He was a specialist of Ancient Greek philosophical literature in prose, and widely studied its transmission and reception through Late antiquity and Byzantine Empire.
His first major publication being an edition of Psellos' "De omnifaria doctrina", he worked mainly on Plato and Neoplatonism, including the Byzantine philosophers and commentators Proclus, Olympiodorus and Damascius.
[a] In parallel, he worked on Greek medical texts and the transmission and reception of ancient medicine, contributing to the edition of the "Lectures on Galen's De sectis" by a 6th-century professor of medicine named Agnellus, and publishing the critical texts of the "Commentaries on Hippocrates' Aphorisms" by Stephanus of Athens.
Germanus' treatise "On the Predestined Terms of Life", Simocates' on the same topic, Mazaris' satira and Agnellus' "Lectures" were edited co-working with the members of Seminar 609 of the University at Buffalo, and published in the departmental series "Arethusa Monographs".
He prepared the critical text of several works by Damascius, including the "Treatise of the First Principles" (3 vols., 1986–1991) and the "Commentary on Plato's Parmenides" (published posthumously, 1992) for the Collection Budé; in 1973, he edited the letters of the Byzantine statesman Nicetas Magistros (fl.