A pupil of Valentinus the Gnostic who was active during the mid-second century. He was referred to by Clement of Alexandria as “the most esteemed member of the school of Valentinus.” He wrote an important commentary on the of that was excerpted by Origen in his own commentary on John.

Although he is reported by Hippolytus to have been a member of the “Western” or “Italic” branch of the School, he was probably an Alexandrian, and his commentary was probably in between 160 and 180.