Manley and Wasserman (2008) have provided a convincing case against analyses of dispositions in terms of one conditional, and a very interesting positive proposal that links any disposition to a ‘suitable proportion’ of a particular set of precise conditionals. I focus on their positive proposal and ask just how precise those conditionals are to be. I argue that, contrary to what Manley and Wasserman imply in their paper, they must be maximally specific, describing in their antecedents complete centred worlds. This (...) suggests a natural semantics for dispositional expressions, which I briefly explore to argue that it lacks uniformity. I end by suggesting a variation on Manley and Wasserman's view which would preserve uniformity, though at the cost of some new puzzling questions. (shrink)

There is widespread agreement, even among those who accept the possibility of backward causation, that it is impossible to change the past. I argue that this agreement corresponds to a relatively uninteresting understanding of what changing the past amounts to. In one sense it is indeed impossible to change the past: in no possible world is an action performed which makes the past in that world different from the past in that world. In another sense, however, it may be possible (...) to change the past: maybe in some possible world an action is performed which makes the past in that world different from the actual past. I argue that those who accept the possibility of backward causation are committed to accepting the possibility that the past changes in the latter sense. (shrink)

Analyses of dispositional ascriptions in terms of conditional statements famously confront the problems of finks and masks. We argue that conditional analyses of dispositions, even those tailored to avoid finks and masks, face five further problems. These are the problems of: (i) Achilles' heels, (ii) accidental closeness, (iii) comparatives, (iv) explaining context sensitivity, and (v) absent stimulus conditions. We conclude by offering a proposal that avoids all seven of these problems.

In no possible world does a time traveler succeed in killing herearlier self before she ever enters a time machine. So if many,many time travelers went back in time trying to kill theirunprotected former selves, the time travelers would fail inmany strange, coincidental ways, slipping on bananapeels, killing the wrong victim, and so on. Such cases producedoubts about time travel. How could ``coincidences'' beguaranteed to happen? And wouldn't the certainty of coincidentalfailure imply that time travelers are not free to killtheir (...) earlier selves? But if so, what would inhibit theirfreedom? Despite initial appearances, these and other doubtsmay be answered: the possibility of time travel survives yetanother challenge. (shrink)

Dispositional compatibilists argue that a proper understanding of our abilities vindicates both compatibilism and the principle of Alternate Possibilities (the claim that the ability to do otherwise is required for freedom and moral responsibility). In this paper, I argue that this is mistaken. Both analyses of dispositions and abilities should distinguish between local and global dispositions or abilities. Once this distinction is in place, we see that neither thesis is established by an analysis of abilities.