THE SEARCH FOR TRUTH AND CAUSES
LESSON 1: The Acquisition of Truth: Its Ease and Its Difficulty LESSON 2: The Supreme Science of Truth, and Knowledge of Ultimate Causes LESSON 3: The Existence of a First Efficient Cause and of a First Material Cause LESSON 4: The Existence of a First in Final and Formal Causes LESSON 5: The Method to Be Followed in the Search for Truth
The Acquisition of Truth: Its Ease and Its Difficulty
ARISTOTLE’S TEXT Chapter 1: 993a 30-993b 19
144. Theoretical, i.e., speculative, knowledge of truth is in one sense difficult and in another, easy.
145. An indication of this is found in the fact that, while no one can attain an adequate knowledge of it, all men together do not fail, because each one is able to say something true about nature.
146. And while each one individually contributes nothing or very little to the truth, still as a result of the combined efforts of all a great amount of truth becomes known.
147. Therefore, if the situation in the case of truth seems to be like the one which we speak of in the proverb “Who will miss a door?” then in this respect it will be easy to know the truth.
148. But the fact that we cannot simultaneously grasp a whole and its parts shows the difficulty involved.”
149. However, since the difficulty is twofold, perhaps its cause is not in things but in us; for just as the eyes of owls are to the light of day, so is our soul’s intellective power to those things which are by nature the most evident of all.
150. Now it is only right that we should be grateful not merely to those with whose views we agree but also to those who until now have spoken in a superficial way; for they too have made some contribution because they have made use of the habit which we now exercise. Thus if there had been no Timotheus, we would not have a great part of our music; and if there had been no Phrynis, there would have been no Timotheus. The same is true of those who have made statements about the truth; for we have accepted certain opinions from some of them, and others have been the cause of them attaining their knowledge as they have been the cause of us attaining ours.
273. Having criticized the ancient philosophers’ opinions about the first principles of things, with which first philosophy is chiefly concerned, the Philosopher now begins to establish what is true.
First philosophy considers truth in a different way than the particular sciences do. Each of the particular sciences considers a particular truth out a definite class of beings; e.g., geometry deals with the continuous quantities of bodies, and arithmetic with numbers; whereas first philosophy considers what is universally true of things. Therefore, it pertains to this science to consider in what respects man is capable of knowing the truth.
274. First, he states what he intends to prove. He says that “theoretical knowledge,” i.e., the contemplative or speculative understanding of truth, is in one sense easy and in another, difficult.
275. An indication of this (145).
Second, he explains what he intends to prove: first, in what sense it is easy to know the truth; and second (278), in what sense it is difficult (“But the fact”). He shows in what sense it is easy to know the truth, by giving three indications:
The first is this: while no man can attain a complete knowledge of the truth, still no man is so completely devoid of truth that he knows nothing about it. This is shown by the fact that anyone can make a statement about the truth and the nature of things, which is a sign of intellectual reflection.
276. And while each one individually (146).
Here he gives the second indication. He says that, while the amount of truth that one man can discover or contribute to the knowledge of truth by his own study and talents is small compared with a complete knowledge of truth, nevertheless what is known as a result of “the combined efforts” of all, i.e., what is discovered and collected into one whole, becomes quite extensive. This can be seen in the case of the particular arts, which have developed in a marvelous manner as a result of the studies and talents of different men.
277. Therefore, if the situation (147).
Third, he shows that the same thing is true by citing a common proverb. He concludes from the foregoing that since anyone can attain some knowledge of the truth, even though it be little, the situation in the case of knowledge is like the one that we speak of in the proverb “Who will miss a door?” i.e., the outer door of a house. For it is difficult to know what the interior of a house is like, and a man is easily deceived in such matters; but just as no one is mistaken about the entrance of a house, which is evident to all and is the first thing that we perceive, so too this is the case with regard to the knowledge of truth; for those truths through which we enter into a knowledge of others are known to all, and no man is mistaken about them. Those first principles which are naturally apprehended are truths of this sort, e.g., “It is impossible both to affirm and deny something at the same time,” and “Every whole is greater than each of its parts,” and so on. On the other hand, there are many ways in which error may arise with respect to the conclusions into which we enter through such principles as through an outer door. Therefore, it is easy to know the truth if we consider that small amount of it which is comprised of self-evident principles, through which we enter into other truths, because this much is evident to all.
278. But the fact that we cannot (148).
Here he explains in what sense it is difficult to know the truth. He says that our inability to grasp the whole truth and a part of it shows the difficulty involved in the search for truth. In support of this we must consider his statement that the truth through which we gain admission to other truths is known to all. Now there are two ways in which we attain knowledge of the truth.
The first is the method of analysis, by which we go from what is complex to what is simple or from a whole to a part, as it is said in Book I of the Physics that the first objects of our knowledge are confused wholes. Now our knowledge of the truth is perfected by this method when we attain a distinct knowledge of the particular parts of a whole.
The other method is that of synthesis, by which we go from what is simple to what is complex; and we attain knowledge of truth by this method when we succeed in knowing a whole. Thus the fact that man is unable to know perfectly in things a whole and a part shows the difficulty involved in knowing the truth by both of these methods.
279. However, since the difficulty is twofold (149).
He gives the reason for this difficulty. Here too it must be noted that, in all cases in which there is a certain relationship between two things, an effect can fail to occur in two ways, i.e., because of either one of the things involved. For example, if wood does not burn, this may happen either because the fire is not strong enough or because the wood is not combustible enough. And in a similar way the eye may be prevented from seeing a visible object either because the eye is weak or because the visible object is in the dark. Therefore, in like manner, it may be difficult to know the truth about things either (1) because things themselves are imperfect in some way or (2) because of some weakness on the part of our intellect.
280. (1) Now it is evident that we experience difficulty in knowing the truth about some things because of the things themselves; for since each thing is knowable insofar as it is an actual being, as will be stated below in Book IX (1894) of this work, then those things which are deficient and imperfect in being are less knowable by their very nature; e.g., matter, motion, and time are less knowable because of the imperfect being which they have, as Boethius says in his book The Two Natures.
