Σιμμίας, (or, in the MSS. of Diog. Laert., Σιμίας) literary.

1. Of Thebes, first the disciple of the Pythagorean philosopher Philolaüs, and afterwards the friend and disciple of Socrates, at whose death he was present, having come from Thebes, with his brother Cebes, bringing with him a large sum of money, to assist in Criton's plan for the liberation of Socrates (Plat. Crit. p. 45b., Phaed. pp. 59, c., 92, a., et passim; comp. Ael. VH 1.16). At this time he and Cebes were both young men (Phaed. p. 89a.). The two brothers are the principal speakers, besides Socrates himself, in the and the skill with which they argue, and the respect and affection with which Socrates treats them, prove the high place they held among his disciples, not only in the judgment of Plato. but in the general opinion. In the (p. 242. a., b.) also, Socrates is made to refer to Simmias as one of the most powerful reasoners of his day.

According to Plutarch, who introduces Simmias as a speaker in his dialogue de Genio Socratis (p. 578a., &c.), he studied much in Egypt, and became conversant with the mystical religious philosophy of that country.

There is a very brief account of him in Diogenes Laertius (2.124), who states that there was a collection of twenty-three dialogues by him, in one volume. The titles of these dialogues are also given, with a slight variation, by Suidas (s. v.) ; they embrace a large range of philosophical subjects, but are chiefly ethical.

Two epitaphs on Sophocles, in the Greek Anthology, are ascribed to Simmias of Thebes in the Palatine Codex (Brunck, Anal. vol. i. p. 168; Jacobs, Anth. Graec. vol. i. p. 100, Anth. Pal. 7.21, 22, vol. i. p. 312). There is also an epitaph on Aristocles, among the epigrams of Simmias of Rhodes, which Brunck would refer to Simmias of Thebes; probabilis conjectura, says Jacobs. (Brunck, Anal. vol. i. p. 204, No. 2; Jacobs, Animadv. vol. i. pt. ii. p. 4.)