Metrocles of Maroneia was the brother of Hipparchia. He had been formerly a pupil of Theophrastus the Peripatetic, and had been so far corrupted by weakness that, when he made a breach of good manners in the course of rehearsing a speech, it drove him to despair, and he shut himself up at home, intending to starve himself to death. On learning this Crates came to visit him as he had been asked to do, and after advisedly making a meal of lupins, he tried to persuade him by argument as well that he had committed no crime, for a prodigy would have happened if he had not taken the natural means of relieving himself. At last by reproducing the action he succeeded in lifting him from his dejection, using for his consolation the likeness of the occurrences. From that time forward Metrocles was his pupil, and became proficient in philosophy.
Lives of the Eminent Philosophers (1925) by Diogenes Laërtius, translated by Robert Drew Hicks