Abstract

This paper presents a dilemma which it has been alleged by Kim Frost must be faced by any defender of the notion of a two-way power and offers a solution to the dilemma which is distinct from Frost’s own. The dilemma is as follows: assuming that powers are to be individuated by what they are powers to do or undergo, then either there is a unified description of the manifestation-type which individuates the power, or there is not. If there is, then two-way powers are revealed really to be one-way powers, after all. If there is not, then it is difficult to explain why the two-way power does not simply dissolve into a mere combination of two one-way powers. The paper offers an account of what a two-way power is that is distinct from the one Frost takes for granted, and argues that this different conception is the key to avoiding the dilemma. It is also argued that this alternative conception has several further advantages over its rival and also that it has no less of a claim than Frost’s notion to be prefigured in Aristotle’s original discussion.