up to overturn the established philosophy, and to shelter himself under the authority of those men who asserted that nothing could be known or perceived; in which number we ought not to include Plato or Socrates; the one because he left behind him a most perfect school, namely, the Peripatetics and Academics, differing in name, but agreeing in all substantial matters: and from whom the Stoics themselves differ in words rather than in opinions. But Socrates, who always disparaged himself in arguing, attributed more knowledge to those whom he wished to refute. So, as he was speaking differently from what he really thought, he was fond of using that kind of dissimulation which the Greeks call εἰρωνεία; which Fannius says Africanus also was in the habit of indulging in, and that that ought not be considered a bad habit in him, as it was a favourite practice of Socrates. VI. But, however, we will allow, if you like, that all those things were unknown to the ancients:—was nothing effected then, by their being thoroughly investigated, after that Arcesilas, disparaging Zeno, (for that is supposed to have been his object,) as discovering nothing new, but only correcting previous changes of names, while seeking to upset his definitions, had attempted to envelop the clearest possible matters in darkness? And his system, which was at first not at all approved of, although it was illustrated both by acute genius and by an admirable wittiness of language, was in the next generation adopted by no one but Lacydes; but subsequently it was perfected by Carneades, who was the fourth in succession from Arcesilas; for he was the pupil of Hegesinus, who had been the pupil of Evander, the disciple of Lacydes, and Lacydes himself had been the pupil of Arcesilas; but Carneades maintained it for a long time, for he lived ninety years; and those who had been his pupils had a very high reputation, of whom Clitomachus displayed the most industry, as the number of books which he composed testifies; nor was there less brilliancy of genius in him than there was of eloquence in Charmadas, or of sweetness in Melanthius of Rhodes. But Metrodorus of Stratonice was thought to be the one who had the most thorough understanding of Carneades. And your friend Philo attended the lectures of Clitomachus for many years; but as long as Philo was alive the Academy was never in want of a head.