The cohabitation theory is a popular solution to the problem of personal fission. It affirms that all the people who result from fission were there cohabiting the pre-fission body all along. Adopting this solution is an uncontroversial move for four-dimensionalists, but is it open to three-dimensionalists too? Some have thought so, but Katherine Hawley, Mark Johnston, and Eric Olson have argued to the contrary. They claim three-dimensionalists simply cannot be cohabitation theorists. In this paper, I explain how they can.

In the current debate on how ordinary objects persist through time, more than one philosopher has endorsed the following two theses: stage theory and diachronic universalism. In this paper, I would like to offer a solution to the problem that Balashov poses to the joint acceptance of these theses. I will also offer a number of reasons why, even if it is not necessary to undermine Balashov’s counterexamples, stage theorists can, without making their theory less appealing, reject Balashov’s understanding of (...) sorts, which plays a crucial role in his criticisms of stage universalism. (shrink)

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.

An introduction to the theories of endurantism and perdurantism, and persistence more broadly.