281. Now there were some philosophers who claimed that the difficulty experienced in knowing the truth is wholly attributable to things themselves, because they maintained that nothing is fixed and stable in nature but that everything is in a state of continual change, as will be stated in Book IV (683) of this work. But the Philosopher denies this, saying that even though the difficulty experienced in knowing the truth can perhaps be twofold because of different things, i.e., our intellect and things themselves, still the principal source of the difficulty is not things but our intellect.
282. He proves this in the following way. If this difficulty were attributable principally to things, it would follow it we would know best those things which are most knowable by nature. But those things which are most knowable by nature are those which are most actual, i.e., immaterial and unchangeable things, yet we know these least of all.
Obviously, then, the difficulty experienced in knowing the truth is due principally to some weakness on the part of our intellect. From this it follows that our soul’s intellectual power is related to those immaterial beings, which are by nature the most knowable of all, as the eyes of owls are to the light of day, which they cannot see because their power of vision is weak, although they do see dimly lighted things.
283. But it is evident that this simile is not adequate; for since a sense is a power of a bodily organ, it is made inoperative as a result of its sensible object being too intense. But the intellect is not a power of a bodily organ and is not made inoperative as a result of its intelligible object being too intelligible. Therefore, after understanding objects that are highly intelligible our ability to understand less intelligible objects is not decreased but increased, as is stated in Book III of The Soul.
284. Therefore it must be said that a sense is prevented from perceiving some sensible object for two reasons: first, (1) because a sensory organ is rendered inoperative as a result of its sensible object being too intense (this does not occur in the case of the intellect); second, (2) because of some deficiency in the ability of a sensory power to perceive its object; for the powers of the soul in all animals do not have the same efficacy. Thus, just as it is proper to man by nature to have the weakest sense of smell, in a similar way it is proper to an owl to have the weakest power of vision, because it is incapable of perceiving the light of day.
285. Therefore, since the human soul occupies the lowest place in the order of intellective substances, it has the least intellective power. As a matter of fact, just as it is by nature the actuality of a body, although its intellective power is not the act of a bodily organ, in a similar way it has a natural capacity to know the truth about corporeal and sensible things. These are less knowable by nature because of their materiality, although they can be known by abstracting sensible forms from phantasms. And since this process of knowing truth befits the nature of the human soul insofar as it is the form of this kind of body (and whatever is natural always remains so), it is possible for the human soul, which is united to this kind of body, to know the truth about things only insofar as it can be elevated to the level of the things which it understands by abstracting from phantasms. However, by this process it cannot be elevated to the level of knowing the quiddities of immaterial substances because these are not on the same level as sensible substances. Therefore it is impossible for the human soul, which is united to this kind of body, to apprehend separate substances by knowing their quiddities.
286. For this reason the statement which Averroes makes at this point in his Commentary is evidently false, i.e., that the Philosopher does not prove here that it is just as impossible for us to understand abstract substances as it is for a bat to see the sun. The argument that he gives is wholly ridiculous; for he adds that, if this were the case, nature would have acted in vain because it would have made something that is naturally knowable in itself to be incapable of being known by anything else. It would be the same as if it had made the sun incapable of being seen.
This argument is not satisfactory for two reasons. First, the end of separate substances does not consist in being understood by our intellect, but rather the converse. Therefore, if separate substances are not known by us, it does not follow that they exist in vain; for only that exists in vain which fails to attain the end for which it exists. Second, even though the quiddities of separate substances are not understood by us, they are understood by other intellects. The same is true of the sun; for even though it is not seen by the eye of the owl, it is seen by the eye of the eagle.
287. Now it is only right (150).
He shows how men assist each other to know the truth; for one man assists another to consider the truth in two ways—directly and indirectly.
One is assisted directly by those who have discovered the truth; because, as has been pointed out, when each of our predecessors has discovered something about the truth, which is gathered together into one whole, he also introduces his followers to a more extensive knowledge of truth.
One is assisted indirectly insofar as those who have preceded us and who were wrong about the truth have bequeathed to their successors the occasion for exercising their mental powers, so that by diligent discussion the truth might be seen more clearly.
288. Now it is only fitting that we should be grateful to those who have helped us attain so great a good as knowledge of the truth. Therefore he says that “It is only right that we should be grateful,” not merely to those whom we think have found the truth and with whose views we agree by following them, but also to those who, in the search for truth, have made only superficial statements, even though we do not follow their views; for these men too have given us something because they have shown us instances of actual attempts to discover the truth. By way of an example he mentions the founders of music; for if there “had been no Timotheus,” who discovered a great part of the art of music, we would not have many of the facts that we know about melodies. But if Timotheus had not been preceded by a wise man named “Phrynis,” he would not have been as well off in the subject of music. The same thing must be said of those philosophers who made statements of universal scope about the truth of things; for we accept from certain of our predecessors whatever views about the truth of things we think are true and disregard the rest. Again, those from whom we accept certain views had predecessors from whom they in turn accepted certain views and who were the source of their information.
The Supreme Science of Truth, and Knowledge of Ultimate Causes
ARISTOTLE’S TEXT Chapters 1 & 2: 993b 19-994b 11
151. It is only right to call philosophy the science of truth. For the end of theoretical knowledge is truth, whereas that of practical knowledge is action; for even when practical men investigate the way in which something exists, they do not consider it in itself but in relation to some particular thing and to the present moment. But we know a truth only by knowing its cause. Now anything which is the basis of a univocal predication about other things has that attribute in the highest degree. Thus fire is hottest and is actually the cause of heat in other things. Therefore that is also true in the highest degree which is the cause of all subsequent things being true. For this reason the principles of things that always exist must be. true in the highest degree, because they are not sometimes true and sometimes not true. Nor is there any cause of their being, but they are the cause of the being of other things. Therefore insofar as each thing has being, to that extent it is true.
