an ecclesiastical writer who flourished in the reign of Hadrian (about A.D. 135), and is highly spoken of by Eusebius and St. Jerome. He is the first who is said to have written against heresy, and wrote a most accurate Confutation of the Ε᾿ξηγητικά of Basilides, a fragment of which alone remains in Eusebius (iv, 7). Theodoret seems to imply that he wrote another work in refutation of Isidorus, the son of Basilides. See Cave, Historia Literaria, Sec. II, i, 57. .