"Gnosticism" (from the Greek gnosis, "knowledge") designates a broad variety of religious teachings that were rife in the Hellenized Near East of the first centuries CE and purported to offer knowledge of the otherwise hidden truth of total reality as the indispensable key to man's salvation. Most of the schools or sects in question were ostensibly Christian by the time our earliest witnesses, the Church Fathers, were familiar with them, and in consequence the whole movement was long regarded as essentially an aberration from Christian doctrine. However, although Gnosticism provided the first chapter in the history of Christian heresies, the Christian veneer of the systems playing that role is often thin to the point of transparency; and clearly non-Christian writings have come to light that by all criteria of content must be classed as Gnostic as well. The details of the literary evidence point to highly syncretistic origins...