152. Further, it is evident that there is a [first] principle, and that the causes of existing things are not infinite either in series or in species. For it is impossible that one thing should come from something else as from matter in an infinite regress, for example, flesh from earth, earth from air, air from fire, and so on to infinity. Nor can the causes from which motion originates proceed to infinity, as though man were moved by the air, the air by the sun, the sun by strife, and so on to infinity. Again, neither can there be an infinite regress in the case of the reason for which something is done, as though walking were for the sake of health, health for the sake of happiness, and happiness for the sake of something else, so that one thing is always being done for the sake of something else. The same is true in the case of the quiddity.
289. Having shown how man is disposed for the study of truth, the Philosopher now shows that the knowledge of truth belongs pre-eminently to first philosophy. Regarding this he does two things... First (290), he shows that knowledge of the truth belongs pre-eminently to first philosophy. Second (290), that it belongs in the highest degree to this science (“But we know a truth”).
He proves these two propositions from two things established above in the prologue of this book, i.e., that wisdom is not a practical but a speculative science (53), and that it knows first causes (48).
290. He argues from the first of these to the first conclusion in this way. Theoretical, i.e., speculative, knowledge differs from practical knowledge by its end; for the end of speculative knowledge is truth, because it has knowledge of the truth as its objective. But the end of practical knowledge is action, because, even though “practical men,” i.e., men of action, attempt to understand the truth as it belongs to certain things, they do not seek this as an ultimate end; for they do not consider the cause of truth in and for itself as an end but in relation to action, either by applying it to some definite individual, or to some definite time. Therefore, if we add to the above the fact that wisdom or first philosophy is not practical but speculative, it follows that first philosophy is most fittingly called the science of truth.
291. But since there are many speculative sciences, which consider the truth, such as geometry and arithmetic, therefore it was necessary to show that first philosophy considers truth in the highest degree inasmuch as it has been shown above that it considers first causes (48). Hence he argues as follows. We have knowledge of truth only when we know a cause. This is apparent from the fact that the true things about which we have some knowledge have causes which are also true, because we cannot know what is true by knowing what is false, but only by knowing what is true. This is also the reason why demonstration, which causes science, begins with what is true, as is stated in Book I of the Posterior Analytics.
292. Then he adds the following universal proposition. When a univocal predicate is applied to several things, in each case that which constitutes the reason for the predication about other things has that attribute in the fullest sense. Thus fire is the cause of heat in compounds. Therefore, since heat is predicated univocally both of fire and of compound bodies, it follows that fire is hottest.
293. Now he says “univocal” because sometimes it happens that an effect does not become like its cause, so as to have the same specific nature, because of the excellence of that cause; for example, the sun is the cause of heat in these lower bodies, but the form which these lower bodies receive cannot be of the same specific nature as that possessed by the sun or any of the celestial bodies, since they do not have a common matter. This is why we do not say that the sun is hottest, as we say fire is, but that it is something superior to the hottest.
294. Now the term truth is not proper to one class of beings only, but is applied universally to all beings. Therefore, since the cause of truth is one having the same name. and intelligible structure as its effect, it follows that whatever causes subsequent things to be true is itself most true.
295. From this he again concludes that the principles of things which always exist, i.e., the celestial bodies, must be most true. He does this for two reasons. First, they are not “sometimes true and sometimes not true,” and therefore surpass the truth of things subject to generation and corruption, which sometimes exist and sometimes do not. Second, these principles have no cause but are the cause of the being of other things. And for this reason they surpass the celestial bodies in truth and in being; and even though the latter are incorruptible, they have a cause not only of their motion, as some men thought, but also of their being, as the Philosopher clearly states in this place.
296. Now this is necessary, because everything that is composite in nature and participates in being must ultimately have as its causes those things which have existence by their very essence. But all corporeal things are actual beings insofar as they participate in certain forms. Therefore a separate substance which is a form by its very essence must be the principle of corporeal substance.
297. If we add to this conclusion the fact that first philosophy considers first causes, it then follows, as was said above (291), that first philosophy considers those things which are most true. Consequently this science is pre-eminently the science of truth.
298. From these conclusions he draws a corollary: since those things which cause the being of other things are true in the highest degree, it follows that each thing is true insofar as it is a being; for things which do not always have being in the same way do not always have truth in the same way, and those which have a cause of their being also have a cause of their truth. The reason for this is that a thing’s being is the cause of any true judgment which the mind makes about a thing; for truth and falsity are not in things but in the mind, as will be said in Book VI (1230) of this work.
299. He rejects a position that would render the above proof untenable; for this proof proceeded on the supposition that first philosophy considers first causes. But if there were an infinite regress in causes, this proof would be destroyed, for then there would be no first cause. So his aim here is to refute this position. Concerning this he does two things. First (152), he points out what he intends to prove. Second (300, he proceeds to do so.
He says, first, that from what has been said it can clearly be shown that there is some [first] principle of the being and truth of things. He states that the causes of existing things are not infinite in number because we cannot proceed to infinity in a series of causes belonging to one and the same class, e.g., the class of, efficient causes. Nor again are causes infinite in species, as though the classes of causes were infinite in number.
300. Then he explains his statement about an infinite number of causes in a series. He does this, first, in regard to the class of material causes. For it is impossible to have an infinite series in the sense that one thing always comes from something else as its matter, e.g., that flesh comes from earth, earth from air, and air from fire, and that this does not terminate in some first entity but goes on to infinity.
Second, he gives an example of this in the class of efficient cause. He says that it is impossible to have an infinite series in the class of cause which we define as the source of motion; e.g., when we say that a man is moved to put aside his clothing because the air becomes warm, the air having been heated in turn by the sun, the sun having been moved by something else, and so on to infinity.
