Gnostic heretics so designated by heresiologists. According to some accounts, they had an elaborate myth in which Seth, son of Adam, played a prominent role as of gnosis and was equated by some with Jesus Christ. In this system, Gnostics are referred to as the “seed” or “race” of Seth. Several of the treatises preserved in Coptic in the Nag Hammadi Codices contain, or allude to, a related mythological system. The most important of these treatises is the Apocryphon of (NHC II, 1; III, 1; IV, 1; BG, 2). attributes a completely different mythological system to heretics he also refers to as “Sethians.”

This system posits three first principles: Light, Darkness, and Spirit. According to Hippolytus, this system is elaborated in a writing called “The Paraphrase of Seth,” although is not a prominent figure in the system. A similar based on the same first principles—Light, Darkness, and Spirit—is found in one of the Nag Hammadi Codices, The Paraphrase of Shem (NHC VII, 1). See also THREE STELES OF SETH; ZOSTRIANOS.