 It seems that there is an alternative to the Aristotelian solution, because Taylor’s presupposition 5 seems dubious. A symptom of this is that it seems to yield the fatalist conclusion a bit too easily. For supposing that I do not perform act S (whatever it is), then it follows immediately that there is lacking a necessary condition for my performing S, namely the occurrence of S. So, if presupposition 5 is right, it follows immediately that I never have the power to perform any act which I do not actually perform. Of course, that does not show that this conclusion is wrong; but it enough to make one question the presupposition which entails it. And one might suggest that not only is this presupposition false, but that it seems true because it is easily confused with another much more plausible proposition (equivalent to Hasker’s PEP5; see Hasker 1989, 115):