THREE:To understand Descartes aright, we must provisionally disregard the account given in his work on Method of the process by which he arrived at a new theory of the world; for, in truth, there was nothing new about it except the pro388portion in which fragments taken from older systems were selected and recombined. As we have already noticed, there is no such thing as spinning philosophies out of ones own head; and, in the case of Descartes, even the belief that he was so doing came to him from Plato; for, along with Aristotles dogmatic errors, his sound teaching with regard to the derivation of knowledge had fallen into oblivion. The initial doubt of the Discourse on Method and the Meditations is also Platonic; only it is manifested under an individual and subjective, instead of a universal and objective form. But to find the real starting-point of Descartes enquiries we must look for it in his mathematical studies. A geometrician naturally conceives the visible world under the aspect of figured extension; and if he thinks the figures away, nothing will remain but extension as the ultimate material out of which all determinate bodies are shaped. Such was the result reached by Plato in his Timaeus. He identified matter with space, viewing this as the receptacle for his eternal and self-existent Ideas, or rather the plastic medium on which their images are impressed. The simplest spatial elements are triangles; accordingly it is with these that he constructs his solid bodies. The theory of triangular elements was probably suggested by Atomism; it is, in fact, a compromise between the purely mathematical and the materialistic methods. Like all Platos fancies, this theory of matter was attacked with such convincing arguments by Aristotle that, so long as his physics remained in the ascendent, it did not find a single supporter; although, as we saw in the last chapter, Plotinus very nearly worked his way back to it from the Peripatetic definition. Even now, at the moment of Aristotles fall, it might have failed to attract attention, had not the conditions under which it first arose been almost exactly repeated. Geometrical demonstration had again become the type of all reasoning; there was again a sceptical spirit abroad, forcing men to fall back on the most elementary and universal con389ceptions; an atomistic materialism again threatened to claim at least the whole field of physical enquiry for its own. That Descartes followed the Timaeus in identifying matter with extension cannot be doubted; especially when we see that he adopts Platos analysis of body into elementary triangles; but the theory agreed so well with his intellectual predispositions that he may easily have imagined it to be a necessary deduction from his own priori ideas. Moreover, after the first two steps, he parts company with Plato, and gives himself up, so far as his rejection of a vacuum will permit, to the mechanical physics of Democritus. Much praise has recently been bestowed on his attempt to interpret all physical phenomena in terms of matter and motion, and to deduce them from the unaided operation of natural causes; but this is no more than had been done by the early Greek thinkers, from whom, we may observe, his hypothesis of an initial vortex was also derived. His cosmogony is better than theirs, only in so far as it is adapted to scientific discoveries in astronomy and physiology not made by Descartes himself; for where his conjectures go beyond these they are entirely at fault.In person Aristotle resembled the delicate student of modern times rather than the athletic figures of his predecessors. He was not a soldier like Socrates, nor a gymnast like Plato. To judge from several allusions in his works, he put great faith in walking as a preservative of healtheven when lecturing he liked to pace up and down a shady avenue. And, probably, a constitutional was the severest exercise that290 he ever took. He spoke with a sort of lisp, and the expression of his mouth is said to have been sarcastic; but the traits preserved to us in marble tell only of meditation, and perhaps of pain. A free-spoken and fearless critic, he was not over-sensitive on his own account. When told that somebody had been abusing him in his absence, the philosopher replied, He may beat me, too, if he likesin my absence. He might be abused, even in his own presence, without departing from the same attitude of calm disdain, much to the disappointment of his petulant assailants. His equanimity was but slightly disturbed by more public and substantial affronts. When certain honorary distinctions, conferred on him by a popular vote at Delphi, were withdrawn, probably on the occasion of his flight from Athens, he remarked with his usual studied moderation, that, while not entirely indifferent, he did not feel very deeply concerned; a trait which illustrates the character of the magnanimous man far better than anything related of Alexander. Two other sayings have an almost Christian tone; when asked how we should treat our friends, he replied, As we should wish them to treat us; and on being reproached with wasting his bounty on an unworthy object, he observed, it was not the person, but the human being that I pitied.181