Third, he gives an example of this in the class of final causes. He says that it is also impossible to proceed to infinity in the case of “the reason for which” something is done, i.e., the final cause; for example, if we were to say that a journey or a walk is undertaken for the sake of health, health for the sake of happiness, happiness for the sake of something else, and so on to infinity.
Finally, he mentions the formal cause. He says that it is also impossible to proceed to infinity in the case of the “quiddity,” i.e., the formal cause, which the definition signifies. However, he omits examples because these are evident, and because it was shown in Book I of the Posterior Analytics that it is impossible to proceed to infinity in the matter of predication, as though animal were predicated quidditatively of man, living of animal, and so on to infinity.
The Existence of a First Efficient Cause and of a First Material Cause
ARISTOTLE’S TEXT Chapter 2: 994a 11-994b 9
153. For intermediate things in a series limited by some first and last thing must have as their cause the first member of the series, which they follow; because if we had to say which one of these three is the cause of the others, we would say that it is the first. What is last is not the cause, since what is last is not a cause of anything. Neither is the intermediate the cause, because it is the cause of only one; for it makes no difference whether one or several intermediates exist, or an infinite or finite number. Indeed, in series that are infinite in this way or in the infinite in general, all parts are intermediates to the same degree right down to the present one. Therefore, if there is nothing first in the whole series, nothing in the series is a cause.
154. Neither is it possible to proceed to infinity in a downward direction, where there is a starting-point in an upward direction, so that water comes from fire, earth from water, and some other class of things always being generated in this way.
155. Now there are two ways in which one thing comes from (ex) another. I do not mean from in the sense of after, as the Olympian games are said to come from the Isthmian, but either in the way in which a man comes from a boy as a result of a boy changing, or in the way in which air comes from water.
156. We say, then, that a man comes from a boy in the sense that what has come into being comes from what is coming into being, or in the sense that what has been completed comes from what is being completed. For generation is always midway between being and non-being, and thus whatever is coming into being is midway between what is and what is not. Now a learner is one who is becoming learned, and this is the meaning of the statement that the man of science comes from the learner. But water comes from air in the sense that it comes into being when the latter ceases to be.
157. This is why changes of the former kind are not reversible, and thus a boy does not come from a man. The reason is that the thing which comes into being does not come from generation but exists after generation. This is the way in which the day comes from the dawn, i.e., in the sense that it exists after the dawn; and this is why the dawn cannot come from the day. On the other hand, changes of the latter sort are reversible.
158. Now in neither way is it possible to proceed to infinity; for existing intermediaries must have some end, and one thing may be changed into the other because the corruption of one is the generation of the other.
159. At the same time it is impossible that an eternal first cause should be corrupted; for since generation is not infinite in an upward direction, then a first principle by whose corruption something else is produced could not be eternal.
301. Having assumed above that the causes of beings are not infinite in number, the Philosopher now proves this. First (153:C 300, he proves that there are not an infinite number of causes in a series; and second (170:C 330), that the classes of causes are not infinite in number (“Again, if the classes of causes”).
In regard to the first he does four things. First, he proves his assumption in the case of efficient or moving causes; second (154:C 305), in the case of material causes (“Neither is it possible”); third (160:C 316), in the case of final causes (“Again, that for the sake of which”); and fourth (164:C 320), in the case of formal causes (“Nor can the quiddity”).
In regard to the first he proceeds as follows. First, he lays down this premise: in the case of all those things which lie between two extremes, one of which is last and the other first, the first is necessarily the cause of those which come after it, namely, what is intermediate and what is last.
302. Then he proves this premise by a process of elimination. For if we had to say which of the three, i.e., the first, the intermediate, or the last, is the cause of the others, we would have to say that the first is the cause. We could not say that what is last is the cause of all the others, because it is not a cause of anything; for in other respects what is last is not a cause, since an effect follows a cause. Nor could we say that the intermediate is the cause of all the others, because it is the cause of only one of them, namely, what is last.
303. And lest someone should think that an intermediate is followed by only one thing, i.e., what is last (for this occurs only when there is a single thing between two extremes), in order to exclude this interpretation he adds that it makes no difference to the premise given above whether there is only one intermediate or several, because all intermediates are taken together as one insofar as they have in common the character of an intermediate. Nor again does it make any difference whether there are a finite or infinite number of intermediates, because so long as they have the nature of an intermediate they cannot be the first cause of motion. Further, since there must be a first cause of motion prior to every secondary cause of motion, then there must be a first cause prior to every intermediate cause, which is not an intermediate in any sense, as though it had a cause prior to itself. But if we were to hold that there is an infinite series of moving causes in the above way, then all causes would be intermediate ones. Thus we would have to say without qualification that all parts of any infinite thing, whether of a series of causes or of continuous quantities, are intermediate ones; for if there were a part that was not an intermediate one, it would have to be either a first or a last; and both of these are opposed to the nature of the infinite, which excludes every limit, whether it be a starting-point or a terminus.
304. Now there is another point that must be noted, i.e., that if there are several intermediate parts in any finite thing, not all parts are intermediate to the same degree; for some are closer to what is first, and some to what is last. But in the case of some infinite thing in which there is neither a first nor last part, no part can be closer to or farther away from either what is first or what is last. Therefore all parts are intermediates to the same degree right down to the one you designate now. Consequently, if the causes of motion proceed to infinity in this way, there will be no first cause. But a first cause is the cause of all things. Therefore it will follow that all causes are eliminated; for when a cause is removed the things of which it is the cause are also removed.
305. Neither is it possible (154)
He shows that it is impossible to proceed to infinity in the case of material causes. First (154:C 300, he states what he intends to prove. Second (155:C 308), he proceeds with his proof (“Now there are two ways”).
