Hence loss of being follows lack of food.
Et quia dixerat, quod principium nutritionis est potentia animae, cuius principium est etiam alimentum, ut ex dictis patet; ideo secundo ibi quoniam autem ostendit quomodo differenter potentia animae et alimentum sunt principia nutritionis. Dicit ergo, quia in nutritione sunt tria: quod alitur, quo alitur et alens primum. Primum quidem alens est prima anima, scilicet anima vegetabilis. Illud vero quod alitur est corpus habens hanc animam, sed illud quo alitur est alimentum. Sic igitur potentia animae est principium nutritionis, ut agens principale; alimentum autem, ut instrumentum. 346. And, having remarked ‘that the source of nutritive activity is a capacity in the soul relating essentially to food, he goes on, at ‘Since there are three’, to show how that power and the food itself differ as sources of nutrition. Nutrition, he says, involves three factors: what is fed; that, wherewith it is fed; and the primary agent in feeding: this primary agent is the primary, i.e. vegetative, soul. What is fed is its body; and that wherewith it is fed is food. Thus a capacity in the soul is the cause of taking food as the principal agent; but food as the instrumental agent.
Deinde cum dicit quoniam autem definit ipsam primam animam, quae dicitur anima vegetabilis; quae quidem in plantis est anima, in animalibus pars animae. Et circa hoc duo facit. Primo definit huiusmodi animam. Ad cuius definitionis intellectum, sciendum est, quod inter tres operationes animae vegetabilis, est quidam ordo. Nam prima eius operatio est nutritio, per quam salvatur aliquid ut est. Secunda autem perfectior est augmentum, quo aliquid proficit in maiorem perfectionem, et secundum quantitatem et secundum virtutem. Tertia autem perfectissima et finalis est generatio per quam aliquid iam quasi in seipso perfectum existens, alteri esse et perfectionem tradit. Tunc enim unumquodque maxime perfectum est, ut in quarto Meteororum dicitur, cum potest facere alterum tale, quale ipsum est. Quia igitur iustum est, ut omnia definiantur et denominentur a fine, finis autem operum animae vegetabilis est generare alterum tale quale ipsum est, sequitur quod ipsa sit conveniens definitio primae animae, scilicet vegetabilis, ut sit generativa alterius similis secundum speciem. 347. Next, at ‘Since all things’, he defines that primary or vegetative soul (the entire soul of plants, but only part of any animal’s soul). To understand his definition, we must realise that the three vegetative activities fall into a certain order. First is taking food, by which things are maintained in being; the second and more perfect activity is growth, by which a thing increases in both quantity and capacity; while the third and most perfect and ultimate vegetative activity is reproduction, by which a being, already pretty complete in itself, gives existence and perfection to another being. For each thing is at its best, as is said in the Meteorologica, Book IV, when it can reproduce its likeness in another. If then all things are rightly defined and named in terms of their end, and the end of all the activities of the vegetative soul is to generate its likeness in another, it follows that we can suitably define this ‘primary soul’ as that which is reproductive of another, like to itself in kind.
Et quia dixerat, quod alimentum est instrumentum huius animae, ne credatur quod non habeat aliud instrumentum, ideo secundo ibi est autem ostendit quod habeat aliud instrumentum: et dicit quod duplex est instrumentum quod alitur, sicut duplex est instrumentum gubernationis: gubernator enim gubernat manu, et temone: manus enim est instrumentum coniunctum, cuius forma est anima. Unde temo est instrumentum movens navem, et motum a manu; sed manus non est instrumentum motum ab aliquo exteriori, sed solum a principio intrinseco: est enim pars hominis moventis seipsum. Sic igitur et nutritionis instrumentum est duplex. Et ut separatum quidem, et cuius forma nondum est anima, est nutrimentum. Oportet autem, quod aliud sit instrumentum nutritionis coniunctum. Necesse est enim, quod alimentum decoquatur: quod autem operatur decoctionem, est aliquid calidum. Sicut igitur gubernator movet temonem manu, navem autem temone, ita anima movet calido alimentum, et alimento nutrit. Sic igitur calidum aliquod est instrumentum coniunctum huius animae, in quo scilicet radicaliter est calor naturalis digerens; et propter hoc oportet, quod omne animatum, quod nutritur, habeat calorem naturalem, qui est digestionis principium. Si autem haec anima non haberet instrumentum coniunctum, non esset actus alicuius partis corporis: quod soli intellectui competit. 348. And in view of his previous remark that this primary soul’s instrument was food, to prevent anyone thinking that it had no other instrument, he shows, at ‘That by which’ that the subject fed has another instrument wherewith it is fed; just as in steering a ship there are two instruments. For the pilot steers with both hand and rudder. Now the hand is a conjoined instrument which has the soul for its form. Whilst, then, the rudder is an instrument which moves the boat and itself is moved by the hand, the hand itself is not moved by an exterior motive force, but by an interior one; for it is a part of the man and the man moves himself. Similarly, the instrument of nutrition is twofold. There is the separated instrument not yet informed by the soul; and this is food. But there must also be a conjoined instrument; for the food must be digested; and this requires heat. As then a pilot moves the rudder with his hand, and the boat with the rudder, so the soul moves the food with heat and, by means of the food, nourishes itself. The heat is the soul’s conjoined instrument; a natural warmth inseparably rooted in the soul and necessary to all living things as the condition of their digesting their food. And it. is because this primary soul is, unlike the intellect, the actuality of a. part of the body that it has a conjoined instrument.
Ultimo epilogans quod dixerat, concludit quod figuraliter, id est universaliter dictum est quid sit alimentum; sed posterius certius tractandum est de alimento, in propriis rationibus. Fecit enim unum specialem librum de alimento, sicut de generatione animalium, et de motu animalium. 349. Summarising, Aristotle says that he has defined ‘in outline’, that is in general, what food is; later he will treat of it with more precision and finality. For he wrote a special book on food, as also on the generation and movement of animals.

TEXT
416b32–417a21
BOOK II, CHAPTER V
ΚΕΦΑΛΑΙΟΝ Ε'

SENSITIVITY POTENCY AND ACT IN SENSATION

416b32 1. Διωρισμένων δὲ τούτων λέγωμεν κοινῇ περὶ πάσης αἰσθήσεως. ἡ δ' αἴσθησις ἐν τῷ κινεῖσθαί τε καὶ πάσχειν συμβαίνει, καθάπερ εἴρηται· δοκεῖ γὰρ ἀλλοίωσίς τις εἶναι. φασὶ δέ τινες καὶ τὸ ὅμοιον ὑπὸ τοῦ ὁμοίου πάσχειν. 417a τοῦτο δὲ πῶς δυνατὸν ἢ ἀδύνατον, εἰρήκαμεν ἐν τοῖς καθόλου λόγοις περὶ τοῦ ποιεῖν καὶ πάσχειν. These questions being settled, let us speak of sensation in general. As has been said, sensation occurs in a being moved and acted upon; for it appears to be a kind of alteration. Some say, ‘like is acted on by like’. How far this is possible or impossible has been stated in our general discussion of activity and passivity. §§ 350-1
2. ἔχει δ' ἀπορίαν διὰ τί καὶ τῶν αἰσθήσεων αὐτῶν οὐ γίνεται αἴσθησις, καὶ διὰ τί ἄνευ τῶν ἔξω οὐ ποιοῦσιν αἴσθησιν, ἐνόντος πυρὸς καὶ γῆς καὶ τῶν ἄλλων στοιχείων, ὧν ἐστιν ἡ αἴσθησις καθ' αὑτὰ ἢ τὰ συμβεβηκότα τούτοις. δῆλον οὖν ὅτι τὸ αἰσθητικὸν οὐκ ἔστιν ἐνεργείᾳ, ἀλλὰ δυνάμει μόνον, διὸ οὐκ αἰσθάνεται, καθάπερ τὸ καυστὸν οὐ καίεται αὐτὸ καθ' αὑτὸ ἄνευ τοῦ καυστικοῦ· ἔκαιε γὰρ ἂν ἑαυτό, καὶ οὐθὲν ἐδεῖτο τοῦ ἐντελεχείᾳ πυρὸς ὄντος. It may be asked why there is no sensation of the senses themselves; and why they do not produce sensation without something extraneous, seeing that they contain within themselves fire and earth and the other elements that give rise to sensation, either of themselves or through their accidental qualities. It becomes evident that the sensitive power is not an actuality, but is only potential; which explains why it does not sense [without an exterior object] as the combustible does not bum of itself without something to make it burn. Otherwise it would burn itself, and not need a fire already alight. § 352-4
ἐπειδὴ δὲ τὸ αἰσθάνεσθαι λέγομεν διχῶς (τό τε γὰρ δυνάμει ἀκοῦον καὶ ὁρῶν ἀκούειν καὶ ὁρᾶν λέγομεν, κἂν τύχῃ καθεῦδον, καὶ τὸ ἤδη ἐνεργοῦν), διχῶς ἂν λέγοιτο καὶ ἡ αἴσθησις, ἡ μὲν ὡς δυνάμει, ἡ δὲ ὡς ἐνεργείᾳ. ὁμοίως δὲ καὶ τὸ αἰσθητόν, τό τε δυνάμει ὂν καὶ τὸ ἐνεργείᾳ. But as we speak of sensing in two ways, (for we say that one who sees and hears in potency sees and hears, even when he happens to be asleep; and also that one does so actually) so we may speak of ‘sense’ in two ways,—as in potency and as in act. Likewise, to perceive is both potential and actual. § 355
3. πρῶτον μὲν οὖν ὡς τοῦ αὐτοῦ ὄντος τοῦ πάσχειν καὶ τοῦ κινεῖσθαι καὶ τοῦ ἐνεργεῖν λέγωμεν· καὶ γὰρ ἔστιν ἡ κίνησις ἐνέργειά τις, ἀτελὴς μέντοι, καθάπερ ἐν ἑτέροις εἴρηται. To start with then, let us speak as if being acted upon and moved were the same as action and moving. For movement is a kind of activity, though imperfect, as has been stated elsewhere. § 356
πάντα δὲ πάσχει καὶ κινεῖται ὑπὸ τοῦ ποιητικοῦ καὶ ἐνεργείᾳ ὄντος. διὸ ἔστι μὲν ὡς ὑπὸ τοῦ ὁμοίου πάσχει, ἔστι δὲ ὡς ὑπὸ τοῦ ἀνομοίου, καθάπερ εἴπομεν· πάσχει μὲν γὰρ τὸ ἀνόμοιον, πεπονθὸς δ' ὅμοιόν ἐστιν. All things are moved and affected by an agent, or something in act. Hence it is, that a thing is affected both by its similar and also by its dissimilar, as we have said. What is being affected is dissimilar: what has been affected is similar. § 357
ST. THOMAS’S COMMENTARY

