  There is reason to think that the task facing Leo the Mathematician, as he was appointed to the chair of philosophy at the Magnaura School in the mid-9th century, was to teach Aristotelian logic. In fact, elementary Aristotelian logic and natural philosophy combined with elementary mathematics would always form the standard philosophical curriculum in Byzantium. Perhaps the range of courses was slightly expanded in the late 1040s to the 1070s, when Michael Psellos and John Italos were Consuls of the Philosophers, but the standard curriculum was certainly back in force at the Imperial School under George Akropolites in the 1260s and early 1270s. The logic texts usually studied were Porphyry’s Isagoge as well as Aristotle’s Categories, De interpretatione, Prior Analytics 1.1–7 and Sophistici elenchi 1–7. Periodically, there seems to have been significant interest also in the Posterior Analytics, since we have no fewer than four extant Byzantine commentaries on the second book — in addition to the ancient paraphrase by Themistius and the commentary by pseudo-Philoponus — which probably were intended to supplement Philoponus’ commentary on the first book. In natural philosophy, extracts from Aristotle’s Physics, De generatione et corruptione and Meteorology would be read, whereas the mathematics course consisted mainly of Nicomachus’ Introductio arithmetica and the first six books of Euclid’s Elements. In many cases, students would replace some or all of these texts with compendia such as the widely circulated Epitome logica and Epitome physica by Nikephoros Blemmydes, or the Logic and Quadrivium by the anonymous of 1007 (‘Anonymus Heiberg’)—or indeed John of Damascus’ Dialectica.