In regard to the first it must be noted that a patient is subjected to the action of an agent. Therefore to pass from agent to agent is to proceed in an upward direction, whereas to pass from patient to patient is to proceed in a downward direction. Now just as action is attributed to the cause of motion, so is undergoing action attributed to matter. Therefore among the causes of motion the process is in an upward direction, whereas amon’,g material causes the process is in a downward direction. Consequently, since he showed among moving causes that it is impossible to proceed to infinity, as it were, in an upward direction, he adds that it is impossible to proceed to infinity in a downward direction, i.e., in the process of material causes, granted that there is a starting-point in an upward direction among the causes of motion.
306. He illustrates this by way of the process of natural bodies, which proceeds in a downward direction, as if we were to say that water comes from fire, earth from water, and so on to infinity. He uses this example in accordance with the opinion of the ancient philosophers of nature, who held that one of these elements is the source of the others in a certain order.
307. However, this can also be explained in another way, inasmuch as we understand that in the case of moving causes there are evident to the senses certain ultimate effects which do not move anything else. Therefore we do not ask if there is an infinite regress in the lower members of that class, but if there is an infinite regress in the higher ones. But in regard to the class of material causes, he assumes that there is one first cause which is the foundation and basis of the others; and he inquires whether there is an infinite regress in a downward direction in the process of those things which are generated from matter. The example which he gives illustrates this, because he does not say that fire comes from water and this in turn from something else, but the converse, i.e., that water comes from fire, and something else again from this. For this reason first matter is held to exist; and he asks whether the things that are generated from matter proceed to infinity.
308. Now there are two ways in which (155)
He proves his original thesis. Concerning this he does four things. First (155:C 308), he distinguishes between the two ways in which one thing comes from something else. Second (156:C 31o), he shows that these two ways differ in two respects (“We say, then, that a man”). Third (158:C 312), he shows that it is impossible to proceed to infinity in either of these ways (“Now in neither way”). Fourth (159:C 314), he shows in which of these ways other things come from the first material principle (“At the same time”).
He says, first, that one thing “comes from” another properly and essentially in two ways. He speaks thus in order to exclude that way in which something is said in an improper sense to come from something else only by reason of the fact that it comes after it as when it is said that certain feasts of the Greeks called the Olympian come from those called the Isthmian, or as we were to say that the feast of Epiphany comes from the the Nativity. But this is an improper use of the word, because the process of coming to be is a change, and in a change it is not only necessary that an order exist between the two limits of the change but also that both limits have the same subject. Now this is not the case in the above example, but we speak in this way insofar as we think of time as the subject of different feasts.
309. Now properly speaking it is necessary to say that one thing comes from something else when some subject is changed from this into that. This occurs in two ways: first, as when we say that a man comes from a boy in the sense that a boy is changed from boyhood to manhood; second, as when we say that air comes from water as a result of substantial change.
310. We say, then, that a man (156).
He explains the twofold sense in which these two ways differ. First, we say that a man comes from a boy in the sense that what has already come into being comes from what is coming into being, or in the sense that what has already been completed comes from what is being completed. For anything in a state of becoming and of being completed is midway between being and non-being, just as generation is midway between existence and nonexistence. Therefore, since we reach an extreme through an intermediate, we say that what has been generated comes from what is being generated, and that what has been completed comes from what is being completed. Now this is the sense in which we say that a man comes from a boy, or a man of science from a learner, because a learner is one who is becoming a man of science. But in the other sense, i.e., the one in which we say that water comes from fire, one of the limits of the change is not related to the other as a passage or intermediate, as generation is to being, but rather as the limit from which a thing starts in order to reach another limit. Therefore one comes from the other when the other is corrupted.
311. This is why changes (157)
He infers another difference from the foregoing one. For since, in the first way, one thing is related to the other as generation is to being, and as an intermediate to a limit, it is evident that one is naturally ordained to the other. Therefore they are not reversible so that one comes from the other indifferently. Consequently we do not say that a boy comes from a man, but the reverse. The reason for this is that those two things, of which one is said to come from the other in this way, are not related to each other in the same way as the two limits of a change, but as two things one of which comes after the other in sequence. And this is what he means when he says that “what has come into being” (i.e., the terminus of generation or being) does not come from generation as though generation itself were changed into being, but is that which exists after generation, because it follows generation in a natural sequence; just as one’s destination comes after a journey, and as what is last comes after what is intermediate. Therefore, if we consider these two things, i.e., generation and being, the way in which they are related does not differ from the one we have excluded, in which sequence alone is considered, as when we say that the day comes from the dawn because it comes after the dawn. Moreover, this natural sequence prevents us from saying in an opposite way that the dawn comes “from the day,” i.e., after the day; and for the same reason a boy cannot come from a man. But in the other sense in which one thing comes from another, the process is reversible; for just as water is generated by reason of air being corrupted, in a similar way air is generated by reason of water being corrupted. The reason is that these two are not related to each other in a natural sequence, i.e., as an intermediate to a limit, but as two limits, either one of which can be first or last.
312. Now in neither way (158).
He shows that it is impossible to proceed to infinity in either of these ways. First, in the way in which we say that a man comes from a boy; for the thing from which we say something else comes as a man comes from a boy has the position of an intermediary between two limits, i.e., between being and non-being. But an infinite number of intermediates cannot exist when certain limits are held to exist, since limits are opposed to infinity. Therefore, it is impossible to have an infinite series in this way.
313. In like manner it is impossible to have an infinite series in the other way; for in that way one limit is con; verted into the other, because the corruption of one is the generation of the other, as has been explained. Now wherever a reversible process exists there is a return to some first thing in the sense that what was av first a starting-point is afterwards a terminus. This cannot occur in the case of things that are infinite, in which there is neither a starting-point nor a terminus. Consequently, there is no way in which one thing can come from another in an infinite regress.
314. At the same time it is impossible (159).
He shows in which of these ways something comes from first matter. Now it must be noted that in this place Aristotle uses two common suppositions accepted by all of the ancient philosophers: first, that there is a primary material principle, and therefore that in the process of generation there is no infinite regress on the part of the higher, i.e., of that from which a thing is generated; second, that matter is eternal. Therefore, from this second supposition he immediately concludes that nothing comes from first matter in the second way, i.e., in the way in which water comes from air as a result of the latter’s corruption, because what is eternal cannot be corrupted.
