Prior to the discovery of the Nag Hammadi Library, the Letter was one of the few authentic Gnostic works available to scholars.
The letter was included in full in Epiphanius's Panarion, an unsympathetic text which condemns its theology as heretical.
He divides the Law among three types: the pure legislation of God embodied in the Decalogue, the mixed legislation "laid down for vengeance" affected by the world-situation of its first hearers (the world being inherently evil to a Gnostic), and Though making points of a decidedly dualistic nature, Ptolemy supports his readings from "sayings" texts or logia: "We shall draw the proofs of what we say from the words of the Savior, which alone can lead us without error to the comprehension of reality."
Ptolemy states in the letter that, "For if the Law was not ordained by the perfect God himself, as we have already taught you, nor by the Devil, a statement one cannot possibly make, the legislator must be someone other than these two.
Such a publicly circulated Epistle may have been a literary form, rather than an actual missive sent by a "Ptolemy" to a "Flora.” The Letter was the classical equivalent of the Renaissance and modern Essay format.