LECTIO 10
Postquam determinavit philosophus de parte vegetativa, hic incipit determinare de parte sensitiva. Et dividitur in partes duas: in prima determinat de eo quod apparet in hac parte, scilicet de sensibus exterioribus. In secunda determinat de eo quod latet in parte sensitiva, ibi, quod autem non sit sensus alter et cetera. Prima dividitur in partes duas. In prima ostendit quomodo se habet sensus ad sensibile. In secunda determinat de sensibili et sensu, ibi, dicendum est autem secundum unum. Circa primum duo facit. Primo resumit quaedam, quae sunt prius dicta. Secundo investigat propositum, ibi, habet autem dubitationem, et cetera. 350. After treating of the vegetative part of soul the Philosopher now begins to examine the sensitive part. This treatment divides into two sections, the first of which deals with what is most apparent in sensitivity, i.e. the exterior senses, while the second, beginning at ‘That there is no other sense’, treats of what is latent therein. In the former section Aristotle first explains how sense-faculties are related to sensible objects, and then, at ‘In treating of each sense’ he defines both faculty and object. Regarding the former point, he first repeats some earlier observations and then, at ‘It may be asked’, proceeds to the present problem.
Dicit ergo primo, quod determinatis his quae pertinent ad animam vegetativam, dicendum est de his quae pertinent ad sensum in communi. De his enim quae pertinent ad unumquemque sensum specialiter, postmodum dicet. Duo autem resumit dicta de sensu: quorum unum est, quod sentire consistit in moveri et pati. Est enim sensus in actu, quaedam alteratio: quod autem alteratur, patitur et movetur. Aliud autem quod resumit est, quod quidam dicunt simile a simili pati, et propter hoc sentire est pati. First of all, then, he remarks that this is the place to start discussing the sensitive soul, beginning with a general view of the subject and going on later to a more detailed treatment. And he repeats two things already said: that to sense is to be moved or acted upon in some way, for the act of sensation involves a certain alteration of the subject; and secondly, that it was the view of some enquirers that the passivity of sensation was an instance of like being acted upon by like.
Quidam antiqui philosophi posuerunt, quod simile simili cognoscitur et sentitur; sicut Empedocles posuit quod terra, terra cognoscitur, ignis igne, et sic de aliis. Sed hoc quomodo esse possit, vel non, quod simile simili patiatur, dictum est in universalibus rationibus de agere et pati, idest in libro de generatione, ubi determinavit de actione et passione in communi. Dictum est enim ibi, quod id quod patitur, a principio dum patitur est contrarium agenti, sed in fine, quando iam est passum, est simile. Agens enim agendo assimilat sibi patiens. 351. For some early thinkers held that like is known and sensed by like: as Empedocles said, earth knows earth, fire knows fire, and so on. Now the general problem of the action of like upon like is discussed in the De Generatione, where Aristotle’s conclusion is that, although at the start of any action the agent and patient are contrary, when the action is finished they are similar. For the agent, in acting, assimilates the patient.
Deinde cum dicit habet autem determinat veritatem circa propositum. Et circa hoc facit tria. Primo ostendit, quod sensus sit in potentia. Secundo quod quandoque est in actu, ibi, quoniam autem sentire et cetera. Tertio ostendit quomodo sensus reducatur de potentia in actum, ibi, dicendum autem et cetera. 352. Then, at ‘It may be asked’, he proceeds to the present problem. He shows that in themselves the senses are in potency; then, at ‘But since we speak of sensing in two ways’, that they are sometimes in act; and thirdly, at ‘Distinctions however’, he shows how they move from potency into act.
Circa primum considerandum est, quod Empedocles et quicumque posuerunt simile simili cognosci, posuerunt sensum esse actu ipsa sensibilia. Ut enim cognosceret omnia sensibilia, posuerunt animam sensitivam esse compositam quodammodo ex omnibus sensibilibus, inquantum constabat, secundum eos, ex elementis sensibilium. To understand the first of these three points, note that all who, like Empedocles, said that like was known by like, thought that the senses were actually the sense-objects themselves,—that the sensitive soul was able to know all sense-objects because it consisted somehow of those objects; that is, of the elements of which the latter are composed.
Duo ergo ad hanc positionem consequebantur. Quorum unum est, quod sensus est ipsa sensibilia in actu, utpote compositus ex eis: et cum ipsa sensibilia in actu sentiri possint, sequeretur quod ipsi sensus sentiri possent. Secundum est, quod cum sensus sentire possit praesentibus sensibilibus, si sensibilia actu sunt in sensu, utpote ex eis composito, sequitur quod sensus possit sentire sine exterioribus sensibilibus. Utrumque autem horum est falsum. Et ideo haec duo inconvenientia, quae sequuntur ad antiquorum positionem, sub quaestione proposuit, tamquam quae per antiquos solvi non possint. Hoc est ergo quod dicit, quod dubitationem habet, propter quid non sunt sensus ipsorum sensuum, id est quare ipsi sensus non sentiantur: hoc enim videtur sequi, si sensus sint similes sensibilibus. 353. Two things follow from this hypothesis. (1) If the senses actually are, or are made up of, the sense-objects, then, if the latter can be sensed, the senses themselves can be sensed. (2) Since the presence of its object suffices, to enable the sense-faculty to sense, then, if this object actually exists in the faculty as part of its composition, it follows that sensation can take place in the absence of external objects. But both these consequences are false. He introduces them here as specimens of the problems which the early philosophers could not solve. So he says, ‘It may be asked why there is no sensation of the senses’, i.e. why the senses themselves are not sensed; for it seems they would be sensed if they, the faculties, were really like their objects.
Etiam habet dubitationem, quare non faciunt sensum, id est quare sensus non sentiunt actu, sine his, quae sunt extra, id est sine exterioribus sensibilibus, cum tamen interius existant in ipsis sensibus secundum opinionem antiquorum ignis, et terra, et alia elementa, quae sunt sensibilia, aut secundum se, id est secundum suam substantiam, secundum eos, qui non discernunt inter sensum et intellectum: intellectus enim est proprie cognoscitivus substantiae, aut secundum accidentia propria, scilicet calidum et frigidum, et alia huiusmodi, quae sunt per se sensibilia. Quia igitur hae dubitationes per se solvi non possunt, si sensus habet sensibilia in actu, ut antiqui posuerunt, concludit tamquam manifestum, quod anima sensitiva non est actu sensibilis, sed potentia tantum. Et propter hoc, sensus non sentiunt sine exterioribus sensibilibus, sicut combustibile, quod est potentia tantum ignitum, non comburitur a seipso, sine exteriori combustivo. Si enim esset actu ignitum, combureret seipsum, et non indigeret exteriori igne ad hoc quod combureretur. 354. It is also hard to see ‘why they do not produce sensation’, i.e. why actual sensation does not occur, ‘without something extraneous’, i.e. without exterior sense-objects; since, in the opinion of the ancients, fire, earth and the other elements belong to the inner nature of the sense-faculty and are perceptible by sense, either in themselves, i.e. in their essence (as these philosophers thought, not distinguishing between the senses and the intellect which alone perceives essence), or in the accidental qualities proper to them, namely heat and cold and so forth, which are essentially sense-perceptible. Now since these difficulties are insurmountable if the sense-faculty consists of its objects in their actuality (as the early philosophers thought), Aristotle concludes that the sensitive soul is clearly not actually, but only potentially, the sense-object. That is why sensation will not occur without an exterior sense-object, just as combustible material does not burn of itself, but needs to be set on fire by an exterior agent; whereas if it were actually fire it would burn simply by itself.
Deinde cum dicit quoniam autem ostendit quod etiam sensus est quandoque actu. Et circa hoc tria facit. Primo ostendit sensum quandoque esse in actu, per hoc, quod dupliciter dicimus aliquem sentire: quandoque enim dicimus aliquem videre et audire, qui audit et videt in potentia: puta cum aliquis est dormiens: quandoque autem dicimus aliquem videre et audire, eo quod est in ipsa operatione audiendi et videndi. Ex quo patet, quod sensus et sentire dicuntur dupliciter, scilicet in actu et in potentia. 355. Then, at ‘But as we speak of sensing’, he shows, by the two ways in which we speak of anyone sensing, that sensation is intermittently actual. For we sometimes say that a man sees or hears when he only does these things potentially, as when he is asleep; but sometimes we mean that what he is actually doing is seeing or hearing. Clearly, then, sensation and sensing may be referred to either in act or in potency.
Secundo ibi primum igitur manifestat quomodo intelligendum sit quod dictum est. Videbatur enim repugnare, quod sentire dicitur in actu, ei quod dictum est, quod sentire est quoddam pati et moveri. Esse enim in actu videtur magis pertinere ad agere. Et ideo ad hoc exponendum dicit, quod ita dicimus sentire in actu, ac si dicamus, quod pati et moveri sint quoddam agere, id est quoddam esse in actu. Nam motus est quidam actus, sed imperfectus, ut dictum est in tertio physicorum. Est enim actus existentis in potentia, scilicet mobilis. Sicut igitur motus est actus, ita moveri et sentire est quoddam agere, vel esse secundum actum. Per hoc autem quod dicit primum, significat quod quaedam alia postmodum subdet ad ostendendum, quomodo sensus fiat in actu. 356. Next, at ‘To start with then,’ he explains the above. For to speak of sensation as ‘in act’ might seem contradictory to his previous statement that it was a certain passive being acted upon or moved; for to be in act seems to pertain to an active agent. So he explains that in calling sensation an ‘act’ he is referring precisely to the state of being acted upon or moved; inasmuch as this is a certain state of being actual. For movement has a certain actuality; which is the actuality (as he says in the Physics, Book III) of the imperfect or potential, that is to say, of changeable being. In the same way, being moved and sensation itself are a sort of action, as implying an actuality of being. The phrase ‘To start with’, however, means that he will add something later to show how the senses become actual in fact.
Tertio ibi omnia autem ostendit secundum praedicta, quomodo antiquorum positio non possit esse vera, scilicet quod simile simili sentitur. Dicit ergo, quod omnia quae sunt in potentia, patiuntur et moventur ab activo, et existente in actu; quod scilicet dum facit esse in actu ea, quae patiuntur, assimilat ea sibi: unde quodammodo patitur aliquis aliquid a simili, et quodammodo a dissimili, ut dictum est; quia a principio dum est in transmutari et pati, est dissimile; in fine autem, dum est in transmutatum esse et passum, est simile. Sic igitur et sensus postquam factus est in actu a sensibili, est similis ei: sed ante non est similis. Quod antiqui non distinguentes erraverunt. 357. Thirdly, at ‘All things are moved and affected’, he shows how it follows from the above that the old theory that like senses like cannot be true. Everything potential, he says, is acted upon and moved by some active agent already existing; which in its actualising function makes the potential thing like itself In some sense, then, a thing is acted upon by both its like and its unlike (as we have already remarked). At first, and while the transforming process is going on, there is dissimilarity; but at the end, when the thing is transformed and changed, there is similarity. And so it is as between the sense-faculty and its object. And the early philosophers went wrong because they missed this distinction.

