Abstract
Most libertarians think that some version of the Principle of Alternative Possibilities (PAP) is true. A number of libertarians, which I call ‘Frankfurt-libertarians,’ think that they need not embrace any version of PAP. In this paper, I examine the writings of one such Frankfurt-libertarian, Eleonore Stump, for her evaluation of the impact of Frankfurt-style counterexamples (FSCs) to PAP. I show how, contrary to her own claims, Stump does need a PAP-like principle for her account of free action. I briefly argue that this discussion also goes some distance to showing that any Frankfurt-libertarian is in a similar position regarding the need for some PAP-like principle. If I am correct, then Frankfurt-libertarians must either renounce their incompatibilism or concede that FSCs fail to show all PAP-like principles to be false.