Elsewhere, I've shown how important 'new authorial works' spread slowly, over decades. Because there's no influence whatsoever of 3rd C. Plotinus on 4th C NHL, material of the books is certainly older (not younger) -- despite these copies post-dating Plotinus by ~3 generations. It's likely that copyist(s) of the NHL (c.367 AD) would have known of Plotinus' famed teacher in Alexandria, Ammonius Saccas (240 AD), but I want to look more closely at a Sethian text, the Book of Zostrianos (c.175-200 AD).
16: Ἀμέλιος δὲ ἄχρι τεσ σαράκοντα βιβλίων προκεχώρηκε πρὸς τὸ Ζωστριανοῦ βιβλίον ἀντιγράφων. Πορφύριος δὲ ἐγὼ πρὸς τὸ Ζωροά στρου συχνοὺς πεποίημαι ἐλέγχους͵ ὅλως νόθον τε καὶ νέον τὸ βιβλίον παραδεικνὺς πεπλασμένον τε ὑπὸ τῶν τὴν αἵρεσιν συστησαμένων εἰς δόξαν τοῦ εἶναι τοῦ παλαιοῦ Ζωροάστρου τὰ δόγματα͵ ἃ αὐτοὶ εἵλοντο πρεσβεύειν.
And Amelius proceeded to his fortieth treatise, on the Book of Zostrianos. I, Porphyrius, {also} purposed to conduct tedious examinations of the utterly illegitimate and innovative/strange book, to model the counterfeit and the heretics who were thereby constituted so as to honor the essence of ancient Zoroaster’s dogmata, which they themselves chose to represent or hold in first-place.
And Amelius proceeded to his fortieth treatise, on the Book of Zostrianos. I, Porphyrius, {also} purposed to conduct tedious examinations of the utterly illegitimate and innovative/strange book, to model the counterfeit and the heretics who were thereby constituted so as to honor the essence of ancient Zoroaster’s dogmata, which they themselves chose to represent or hold in first-place.
Tuscan Amelius joined Plotinus in 246 AD; he had already studied under a Lysimachus and completed a transcription (into Latin?) of Numenius' canon, c.245 AD, five years? ~240-6 AD); presumably, Amelius was about 25 (born c.225 AD) when he joined Plotinus, and did not begin writing his own material until ~265 AD. At more or less the same rate as his mentor, Amelius' fortieth book would have been composed after 275 AD; it seems Porphyry also wrote one later (c.285 AD?)
Another contemporary ~15 yrs older than Porphyry, Amelios wrote against the supposedly ancient Book of Zostrianos around 275-280 AD. Zoroaster (c.900-600 BC) was certainly well-known as "venerable/ancient" by the mid-3rd C. AD. Why should Zostrianos (Ζωστριανοῦ) ever have been confused with Zoroaster (Ζωροάστρου), different names. Nor is it obvious why any Sethian and Manichean Gnostic group could not have borrowed anything from Zoroastrianism, though evidence of that here is weak. In Alexandria (for example), anyone might have elaborated a lightly syncretistic Gnostic interpretation without strong traces to Zoroastrianism -- a writer named 'Zostrianos' didn't even require a definite Seleucid/Persian ancestry. The explanation for the general confusion is itself confounding; we may only speculate. Porphyry does not detail this, unfortunately. I suspect that the Syrian Barbelo mythos forced into overtook the Sethian system c.70-115 AD, as Hermeticism slowly began to decline, with a foreign character more noticeable in the day (and hence, the crude Oriental conflation).
I would guess Amelius (somewhat older than Porphyry, and apparently Plotinus' secretary) should have produced his 40th volume around 280 AD Age 60 (if he produced at the rate of Plotinus), in regards to material ~75 years older. For anyone to think the book was "ancient" required either a long pedigree or for it to have seemed 'ancient' thematically. Why did pagan Porphyry (c.290 AD) label these Gnostics "heretics" -- well, it's Sethian, and from Josephus 90 AD, we know they're an "ancient" Jewish heres). Indeed, the Gnostic ideas of Zostrianos (c.175-200 AD) are NOT Christian but rather Late Sethian if perhaps somewhat Nazorean. So heretical Jewish material was plausibly old enough to convince some readers of a great antiquity (i.e. the Seth/Enoch mythos) tracing back to Chaldaea. It makes sense that Porphyry would know Sethians as "heretics" (from Judaism) without any mention of the 'orthodox Christian' nonsense that everyone wrongly assumes.
If Gnosticism was relatively recent to the period Plotinus was born at (c.204 AD) or later studied in Alexandria (c.232-243 AD), this fact would have been mentioned. Plotinus later argued with sectarians from schools active in his youth, against scholars taught Alexandrian-derivative philosophy which he knew was not 'ancient' -- that doesn't mean it was "new" either. I am curious about anything in Porphyry's work that mentions Hermeticism; I see that Iamblichus claims Porphyry read Hermetic books: what evidence is there of that? (Not Iamblichus' Responses.) Again, Iamblichus would insist there is a Porphyry dialogue w/ against Hermeticism, but I'm not seeing it.