TEXT
417a 22–417b17
BOOK II, CHAPTER V, CONTINUED

SENSITIVITY
POTENCY AND ACT CONTINUED

4. διαιρετέον δὲ καὶ περὶ δυνάμεως καὶ ἐντελεχείας· νῦν γὰρ ἁπλῶς ἐλέγομεν περὶ αὐτῶν. Distinctions however must be made concerning potency and act; for at present we are speaking of these in one sense only. § 358
ἔστι μὲν γὰρ οὕτως ἐπιστῆμόν τι ὡς ἂν εἴποιμεν ἄνθρωπον ἐπιστήμονα ὅτι ὁ ἄνθρωπος τῶν ἐπιστημόνων καὶ ἐχόντων ἐπιστήμην· ἔστι δ' ὡς ἤδη λέγομεν ἐπιστήμονα τὸν ἔχοντα τὴν γραμματικήν· ἑκάτερος δὲ τούτων οὐ τὸν αὐτὸν τρόπον δυνατός ἐστιν, ἀλλ' ὁ μὲν ὅτι τὸ γένος τοιοῦτον καὶ ἡ ὕλη, ὁ δ' ὅτι βουληθεὶς δυνατὸς θεωρεῖν, ἂν μή τι κωλύσῃ τῶν ἔξωθεν· ὁ δ' ἤδη θεωρῶν, ἐντελεχείᾳ ὢν καὶ κυρίως ἐπιστάμενος τόδε τὸ Α. For there is such a thing as ‘a knower’, in one sense, as when we say that man is ‘a knower’ because man is of the class of beings able to have knowledge. But also as when we speak of a, man as ‘knowing’ because he possesses the science of grammar. These two are not capable in the same way; but the former’s power is, as it were, generic and comparable to matter; whereas the latter has the power to consider at will, so long as no extraneous obstacle intervenes. Yet again, only he who is actually attending to (say) the letter A, is in the strictest sense knowing. §§ 359-61
ἀμφότεροι μὲν οὖν οἱ πρῶτοι, κατὰ δύναμιν ἐπιστήμονες <ὄντες, ἐνεργείᾳ γίνονται ἐπιστήμονες,> ἀλλ' ὁ μὲν διὰ μαθήσεως ἀλλοιωθεὶς καὶ πολλάκις ἐξ ἐναντίας μεταβαλὼν ἕξεως, ὁ δ' ἐκ τοῦ ἔχειν τὴν ἀριθμητικὴν ἢ τὴν γραμματικήν, μὴ ἐνεργεῖν δέ, εἰς τὸ ἐνεργεῖν, ἄλλον τρόπον. Therefore the first two are knowing in potency. But one has undergone a change through being taught, and is often altered from the contrary state, whereas the other is moved to action from simply having sense or grammar without acting [accordingly]; but in a different way from formerly when he had not yet acquired any habit [of knowing]. §§ 362-4
417b2         5. οὐκ ἔστι δ' ἁπλοῦν οὐδὲ τὸ πάσχειν, ἀλλὰ τὸ μὲν φθορά τις ὑπὸ τοῦ ἐναντίου, τὸ δὲ σωτηρία μᾶλλον ὑπὸ τοῦ ἐντελεχείᾳ ὄντος τοῦ δυνάμει ὄντος καὶ ὁμοίου οὕτως ὡς δύναμις ἔχει πρὸς ἐντελέχειαν· Nor is ‘being acted on’ a simple term. It is one thing to be somehow destroyed by a contrary; quite another when what is in potency is maintained by what is in act, and is of a similar nature, being related to the latter as potency to act. §§ 365-6
θεωροῦν γὰρ γίνεται τὸ ἔχον τὴν ἐπιστήμην, ὅπερ ἢ οὐκ ἔστιν ἀλλοιοῦσθαι (εἰς αὑτὸ γὰρ ἡ ἐπίδοσις καὶ εἰς ἐντελέχειαν) ἢ ἕτερον γένος ἀλλοιώσεως. διὸ οὐ καλῶς ἔχει λέγειν τὸ φρονοῦν, ὅταν φρονῇ, ἀλλοιοῦσθαι, ὥσπερ οὐδὲ τὸν οἰκοδόμον ὅταν οἰκοδομῇ. τὸ μὲν οὖν εἰς ἐντελέχειαν ἄγειν ἐκ δυνάμει ὄντος [κατὰ] τὸ νοοῦν καὶ φρονοῦν οὐ διδασκαλίαν ἀλλ' ἑτέραν ἐπωνυμίαν ἔχειν δίκαιον· For when a man possessed of knowledge becomes actually thinking, there is certainly either no ‘alteration’—there being a new perfection in him, and an increase of actuality;—or it is some novel kind of alteration. Hence it is as misleading a statement to say that a man is ‘altered’ when he thinks, as to say this of the builder when he builds. The process from being in potency to understand and think to actually doing so should not be called instruction, but has by rights some other name. §§ 367-8
τὸ δ' ἐκ δυνάμει ὄντος μανθάνον καὶ λαμβάνον ἐπιστήμην ὑπὸ τοῦ ἐντελεχείᾳ ὄντος καὶ διδασκαλικοῦ ἤτοι οὐδὲ πάσχειν φατέον, [ὥσπερ εἴρηται,] ἢ δύο τρόπους εἶναι ἀλλοιώσεως, τήν τε ἐπὶ τὰς στερητικὰς διαθέσεις μεταβολὴν καὶ τὴν ἐπὶ τὰς ἕξεις καὶ τὴν φύσιν. The change from being in potency, in one who learns and receives instruction from another (who actually has learning and teaches) either should not be called a ‘being acted upon’ (as we have said), or there are two modes of alteration, one a change to a condition of privation, the other to possession and maturity. §§ 369-72
ST. THOMAS’S COMMENTARY

