the son of Antisthenes, an Athenian, was the founder of the sect of the Cynics, which of all the Greek schools of philosophy was perhaps the most devoid of any scientific purpose.
He flourished B. C. 366 (Diod. 15.76), and his mother was a Thracian (Suidas, s.v. D. L. 6.1), though some say a Phrygian, an opinion probably derived from his replying to a man who reviled him as not being a genuine Athenian citizen, that the mother of the gods was a Phrygian.
In his youth he fought at Tanagra (B. C. 426), and was a disciple first of Gorgias, and then of Socrates, whom he never quitted, and at whose death he was present. (Plat. Phaed. § 59.)
He never forgave his master's persecutors, and is even said to have been instrumental in procuring their punishment. (D. L. 6.10.)
He survived the battle of Leuctra (B. C. 371), as he is reported to have compared the victory of the Thebans to a set of schoolboys beating their master (Plut. Lyc. 30), and died at Athens, at the age of 70. (Eudocia, Viola