One of the strengths of the book is that it highlights the importance of the so-called Philosophical collection, a set of Byzantine manuscripts containing philosophical texts, mostly related to the Neoplatonic tradition. It is an essential intermediary in the process of transmission of philosophical texts from Antiquity, so essential that, according to Richard Goulet, without it "we would only have kept from ancient philosophy a very small corpus of texts, maybe Aristotle's Organon, as is the case in several eastern traditions" (p. 54, translation is mine). This set of 17 Greek manuscripts which present similar codicological and palaeographical characteristics, comes from a copying centre which is considered to have been situated in Constantinople around 850. It comprises nothing less than: Plato's dialogues, the De anima, the De fato and Quaestiones of Alexander of Aphrodisias, the Didaskalikos of Alkinoos, the Dissertations of Maximus of Tyre, the treatises of Plotinus, the commentaries on the Republic and the Timaeus of Proclus, the commentary on the Parmenides and the treatise De primis principiis of Damascius, the commentaries on the Physics and the Categories by Simplicius, the commentaries on the Gorgias, the Phaedrus, and the Alcibiades by Olympiodorus, the treatise Contra Proclum de aeternitate mundi by John Philoponus, the commentary on the De interpretatione by Ammonius, the De caelo, the De generatione et corruptione, the History of animals, the Metaphysics, the Meteorology and the Physics of Aristotle, as well as Patristic texts and geographical and astrological writings. The "Platonic" nucleus of the Philosophical collection is probably made up of copies of remnants of the library of the philosophical school of Alexandria which had been brought from Alexandria to Constantinople at a date impossible to state precisely, but probably falling between the beginning of the seventh century and the beginning of the ninth century, as has been suggested by L. G. Westerink.It wasn't the Syriac that caught my eye, but rather something that isn't mentioned in the review, although I imagine the book must note it somewhere. Some biblical (sort of) apocrypha and pseudepigrapha, specifically apocalypses, were included in Neoplatonist libraries as well. The evidence is found in Porphyry's Life of Plotinus:
Henri Dominique Saffrey proposes, in an insightful essay, a study of one of the manuscripts of the Philosophical collection, the Parisinus graecus 1807 which contains among other things tetralogies VIII (Clitophon, Republic, Timaeus, Critias) and IX (Minos, Laws, Epinomis, Letters) of Plato, with the Definitions and the Spuria. It is the manuscript A for Plato, made around 850, the model of which went from Alexandria to Byzantium, and which travelled from Byzantium to Armenia, and then to the library of Francesco Petrarca.
Guglielmo Cavallo, Philippe Hoffman and Didier Marcotte provide remarks which complete this study of the Philosophical collection. The textual tradition of Syrianus' commentary on the Metaphysics and the influence of Neoplatonists on Byzantine thought are also studied. The second part of the book contains studies on the dissemination of Neoplatonic texts in the Syriac-speaking and Arabic-speaking areas. Henri Hugonnard-Roche provides a useful synthesis article on Syriac philosophical literature in the sixth and seventh centuries. As to the Arabic tradition, the influence of Neoplatonism during the Abbasid period, in particular on al-Kindi (P. Adamson, G. Endress), the presence of Proclus, and the proximity between sixth-century Alexandrian commentators and the Baghdad Aristotelian Ibn al-Tayyib are considered.
16. Many Christians of this period--amongst them sectaries who had abandoned the old philosophy, men of the schools of Adelphius and Aquilinus--had possessed themselves of works by Alexander of Libya, by Philocomus, by Demostratus, and by Lydus, and exhibited also Revelations [i.e., apocalypses - JRD] bearing the names of Zoroaster, Zostrianus, Nicotheus, Allogenes, Mesus, and others of that order. Thus they fooled many, themselves fooled first; Plato, according to them, had failed to penetrate into the depth of Intellectual Being.Both Zostrianos and Allogenes were recovered in the Nag Hammadi Coptic Gnostic library. As far as I know, the others are still lost. I haven't noted the lost Apocalypses of Zoroaster, Nicotheus, and Mesus in my earlier discussions of lost books (here, here, and here), perhaps because they aren't obviously to be counted as Old Testament pseudepigrapha. But it seems likely that at least Zoroaster was, as an ancient Gentile prophet co-opted into the Judeo-Christian tradition as we find the Sibyl in the Sibylline Oracles and Zoroaster himself in Zostrianos
Plotinus fequently attacked their position at the Conferences and finally wrote the treatise which I have headed Against the Gnostics: he left to us of the circle the task of examining what he himself passed over. Amelius proceeded as far as a fortieth treatise in refutation of the book of Zostrianus: I myself have shown on many counts that the Zoroastrian volume is spurious and modern, concocted by the sectaries in order to pretend that the doctrines they had embraced were those of the ancient sage.
UPDATE: Note also that Messos (Mesus?) is the recipient of the revelation in Allogenes and that the Zostrianos closes with the line "Teaching of Zoroaster" (as pointed out by the editors [Wire and Wintermute] of Allogenes in the Robinson translation of the Nag Hammadi Library). So it may be that Porphyry got all four names from just these two works. Wire and Wintermute also report that Allogenes can be a designation for the biblical patriarch Seth, who was important for the Sethian Gnostic movement.