According to Bentley Layton "Classical Gnosticism" and "The School of Thomas" antedated and influenced the development of Valentinus, whom Layton called "the great reformer" and "the focal point" of Gnostic development. While in Alexandria, where he was born, Valentinus probably would have had contact with the Gnostic teacher Basilides, and may have been influenced by him. Simone Petrement, while arguing for a Christian origin of Gnosticism, places Valentinus after Basilides, but before the Sethians. According to Petrement, Valentinus represented a moderation of the anti-Judaism of the earlier Hellenized teachers; the demiurge, widely regarded as a mythological depiction of the Old Testament God of the Hebrews (i.e. Jehova), is depicted as more ignorant than evil.