Abstract

Alexander’s comments on Aristotle’s Metaphysics often uncover fruitful doctrinal tensions that help deepen our understanding of some Peripatetic tenets, by disclosing implications that would otherwise lay hidden. Nowhere else does this become clearer than in Alexander’s exposition of the several meanings of δύναμις laid down by Aristotle in his philosophical lexicon. The point discussed therein is of the utmost importance: it concerns the well-known divide between active and passive capacities, whose joint activation brings about change, that most basic feature of the physical world. The cleavage between these two kinds of power seems clear-cut. There are, however, some borderline cases that call into question their subsumption under any of those major headings. The problem that troubles Alexander concerns the way soul and nature fit into this global picture of capacities and the right way in which to think of them as causal powers. After presenting the general account of Aristotelian δυνάμεις, the paper outlines two mutually related questions Alexander raises about them, both of which call for careful consideration, since they seem to give a wrong picture of φύσις. The paper concludes by dispelling doubts and by highlighting some presuppositions that may explain the difficulties Alexander finds in Aristotle’s account.