 One might think that (ii) and (iii) are incompatible with (i). Consider again Luke, our agoraphobic. Suppose that his agoraphobia affects him in such a way that he will only intentionally go outside if he chooses to go outside, and yet his agoraphobia makes it impossible for him to make this choice. In this case, a necessary condition for Luke’s intentionally going outside is his choosing to go outside. Moreover, Luke is not able to choose or cause himself to choose to go outside. Intuitively, this would seem to imply that Luke lacks the freedom to go outside. But this implication does not follow for Lewis. From the fact that Luke is able to go outside only if he chooses to go outside and the fact that Luke is not able to choose to go outside, it does not follow, on Lewis’s account, that Luke lacks the ability to go outside. Consequently, Lewis’s account fails to explain why Luke lacks the ability to go outside (cf. Speak 2011). (For other important criticisms of Lewis, see Ginet [1990, ch. 5] and Fischer [1994, ch. 4].)