Aristotle, for his part, names this constituent Matter (λn), and thereby involves his own theory in the same final perplexity in which the Platonic is entangled. These groups of individuals, sharing in a common constitutive or essential character, are what Aristotle called 'the lowest species' (ǎтoμov eidos); and he is justified, so far as the terms allow of justification, in saying that in them the essence is inherent. Beyond them, outside of them, the essence, the form, has no existence. Sharing with Plato the view that the world of generation is eternal, Aristotle therefore regards the origination of these constitutive forms of the lowest species as not a problem requiring solution. Our knowledge of the field of experience is completed when we have reached insight into the constitutive naturethe forms-and are able to deduce therefrom all that follows from the original nature of the things themselves. Such knowledge, then, must be regarded as having, so to speak, a number of quite independent roots. Each type of things has its own individual character; and consequently, according to the Aristotelian view, there are distinct sciences, each with its own ultimate principles; and it is therefore impossible that there should be any one all-comprehensive science such, for example, as Plato seemed to contemplate in his Dialectic. Common principles there may undoubtedly be, for the work or process of knowing is the same in kind throughout the several sciences; but from common principles no specific knowledge can ever be deduced. The hypothesis, therefore, of a science which deals only with abstract principles severed from things, and which attempts to deduce therefrom the specific character of the things themselves, is illusory whether the abstractions be represented as generic universals in the fashion of the earlier Platonic view, or as mathematical ratios, in conformity with the later view. The severance of the Idea from the particulars, therefore, in Aristotle's view rendered knowledge of the particulars themselves quite inexplicable. The second main objection which Aristotle presses is that the Ideas afford no explanation of what is above all characteristic of the world of generation-namely, Change. "All philosophy of nature," says Aristotle, "is cut off by the hypothesis of Ideas";1 for from the permanence and unchangeability of the Ideas it is obviously impossible to deduce the counter-opposite-transitoriness and change. Nor will Aristotle acknowledge that anything is gained by the intermediary, the soul, with which in the Platonic theory explanation of change appears to be given. In so far as the soul operates in and through contemplation of the Ideas it ought to operate without change, if the expression be allowed. The Ideas, says Aristotle, are always there; why are the particulars not always there? Just in so far as the soul is supposed to operate apart from the Ideas, a ground of explanation that is not the Ideas themselves is resorted to. We have seen abundantly that Plato's theory is open to this criticism. Accordingly Aristotle insists that, in the long-run, the Platonic theory would be compelled to have recourse to a duality of active principles, and that therefore an explanation cannot be found in the Ideas alone. Perhaps the nature of the difficulty which Aristotle here presses may become clearer if we follow out now, in a few words, his own attempt to find a solution in accordance with the view he takes of the world of generation. The fundamental fact of movement or change in the world of generation Aristotle recognises; he recognises also that there cannot be an endless sequence of determined movements-that in some way the original impulse must be given by that which is not itself impelled. As such an original 1 Arist. Met. A 992 b 8. ground of movement cannot be found within the world of generation, it must be supposed to exist outside thereof. A First Mover who communicates movement to the world of generation-that is Aristotle's solution. The movement is communicated first of all to that external all-embracing sphere which closes in the world of generation, and is transmitted downwards,' becoming at each step more and more irregular, until in the terrestrial province it presents itself as the rather chaotic interchange of the elementary opposites, Hot and Cold, Dry and Moist. This Aristotelian solution has very much the same difficulties as the Platonic, and leaves them in the same way unsolved. Even assuming it to be true that a first cause of motion is a necessity, the difficulty of the notion of an unchanging cause of change, an unmoved mover, is not diminished by putting it outside the world of generation. And, as regards the changes of the cycle of generation, the Aristotelian solution works out very imperfectly. In strictness it would imply a wholly mechanical conception of the universe,-a conception from which Aristotle always recoiled, and quite irreconcilable with his view of the essential forms. Moreover, Aristotle shares with Plato the conception of a teleological direction of movement. Plato, as we saw, simply puts the teleological and mechanical side by side: the soul as principle of change works with purpose as contemplating the perfect model of the Ideas; alongside of it there is natural necessity, mechanical movement. So in Aristotle: in his view the most important changes that come about in the world of generation are purposive, those which constitute the development from the potential stage of existence to that of completed actuality. A type of objects, for example, exhibits to us a number of individuals passing through stages of development determined throughout as a striving towards the complete realisation of the typical form. Such purposive movement or change is wholly inexplicable by mechanical causes; and Aristotle, using more precise language than Plato, has to recognise, alongside of such change, Chance (τύχη) and Spontaneity (τὸ αὐτόματον). And if we ask further what explanation can be given of the purposive movement, the teleological connexion, Aristotle is able only to offer a confused reproduction of one element in the Platonic theory. Somehow the world of generation strives towards a perfection which lies outside of itself. It is to be regarded, therefore, strictly in the Platonic fashion as an imperfect copy, but animated by a desire to attain a completeness which it does not yet possess. 138 CHAPTER VI THE SCHOOL OF PLATO SPEAKING generally, the philosophy of Aristotle has its roots in the Platonic doctrine. Despite the constant opposition to the Platonic philosophy in its main concepts and in many of its characteristic details, Aristotle's system is nevertheless to be regarded as a natural development from the Platonic position. Aristotle himself was for many years a member of the Platonic school. He was familiar, therefore, in particular with what we must call the latest tendencies of the Platonic thinking. Perhaps on this account we may explain the otherwise remarkable fact that Aristotle's criticisms of Plato refer so seldom to parts of the Platonic work which the modern world holds in highest estimation. In the later period of Plato's teaching it is probable that there were many discussions of fundamental points in the theory of Ideas; and it is possible that the opposition to the doctrine of ideas which is a salient feature of Aristotle's system had already made itself apparent while Aristotle was connected with the Platonic school. Indeed some recent critics 2 of Plato have thought that there could be discerned in certain Platonic dialogues traces of the influence of criticisms so closely resembling those later advanced by Aristotle that 1 Aristotle entered the Academy about 367 B.C. He was a native of Stagira; born 384, died 322. |