315. But since someone could say that the philosophers did not hold that the first material principle is eternal because it remains numerically one eternally but because it is eternal by succession (as if the human race were held to be eternal), he therefore excludes this from the first supposition. He says that since generation is not infinite in an upward direction but stops at a first material principle, then if there is a first material principle by reason of whose corruption other things come into being, it must not be the eternal principle of which the philosophers speak. The reason is that the first material principle cannot be eternal if other things are generated by reason of its corruption, and it in turn is generated by the corruption of something else. It is evident, then, that a thing comes from this first material principle as something imperfect and potential which is midway between pure nonbeing and actual being, but not as water comes from air by reason of the latter’s corruption.
The Existence of a First in Final and Formal Causes
ARISTOTLE’S TEXT Chapter 2: 994b 9-994b 31
160. Again, that for the sake of which something comes to be is an end. Now such a thing is not for the sake of something else, but other things are for its sake. Therefore, if there is such a thing as an ultimate end, there will not be an infinite regress; but if there is no ultimate end, there will be no reason for which things come to be.
161. Now those who posit infinity do away with the nature of the good without realizing it.
162. But no one will attempt to do anything unless he thinks he can carry it through to its term.
163. Nor will there be any intelligence in such matters, because one who has intelligence always acts for the sake of something since this limit is the end of a thing.
164. Nor can the quiddity be reduced to a definition which adds to the defining notes.
165. For a prior definition is always more of a definition, whereas a subsequent one is not; and where the first note does not apply, neither does a later one.
166. Again, those who speak in this way do away with science, because it is impossible to have science until we reach what is undivided.
167. Nor will knowledge itself exist; for how can one understand things which are infinite in this way?
168. This case is not like that of a line, whose divisibility has no limit, for it would be impossible to understand a line if it had no limits. This is why no one will count the sections, which proceed to infinity.
169. But it is necessary to understand that there is matter in everything that is moved, and that the infinite involves nothingness, but essence does not. But if there is no infinite, what essence [i.e., definition] does the infinite have?
170. Again, if the classes of causes were infinite in number, it would also be impossible to know anything; for we think that we have scientific knowledge when we know the causes themselves of things; but what is infinite by addition cannot be traversed in a finite period of time.
316. Having shown that there is no infinite regress either among the causes of motion or among material causes, the Philosopher now shows that the same thing is true of the final cause, which is called “that for the sake of which” something comes to be (160).
He proves this by four arguments. The first is as follows. That for the sake of which something comes to be has the character of an end. But an end does not exist for the sake of other things, but others exist for its sake. Now such a thing either exists or not. If there is something of such a kind that all things exist for its sake and not it for the sake of something else, it will be the last thing in this order; and thus there will not be an infinite regress. However, if no such thing exists, no end will exist; and thus the class of cause called “that for the sake of which” will be eliminated.
317. Now those who posit infinity (161).
He gives the second argurgent, which is derived from the foregoing one; for from the first argument he concluded that those who posit an infinite regress in final causes do away with the final cause. Now when the final cause is removed, so also is the nature and notion of the good; because good and end have the same meaning, since the good is that which all desire, as is said in Book I of the Ethics. Therefore those who hold that there is an infinite regress in final causes do away completely with the nature of the good, although they do not realize this.
318. But no one will attempt (162).
He gives the third argument, which is as follows. If there were an infinite number of final causes, no one could reach a last terminus, because there is no last terminus in an infinite series. But no one will attempt to do anything unless he thinks he is able to accomplish something as a final goal. Therefore, those who hold that final causes proceed to infinity do away with every attempt to operate and even with the activities of natural bodies; for a thing’s natural movement is only toward something which it is naturally disposed to attain.
319. Nor will there be (163).
He states the fourth argument, which is as follows. One who posits an infinite number of final causes does away with a limit, and therefore with the end for the sake of which a cause acts. But every intelligent agent acts for the sake of some end. Therefore it would follow that there is no intellect among causes which are productive; and thus the practical intellect is eliminated. But since these things are absurd, we must reject the first position, from which they follow, i.e., that there is an infinite number of final causes.
320. Nor can the quiddity (164).
He shows that there is not an infinite number of formal causes. In regard to this he does two things. First (164:C 320), he states what he intends to prove. Second (165:C 322), he proves it (“For a prior definition”).
Regarding the first we must understand that each thing derives its particular species from its proper form, and this is why the definition of a species signifies chiefly a thing’s form. Therefore we must understand that a procession of forms is consequent upon a procession of definitions; for one part of a definition is prior to another just as genus is prior to difference and one difference is prior to another. Therefore an infinite regress in forms and in the parts of a definition is one and the same thing. Now since Aristotle wishes to show that it is impossible to proceed to infinity in the case of formal causes, he holds that it is impossible to proceed to infinity in the parts of a definition. Hence he says that it is impossible for a thing’s quiddity to be reduced to another definition, and so on to infinity, so that the defining notes are always increased in number. For example, one who defines man gives animal in his definition, and therefore the definition of man is reduced to that of animal, and this in turn to the definition of something else, thereby increasing the defining notes. But to proceed to infinity in this way is absurd.
321. Now we do not mean by this that there are the same number of forms in each individual as there are genera and differences, so that in man there is one form by which he is man, another by which he is animal, and so on; but we mean that there must be as many grades of forms in reality as there are orders of genera and differences [in knowledge]. For we find in reality one form which is not the form of a body, another which is the form of a body but not of an animated body, and so on.
322. For a prior definition (165).
He proves his premise by four arguments. The first is this. Wherever there are a number of forms or defining notes, a prior definition is always “more of a definition.” This does not mean that a prior form is more complete (for specific forms are complete), but that a prior form belongs to more things than a subsequent form, which is not found wherever a prior form is found; e.g., the definition of man is not found wherever that of animal is found. From this he argues that if the first note [of a series] does not fit the thing defined, “neither does a later one.” But if there were an infinite regress in definitions and forms, there would be no first definition or definitive form. Hence all subsequent definitions and forms would be eliminated.