LECTIO 11
Postquam philosophus ostendit sensum esse in potentia et actu, et nunc intendit ostendere quomodo educatur de potentia in actum. Et dividitur in partes duas. In prima distinguit potentiam et actum, et ostendit quomodo diversimode aliquid educatur de potentia in actum, utens exemplo in intellectu. In secunda parte ostendit propositum circa sensum, ibi, sensitivi autem. 358. Having explained how the sensitive faculties are both in act and in potency, the Philosopher now goes on to say how they are brought from potency into act. This he does in two parts: first distinguishing between act and potency, and between the diverse ways in which a thing may pass from one state to the other, taking his example from the intellect; and secondly, at ‘The first change in the sensitive being’, he applies all this to the case of sensation.
Circa primum tria facit. Primo dicit de quo est intentio. Secundo distinguit potentiam et actum circa intellectum, ibi, est quidem enim sic sciens et cetera. Tertio ostendit quomodo educitur aliquid de utraque potentia in actum, ibi, ambo quidem igitur et cetera. As regards the first of these parts he does three things: (a) he states his intention; (b) he distinguishes, at ‘For there is such a thing as’, between act and potency in the intellect; and (c) he explains, at ‘Therefore the first two’ how what is potential, in both the two senses of the term which have been distinguished, becomes actual.
Dicit ergo primo, quod dicendum est de potentia et actu, id est ostendendum quot modis dicitur aliquid in potentia, et quot modis in actu: quod necessarium fuit, quia in superioribus, simpliciter, id est absque distinctione usus est potentia et actu. First of all, then, he says he is about to discuss potency and act, in order to show the diverse ways in which things can be said to be actual or potential—because so far the two terms have been used ‘in one sense only’, i.e. without distinctions.
Deinde cum dicit est enim distinguit potentiam et actum circa intellectum. Et dicit, quod uno modo dicitur aliquid in potentia, puta homo sciens, quia habet naturalem potentiam ad sciendum, sicut homo dicitur esse de numero scientium et habentium scientiam, inquantum habet naturam ad sciendum, et ad habendum habitum scientiae. Secundo modo dicimus aliquem esse scientem, quod aliqua sciat; sicut dicimus habentem habitum alicuius scientiae, puta grammaticae, esse iam scientem. 359. Then at ‘For there is such a thing as’, he distinguishes act and potency in the intellect. We speak, he says, in one sense of potency when we say that man is a knower, referring to his natural capacity for knowledge. Man, we say, is one of that class of beings that know or have knowledge, meaning that his nature can know and form habits of knowing. In another sense, however, we say of someone that he knows, meaning that he knows certain definite things; thus we say of one who has the habit of some science—e.g. Grammar—that he is now one who knows.
Manifestum est autem quod uterque horum dicitur sciens, ex eo quod aliquid potest: sed non eodem modo uterque est potens ad sciendum. Sed primus quidem dicitur potens, quia est genus huiusmodi et materia, scilicet quia habet naturalem potentiam ad sciendum, per quam collocatur in tali genere; et quia est in potentia, puta ad scientiam, sicut materia ad formam. Secundus autem, scilicet qui habet habitum scientiae, dicitur potens, quia cum vult, potest considerare, nisi aliquid extrinsecum per accidens impediat; puta vel occupatio exterior, vel aliqua indispositio ex parte corporis. 360. Now, obviously, in both cases the man’s capacities are implied by calling him a knower; but not in the same way in both cases. In the first case man is said to be ‘able’ through belonging to a certain genus or ‘matter’, i.e. his nature has a certain capacity that puts him in this genus, and he is in potency to knowledge as matter to its form. But the second man, with his acquired habit of knowing, is called ‘able’ because when he wishes he can reflect on his knowledge—unless, of course, he is accidentally prevented, e.g. by exterior preoccupations or by some bodily indisposition.
Tertius autem, qui iam considerat, est in actu; et iste est qui proprie et perfecte scit ea quae sunt alicuius artis; puta hanc literam a, quae pertinet ad grammaticam, de qua supra fecit mentionem. Horum igitur trium, ultimus est in actu tantum: primus in potentia tantum; secundus autem in actu respectu primi, et in potentia respectu secundi. Unde manifestum est, quod esse in potentia, dicitur dupliciter, scilicet de primo et secundo; et esse in actu dicitur dupliciter, scilicet de secundo et tertio. 361. A third case would be that of a man who ‘was actually thinking about something here and now. He it is who most properly and perfectly is a knower in any field; e.g. knowing the letter A, which belongs to the above-mentioned science of Grammar. Of the three, then, the third is simply in act; the first is simply in potency; while the second is in act as compared with the first and in potency as compared with the third. Clearly, then, potentiality is taken in two senses (the first and second man); and actuality also in two senses (the second and third man).
Deinde cum dicit ambo igitur ostendit quomodo de utraque potentia aliquid reducitur in actum. Et circa hoc duo facit. Primo ostendit quomodo de utraque potentia aliquid in actum reducitur. Secundo ostendit utrum talis reductio sit secundum aliquam passionem, ibi, non est autem simpliciter neque pati et cetera. 362. Then where he says ‘Therefore the first two’, he explains (1) how both these types of potency are actualised, and (2), at ‘Nor is being acted on’, he discusses whether this actualisation is the result of a being acted upon.
Dicit ergo primo, quod cum ambo primi sint scientes secundum potentiam, et id quod est in potentia, reducatur in actum; alio modo reducitur in actum aliquid de potentia prima, et aliter de secunda. Nam quod est in potentia primo modo, reducitur in actum, quasi alteratus per doctrinam, et motus ab aliquo alio existente in actu, sicut a magistro; et multoties talis mutatio est ex contrario habitu. Quod ideo dicit, quia cum aliquis reducitur de potentia prima in actum, ex ignorante fit sciens. First, then, he remarks that while in the two first cases there is potential knowledge, and while potency as such is able to be actualised, there is a difference, in respect of actualisation, between a primary and a secondary potency. One in primary potency to knowledge is brought into act through being, as it were, changed or altered by teaching received from another (the teacher) who already knows actually. And often, he says, this change is from a contrary habit; alluding to those who come to actual knowledge from a state of ignorance.
Ignorans autem dicitur dupliciter: uno modo secundum simplicem negationem, quando nec veritatem cognoscit nec contrario errore detinetur: et qui sic ignorans est, fit actu sciens; non quod mutatus de contrario habitu, sed solum sicut acquirens scientiam. Alio modo dicitur aliquis ignorans, secundum pravam dispositionem; utpote quia detinetur errore contrario veritati; et hic in actum scientiae reducitur quasi de contrario habitu mutatus. 363. Ignorance has two meanings. it can be purely negative: when the ignorant person neither knows the truth nor is involved in the opposite error; and in this case he is simply brought into actual knowledge, not changed by being rid of a contrary habit. On the other hand, ignorance may imply the bad condition of being involved in error contrary to the truth; and to acquire knowledge, then, one must be changed by being delivered from that contrary habit.
Qui vero est in potentia secundo modo, ut scilicet iam habens habitum, transit ex eo quod habet sensum aut scientiam et non agit secundum ea, in agere; quia scilicet fit agens secundum scientiam. Sed alio modo iste fit actu, et alio modo primus. 364. But one in potency in the secondary sense—i.e. as already possessing the habit—passes from the state of having, indeed, sensations or knowledge but not exercising them, into the state of actually knowing something here and now. And this kind of actualisation differs from the other.
Deinde cum dicit non est autem manifestat utrum secundum quod aliquid educitur de potentia in actum scientiae primo modo, vel secundo, possit dici pati. Et circa hoc duo facit. Primo ostendit quot modis dicitur pati. Secundo manifestat propositum, ibi, speculans autem fit habens scientiam. Dicit ergo primo, quod sicut potentia et actus non dicuntur simpliciter, sed multipliciter; ita et pati non uno modo, sed multipliciter. Dicitur enim pati uno modo, secundum quamdam corruptionem, quae fit a contrario. Passio enim proprie dicta, videtur importare quoddam decrementum patientis, inquantum vincitur ab agente: decrementum autem patienti accidit secundum quod aliquid a patiente abiicitur. Quae quidem abiectio, corruptio quaedam est: vel simpliciter, sicut quando abiicitur forma substantialis; vel secundum quid, sicut quando abiicitur forma accidentalis. Huiusmodi autem formae abiectio fit a contrario agente: abiicitur enim forma a materia vel subiecto, per introductionem contrariae formae; et hoc est a contrario agente. Primo igitur modo proprie dicitur passio, secundum quod quaedam corruptio fit a contrario. 365. Then at ‘Nor is being acted on’ he discusses the question whether both kinds of actualisation can be called being acted upon. First, he explains the different meanings of ‘being acted on’. Then at ‘For when a man possessed of etc.’, he applies these distinctions to the present problem. First, then, he remarks that being acted upon has several meanings, like potency and act. In one sense it implies some kind of destruction caused by a contrary quality. For in the strict sense the state of being passive to action seems to connote, on the side of the patient, a loss of something proper to it through its being overcome by the agent; and this loss is a sort of destruction, either absolutely, as when the patient loses its substantial form, or relatively, as in the loss of an accidental form. And the loss implies a contrariety in the agent, the imposition upon the patient’s matter, or being, of a contrary form from outside. In the first and strict sense, then, ‘being acted on’ means a destruction caused by a contrary agent.
Alio modo passio communiter dicitur et minus proprie, secundum scilicet quod importat quamdam receptionem. Et quia quod est receptivum alterius, comparatur ad ipsum sicut potentia ad actum: actus autem est perfectio potentiae; et ideo hoc modo dicitur passio, non secundum quod fit quaedam corruptio patientis, sed magis secundum quod fit quaedam salus et perfectio eius quod est in potentia, ab eo quod est in actu. Quod enim est in potentia, non perficitur nisi per id quod est in actu. Quod autem in actu est, non est contrarium ei quod est in potentia, inquantum huiusmodi, sed magis simile: nam potentia nihil aliud est quam quidam ordo ad actum. Nisi autem esset aliqua similitudo inter potentiam et actum, non esset necessarium quod proprius actus fieret in propria potentia. Potentia igitur sic dicta, non est a contrario, sicut potentia primo modo dicta; sed est a simili, eo modo quo potentia se habet secundum similitudinem ad actum. 366. In another and looser sense the term connotes any reception of something from outside. And as a receiver is to what it receives as a potency to its actuality; and as actuality is the perfection of what is potential; so being acted upon in this sense implies rather that a certain preservation and perfection of a thing in potency is received from a thing in act. For only the actual can perfect the potential; and actuality is not, as such, contrary to potency; indeed the two are really similar, for potency is nothing but, a certain relationship to act. And without this likeness there would be no necessary correspondence between this act and this potency. Hence potency in this sense is not actualised from contrary to contrary, but rather from like to like, in the sense that the potency resembles its act.
Deinde cum dicit speculans enim manifestat, utrum quod educitur de potentia in actum scientiae patiatur. Et primo manifestat hoc circa id quod educitur de secunda potentia in actum purum. Secundo autem manifestat hoc circa id quod educitur de potentia prima in habitum, ibi, ex potentia autem et cetera. Dicit ergo primo, quod habens scientiam, id est habitualiter sciens, fit actu speculans. Sed hoc aut non est vere et proprie alterari et pati; quia, ut dictum est, non est proprie passio et alteratio, cum de potentia procedit in actum, sed cum aliquid de contrario mutatur in contrarium. Cum autem habitualiter sciens, fit speculans actu, non mutatur de contrario in contrarium, sed proficit in eo quod iam habet. Et hoc est quod dicit quod est additio in ipsum, et in actum. Additur enim ei perfectio secundum quod proficit in actum. Aut si dicatur alterari et pati, erit aliud genus alterationis et passionis non proprie dictae. Et hoc manifestat per exemplum; dicens, quod non bene se habet, dicere sapientem habitualiter, cum sapiat actu, alterari, sicut neque dicimus aedificatorem alterari, cum aedificat. 367. Next at ‘When a man possessed of’, Aristotle discusses whether the actualising of already acquired knowledge involves a being acted upon. And he takes first the transit from secondary potentiality into fullest actuality; and then at ‘The change from being in potency’, that from primary potentiality into the acquired habit of knowledge. Now, as to the former point, he asserts that this movement into actual thinking is not truly a passive being altered; for, as we have seen, no movement into act, as movement into act, is such. The term applies, strictly, only to the alteration of a subject from one to the other of two mutually exclusive qualities. But this is not what happens when a man begins to exercise his mind on knowledge he already possesses; rather, he is developing a quality already possessed; as Aristotle says here, it is ‘a new perfection in him and an increase of actuality’; for perfection increases with actuality. And if one insists on using the terms ‘actuality’ and ‘being acted upon’, they must be taken in a wider and less strict sense. And to illustrate the point he adds that it is just as inept to speak of a thinker being ‘altered’ when he actually thinks as to say of a builder that he is altered by building.
Concludit autem ulterius, quod cum ille qui transit de habitu in actum, non accipiat de novo scientiam, sed proficiat, et perficiatur in eo quod habet: doceri autem, scientiam est acquirere: manifestum est, quod cum educitur aliquis de potentia in actum, secundum hoc quod incipit facere eum intelligere actu et sapere, non est iustum quod talis exitus de potentia in actum habeat denominationem doctrinae; sed aliquam aliam potest habere, quae quidem forte non est posita, sed potest poni. 368. A further conclusion: if it be granted that to pass from habitual to actual knowing is not a reception of new knowledge, but rather a drawing out and perfection of knowledge possessed already, it remains true that to be taught is to acquire new knowledge. Therefore, when a man is brought simply to the act of knowing or understanding, this ought not, strictly speaking, to be called ‘instruction’; it might be given some other name, though perhaps no other has in fact been found for it.
Deinde cum dicit ex potentia manifestat, utrum cum aliquis exit de prima potentia in actum scientiae, alteretur et patiatur: et dicit quod cum aliquis prius sciens in potentia tantum fit addiscens et accipiens scientiam ab eo qui est actu sciens, et a magistro; vel non debet dici pati simpliciter et alterari; aut dicendum est esse duos modos alterationis: quorum unus alterationis est secundum mutationem, in privationis dispositiones, id est in dispositiones contrarias, quibus privantur, propter dispositiones prius existentes, quia unum contrariorum est privatio alterius. Alter vero alterationis modus est secundum mutationem in habitum et naturam, id est secundum quod recipiuntur aliqui habitus et formae, quae sunt perfectiones naturae, absque eo quod aliquid abiiciatur. Ille igitur, qui addiscit scientiam, non alteratur neque patitur primo modo, sed secundo. 369. Then at ‘The change from being in potency’, he discusses whether the transit from potency to act of one who acquires completely fresh knowledge is an ‘alteration’, in the sense of a ‘being acted upon’. He says that when a learner, previously knowing only potentially, is instructed by a master already knowing actually, one should either call this simply not a case of alteration and being acted upon, or else distinguish two kinds of alteration. The one kind is ‘a change to a condition of privation’, i.e. into qualities opposed to those which the thing already has, and incompatible with these, and therefore until now excluded by them. The other kind is ‘by a change to a possession and maturity’, i.e. through receiving habits and forms which perfect the thing’s nature and involve no loss of what it already has. And the learner is altered in this second sense, not in the first.
Videtur autem hoc esse contrarium eius quod supra dixit, quod multoties qui addiscit scientiam, mutatus est a contrario habitu; et ita videtur quod sit alteratio secundum mutationem in privativas dispositiones. Sed dicendum, quod cum aliquis ab errore reducitur ad scientiam veritatis, est ibi quaedam similitudo alterationis, quae est de contrario ad contrarium; non tamen vere est ibi talis alteratio. Nam alterationi, quae est de contrario in contrarium, utrumque per se et essentialiter competit: scilicet quod sit a contrario, et quod sit in contrarium. Sicut enim dealbatio non est nisi ad album, ita non est nisi a nigro vel medio, quod respectu albi, est quodammodo nigrum. Sed in acquisitione scientiae accidit quod ille qui acquirit scientiam veritatis, prius fuerit in errore: absque hoc enim potest adduci ad scientiam veritatis; unde non est vere alteratio de contrario in contrarium. 370. Now this seems to contradict what was said above, that learners often changed from a contrary habit, and thus, it would seem, acquired qualities opposed to their former ones. But really, when one is brought from error to the knowledge of truth there is indeed a certain likeness to the change from one quality to its opposite, but it is only a likeness. For where there is true alteration both the opposed qualities—the terms of the process—are necessarily and essentially involved, e.g. becoming white involves not only white, but also black, or some intermediary colour which in relation to white is a sort of blackness. But where knowledge is acquired it is quite accidental that the learner was previously in error. He could learn without first being in error. Hence it is not in the true sense an alteration.,
Item dubitatur de hoc quod dicit, quod ille qui accipit scientiam fit actu sciens a sciente in actu, et magistro. Hoc enim non semper fit; scientiam enim aliquis acquirit, non solum addiscendo a magistro, sed etiam per se inveniendo. Et ad hoc dicendum est, quod semper cum aliquis est in potentia sciens, si fiat actu habens scientiam, oportet quod hoc sit ab eo quod est actu. Considerandum tamen est, quod aliquid aliquando reducitur de potentia in actum ab extrinseco principio tantum: sicut aer illuminatur ab eo quod est actu lucidum: quandoque autem et a principio intrinseco, et a principio extrinseco: sicut homo sanatur, et a natura, et a medico; utrobique autem sanatur a sanitate in actu. Manifestum est enim quod in mente medici est ratio sanitatis, secundum quam sanat. Oportet etiam in eo qui sanatur secundum naturam, esse aliquam partem sanam, scilicet cor, cuius virtute aliae partes sanantur. Et cum medicus sanat, hoc modo sanat, sicut natura sanaret, scilicet calefaciendo, aut infrigidando, aut aliter transmutando. Unde medicus nihil aliud facit quam quod auxiliatur naturae ad expellendum morbum; quo auxilio natura non egeret, si esset fortis. 371. Another difficulty occurs where he says that the learner as such is taught by a master who already knows. For it does not always happen thus; a man may acquire knowledge by finding out for himself. To this we reply that whenever a potential knower becomes an actual knower, he must indeed be actualised by what is already in act. But this may be effected either by a purely extrinsic cause, as when air is lit up by an already actual fight, or by an intrinsic cause as well, as when a man is healed both by nature and by a doctor. In this latter case both causes of healing are actual health; for obviously health exists both in the mind of a doctor and in some healthy part of the man’s nature (i.e. the heart) in virtue of which the rest of the man recovers health. Doctors make use of such natural means to health as warmth or cold or other variable dispositions, so that we can say that the whole of their skill consists in helping nature to drive out sickness. If nature were strong enough she could do this by herself without a doctor’s aid.
Eodem autem modo se habet in scientiae acquisitione. Homo enim acquirit scientiam, et a principio intrinseco, dum invenit, et a principio extrinseco, dum addiscit. Utrobique autem reducitur de potentia in actum, ab eo quod est actu. Homo enim per lumen intellectus agentis, statim cognoscit actu prima principia naturaliter cognita; et dum ex eis conclusiones elicit, per hoc quod actu scit, venit in actualem cognitionem eorum quae potentia sciebat. Et eodem modo exterius docens ei auxiliatur ad sciendum; scilicet ex principiis addiscenti notis deducens eum per demonstrationem in conclusiones prius ignotas. Quod quidem auxilium exterius homini necessarium non esset, si adeo esset perspicacis intellectus quod per seipsum posset ex principiis notis conclusiones elicere: quae quidem perspicacitas hominibus adest secundum plus et minus. 372. And the case is the same when a man acquires knowledge. For here again there are two principles involved: an intrinsic one, which a man uses when he finds things out for himself; and an extrinsic one, as when he learns from others. But in both cases a potency is actualised by something already in act. The fight of the agent intellect gives a man immediate actual knowledge of the first principles which we know by nature, and in virtue of this actual knowing he is led to actual knowledge of conclusions previously known by him only potentially. In like manner too a teacher can help him towards knowledge, leading him step by step from principles he already knows to conclusions hitherto unknown to him. Nor would this external aid be necessary if the human mind were always strong enough to deduce conclusions from the principles it possesses by nature; and indeed the power so to deduce is present in men, but in varying degrees.

