Michael of Ephesus was the first medieval author to comment upon Book V of the Nicomachean Ethics. In his work, he paid special attention to passage 1134b18-1135a5, in which Aristotle delineates the distinction between that which is just by nature and that which is just by convention. Michael not only detects the fundamental questions arising from this text that have occupied the attention of interpreters in the intervening centuries, he also manages to offer original solutions, especially with regards to the problem of change in those things that are just by nature.
Among Aristotelian scholars in Byzantium, Michael of Ephesus occupies a special place, because he is the author who commented most widely upon the works of Aristotle; 1 in fact, he is -along with Aspasius -one of the few early commentators on Aristotle's Nicomachean Ethics. Specifically, in addition to the most frequently studied texts, his exegetical activity extended to works that other commentators ignored (such as the Politics and De motu animalium). 2 Michael belonged to the intellectual circle that gathered around Anna Komnenos (1083-ca. 1153/54), the daughter of Emperor Alexios I, at the time when she had to distance herself from politics and retire to a monastery for conspiring against her brother John II, their father's successor. 3 At that point (or perhaps even earlier), 4 she used her 1 See Kapriev 2005, 215; Benakis 2009, 65. 2 See Mercken 1990, 433 (this essay by Mercken is the most important study regarding Michael as a commentator on the Ethics). In the same vein: Praechter 1990 and Kaldellis 2009, 38. Praechter characterizes Michael as "a truly respectable interpreter of Aristotle" (51) and emphasizes the multifaceted nature of his studies on Aristotle (ibid.). The bibliography that deals with Michael is limited as one can appreciate in Benakis 1987, 373, and almost nonexistent when it comes to his practical philosophy, with the exceptions already cited of Benakis, Mercken, and O'Meara 2008 who study the texts that remain to us from Michael's commentary on the Politics. 3