Aristotle, then, was the first to undermine the doctrine of species, which I have just now mentioned, and which Plato had embraced in a wonderful manner; so that he even affirmed that there was something divine in it. But Theophrastus, a man of very delightful eloquence, and of such purity of morals that his probity and integrity were notorious to all men, broke down more vigorously still the authority of the old school; for he stripped virtue of its beauty, and made it powerless, by denying that to live happily depended solely on it. For Strato, his pupil, although a man of brilliant abilities, must still be excluded entirely from that school; for, having deserted that most indispensable part of philosophy which is placed in virtue and morals, and having devoted himself wholly to the investigation of nature, he by that very conduct departs as widely as possible from his companions. But Speusippus and Xenocrates, who were the earliest supporters of the system and authority of Plato,—and, after them, Polemo and Crates, and at the same time Crantor,—being all collected together in the Academy, diligently maintained those doctrines which they had received from their predecessors. Zeno and Arcesilas had been diligent attenders on Polemo; but Zeno, who preceded Arcesilas in point of time, and argued with more subtilty, and was a man of the greatest acuteness, attempted to correct the system of that school. And, if you like, I will explain to you the way in which he set about that correction, as Antiochus used to explain it. Indeed, said I, I shall be very glad to hear you do so; and you see that Pomponius intimates the same wish.