323. Again, those who speak (166).
He gives the second argument, which is as follows. It is impossible to have scientific knowledge of anything until we come to what is undivided. Now in this place “undivided” cannot mean the singular, because there is no science of the singular. However, it can be understood in two other ways. First, it can mean the definition itself of the last species, which is not further divided by essential differences. In this sense his statement can mean that we do not have complete knowledge of a thing until we reach its last species; for one who knows the genus to which a thing belongs does not yet have a complete knowledge of that thing. According to this interpretation we must say that, just as the first argument concluded that it is impossible to have an infinite regress in an upward direction among formal causes, in a similar fashion this second argument concludes that it is impossible to have an infinite regress in a downward direction, otherwise it would be impossible to reach a last species. Therefore this position destroys any complete knowledge.
324. Now a formal division exists not only when a genus is divided by differences (and when such division is no longer possible the last species can be said to be undivided), but also when the thing defined is divided into its definitive parts, as is evident in Book I of the Physics. Therefore in this place “undivided” can also mean a thing whose definition cannot be resolved into any definitive parts. Now according to this the supreme genus is undivided; and from this point of view his statement can mean that we cannot have scientific knowledge of a thing by definition unless we reach its supreme genera; because when these remain unknown it is impossible to know its subsequent genera. And according to this the second argument concludes, as the former one did, that it is impossible to proceed to infinity in an upward direction among formal causes.
325. Or, in order to reach the same conclusion, “undivided” can be explained in another way, i.e., in the sense that an immediate proposition is undivided. For if it were possi ‘ hie to proceed to infinity in an upward direction in the case of definitions, there would be no immediate proposition, and thus science as such, which is about conclusions derived from immediate principles, would be destroyed.
326. Nor will knowledge (167)
He gives the third argument, which proceeds to [show that such an infinite regress would] destroy not only science but any kind of human knowing whatsoever. In regard to this argument he does two things. First (167:C 326), he gives his argument. Second (168:C 327), he refutes an objection raised against it (“This case is not like”).
The argument is as follows. We know each thing by understanding its form. But if there were an infinite regress in forms, these forms could not be understood, because the intellect is incapable of understanding the infinite as infinite. Therefore this position destroys knowing in its entirety.
327. This case is not like (168).
He disposes of an objection; for someone could say that a thing having an infinite number of forms can be understood in the same way as a line which is divided to infinity. But he denies this. He says that this case is not the same as that of a line, whose divisions do not stop but go on to infinity. For it is impossible to understand anything unless some limit is set to it. Therefore a line can be understood inasmuch as some actual limit is given to it by reason of its extremes. However, it cannot be understood insofar as its division does not terminate. Hence no one can count the divisions of a line insofar as they are infinite. But as applied to forms “infinite” means actually infinite, and not potentially infinite as it does when applied to the division of a line. Therefore, if there were an infinite number of forms, there would be no way in which a thing could be known either scientifically or in any way at all.
328. But it is necessary (169).
He gives the fourth argument, which runs thus. Matter must be understood to exist in everything that is moved; for whatever is moved is in potentiality, and what is in potentiality is matter. But matter itself has the character of the infinite, and nothingness belongs to the infinite in the sense of matter, because matter taken in itself is understood without any of kind of form. And since nothingness belongs to the infinite, it follows contrariwise that the principle by which the infinite is a being is itself not infinite, and that it does not belong “to the infinite,” i.e., to matter, to be infinite in being. But things are by virtue of their form. Hence there is no infinite regress among forms.
329. However, it must be noted that in this place Aristotle holds that the infinite involves the notion of nothingness, not because matter involves the notion of privation (as Plato claimed when he failed to distinguish between privation and matter), but because the infinite involves the notion of privation. For a potential being contains the notion of the infinite only insofar as it comes under the nature of privation, as is evident in Book III of the Physics.
330. Again, if the classes (170).
He shows that the classes of causes are not infinite in number, and he uses the following argument. We think that we have scientific knowledge of each thing when we know all its causes. But if there were an infinite number of causes in the sense that one class of cause may be added to another continuously, it would be impossible to traverse this infinity in such a way that all causes could be known. Hence in this way too the knowing of things would be destroyed.
The Method to Be Followed in the Search for Truth
ARISTOTLE’S TEXT Chapter 3: 994b 32-995a 20
171. The way in which people are affected by what they hear depends upon the things to which they are accustomed; for it is in terms of such things that we judge statements to be true, and anything over and above these does not seem similar but less intelligible and more remote. For it is the things to which we are accustomed that are better known.
172. The great force which custom has is shown by the laws, in which legendary and childish elements prevail over our knowledge of them, because of custom.
173. Now some men will not accept what a speaker says unless he speaks in mathematical terms; and others, unless he gives examples; while others expect him to quote a poet as an authority. Again, some want everything stated with certitude, while others find certitude annoying, either because they are incapable of comprehending anything, or because they consider exact inquiry to be quibbling; for there is some similarity. Hence it seems to some men that, just as liberality is lacking in the matter of a fee for a banquet, so also is it lacking in arguments.
174. For this reason one must be trained how to meet every kind of argument; and it is absurd to search simultaneously for knowledge and for the method of acquiring it; for neither of these is easily attained.
175. But the exactness of mathematics is not to be expected in all cases, but only in those which have no matter. This is why its method is not that of natural philosophy; for perhaps the whole of nature contains matter. Hence we must first investigate what nature is; for in this way it will become evident what the things are with which natural philosophy deals, and whether it belongs to one science or to several to consider the causes and principles of things.
