Material objects extend through space by having different spatial parts in different places. But how do they persist through time? According to some philosophers, things have temporal parts as well as spatial parts: accepting this is supposed to help us solve a whole bunch of metaphysical problems, and keep our philosophy in line with modern physics. Other philosophers disagree, arguing that neither metaphysics nor physics give us good reason to believe in temporal parts.

This is a very introductory introduction to some ways in which the special and general theories of relativity may bear upon metaphysical questions about the nature of time and space, and the persistence of objects.

This essay explores what is at stake while considering the change and identity of objects over time. Philosophers worry about an object having incompatible properties in part due to the fact that it is ruled out by Leibniz's Law. They have preferred to hold on to Leibniz's Law and to find some other way to resolve the problem of an object's changing its properties over time. The chapter examines three accounts of how objects change over time without violating Leibniz's Law: (...) endurance, perdurance, and exdurance. The chapter finally provides a brief discussion of something that has been much neglected in the literature on persistence, namely, mixed theories. (shrink)

How is the debate between endurantism and perdurantism affected by the transition from pre-relativistic spacetimes to relativistic ones? After suggesting that the endurance vs. perdurance distinction may run together a pair of cross-cutting distinctions, I discuss two recent attempts to show that the transition in question does serious damage to endurantism.