TEXT
417b18–418a25
BOOK II, CHAPTER V, CONTINUED

SENSITIVITY
ACTUALISATIONS OF SENSE AND INTELLECT COMPARED

6. τοῦ δ' αἰσθητικοῦ ἡ μὲν πρώτη μεταβολὴ γίνεται ὑπὸ τοῦ γεννῶντος, ὅταν δὲ γεννηθῇ, ἔχει ἤδη, ὥσπερ ἐπιστήμην, καὶ τὸ αἰσθάνεσθαι. The first change in the sensitive being is caused by the parent. When it is born it is already endowed as with knowledge. Actual sensation corresponds to the act of thinking. §§ 373-4
τὸ κατ' ἐνέργειαν δὲ ὁμοίως λέγεται τῷ θεωρεῖν· διαφέρει δέ, ὅτι τοῦ μὲν τὰ ποιητικὰ τῆς ἐνεργείας ἔξωθεν, τὸ ὁρατὸν καὶ τὸ ἀκουστόν, ὁμοίως δὲ καὶ τὰ λοιπὰ τῶν αἰσθητῶν. αἴτιον δ' ὅτι τῶν καθ' ἕκαστον ἡ κατ' ἐνέργειαν αἴσθησις, ἡ δ' ἐπιστήμη τῶν καθόλου· ταῦτα δ' ἐν αὐτῇ πώς ἐστι τῇ ψυχῇ. διὸ νοῆσαι μὲν ἐπ' αὐτῷ, ὁπόταν βούληται, αἰσθάνεσθαι δ' οὐκ ἐπ' αὐτῷ· ἀναγκαῖον γὰρ ὑπάρχειν τὸ αἰσθητόν. ὁμοίως δὲ τοῦτο ἔχει κἀν ταῖς ἐπιστήμαις ταῖς τῶν αἰσθητῶν, καὶ διὰ τὴν αὐτὴν αἰτίαν, ὅτι τὰ αἰσθητὰ τῶν καθ' ἕκαστα καὶ τῶν ἔξωθεν. 7. ἀλλὰ περὶ μὲν τούτων διασαφῆσαι καιρὸς γένοιτ' ἂν καὶ εἰςαῦθις· They differ, however. For the actuation of sense-operations is from without; namely from the visible, the audible, and so on for the other senses. The cause [of the difference] is that sensation, even in act, is of particulars: whereas scientific knowledge is of universals. For the latter are, in a way, within the soul itself; hence the act of the intellect is interior and at will; whereas sensation is not from within the soul, and requires that a sense-object be presented. The same holds good of the sciences which concern sense-objects, and for the same reason, i.e. that sense objects are singulars and are external. But there will be time later to deal with these more conclusively. §§ 375-80
νῦν δὲ διωρίσθω τοσοῦτον, ὅτι οὐχ ἁπλοῦ ὄντος τοῦ δυνάμει λεγομένου, ἀλλὰ τοῦ μὲν ὥσπερ ἂν εἴποιμεν τὸν παῖδα δύνασθαι στρατηγεῖν, τοῦ δὲ ὡς τὸν ἐν ἡλικίᾳ ὄντα, οὕτως ἔχει [418a] τὸ αἰσθητικόν. ἐπεὶ δ' ἀνώνυμος αὐτῶν ἡ διαφορά, διώρισται δὲ περὶ αὐτῶν ὅτι ἕτερα καὶ πῶς ἕτερα, χρῆσθαι ἀναγκαῖον τῷ πάσχειν καὶ ἀλλοιοῦσθαι ὡς κυρίοις ὀνόμασιν. τὸ δ' αἰσθητικὸν δυνάμει ἐστὶν οἷον τὸ αἰσθητὸν ἤδη ἐντελεχείᾳ, καθάπερ εἴρηται. πάσχει μὲν οὖν οὐχ ὅμοιον ὄν, πεπονθὸς δ' ὡμοίωται καὶ ἔστιν οἷον ἐκεῖνο. For the present it is sufficiently established that ‘in potency’ is not univocally predicated; but it means one thing when, for example, we say that a child is able to be a soldier, and quite another thing when we say this of an adult. The same holds of the sensitive power. Since, however, this distinction has no name, and yet it is settled that the [two stages] differ, and in what way, it is necessary to use the expressions ‘to be acted upon’ and ‘to be altered’ as if they were precise terms. The sensitive power is potentially that which the sense-object is actually, as we have said. It is acted upon in so far as it is not like: it becomes like, in being acted upon; and is then such as is the other. §§ 381-2
ST. THOMAS’S COMMENTARY