331. Having shown that the study of truth is in one sense difficult and in another easy, and that it belongs preeminently to first philosophy, the Philosopher now exposes the proper method of investigating the truth. In regard to this he does two things. First (171:C 331), he gives the different methods which men follow in the study of truth. Second (335), he shows which method is the proper one (“For this reason one must”).
In regard to the first he does two things. First, he shows how powerful custom is in the study of truth. Second (172:C 333), he makes this clear by an example (“The great force”).
He says, first, that the way in which people are affected by what they hear depends upon the things to which they are accustomed, because such things are more willingly heard and more easily understood. For things spoken of in a manner to which we are accustomed seem to us to be acceptable; and if any things are said to us over and above what we have been accustomed to hear, these do not seem to have the same degree of truth. As a matter of fact they seem less intelligible to us and further removed from reason just because we are not accustomed to them; for it is the things which we are accustomed to hear that we know best of all.
332. Now the reason for this is that things which are customary become natural. Hence a habit, which disposes us in a way similar to nature, is also acquired by customary activity. And from the fact that someone has some special sort of nature or special kind of habit, he has a definite relationship to one thing or another. But in every kind of cognition there must be a definite relationship between the knower and the object of cognition. Therefore, to the extent that natures and habits differ, there are diverse kinds of cognition. For we see that there are innate first principles in men because of their human nature, and that what is proper to some special virtue appears good to one who has this habit of virtue; and, again, that something appears palatable to the sense of taste because of its disposition. Therefore, since custom produces a habit which is similar to nature, it follows that what is customary is better known.
333. The great force (172)>
Here he makes his previous statement clear by giving a concrete case. He says that the laws which men pass are positive evidence of the force of custom; for the legendary and childish elements in these laws are more effective in winning assent than is knowledge of the truth. Now the Philosopher is speaking here of the laws devised by men, which have as their ultimate end the preservation of the political community. Therefore the men who have established these laws have handed down in them, in keeping with the diversity of peoples and nations involved, certain directives by which human souls might be drawn away from evil and persuaded to do good, although many of them, which men had heard from childhood and of which they approved more readily than of what they knew to be true, were empty and foolish.
But the law given by God directs men to that true happiness to which everything false is opposed. Therefore there is nothing false in the divine law.
334. Now some men (173).
Here he shows how men as a result of custom use different methods in the study of truth. He says that some men listen to what is said to them only if it is mathematical in character; and this is acceptable to those who have been educated in mathematics because of the habits which they have. Now since custom is like nature, the same thing can also happen to certain men (1) because they are poorly disposed in some respect, e.g., those who have a strong imagination but little intelligence. (2) Then there are others who do not wish to accept anything unless they are given a concrete example, either because they are accustomed to this or because their sensory powers dominate and their intellect is weak. (3) Again, there are some who think that nothing is convincing enough unless a poet or some authority is cited. This is also a result either of custom or of poor judgment, because they cannot decide for themselves whether the conclusion of an argument is certain; and therefore, having no faith in their own judgment, as it were, they require the judgment of some recognized authority. (4) Again there are others who want everything said to them with certitude, i.e., by way of careful rational investigation. This occurs because of the superior intelligence of the one making the judgment and the arguments of the one conducting the investigation, provided that one does not look for certitude where it cannot be had. (5) On the other hand there are some who are annoyed if some matter is investigated in an exact way by means of a careful discussion. This can occur for two reasons. (a) First, they lack the ability to comprehend anything; for since their reasoning power is poor they are unable to understand the order in which premises are related to conclusions. (b) Second, it occurs because of quibbling, i.e., reasoning about the smallest matters, which bears some resemblance to the search for certitude since it leaves nothing undiscussed down to the smallest detail. (c) Then there are some who think that, just as liberality is lacking when the smallest details are taken into account in estimating the fee for a banquet, in a similar way there is a lack of civility and liberality when a man also wishes to discuss the smallest details in the search for truth.
335. For this reason one must be trained (174).
He exposes the proper method of investigating the truth. Concerning this he does two things. First ( 335), he shows how a man can discover the proper method of investigating the truth. Second (336), he explains that the method which is absolutely the best should not be demanded in all matters (“But the exactness of mathematics”) .
He says, first, that since different men use different methods in the search for truth, one must be trained in the method which the particular sciences must use to investigate their subject. And since it is not easy for a man to undertake two things at once (indeed, so long as he tries to do both he can succeed in neither), it is absurd for a man to try to acquire a science and at the same time to acquire the method proper to that science. This is why a man should learn logic before any of the other sciences, because logic considers the general method of procedure in all the other sciences. Moreover, the method appropriate to the particular sciences should be considered at the beginning of these sciences.
336. But the exactness of mathematics (175).
He shows that the method which is absolutely the best should not be demanded in all the sciences. He says that the “exactness,” i.e., the careful and certain demonstrations, found in mathematics should not be demanded in the case of all things of which we have science, but only in the case of those things which have no matter; for things that have matter are subject to motion and change, and therefore in their case complete certitude cannot be had. For in the case of these things we do not look for what exists always and of necessity, but only for what exists in the majority of cases.
Now immaterial things are most certain by their very nature because they are unchangeable, although they are not certain to us because our intellectual power is weak, as was stated above (279). The separate substances are things of this kind. But while the things with which mathematics deals are abstracted from matter, they do not surpass our understanding; and therefore in their case most certain reasoning is demanded.
Again, because the whole of nature involves matter, this method of most certain reasoning does not belong to natural philosophy. However, he says “perhaps” because of the celestial bodies, since they do not have matter in the same sense that lower bodies do.
337. Now since this method of most certain reasoning is not the method proper to natural science, therefore in order to know which method is proper to that science we must investigate first what nature is; for in this way we will discover the things which natural philosophy studies. Further, we must investigate “whether it belongs to one science,” i.e., to natural philosophy, or to several sciences, to consider all causes and principles; for in this way we will be able to learn which method of demonstration is proper to natural philosophy. He deals with this method in Book II of the Physics, as is obvious to anyone who examines it carefully.