(Κόπαξ), a Sicilian, who, after the expulsion of Thrasybulus from Syracuse (B. C. 467), by his oratorical powers acquired so much influence over the citizens, that for a considerable time he was the leading man in the commonwealth. The great increase of litigation consequent on the confusion produced by the expulsion of the tyrants and the claims of those whom they had deprived of their property, gave a new impulse to the practice of forensic eloquence. Corax applied himself to the study of its principles, opened a school of rhetoric, and wrote a treatise (entitled ) embodying such rules of the art as he had discovered. He is commonly mentioned, with his pupil Tisias, as the founder of the art of rhetoric; he was at any rate the earliest writer on the subject. His work has entirely perished. It has been conjectured (by Garnier, Mem. de l'Institut. de France, Classe d'Histoire, vol. ii. p. 44, &c., and others), though upon very slight and insufficient grounds, that the treatise entitled found amongst the works of Aristotle, is the supposed lost work of Corax. (Cic. Brut. 12, de Orat. 1.20, 3.21; Aristot. Rh. 2.24; Quint. Inst. 3.1. Mongitor, Bibl. Sicul. i. p. 146, &c., ii. p. 267, &c.; Westernsann, Gesch. der Griech. Beredtsamkeit, 1.27, note 5, &c., § 68, notes 8, 27.)