LECTIO 12
Postquam philosophus distinxit potentiam et actum, et ostendit quomodo aliquid de potentia in actum exeat circa intellectum, quod dixerat de intellectu adaptat ad sensum. Et circa hoc tria facit. Primo ostendit quomodo circa sensum aliquid educitur de potentia in actum. Secundo ostendit differentiam inter sensum et intellectum, ibi, differunt autem, quia huius quidem accidentia et cetera. Tertio colligit epilogando quae dixerat de sensu, ibi, nunc autem in tantum. 373. After distinguishing between potency and act, and elucidating in terms of intellectual activity the transit from one state to the other, the Philosopher now applies what he has said to the case of sensation. First, he shows how there is a transit from potency to act in sensing. Secondly, at ‘They differ, however’ he explains the difference between the two cases. Thirdly, at ‘For the present it is sufficiently established’, he recapitulates what has been said about sensation.
Considerandum est ergo circa primum, quod sicut in scientia est duplex potentia et duplex actus, ita est et circa sensum. Nam quod nondum habet sensum et natum est habere, est in potentia ad sensum. Et quod iam habet sensum et nondum sentit, est potentia sentiens, sicut circa scientiam dicebatur. Sicut autem de potentia prima aliquid mutatur in primum actum, dum acquirit scientiam per doctrinam; ita de prima potentia ad sensum, aliquid mutatur in actum, ut scilicet habeat sensum per generationem. Sensus autem naturaliter inest animali: unde sicut per generationem acquirit propriam naturam, et speciem, ita acquirit sensum. Secus autem est de scientia, quae non inest homini per naturam sed acquiritur per intentionem et disciplinam. Regarding the first point, we must take into account that, as in intellectual cognition, so too in sensation, potency and act are each two-fold. For what so far possesses no sense-faculty but is due by nature to have one, is in potency to sensation; and what has the sense-faculty, but does not yet sense, is in potency to actual sensation in the same way as we have seen in the case of acquired intellectual knowledge. Now, as a subject moves from primary potency into primary actuality when it acquires knowledge through teaching, so too a subject’s primary potency to the possession of a sense-faculty is actualised by his birth. But whereas a sense-faculty is natural to every animal,—so that in the act of being generated it acquires a sense-faculty along with its own specific nature—the case is not the same with intellectual knowledge; this is not naturally inborn in man; it has to be acquired through application and discipline.
Hoc est ergo quod dicit, quod prima mutatio sensitivi fit a generante. Manifestat autem primam mutationem, quae est de pura potentia in actum primum ducens. Haec autem mutatio fit a generante; nam per virtutem, quae est in semine, educitur anima sensitiva de potentia in actum cum omnibus suis potentiis. Cum autem animal iam generatum est, tunc hoc modo habet sensum, sicut aliquis habet scientiam quando iam didicit. Sed quando iam sentit secundum actum, tunc se habet sicut ille qui iam actu considerat. 374. This is what he means by saying that ‘the first change in the sensitive being’ is caused by the parent. This ‘first change’, he explains, is from sheer potency to the primary actuality; and it is due to the parent; because there is a power in the semen to actualise the sensitive soul with all its capacities. Once an animal has been generated it has its senses in the same way as a man who has been taught possesses knowledge. And when it actually senses it corresponds to the man who actually exercises his knowledge by thinking.
Deinde cum dicit differunt tamen quia posuerat similitudinem inter sentire in actu et considerare, vult ostendere differentiam inter ea: cuius quidem differentiae causam assignare incipit ex differentia obiectorum, scilicet sensibilium, et intelligibilium, quae sentiuntur et considerantur in actu. Sensibilia enim quae sunt activa operationis sensitivae, scilicet visibile et audibile, et alia huiusmodi, sunt extra animam. Cuius causa est, quia sensus secundum actum, sunt singularium quae sunt extra animam, sed scientia est universalium quae quodammodo sunt in anima. Ex quo patet, quod ille qui iam habet scientiam, non oportet quod quaerat extra sua obiecta, sed habet ea in se; unde potest considerare ea cum vult, nisi forte per accidens impediatur. Sed sentire non potest aliquis cum vult; quia sensibilia non habet in se, sed oportet quod adsint ei extra. 375. Then at ‘They differ, however’, he sets himself to discriminate between actual sensation and thinking; and he finds the first reason for distinguishing these activities in the difference between their objects, i.e. the sense-objects and intelligible objects which are attained by actual sensation and actual thinking respectively. The sense-objects which actuate sensitive activities—the visible, the audible, etc.—exist outside the soul; the reason being that actual sensation attains to the individual things which exist externally; whereas rational knowledge is of universals which exist somehow within the soul. Whence it is clear that the man who already has scientific knowledge about certain things does not need to seek such things outside himself, he already possesses them inwardly, and is able, unless prevented by some incidental cause, to reflect on them whenever he pleases. But a man cannot sense whatever he pleases; not possessing sense-objects inwardly, he is forced to receive them from outside.
Et sicut est de operatione sensuum, ita est in scientiis sensibilium; quia etiam sensibilia sunt de numero singularium, et eorum quae sunt extra animam. Unde homo non potest considerare secundum scientiam, omnia sensibilia quae vult, sed illa tantum, quae sensu percipit. Sed secundum certitudinem determinare de his, iterum erit tempus, scilicet in tertio, ubi agetur de intellectu, et de comparatione intellectus ad sensum. 376. And as with sense-activities, so with the sciences of sense-objects; for the latter are individual things existing outside the soul. Therefore a man cannot speculate scientifically on any sense-objects, but only on such as he perceives in sensation. But there will be time to treat conclusively of this matter later on, in Book III, where we discuss the intellect and its relation to the senses.
Circa ea vero quae hic dicuntur, considerandum est, quare sensus sit singularium, scientia vero universalium; et quomodo universalia sint in anima. 377. Concerning what is said here, we have to ask ourselves (a) why sensation is of individual things, whereas science is of universals; and (b) how exactly universals exist in the soul.
Sciendum est igitur circa primum, quod sensus est virtus in organo corporali; intellectus vero est virtus immaterialis, quae non est actus alicuius organi corporalis. Unumquodque autem recipitur in aliquo per modum sui. Cognitio autem omnis fit per hoc, quod cognitum est aliquo modo in cognoscente, scilicet secundum similitudinem. Nam cognoscens in actu, est ipsum cognitum in actu. Oportet igitur quod sensus corporaliter et materialiter recipiat similitudinem rei quae sentitur. Intellectus autem recipit similitudinem eius quod intelligitur, incorporaliter et immaterialiter. Individuatio autem naturae communis in rebus corporalibus et materialibus, est ex materia corporali, sub determinatis dimensionibus contenta: universale autem est per abstractionem ab huiusmodi materia, et materialibus conditionibus individuantibus. Manifestum est igitur, quod similitudo rei recepta in sensu repraesentat rem secundum quod est singularis; recepta autem in intellectu, repraesentat rem secundum rationem universalis naturae: et inde est, quod sensus cognoscit singularia, intellectus vero universalia, et horum sunt scientiae. As to (a) we should note that while the sense-faculty is always the function of a bodily organ, intellect is an immaterial power—it is not the actuality of any bodily organ. Now everything received is received in the mode of the recipient. If then all knowledge implies that the thing known is somehow present in the knower (present by its similitude), the knower’s actuality as such being the actuality of the thing known, it follows that the sense-faculty receives a similitude of the thing sensed in a bodily and material way, whilst the intellect receives a similitude of the thing understood in an incorporeal and immaterial way. Now in material and corporeal beings the common nature derives its individuation from matter existing within specified dimensions, whereas the universal comes into being by abstraction from such matter and all the individuating material conditions. Clearly, then, a thing’s similitude as received in sensation represents the thing as an individual; as received, however, by the intellect it represents the thing in terms of a universal nature. That is why individuals are known by the senses, and universals (of which are the sciences) by the intellect.
Circa secundum vero considerandum est, quod universale potest accipi dupliciter. Uno modo potest dici universale ipsa natura communis, prout subiacet intentioni universalitatis. Alio modo secundum se. Sicut et album potest accipi dupliciter: vel id, cui accidit esse album, vel ipsummet, secundum quod subest albedini. Ista autem natura, cui advenit intentio universalitatis, puta natura hominis, habet duplex esse: unum quidem materiale, secundum quod est in materia naturali; aliud autem immateriale, secundum quod est in intellectu. Secundum igitur quod habet esse in materia naturali, non potest ei advenire intentio universalitatis, quia per materiam individuatur. Advenit igitur ei universalitatis intentio, secundum quod abstrahitur a materia individuali. Non est autem possibile, quod abstrahatur a materia individuali realiter, sicut Platonici posuerunt. Non enim est homo naturalis, id est realis, nisi in his carnibus, et in his ossibus, sicut probat philosophus in septimo metaphysicae. Relinquitur igitur, quod natura humana non habet esse praeter principia individuantia, nisi tantum in intellectu. 378. As to (b), note that the term ‘universal’ can be taken in two senses. It can refer to the nature itself, common to several things , in so far as this common nature is regarded in relation to those several things; or it can refer to the nature taken simply in itself Similarly, in a ‘white thing’ we can consider either the thing that happens to be white or the thing precisely as white. Now a nature—say, human nature,—which can bethought of universally, has two modes of existence: one, material, in the matter supplied by nature; the other, immaterial, in the intellect. As in the material mode of existence it cannot be represented in a universal notion, for in that mode it is individuated by its matter; this notion only applies to it, therefore, as abstracted from individuating matter. But it cannot, as so abstracted, have a real existence, as the Platonists thought; man in reality only exists (as is proved in the Metaphysics, Book VII) in this flesh and these bones. Therefore it is only in the intellect that human nature has any being apart from the principles which individuate it.
Nec tamen intellectus est falsus, dum apprehendit naturam communem praeter principia individuantia, sine quibus esse non potest in rerum natura. Non enim apprehendit hoc intellectus, scilicet quod natura communis sit sine principiis individuantibus; sed apprehendit naturam communem non apprehendendo principia individuantia; et hoc non est falsum. Primum autem esset falsum: sicut si ab homine albo separarem albedinem hoc modo, quod intelligerem eum non esse album: esset enim tunc apprehensio falsa. Si autem sic separarem albedinem ab homine, quod apprehenderem hominem nihil apprehendendo de albedine eius, non esset apprehensio falsa. Non enim exigitur ad veritatem apprehensionis, ut quia apprehendit rem aliquam, apprehendat omnia quae insunt ei. Sic igitur intellectus absque falsitate abstrahit genus a speciebus, inquantum intelligit naturam generis non intelligendo differentias. Et similiter abstrahit speciem ab individuis, inquantum intelligit naturam speciei, non intelligendo individualia principia. 379. Nevertheless, there is no deception when the mind apprehends a common nature apart from its individuating principles; for in this apprehension the mind does not judge that the nature exists apart; it merely apprehends this nature without apprehending the individuating principles; and in this there is no falsehood. The alternative would indeed be false—as though I were so to discriminate whiteness from a white man as to understand him not to be white. This would be false; but not if I discriminate the two in such wise as to think of the man without giving a thought to his whiteness. For the truth of our conceptions does not require that, merely apprehending anything, we apprehend everything in it. Hence the mind abstracts, without any falsehood, a genus from a species when it understands the generic nature without considering the differences; or it may abstract the species from individuals when it understands the specific nature, without considering the individuating principles.
Sic igitur patet, quod naturae communi non potest attribui intentio universalitatis nisi secundum esse quod habet in intellectu: sic enim solum est unum de multis, prout intelligitur praeter principia, quibus unum in multa dividitur: unde relinquitur, quod universalia, secundum quod sunt universalia, non sunt nisi in anima. Ipsae autem naturae, quibus accidit intentio universalitatis, sunt in rebus. Et propter hoc, nomina communia significantia naturas ipsas, praedicantur de individuis; non autem nomina significantia intentiones. Socrates enim est homo, sed non est species, quamvis homo sit species. 380. It is dear, then, that universality can be predicated of a common nature only in so far as it exists in the mind: for a unity to be predicable of many things it must first be conceived apart from the principles by which it is divided into many things. Universals as such exist only in the soul; but the natures themselves, which are conceivable universally, exist in things. That is why the common names that denote these natures are predicated of individuals; but not the names that denote abstract ideas. Socrates is a ‘man’, not a ‘species’—although ‘man’ is a ‘species’.
Deinde cum dicit nunc autem recolligit quod dictum est de sensu. Et dicit, quod nunc tantum sit definitum, quod non simpliciter dicitur, quod est in potentia, seu simpliciter. Uno enim modo dicimus puerum posse militare, secundum potentiam remotam. Alio modo posse dicimus militare, quoniam iam est in aetate perfecta, et hoc secundum potentiam propinquam. Et similiter se habet in sensitivo. Dupliciter enim est aliquis in potentia ad sentiendum aliquid, ut iam dictum est. Et licet non sint nomina posita, in quibus harum differentia potentiarum ostendatur, tamen determinatum est quod istae potentiae sunt alterae abinvicem, et quomodo sint alterae. 381. Finally, at ‘For the present etc.’, he recapitulates his remarks on sensation and observes that only now has it become clear that what we call potency has more than one meaning. It is in one sense that we say that a boy can be a soldier, i.e. by a remote potentiality. But in another sense we say that a grown man can be a soldier, i.e. by proximate potentiality. And the same distinction applies to sense-perception; as we have seen there are two ways of being in potency to sense anything. Though we have found no terms to express this difference, we have seen, nevertheless, that the two kinds of potency differ, and how they differ.
Et licet alterari et pati non proprie dicatur aliquid, secundum quod exit de potentia secunda in actum, prout habens sensum fit actu sentiens: tamen necesse est uti hoc ipso, quod est pati et alterari, ac si essent nomina propria et convenientia: quia sensitivum in potentia est tale quale est in actu sensibile. Et propter hoc sequitur, quod secundum quod patitur a principio, non est similis sensus sentienti; sed secundum quod iam est passum, est assimilatum sensibili, et est tale quale est illud. Quod quia distinguere nescierunt antiqui philosophi, posuerunt sensum esse compositum ex sensibilibus. 382. And in spite of the fact that a thing which passes from the second stage of potency into act, through actualising its sense-faculty, ought not, strictly speaking, to be said to be ‘altered’ or ‘acted upon’, we cannot help using these terms; and this because the sense-faculty is potentially such as the sense-object is actually. It follows that, whilst at the start of the process of being acted upon the faculty is not like its object, at the term of the process it has this likeness. It was because they failed to make this distinction that the earlier philosophers thought that sense-faculties were composed of the same elements as their objects.

TEXT
418a6–418a26
BOOK II, CHAPTER VI
ΚΕΦΑΛΑΙΟΝ ς'

SENSE OBJECTS IN GENERAL

418a7   1. Λεκτέον δὲ καθ' ἑκάστην αἴσθησιν περὶ τῶν αἰσθητῶν πρῶτον. λέγεται δὲ τὸ αἰσθητὸν τριχῶς, ὧν δύο μὲν καθ' αὑτά φαμεν αἰσθάνεσθαι, τὸ δὲ ἓν κατὰ συμβεβηκός. τῶν δὲ δυοῖν τὸ μὲν ἴδιόν ἐστιν ἑκάστης αἰσθήσεως, τὸ δὲ κοινὸν πασῶν. In treating of each sense we must first discuss sense-objects. We speak of a sense-object in three ways: two [kinds of sense-objects] are perceptible essentially; one incidentally. Of the two former, one is proper to each sense, the other common to all. § 383
2. λέγω δ' ἴδιον μὲν ὃ μὴ ἐνδέχεται ἑτέρᾳ αἰσθήσει αἰσθάνεσθαι, καὶ περὶ ὃ μὴ ἐνδέχεται ἀπατηθῆναι, οἷον ὄψις χρώματος καὶ ἀκοὴ ψόφου καὶ γεῦσις χυμοῦ, ἡ δ' ἁφὴ πλείους [μὲν] ἔχει διαφοράς, ἀλλ' ἑκάστη γε κρίνει περὶ τούτων, καὶ οὐκ ἀπατᾶται ὅτι χρῶμα οὐδ' ὅτι ψόφος, ἀλλὰ τί τὸ κεχρωσμένον ἢ ποῦ, ἢ τί τὸ ψοφοῦν ἢ ποῦ. τὰ μὲν οὖν τοιαῦτα λέγεται ἴδια ἑκάστης, Now, I call that the proper object of each sense which does not fall within the ambit of another sense, and about which there can be no mistake,—as sight is of colour, and hearing of sound, and taste of savour; while touch has several different objects. Each particular sense can discern these proper objects without deception; thus sight errs not as to colour, nor hearing as to sound; I though it might err about what is coloured, or where it is, or about what is giving forth a sound. This, then, is what is meant by the proper objects of particular senses. §§ 384-5
3. κοινὰ δὲ κίνησις, ἠρεμία, ἀριθμός, σχῆμα, μέγεθος· τὰ γὰρ τοιαῦτα οὐδεμιᾶς ἐστὶν ἴδια, ἀλλὰ κοινὰ πάσαις· καὶ γὰρ ἁφῇ κίνησίς τίς ἐστιν αἰσθητὴ καὶ ὄψει. Now the sense-objects in common are movement, rest, number, shape, dimension. Qualities of this kind are proper to no one sense, but are common to all; thus a movement is perceptible both by touch and by sight. These, then, are the essential objects of sensation. § 386
4. κατὰ συμβεβηκὸς δὲ λέγεται αἰσθητόν, οἷον εἰ τὸ λευκὸν εἴη Διάρους υἱός· κατὰ συμβεβηκὸς γὰρ τούτου αἰσθάνεται, ὅτι τῷ λευκῷ συμβέβηκε τοῦτο, οὗ αἰσθάνεται· διὸ καὶ οὐδὲν πάσχει ᾗ τοιοῦτον ὑπὸ τοῦ αἰσθητοῦ. τῶν δὲ καθ' αὑτὰ αἰσθητῶν τὰ ἴδια κυρίως ἐστὶν αἰσθητά, καὶ πρὸς ἃ ἡ οὐσία πέφυκεν ἑκάστης αἰσθήσεως. To be a sense-object ‘incidentally’ is said, for example, of a white object that is the son of Diares. This is perceived incidentally because whiteness happens to belong to what is perceived: but the sense, is unaffected by that object as such. Of objects essentially sense-perceptible, the proper are properly such; and to these the essence of each sense is naturally adapted. §§ 387-98
ST. THOMAS’S COMMENTARY

