Five collections of scripture are included in this book: the classic 'gnostic' (Sethian) scripture, the writings of Valentinus, the works by his followers, the scripture of 'the school of 'St' Thomas', and a selection of other, related writings ...
Part One is classic gnostic scripture, authoritative works read by an ancient group that called themselves “gnostics”—“people fit to have acquaintance (gnōsis) with god.” The name “gnostic” most properly applies to members of this group. In modern scholarship they are sometimes called “Sethians,” “Barbeloites,” “Barbelognostics,” “Ophians,” or “Ophites.” Most of their scripture comes down to us in an obviously Christian or Christianized form. The received Christian form is what is translated here. Some scholars consider the Christian elements to be foreign to the original text.
Part Two consists of writings by Valentinus (AD ca.100—ca.175), the great Christian reformer of 'gnostic' theology. The Gospel of Truth is included here, and its attribution to Valentinus is accepted, following B. Standaert. Valentinus revised 'classic 'gnostic'' tradition in the light of another ['tradition', a so-called] School of 'St' Thomas (represented in Part Four)...stamping the result with his own rhetorical genius (see Table 1).
Part Three illustrates at some length the various kinds of literature written by the followers of Valentinus. It is not feasible in a book such as this to make a complete survey of the Valentinian school in its Eastern and Western branches, since much of the evidence consists of fragments or excerpts whose significance is best conveyed by a detailed discussion of the original Greek. Instead, complete works (in one case a long ancient summary) have been selected, to demonstrate the brilliance of Valentinian scholasticism and the character of Valentinian Christianity. The select bibliographies in Part Three provide the means for interested readers to pursue the history of Valentinian theology in even greater detail.
Part Four presents traditional Christian scripture from northern Mesopotamia, whose patron saint was St. Thomas (Didymus Jude Thomas). Despite their Mesopotamian origin, the works included here enjoyed a wide international circulation in several languages, starting in the second century A.D. In itself the Thomas scripture shows no influence of the gnostic sect. But it expresses a mystical concept of salvation through self-acquaintance, which is identical with one of the main 'Christian' components in Valentinus’s revisionism. In modern discussion, this mystical component seems to be what some scholars mean by “gnosticism,” but in any case it has no direct connection with the gnostics of Part One. The Hymn of the Pearl has been included in this part because it comes down to us as part of the Thomas scripture and because its story and language correspond to the myth presupposed by The Gospel According to Thomas and The Book of Thomas.
Part Five illustrates two other early currents that probably had an influence on the young Valentinus: the system of Basilides (according to St. Irenaeus’s summary) and the Hermetic writings, a non-Christian esoteric philosophy somewhat resembling gnostic myth and imagery. Unlike the Hermetic writings, Basilides’ Christian philosophy is very different from the other scripture translated in this book; its historical relevance lies in a very shadowy connection with Valentinus. It was during his education in Alexandria, A.D. ca. 120, that Valentinus could have encountered these two currents. Further components of his education, including the exegesis of the Jewish Platonist Philo Judaeus and other aspects of Middle Platonic philosophy, are referred to in the appropriate bibliographies.
The five parts thus fit together in a hypothetical family tree (see Table 1) whose focal point is the great reformer Valentinus.
The Gnostic Scriptures, Bentley Layton
This start to the Introduction is in both the 1987 1st edition, Doubleday (first paperback edition, 1995); and the 2nd, edited by David Brakke, Yale University Press, 2021.