(Χαιρεφῶν), of the Athenian demus of Sphettus, a disciple and friend of Socrates, is said by Xenophon to have attended his instructions for the sake of the moral advantage to be derived from them, and to have exemplified in his practice his master's precepts. From the several notices of him in Xenophon and Plato, he appears to have been a man of very warm feelings, peculiarly suceptible of excitement, with a spirit of high and generous emulation, and of great energy in everything that he undertook. He it was that inquired of the Delphic oracle who was the wisest of men, and received the famous answer:

Σοφὸς σοφοκλῆς· σοφώτεροσδ δʼ εὐριπίδης· ἀνδρῶν δὲ πύντων σωκράτης σοφώτατος.

The frequent notices of him in Aristophanes shew that he was highly distinguished in the school of Socrates; while from the nicknames, such as νυκτερίς and πύξινος, by which he was known, and the Aristophanic allusions to his weakness and his sallow complexion (Vesp. 1413, gunaiki\ e)oikw\s qayi/nh comp. Nub. 496), it appears that he injured his health by intense application to study. He attached himself to the popular party in politics, was driven into banishment by the Thirty tyrants, and returned to Athens on the restoration of democracy in B. C. 403. (Plat. Apol. p. 21a.) From the passage just referred to it appears, that he was dead when the trial of Socrates took place in B. C. 399. (Xen. Mem 1.2.48, 2.3; Plat. Charm. p. 153, Gorg. pp. 447, 448; Stallb. ad Plat. Apol. p. 21a.; Athen. 5.218; Aristoph. Cl. 105, 145, 157, 821, 1448, Av. 1296, 1564; Schol. ad ll. cc.)