Abstract

Recently philosophers have raised doubts about the principle that imaginability implies possibility. Their doubts have been due largely to a number of examples involving the notions of identity and essence , in which certain impossibilities nonetheless seem to be imaginable. ;The dissertation responds to this line of argument. Its central thesis is that facts about identity and essence put constraints on what we can imagine, just as they put constraints on what is possible; hence, states of affairs that deny a true identity or a true ascription of essence are not imaginable, just as they are not possible. ;In support of this thesis, I sketch a view of imaginability that entails that the pertinent states of affairs are not imaginable. I then defend this view by distinguishing these states of affairs from others which are often confused with them, and which are imaginable. I argue further that the notion of imaginability is itself commonly conflated with two other modal notions, viz. epistemic possibility and conceivability. We need to distinguish imaginability from these other notions, however, because the target states of affairs are not imaginable, even though they are both epistemically possible and conceivable. ;I conclude that the imaginability-possibility principle survives the Kripke-Putnam examples of identity and essence, even though analogous principles involving epistemic possibility and conceivability do not