How to Make Presentism Consistent with Special Relativity

Abstract This chapter provides a response to the argument that presentism is incompatible with the special theory of relativity—and, in particular, with the relativity of simultaneity. More specifically, this chapter argues that presentists can respond to this argument not by claiming that there’s a privileged frame of reference, but by relativizing their view in a way that makes it compatible with special relativity. In particular, this chapter develops an original version of presentism—R-presentism—that says (somewhat roughly) that (a) for any frame of reference, all that exists is a 3-dimensional spatial manifold, and (b) there’s no frame-independent fact of the matter about which 3-dimensional manifold is the “real” one. R-presentism is counterintuitive because it entails that what exists is relative to a frame of reference; but this chapter defends this view against objections and, in the process, shows that it’s far more believable than it seems at first glance. This chapter doesn’t argue that R-presentism is true; rather, it argues that R-presentism is a viable option and that presentists who don’t want to go out on any unjustified limbs can endorse the disjunctive view that either (a) there’s a privileged frame of reference or (b) R-presentism is true. Alternatively, we can think of this chapter as arguing for the following two claims: (i) special relativity doesn’t entail that eternalism is true; rather, it entails that either eternalism is true, or R-presentism is true, or there’s a privileged frame of reference; and (ii) we don’t have any good reason to favor eternalism over R-presentism.