FL. c.170-180. A Gnostic teacher who is described as the most esteemed (dokimomtatos) of the school of Valentinus and had known Valentinus personally, but who differed in some points from other writers of Valentinus's school. He is the first-known commentator on the Gospel according to John, and parts of his highly allegorizing commentary (hypomnemmata) are preserved in quotations in Origen, while Clement refers to his exposition of Luke 12:8, which suggests that he had commented on that gospel also. It is not known where he taught.