(Κέβης), of Thebes, was a disciple of Philolaus, the Pythagorean, and of Socrates, with whom he was connected by intimate friendship. (Xen. Mem. 1.2.28, 3.11.17; Plat. Crit. p. 45b.) He is introduced by Plato as one of the interlocutors in the Phaedo, and as having been present at the death of Socrates. (Phaed. p. 59c.) He is said on the advice of Socrates to have purchased Phaedo, who had been a slave, and to have instructed him in philosophy. (Gel. 2.18; Macr. 1.11; Lactant. 3.24.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890