On the alleged incompatibility of presentism and temporal parts

Abstract

I In a recent paper in Mind, Trenton Merricks argued for the rather depressing thesis that no possible universe can contain both things that have temporal parts and things that don't. 1 A world in which there are perduring, but no enduring, entities is one in which the only (relevant) things that exist are things with temporal parts; to the extent that I can make sense of such a world, it is a world in which no thing really changes; it is, rather, a world in which things go out of existence and other things come into existence; it is a world in which the idea that things change is simulated but is not realized. Such a world is, I think, Heraclitean. 2 A world in which there are enduring entities, but in which no entities with temporal parts exist, is a world in which, since events have temporal parts, no events occur. And, since a world without events is a world in which, it seems to me, nothing happens, a world populated only by enduring things is also a world in which nothing changes. But, in this case, the world would be Parmenidean. 3 So, Merricks is arguing that the world must be changeless in either a Heraclitean or a Parrnenidean way. This is depressing. I think that it is beyond any doubt that there are physical objects, and that it is beyond any reasonable doubt that they endure. I also think that physical objects change and that, by and large, their changes are events, which are things that have temporal parts. The world I think there is, therefore, is a victim of Merricks' argument, and it is incumbent upon me to meet the challenge posed by it. Merricks' thesis is the conclusion of the following argument which involves theses about the nature of time: