Presentists Should Not Believe in Time Travel

The issue of (in)compatibility between presentism and time travel has intrigued many philosophers for the last few decades. Keller and Nelson [2001] have argued that, if presentism is a feasible theory of time that applies to ordinary (non-time travel) cases, then it should be compatible with time travel. Bigelow [2001] and Sider [2005], on the other hand, have independently argued that the idea of time travel contradicts the presentist conception of time because it involves the (cid:98) spatialisation of time (cid:96) (in a metaphysical sense), which is something that presentists should resist. In support of the latter claim, I offer a new argument via a different route. More specifically, I clarify basic components of the view that I take as (cid:98) orthodox (cid:96) presentism by examining how presentists have considered temporal notions of the existence of things and their property possession. It is because of these notions that presentists can sensibly maintain a dynamic theory of time and should not believe in time travel.