LECTIO 13
Postquam ostendit philosophus, quomodo se habet sensus ad sensibilia, incipit determinare de sensibili et sensu. Et dividit in partes duas. In prima parte determinat de sensibilibus. In secunda de sensu, ibi, quod autem universaliter de omni sensu et cetera. Prima dividitur in duas partes. In prima distinguit sensibilia propria ab aliis modis sensibilium. In secunda determinat de sensibilibus propriis secundum unumquemque sensum, ibi, cuius quidem est visus et cetera. Circa primum duo facit. Primo ponit divisionem sensibilium. Secundo exponit membra divisionis, ibi, dico autem proprium quidem et cetera. 383. Having explained in general terms how sense-faculties are related to their objects, the Philosopher now begins his examination of objects and faculties separately. This enquiry divides into two parts, of which one is concerned with the sense-objects, and the other, starting at ‘It must be taken as a general rule’, with the faculties. The first part again divides into (a) a discrimination of the proper or special sense-objects from the rest, and (b) at ‘That of which there is sight’, an examination of the special objects of each sense. As to (a) he first makes a division of the sense-objects, and then, at ‘Now I call that the proper object,’ explains this division piecemeal.
Dicit ergo primo, quod antequam determinetur de sensu quidnam sit, oportet primo dicere de sensibilibus secundum unumquemque sensum, quia obiecta sunt praevia potentiis. Sensibilia vero tribus modis dicuntur. Uno quidem modo per accidens, et duobus modis per se: quorum uno dicuntur sensibilia illa, quae propria sint singulis sensibus; alio modo dicuntur sensibilia illa, quae communiter sentiuntur ab omnibus quae sentiunt. Beginning then, he observes that before we decide what the senses themselves are we must discuss the objects of each sense; for objects are prior to faculties. Now the term sense-object is used in three ways, in one way incidentally, and in two ways essentially or absolutely; and of the latter we use one in referring to the special objects proper to each sense, and the other in referring to objects that-are common to more than one sense in all sentient beings.
Deinde cum dicit dico autem exponit membra divisionis. Et primo exponit quae sunt sensibilia propria. Et dicit, quod sensibile proprium est quod ita sentitur uno sensu, quod non potest alio sensu sentiri, et circa quod non potest errare sensus: sicut visus proprie est cognoscitivus coloris, et auditus soni, et gustus humoris, id est saporis: sed tactus habet plures differentias appropriatas sibi: cognoscit enim calidum et humidum, frigidum et siccum, grave et leve, et huiusmodi multa. Unusquisque autem horum sensuum iudicat de propriis sensibilibus, et non decipitur in eis; sicut visus non decipitur quod sit talis color, neque auditus decipitur de sono. 384. Then at ‘Now I call that’, he explains the members of the division, and first what he means by a special sense-object. He says that he means by this term what is perceived by one sense and by no other, and in respect of which the perceiving sense cannot err; thus it is proper to sight to know colour, to hearing to know sound, to taste to know flavour or savour. Touch, however, has several objects proper to itself— heat and moisture, cold and dryness, the heavy and the light, etc. Each sense judges the objects proper to itself and is not mistaken about these, e.g. sight with regard to such and such a colour or hearing with regard to sound.
Sed circa sensibilia per accidens vel communia, decipiuntur sensus; sicut decipitur visus, si velit iudicare homo per ipsum, quid est coloratum, aut ubi sit. Et similiter decipitur quis, si velit iudicare per auditum quid est quod sonat. Haec igitur sunt propria sensibilia uniuscuiusque sensus. 385. But the senses can be deceived both about objects only incidentally sensible and about objects common to several senses., Thus sight would prove fallible were one to attempt to judge by sight what a coloured thing was or where it was; and hearing likewise if one tried to determine by hearing alone what was causing a sound. Such then are the special objects of each sense.
Secundo ibi communia autem exponit secundum membrum divisionis; dicens, quod communia sensibilia sunt ista quinque: motus, quies, numerus, figura et magnitudo. Haec enim nullius sensus unius sunt propria, sed sunt communia omnibus. Quod non est sic intelligendum, quasi omnia ista sint omnibus communia; sed quaedam horum, scilicet numerus, motus et quies, sunt communia omnibus sensibus. Tactus vero et visus percipiunt omnia quinque. 386. Next, at ‘Now the sense-objects’, he says, touching the second member of the division, that the common sense-objects are five: movement, rest, number, shape and size. These are not proper to any one sense but are common to all; which we must not take to mean that all these are common to all the senses, but that some of them, i.e. number, movement and rest, are common to all. But touch and sight perceive all five.
Sic igitur manifestum est, quae sint sensibilia per se. It is clear now what are the sense-objects that are such in themselves or absolutely.
Tertio ibi secundum accidens exponit tertium membrum divisionis; et dicit, quod secundum accidens sensibile dicitur, ut si dicimus quod Diarus vel Socrates est sensibile per accidens, quia accidit ei esse album. Hoc enim sentitur per accidens, quod accidit ei quod sentitur per se: accidit autem albo, quod est sensibile per se, quod sit Diarus, unde Diarus est sensibile per accidens. Unde nihil patitur sensus ab hoc, in quantum huiusmodi. 387. Then, at ‘To be a sense-object incidentally’, he takes the third member of the division. We might, he says, call Diarus or Socrates incidentally a sense-object because each happens to be white: that is sensed incidentally which happens to belong to what is sensed absolutely. It is accidental to the white thing, which is sensed absolutely, that it should be Diarus; hence Diarus is a sense-object incidentally. He does not, as such, act upon the sense at all.
Quamvis autem sensibilia communia et sensibilia propria sint per se sensibilia, tamen propria sensibilia sunt proprie per se sensibilia; quia substantia uniuscuiusque sensus et eius definitio est in hoc, quod est aptum natum pati a tali sensibili. Ratio autem uniuscuiusque potentiae consistit in habitudine ad proprium obiectum. While it is true, however, that both common and special sense-objects are all absolutely or of themselves perceptible by sense, yet, strictly speaking, only the special sense-objects are directly perceived, for the very essence and definition of each sense consists in its being naturally fitted to be affected by some such special object proper to itself The nature of each faculty consists in its relation to its proper object.
Dubitatur autem hic de distinctione sensibilium communium a sensibilibus per accidens. Sicut enim sensibilia per accidens non apprehenduntur nisi in quantum sensibilia propria apprehenduntur, sic nec sensibilia communia apprehenduntur, nisi apprehendantur sensibilia propria: nunquam enim visus apprehendit magnitudinem aut figuram, nisi inquantum apprehendit coloratum. Videtur ergo quod sensibilia communia sunt etiam sensibilia per accidens. 388. A difficulty arises here about the distinction between common and incidental sense-objects. For if the latter are only perceived in so far as the special objects are perceived, the same is true of the common sense-objects: the eye would never perceive size or shape if it did not perceive colour. It would seem then that the common objects themselves are incidental objects.
Dicunt igitur quidam, quod huiusmodi communia sensibilia non sunt sensibilia per accidens, propter duas rationes. Primo quidem, quia huiusmodi sensibilia communia sunt propria sensui communi, sicut sensibilia propria sunt propria singulis sensibus. Secundo, quia sensibilia propria non possunt esse sine sensibilibus communibus; possunt autem esse sine sensibilibus per accidens. 389. Now there are some who base the distinction between common and incidental sense-objects upon two reasons. They say that (a) the common objects are proper to the ‘common sense’, as the special objects are to the particular senses; and (b) that the proper objects are inseparable from the common objects, but not from the incidental objects.
Utraque autem responsio incompetens est. Prima quidem, quia falsum est, quod ista sensibilia communia sint propria obiecta sensus communis. Sensus enim communis est quaedam potentia, ad quam terminantur immutationes omnium sensuum, ut infra patebit. Unde impossibile est quod sensus communis habeat aliquod proprium obiectum, quod non sit obiectum sensus proprii. Sed circa immutationes ipsas sensuum propriorum a suis obiectis, quas sensus proprii habere non possunt: sicut quod percipit ipsas immutationes sensuum, et discernit inter sensibilia diversorum sensuum. Sensu enim communi percipimus nos vivere et discernimus inter sensibilia diversorum sensuum, scilicet album et dulce. 390. But both answers are inept. The first is based on the fallacy that these common sense-objects are the special object of the ‘common sense’. As we shall see later, the common sense is the faculty whereat the modifications affecting all the particular senses terminate; hence it cannot have as its special object anything, that is not an object of a particular sense. In fact, it is concerned with those modifications of the particular senses by their objects which these senses themselves cannot perceive; it is aware of these modifications themselves, and of the differences between the objects of each particular sense. It is by the common sense that we are aware of our own life, and that we can distinguish between the objects of different senses, e.g. the white and the sweet.
Praeterea. Dato quod sensibilia communia essent propria obiecta sensus communis, non excluderetur quin essent per accidens sensibilia, respectu sensuum propriorum. Sic enim agitur de sensibilibus, secundum quod habent habitudinem ad sensus proprios: nam potentia sensus communis nondum est declarata. Quod autem est obiectum proprium alicuius interioris potentiae, contingit esse per accidens sensibile, ut postea dicetur. Nec est mirum; quia hoc quod est per se sensibile uni sensuum exteriorum, est per accidens sensibile respectu alterius: sicut dulce est per accidens visibile. 391. Moreover, even granted that the common sense-objects were proper to the common sense, this would not prevent their being the incidental objects of the particular senses. For we are still studying the sense-objects in relation to the particular senses; the common sense has not yet been elucidated. As we shall see later, the special object of an interior faculty may happen to be only incidentally sensible. Nor is this strange; for even as regards the exterior senses, what is in itself and essentially perceptible by one of these exterior senses is incidentally perceptible by another; as sweetness is incidentally visible.
Secunda etiam ratio non est competens. Non enim refert ad id quod est sensibile per accidens, utrum id quod est subiectum sensibilis qualitatis, sit per se subiectum eius, vel non per se. Nullus enim diceret ignem, qui est proprium subiectum caloris, esse per se sensibile tactu. 392. The second reason is also inept. Whether or no the subject of a sensible quality pertains essentially to that quality makes no difference to the question whether the quality itself is an incidental sense-object. No one, for instance, would maintain that fire, which is the essential and proper subject of heat, was directly and in itself an object of touch.
Et ideo aliter dicendum, quod sentire consistit in quodam pati et alterari, ut supra dictum est. Quicquid igitur facit differentiam in ipsa passione vel alteratione sensus, habet per se habitudinem ad sensum, et dicitur sensibile per se. Quod autem nullam facit differentiam circa immutationem sensus, dicitur sensibile per accidens. Unde et in litera dicit philosophus, quod a sensibili per accidens nihil patitur sensus, secundum quod huiusmodi. 393. So we must look for another answer. We have seen that sensation is a being acted upon and altered in some way. Whatever, then, affects the faculty in, and so makes a difference to, its own proper reaction and modification has an intrinsic relation to that faculty and can be called a sense-object in itself or absolutely. But whatever makes no difference to the immediate modification of the faculty we call an incidental sense-object. Hence, the Philosopher says explicitly that the senses are not affected at all by the incidental object as such.
Differentiam autem circa immutationem sensus potest aliquid facere dupliciter. Uno modo quantum ad ipsam speciem agentem; et sic faciunt differentiam circa immutationem sensus sensibilia per se, secundum quod hoc est color, illud autem est sonus, hoc autem est album, illud vero nigrum. Ipsae enim species activorum in sensu, actu sunt sensibilia propria, ad quae habet naturalem aptitudinem potentia sensitiva; et propter hoc secundum aliquam differentiam horum sensibilium diversificantur sensus. 394. Now an object may affect the faculty’s immediate reaction in two ways. One way is with respect to the kind of agent causing this reaction; and in this way the immediate objects of sensation differentiate sense-experience, inasmuch as one such object is colour, another is sound, another white, another black, and so on. For the various kinds of stimulants of sensation are, in their actuality as such, precisely the special sense-objects themselves; and to them the sense-faculty (as a whole) is by nature adapted; so that precisely by their differences is sensation itself differentiated.
Quaedam vero alia faciunt differentiam in transmutatione sensuum, non quantum ad speciem agentis, sed quantum ad modum actionis. Qualitates enim sensibiles movent sensum corporaliter et situaliter. Unde aliter movent secundum quod sunt in maiori vel minori corpore, et secundum quod sunt in diverso situ, scilicet vel propinquo, vel remoto, vel eodem, vel diverso. Et hoc modo faciunt circa immutationem sensuum differentiam sensibilia communia. Manifestum est enim quod secundum omnia haec quinque diversificatur magnitudo vel situs. Et quia non habent habitudinem ad sensum, ut species activorum, ideo secundum ea non diversificantur potentiae sensitivae, sed remanent communia pluribus sensibus. On the other hand there are objects which differentiate sensation with respect, not to the kind of agent, but to the mode of its activity. For as sense-qualities affect the senses corporeally and locally, they do so in different ways, if they are qualities of large or small bodies or are diversely situated, i.e. near, or far, or together, or apart. And it is thus that the common sensibles differentiate sensation. Obviously, size and position vary for all the five senses. And not being related to sensation as variations in the immediate factors which bring the sense into act, they do not properly differentiate the sense-faculties; they remain common to several faculties at once.
Viso igitur quomodo dicantur per se sensibilia, et communia et propria, restat videndum, qua ratione dicatur aliquid sensibile per accidens. Sciendum est igitur, quod ad hoc quod aliquid sit sensibile per accidens, primo requiritur quod accidat ei quod per se est sensibile, sicut accidit albo esse hominem, et accidit ei esse dulce. Secundo requiritur, quod sit apprehensum a sentiente: si enim accideret sensibili, quod lateret sentientem, non diceretur per accidens sentiri. Oportet igitur quod per se cognoscatur ab aliqua alia potentia cognoscitiva sentientis. Et hoc quidem vel est alius sensus, vel est intellectus, vel vis cogitativa, aut vis aestimativa. Dico autem quod est alius sensus; sicut si dicamus, quod dulce est visibile per accidens inquantum dulce accidit albo, quod apprehenditur visu, et ipsum dulce per se cognoscitur ab alio sensu, scilicet a gustu. 395. Having seen how we should speak of the absolute or essential sense-objects, both common and-special, it remains to be seen how anything is a sense-object ‘incidentally’. Now for an object to be a sense-object incidentally it must first be connected accidentally with an essential sense-object; as a man, for instance, may happen to be white, or a white thing happen to be sweet. Secondly, it must be perceived by the one who is sensing; if it were connected with the sense-object without itself being perceived, it could not be said to be sensed incidentally. But this implies that with respect to some cognitive faculty of the one sensing it, it is known, not incidentally, but absolutely. Now this latter faculty must be either another sense-faculty, or the intellect, or the cogitative faculty, or natural instinct. I say ‘another sense-faculty’, meaning that sweetness is incidentally visible inasmuch as a white thing seen is in fact sweet, the sweetness being directly perceptible by another sense, i.e. taste.
Sed, ut proprie loquamur, hoc non est universaliter sensibile per accidens, sed per accidens visibile, sensibile autem per se. Quod ergo sensu proprio non cognoscitur, si sit aliquid universale, apprehenditur intellectu; non tamen omne quod intellectu apprehendi potest in re sensibili, potest dici sensibile per accidens, sed statim quod ad occursum rei sensatae apprehenditur intellectu. Sicut statim cum video aliquem loquentem, vel movere seipsum, apprehendo per intellectum vitam eius, unde possum dicere quod video eum vivere. Si vero apprehendatur in singulari, utputa cum video coloratum, percipio hunc hominem vel hoc animal, huiusmodi quidem apprehensio in homine fit per vim cogitativam, quae dicitur etiam ratio particularis, eo quod est collativa intentionum individualium, sicut ratio universalis est collativa rationum universalium. 396. But, speaking precisely, this is not in the fullest sense an incidental sense-object; it is incidental to the sense of sight, but it is essentially sensible. Now what is not perceived by any special sense is known by the intellect, if it be a universal; yet not anything knowable by intellect in sensible matter should be called a sense-object incidentally, but only what is at once intellectually apprehended as soon as a sense-experience occurs. Thus, as soon as I see anyone talking or moving himself my intellect tells me that he is alive; and I can say that I see him live. But if this apprehension is of something individual, as when, seeing this particular coloured thing, I perceive this particular man or beast, then the cogitative faculty (in the case of man at least) is at work, the power which is also called the ‘particular reason’ because it correlates individualised notions, just as the ‘universal reason’ correlates universal ideas.
Nihilominus tamen haec vis est in parte sensitiva; quia vis sensitiva in sui supremo participat aliquid de vi intellectiva in homine, in quo sensus intellectui coniungitur. In animali vero irrationali fit apprehensio intentionis individualis per aestimativam naturalem, secundum quod ovis per auditum vel visum cognoscit filium, vel aliquid huiusmodi. 397. Nevertheless, this faculty belongs to sensitivity; for the sensitive power at its highest—in man, in whom sensitivity is joined to intelligence—has some share in the life of intellect. But the lower animals’ awareness of individualised notions is called natural instinct, which comes into play when a sheep, e.g., recognises its offspring by sight, or sound, or something of that sort.
Differenter tamen circa hoc se habet cogitativa, et aestimativa. Nam cogitativa apprehendit individuum, ut existens sub natura communi; quod contingit ei, inquantum unitur intellectivae in eodem subiecto; unde cognoscit hunc hominem prout est hic homo, et hoc lignum prout est hoc lignum. Aestimativa autem non apprehendit aliquod individuum, secundum quod est sub natura communi, sed solum secundum quod est terminus aut principium alicuius actionis vel passionis; sicut ovis cognoscit hunc agnum, non inquantum est hic agnus, sed inquantum est ab ea lactabilis; et hanc herbam, inquantum est eius cibus. Unde alia individua ad quae se non extendit eius actio vel passio, nullo modo apprehendit sua aestimativa naturali. Naturalis enim aestimativa datur animalibus, ut per eam ordinentur in actiones proprias, vel passiones, prosequendas, vel fugiendas. 398. Note, however, that the cogitative faculty differs from natural instinct. The former apprehends the individual thing as existing in a common nature, and this because it is united to intellect in one and the same subject. Hence it is aware of a man as this man, and this tree as this tree; whereas instinct is not aware of an individual thing as in a common nature, but only in so far as this individual thing is the term or principle of some action or passion. Thus a sheep knows this particular lamb, not as this lamb, but simply as something to be suckled; and it knows this grass just in so far as this grass is its food. Hence, other individual things which have no relation to its own actions or passions it does not apprehend at all by natural instinct. For the purpose of natural instinct in animals is to direct them in their actions and passions, so as to seek and avoid things according to the requirements of their nature.

