[86] Eudoxus of Cnidos, the son of Aeschines, was an astronomer, a geometer, a physician and a legislator. He learned geometry from Archytas and medicine from Philistion the Sicilian, as Callimachus tells us in his Tables. Sotion in his Successions of Philosophers says that he was also a pupil of Plato. When he was about twenty-three years old and in straitened circumstances, he was attracted by the reputation of the Socratics and set sail for Athens with Theomedon the physician, who provided for his wants. Some even say that he was Theomedon’s favourite. Having disembarked at Piraeus he went up every day to Athens and, when he had attended the Sophists’ lectures, returned again to the port.

[87] After spending two months there, he went home and, aided by the liberality of his friends, he proceeded to Egypt with Chrysippus the physician, bearing with him letters of introduction from Agesilaus to Nectanabis, who recommended him to the priests. There he remained one year and four months with his beard and eyebrows shaved, and there, some say, he wrote his Octaëteris. From there he went to Cyzicus and the Propontis, giving lectures; afterwards he came to the court of Mausolus. Then at length he returned to Athens, bringing with him a great number of pupils: according to some, this was for the purpose of annoying Plato, who had originally passed him over. ¹

[88] Some say that, when Plato gave a banquet, Eudoxus, owing to the numbers present, introduced the fashion of arranging couches in a semicircle. Nicomachus, the son of Aristotle, states that he declared pleasure to be the good. ² He was received in his native city with great honour, proof of this being the decree concerning him. But he also became famous throughout Greece, as legislator for his fellow-citizens, so we learn from Hermippus in his fourth book On the Seven Sages, and as the author of astronomical and geometrical treatises and other important works.

He had three daughters, Actis, Philtis and Delphis.

[89] Eratosthenes in his writings addressed to Baton tells us that he also composed Dialogues of Dogs; others say that they were written by Egyptians in their own language and that he translated them and published them in Greece. Chrysippus of Cnidos, the son of Erineus, attended his lectures on the gods, the world, and the phenomena of the heavens, while in medicine he was the pupil of Philistion the Sicilian.

Eudoxus also left some excellent commentaries. He had a son Aristagoras, who had a son Chrysippus, the pupil of Aëthlius. To this Chrysippus we owe a medical work on the treatment of the eye, speculations upon nature having occupied his mind.

[90] Three men have borne the name of Eudoxus: (1) our present subject; (2) a historian, of Rhodes; (3) a Sicilian Greek, the son of Agathocles, a comic poet, who three times won the prize in the city Dionysia and five times at the Lenaea, so we are told by Apollodorus in his Chronology. We also find another physician of Cnidos mentioned by Eudoxus ³ in his Geography as advising people to be always exercising their limbs by every form of gymnastics, and their sense-organs in the same way.

The same authority, Apollodorus, states that Eudoxus of Cnidos flourished about the 103rd Olympiad, ⁴ and that he discovered the properties of curves. He died in his fifty-third year. When he was in Egypt with Chonuphis of Heliopolis, the sacred bull Apis licked his cloak. From this the priests foretold that he would be famous but shortlived, so we are informed by Favorinus in his Memorabilia.

[91] There is a poem of our own upon him, which runs thus ⁵ :

Eudoxus used to be called Endoxos (illustrious) instead of Eudoxus by reason of his brilliant reputation.

Having now dealt with the famous Pythagoreans, let us next discuss the so-called sporadic philosophers. And first we must speak of Heraclitus.