LESSON 15

The Destruction of the Platonists' Arguments for Ideas

Chapter 9: 991a 8-991b 9

             112. But the most important problem of all that one might raise is what the Forms contribute to sensible things, either to those which are eternal or to those which are generated and corrupted.

             113. For they are not the cause of motion or of any change whatever in these things.

             114. Nor are they of any assistance in knowing other things; for they are not the substance of other things, because if they were they would exist in them. Nor do they contribute anything to the being of other things; for they are not present in the things which participate in them. For if they were they would perhaps seem to be causes, as whiteness mixed with some white thing. But this theory, which was first stated by Anaxagoras and later by Hesiod and certain other thinkers, is easily disposed of. For it is easy to bring many absurd conclusions against such a view. In fact other things are not derived from the Forms in any of the customary senses.

             115. Again, to say that they are exemplars, and that other things participate in them, is to speak with empty talk and to utter poetic metaphors.

             116. For what is the work which looks towards the Ideas [as an examplar]? For one thing may both be and become similar to another thing and not be made in likeness to it. So whether Socrates exists or not, a man such as Socrates might come to be.

             117. Similarly, it is evident that this will be the case even if Socrates is eternal. And there will be many exemplars of the same thing, and for this reason many Forms, as animal and two-footed and man-in-himself will be the Form of man.

             118. Further, the Forms will be the exemplars not only of sensible things but also of the Forms themselves, as the genus of the species. Hence the same thing will be both an exemplar and a copy.

             119. Again, it is thought to be impossible that the substance of a thing and that of which it is the substance should exist apart. Hence, if the Forms are the substances of things, how will they exist apart from them?

             120. But in the Phaedo it is stated that the Forms are the causes both of being and of coming to be. Yet even if the Forms do exist, still the things which participate in them will not come to be unless there is something which produces motion.

             121. And many other things come to be, such as a house and a ring, of which we do not say that there are any Forms. It is evident, then, that other things can exist and come to be because of such causes as those [responsible for the things] just mentioned.

COMMENTARY

             225. Here Aristotle attacks the opinion of Plato insofar as he did not draw the conclusion which he intended to draw. For Plato intended to conclude that there are Ideas by this argument that they are necessary in some way for sensible things. Hence, Aristotle, by showing that the Ideas cannot contribute anything to sensible things, destroys the arguments by which Plato posits Ideas. Thus he says (112) that of all the objections which may be raised against Plato the foremost is that the Forms which Plato posited do not seem to contribute anything to sensible things, either to those which are eternal, as the celestial bodies, or to those which are generated and corrupted, as the elemental bodies. He shows (113) that this criticism applies to each of the arguments by which Plato posited Ideas ("For they are not").

             226. At this point in the text (113) he begins to present his five objections [against the Platonic arguments for Ideas].

             He argues, first (113:C 226), that they are useless in explaining motion; second (114:C 227), that they are useless in explaining our knowledge of sensible things ("Nor are they"); third (115:C 231), that they are of no value as exemplars ("Again, to say"); fourth (119:C 236), that they are of no value as the substances of things ("Again, it is thought"); and fifth (120:C 237), that they are of no value as causes of generation ("But in the Phaedo").

             Accordingly, he says, first (113), that the Forms cannot contribute anything to sensible things in such a way as to be the cause of motion or of any kind of change in them. He does not give the reason for this here but mentioned it above (120:C 237), because it is clear that the Ideas were not introduced to explain motion but rather to explain immutability. For since it seemed to Plato that all sensible things are always in motion, he wanted to posit something separate from sensible things that is fixed and immobile, of which there can be certain knowledge. Hence, according to him, the Forms could not be held to be sensible principles of motion, but rather to be immutable things and principles of immutability; so that, undoubtedly, whatever is found to be fixed and constant in sensible things will be due to participation in the Ideas, which are immutable in themselves.

             227. Nor are they of any assistance (114).

             Second, he shows that the Forms do not contribute anything to the knowledge of sensible things, by the following argument: knowledge of each thing is acquired by knowing its own substance, and not by knowing certain substances which are separate from it. But these separate substances, which they call Forms, are altogether other than sensible substances. Therefore a knowledge of them is of no assistance in knowing other sensible things.

             228. Nor can it be said that the Forms are the substances of these sensible things; for the substance of each thing is present in the thing whose substance it is. Therefore, if these Forms were the substances of sensible things, they would be present in sensible things. This is opposed to Plato's opinion.

             229. Nor again can it be said that the Forms are present in these sensible substances as in things which participate in them; for Plato thought that some Forms are the causes of sensible things in this way. For just as we might understand whiteness itself existing of itself as a certain separate whiteness to be mingled with the whiteness in a subject, and to participate in whiteness, in a similar way we might say that man [in himself], who is separate, is mingled with this man who is composed of matter and the specific nature in which he participates. But this argument is easily "disposed of," i.e., destroyed; for Anaxagoras, who also held that forms and accidents are mingled with things, was the first to state it. Hesiod and certain other thinkers were the second to mention it. Therefore I say that it is easily disposed of, because it is easy to bring many absurd conclusions against such an opinion. For it would follow, as he pointed out above (97:C 194) against Anaxagoras, that accidents and forms could exist without substances. For only those things can exist separately which are naturally disposed to be mixed with other things.

             230. It cannot be said, then, that the Forms contribute in any way to our knowledge of sensible things as their substances. Nor can it be said that they are the principles of being in these substances by way of participation. Nor again can it be said that from these Forms as principles other things--sensible ones--come to be in any of the ways in which we are accustomed to speak. Therefore, if principles of being and principles of knowledge are the same, the Forms cannot possibly make any contribution to scientific knowledge, since they cannot be principles of being. Hence he says "in any of the customary ways" of speaking, because Plato invented many new ways of deriving knowledge of one thing from something else.

