Aristotle On Two-Way Powers

Abstract This paper offers a reading of Aristotle’s view of two-way powers and points out where related views about Aristotle and two-way powers can go wrong. It argues that Aristotelian two-way powers consist in, and are based in, systematic knowledge; that they are all, without exception, principles of change in another, or in oneself as other; and that the topic of voluntary action in Aristotle is a quite different topic. It follows from this that the Aristotelian view of two-way powers has nothing much to do with freedom. The paper also argues that Aristotle’s view of two-way powers is the best in the history of Western philosophy, because it’s the only view on which both contrary exercises of the power are explained as no accident, relative to the power. Subsequent views of two-way powers tend to violate the general principle that powers explain their actualizations as no accident, relative to the power.