TWO:VII.Out of this eternal unchanging divine substance, which he calls aether, are formed the heavenly bodies and the transparent spheres containing them. But there is something beyond it of an even higher and purer nature. Aristotle proves, with great subtlety, from his fundamental assumptions, that the movement of an extended substance cannot be self-caused. He also proves that motion must be absolutely continuous and without a beginning. We have, therefore, no choice but to accept the existence of an unextended, immaterial, eternal, and infinite Power on which the whole cosmos depends.
TWO:Thus the final effect of its communion with the Roman mind was not so much to develope Greek philosophy any further, or to reconcile its warring sects with one another, as to aid in their decomposition by throwing them back on the184 earlier forms whence they had sprung. Accordingly we find that the philosophic activity of Hellas immediately before and after the Christian eraso far as there was any at allconsisted in a revival of the Pythagorean and Cynic schools, accompanied by a corresponding resuscitation of primitive Scepticism. This last takes the shape of a very distinct protest against the fashionable naturalism of the age, just as the scepticism of Protagoras and Gorgiasif our view be correcthad once been called forth by the naturalism of Prodicus and Hippias. The principal representative, if not the founder, of Neo-Scepticism was Aenesidmus, who taught in Alexandria, when we are not informed, but probably after the middle of the first century A.D.291 An avowed disciple of Pyrrho, his object was to reassert the sceptical principle in its original purity, especially as against the Academicians, whom he charged with having first perverted and then completely abandoned it.292 Aenesidmus would hear nothing of probabilities nor of moral certainties. He also claimed to distinguish himself from the Academicians by refusing to assert even so much as that nothing can be asserted; but it appears that, in this point, he had been fully anticipated by Arcesilaus and Carneades.293 For the rest, his own Scepticism recalls the method of Gorgias and Protagoras much more distinctly than the method of the New Academya fresh illustration of the archaic and revivalist tendencies displayed by philosophy at185 this period. In other words, it is not against the reasoning processes that his criticisms are directed, but against the theory of causation on the objective side, and against the credibility of our immediate perceptions on the subjective side.294 But, in both directions, he has worked out the difficulties of the old Sophists with a minuteness and a precision unknown to them; and some of his points have been found worth repeating in a different connexion by modern critics. Thus, in analysing the theory of causation, he draws attention to the plurality of causes as an obstacle to connecting any given consequent with one antecedent more than with another; to the illegitimate assumption that the laws inferred from experience hold good under unknown conditions; to the arbitrary assumption of hypothetical causes not evinced by experience; and to the absurdity of introducing a new difficulty for the purpose of explaining an old one.295 With regard to causation itself, Aenesidmus seems to have resolved it into action and reaction, thus eliminating the condition of186 antecedence and consequence, without which it becomes unintelligible.296