TEXT
418a26–418b26
BOOK II, CHAPTER VII
ΚΕΦΑΛΑΙΟΝ Ζ'

SIGHT. ITS OBJECT

418a26   1. Οὗ μὲν οὖν ἐστιν ἡ ὄψις, τοῦτ' ἐστὶν ὁρατόν, ὁρατὸν δ' ἐστὶ χρῶμά τε καὶ ὃ λόγῳ μὲν ἔστιν εἰπεῖν, ἀνώνυμον δὲ τυγχάνει ὄν· δῆλον δὲ ἔσται ὃ λέγομεν προελθοῦσι. That of which there is sight is the visible; and the visible is colour, and also something which, though it has no name, we can state descriptively. It will be evident what we mean when we have gone further into the matter. § 399
τὸ γὰρ ὁρατόν ἐστι χρῶμα, τοῦτο δ' ἐστὶ τὸ ἐπὶ τοῦ καθ' αὑτὸ ὁρατοῦ· καθ' αὑτὸ δὲ οὐ τῷ λόγῳ, ἀλλ' ὅτι ἐν ἑαυτῷ ἔχει τὸ αἴτιον τοῦ εἶναι ὁρατόν. πᾶν δὲ χρῶμα 418b κινητικόν ἐστι τοῦ κατ' ἐνέργειαν διαφανοῦς, καὶ τοῦτ' ἐστὶν αὐτοῦ ἡ φύσις· διόπερ οὐχ ὁρατὸν ἄνευ φωτός, ἀλλὰ πᾶν τὸ ἑκάστου χρῶμα ἐν φωτὶ ὁρᾶται. διὸ περὶ φωτὸς πρῶτον λεκτέον τί ἐστιν. For the visible is colour, and it is this of which visibility is predicated essentially; not, however, by definition, but because :it has in itself the cause of being visible. For every colour is a motivating force upon the actually transparent: this is its very nature. Hence nothing, is visible without light; but by light each and every colour can be seen. Wherefore, we must first decide what light is. §§ 400-3
2. ἔστι δή τι διαφανές. διαφανὲς δὲ λέγω ὃ ἔστι μὲν ὁρατόν, οὐ καθ' αὑτὸ δὲ ὁρατὸν ὡς ἁπλῶς εἰπεῖν, ἀλλὰ δι' ἀλλότριον χρῶμα. τοιοῦτον δέ ἐστιν ἀὴρ καὶ ὕδωρ καὶ πολλὰ τῶν στερεῶν· οὐ γὰρ ᾗ ὕδωρ οὐδ' ᾗ ἀὴρ διαφανές, ἀλλ' ὅτι ἔστι τις φύσις ἐνυπάρχουσα ἡ αὐτὴ ἐν τούτοις ἀμφοτέροις καὶ ἐν τῷ ἀϊδίῳ τῷ ἄνω σώματι. There is, accordingly, something transparent. By transparent I mean that which is, indeed, visible, yet not of itself, or absolutely, but by virtue of concomitant colour. Air and water and many solids are such. But transparency does not depend on either air or water as such, but on the same quality being found in both, and in the eternal sphere above as well. § 404
φῶς δέ ἐστιν ἡ τούτου ἐνέργεια, τοῦ διαφανοῦς ᾗ διαφανές. δυνάμει δέ, ἐν ᾧ τοῦτ' ἐστί, καὶ τὸ σκότος. τὸ δὲ φῶς οἷον χρῶμά ἐστι τοῦ διαφανοῦς, ὅταν ᾖ ἐντελεχείᾳ διαφανὲς ὑπὸ πυρὸς ἢ τοιούτου οἷον τὸ ἄνω σῶμα· καὶ γὰρ τούτῳ τι ὑπάρχει ἓν καὶ ταὐτόν. Light is the act of this transparency, as such: but in potency this [transparency] is also darkness. Now, light is a kind of colour of the transparent, in so far as this is actualised by fire or something similar to the celestial body; which contains indeed something of one and the same nature as fire. § 405
τί μὲν οὖν τὸ διαφανὲς καὶ τί τὸ φῶς, εἴρηται, ὅτι οὔτε πῦρ οὔθ' ὅλως σῶμα οὐδ' ἀπορροὴ σώματος οὐδενός (εἴη γὰρ ἂν σῶμά τι καὶ οὕτως), ἀλλὰ πυρὸς ἢ τοιούτου τινὸς παρουσία ἐν τῷ διαφανεῖ· We have then indicated what the transparent is, and what light is; that light is not fire or any bodily thing, nor any emanation from a body—[if it were this last,] it would be a sort of body, and so be fire or the presence of something similar in the transparent. § 406
οὔτε γὰρ δύο σώματα ἅμα δυνατὸν ἐν τῷ αὐτῷ εἶναι, For it is impossible for two bodies to exist in the same place at the same time. § 407
3. δοκεῖ τε τὸ φῶς ἐναντίον εἶναι τῷ σκ̥