The term Gnosticism was coined in the eighteenth century to designate a composite ensemble of sects that arose from the late first century to the fourth century CE. These sects were classified by the Church Fathers among the earlier Christian heresies. Their adepts, in contrast with common believers, claimed to be endowed through an extraordinary revelation with spiritual awareness (Gk. gnōsis) concerning both God's hidden nature and the true human self, and to have deduced from that a mythological or theosophical account of the universe, the origin of evil, and otherworldly salvation. But the Gnostic phenomenon as a whole deserves a more flexible approach. Inasmuch as these sects, for the most part, were building up an entire doctrinal system of their own rather than simply discussing existing Christian doctrine...