             231. Again, to say (115).

             Here he gives the third objection against the arguments for separate Forms. He says that the Forms are of no value to sensible things as their exemplars. First (115), he states his thesis; and second (116:C 232), he proves it ("For what is the work").

             Accordingly he says, first (115), that to say that the Forms are the exemplars both of sensible things and the objects of mathematics (because the latter participate in causes of this kind), is untenable for two reasons. First, because it is vain and useless to posit exemplars of this kind, as he will show; and second, because this manner of speaking is similar to the metaphors which the poets introduce, which do not pertain to the philosopher. For the philosopher ought to teach by using proper causes. Hence he says that this manner of speaking is metaphorical, because Plato likened the generation of natural substances to the making of works of art, in which the artisan, by looking at some exemplar, produces something similar to his artistic idea.

             232. For what is the work (116).

             Here he proves his thesis by three arguments. For the work, i.e., the use, of an exemplar, seems to be this, that the artisan by looking at an exemplar induces a likeness of the form in his own artifact. But in the operations of natural beings we see that like things are generated by like, as man is generated by man. Therefore this likeness arises in things which are generated, either because some agent looks toward an exemplar or not. If not, then what is "the work," or utility, of the agent's so looking toward the Ideas as exemplars?--as if to say, none. But if the likeness results from looking at a separate exemplar, then it cannot be said that the cause of this likeness in the thing generated is the form of an inferior agent. For something similar would come into being with reference to this separate exemplar and not with reference to this sensible agent. And this is what he means when he says "and not be like it," i.e., like the sensible agent. From this the following absurdity results: someone similar to Socrates will be generated whether Socrates is held to exist or not. This we see is false; for unless Socrates plays an active part in the process of generation, no one similar to Socrates will ever be generated. Therefore, if it is false that the likeness of things which are generated does not depend on proximate agents, it is pointless and superfluous to posit separate exemplars of any kind.

             233. However, it should be noted that, even though this argument does away with the separate exemplars postulated by Plato, it still does not do away with the fact that God's knowledge is the exemplar of all things. For since things in the physical world are naturally inclined to induce their likeness in things which are generated, this inclination must be traced back to some directing principle which ordains each thing to its end. This can only be the intellect of that being who knows the end and the relationship of things to the end. Therefore this likeness of effects to their natural causes is traced back to an intellect as their first principle. But it is not necessary that this likeness should be traced back to any other separate forms; because in order to have the above-mentioned likeness this direction of things to their end, according to which natural powers are directed by the first intellect, is sufficient.

             234. Similarly, it is evident (117).

             Here he gives the second argument, which runs as follows: just as Socrates because he is Socrates adds something to man, in a similar way man adds something to animal. And just as Socrates participates in man, so does man participate in animal. But if besides this Socrates whom we perceive there is held to be another Socrates who is eternal, as his exemplar, it will follow that there are several exemplars of this Socrates whom we perceive, i.e., the eternal Socrates and the Form man. And by the same reasoning the Form man will have several exemplars; for its exemplar will be both animal and two-footed and also "man-in-himself," i.e., the Idea of man. But that there should be several exemplars of a single thing made in likeness to an exemplar is untenable. Therefore it is absurd to hold that things of this kind are the exemplars of sensible things.

             235. Further (118).

             Here he gives the third argument, which runs thus: just as a Form is related to an individual, so also is a genus related to a species. Therefore, if the Forms are the exemplars of individual sensible things, as Plato held, there will be also certain exemplars of these Forms, that is to say, their genus. But this is absurd, because then it would follow that one and the same thing, i.e., Form, would be an exemplar of one thing, namely, of the individual whom we perceive by the senses, and a copy made in likeness to something else, namely, a genus. This seems to be absurd.

             236. Again, it is thought (119).

             Here he proves his fourth objection, namely, that the Forms contribute nothing to sensible things as their substances or formal causes; because "It is thought by him," that is to say, it is a matter of opinion (to put this impersonally), that it is impossible for a thing's substance to exist apart from the thing whose substance it is. But the Forms exist apart from the things of which they are the Forms, i.e., apart from sensible things. Therefore they are not the substances of sensible things.

             237. But in the "Phaedo" (120).

             Here he shows that the Forms are of no value in accounting for the coming to be of sensible things, although Plato said "in the Phaedo," i.e., in one of his works, that the Forms are the causes both of the being and of the coming to be of sensible things.

             But Aristotle disproves this by two arguments. The first is as follows: to posit the cause is to posit the effect. However, even if the Forms exist, the particular or individual things which participate in the Forms will come into being only if there is some agent which moves them to acquire form. This is evident from Plato's opinion that the Forms are always in the same state. Therefore, assuming that these Forms exist, if individuals were to exist or come into being by participating in them, it would follow that individual substances of this kind would always be. This is clearly false. Therefore it cannot be said that the Forms are the causes of both the coming to be and the being of sensible things. The chief reason is that Plato did not hold that the Forms are efficient causes, as was stated above (113:C 226). For Aristotle holds that the being and coming to be of lower substances proceeds from immobile separate substances, inasmuch as these substances are the movers of the celestial bodies, by means of which generation and corruption are produced in these lower substances.

             238. And many other (121).

             Here he gives the second argument, which runs thus: just as artifacts are related to artificial causes, so are natural bodies to natural causes. But we see that many other things besides natural bodies come into being in the realm of these lower bodies, as a house and a ring, for which the Platonists did not posit any Forms. Therefore "other things," namely, natural things, can both be and come to be because of such proximate causes as those just mentioned, i.e., artificial ones; so that, just as artificial things come to be as a result of proximate agents, so also do natural things.