Dates: c. 435 Summary: In Conference 8 Cassian gives a Sethite reading. The line of Seth, sprung from an excellent root, was by reason of its sanctity termed "angels of God" or "sons of God"; the line of Cain were "children of men." When the sons of Seth took wives from the daughters of Cain, they were led astray, and their offspring were "termed giants by reason of the size of their bodies and their cruelty and wickedness." The same chapter also carries a distinct antediluvian-knowledge tradition: the pure knowledge of nature held by the seed of Seth, and — in its corrupt, forbidden form — Ham inscribing the wicked arts on flood-proof metal and rock to carry them past the Deluge, a Christian version of the "knowledge survives the Flood on inscribed stone" motif treated on the Pillars of Seth.
As long then as there continued that separation of the lines between them, the seed of Seth, as it sprang from an excellent root, was by reason of its sanctity termed "angels of God," or as some copies have it "sons of God;" and on the contrary the others by reason of their own and their fathers' wickedness and their earthly deeds were termed "children of men." … yet after this the sons of Seth who were the sons of God saw the daughters of those who were born of the line of Cain, and inflamed with the desire for their beauty took to themselves from them wives who taught their husbands the wickedness of their fathers… From these sons of Seth then and daughters of Cain, as we have said, there were born still worse children who became mighty hunters, violent and most fierce men who were termed giants by reason of the size of their bodies and their cruelty and wickedness.
— Conference 8, CHAPTER XXI, ccel.org. Cassian identifies the "sons of God" as the sanctified seed of Seth and the giants as their corrupted offspring by the daughters of Cain.
The same chapter frames the giants' rise with an account of antediluvian knowledge and how it survived the Flood. First the pious pole — the knowledge of all nature transmitted purely down the line of Seth so long as it stayed separate from the wicked line:
This knowledge then of all nature the seed of Seth received through successive generations, handed down from the fathers, so long as it remained separate from the wicked line, and as it had received it in holiness, so it made use of it to promote the glory of God and the needs of everyday life. But when it had been mingled with the evil generation, it drew aside at the suggestion of devils to profane and harmful uses what it had innocently learnt, and audaciously taught by it the curious arts of wizards and enchantments and magical superstitions.
Then the impious pole — how that corrupted knowledge was carried past the Flood, by Ham, on indestructible metal and rock:
And so, as ancient traditions tell us, Ham the son of Noah, who had been taught these superstitions and wicked and profane arts, as he knew that he could not possibly bring any handbook on these subjects into the ark, into which he was to enter with his good father and holy brothers, inscribed these nefarious arts and profane devices on plates of various metals which could not be destroyed by the flood of waters, and on hard rocks, and when the flood was over he hunted for them with the same inquisitiveness with which he had concealed them, and so transmitted to his descendants a seed-bed of profanity and perpetual sin.
— Conference 8, CHAPTER XXI, ccel.org. This is the same physical device as the pillars-of-Seth legend — celestial and natural lore inscribed on durable stone and metal so it outlasts the Flood — but in its impious valence, the recovery a sin rather than a rescue. Cassian thus supplies a patristic mirror of that legend: a pious Sethite transmission of knowledge and, beside it, Ham's flood-proofed inscription of its forbidden form. It is weighed on the pillars-of-Seth argument Is the legend the pious inversion of the Watchers' antediluvian astrology?