Diogenes Laertius, Book IV - Polemo
17. Antigonus of Carystus in his Biographies says that his father was foremost among the citizens and kept horses to compete in the chariot-race; that Polemo himself had been defendant in an action brought by his wife, who charged him with cruelty owing to the irregularities of his life; but that, from the time when he began to study philosophy, he acquired such strength of character as always to maintain the same unruffled calm of demeanour. Nay more, he never lost control of his voice. This in fact accounts for the fascination which he exercised over Crantor. Certain it is that, when a mad dog bit him in the back of his thigh, he did not even turn pale, but remained undisturbed by all the clamour which arose in the city at the news of what had happened. In the theatre too he was singularly unmoved. 18. For instance, Nicostratus, who was nicknamed Clytemnestra, was once reading to him and Crates something from Homer; and, while Crates was deeply affected, he was no more moved than if he had not heard him. Altogether he was a man such as Melanthius the painter describes in his work On Painting. There he says that a certain wilfulness and stubbornness should be stamped on works of art, and that the same holds good of character. Polemo used to say that we should exercise ourselves with facts and not with mere logical speculations, which leave us, like a man who has got by heart some paltry handbook on harmony but never practised, able, indeed, to win admiration for skill in asking questions, but utterly at variance with ourselves in the ordering of our lives.
He was, then, refined and generous, and would beg to be excused, in the words of Aristophanes about Euripides, the "acid, pungent style," 19. which, as the same author says, is "strong seasoning for meat when it is high." Further, he would not, they say, even sit down to deal with the themes of his pupils, but would argue walking up and down. It was, then, for his love of what is noble that he was honoured in the state. Nevertheless would he withdraw from society and confine himself to the Garden of the Academy, while close by his scholars made themselves little huts and lived not far from the shrine of the Muses and the lecture-hall. It would seem that in all respects Polemo emulated Xenocrates. And Aristippus in the fourth book of his work On the Luxury of the Ancients affirms him to have been his favourite. Certainly he always kept his predecessor before his mind and, like him, wore that simple austere dignity which is proper to the Dorian mode.