83:3 July 2000
Temporal Parts

Advisory Editor: Achille Varzi, Columbia, New York

On the one hand there are entities, such as processes and events, which have temporal parts: the beginning of the race; the middle of the concert; the delicate part of the conversation. On the other hand there are entities, such as material objects, which are always present in their entirety at any time at which they exist at all. The categorial distinction between entities which do, and entities which do not, have temporal parts is grounded in common sense. Yet various philosophers have been inclined to oppose it. Some – for instance reists like Kotarbinski – have defended an ontology consisting exclusively of things with no temporal parts. Whiteheadians have favored ontologies including only temporally extended processes. Quine has endorsed a four-dimensional ontology in which the distinction between objects and processes vanishes and every entity comprises simply the content of some arbitrarily demarcated portion of space-time. One further option, embraced by philosophers such as David Lewis, accepts the opposition between objects and processes, while still finding a way to allow that all entities have both spatial and temporal parts. Each of the different views reflects a different conception of the scope and nature of mereology. The present issue of The Monist is devoted to the clarification of these different views and to the working out of their implications for such problems as identity through time, spatiotemporal coincidence, and the possibility of a merging and splitting of substances.

Table of Contents:

Yuri Balashov 

Persistence and Space-Time: Philosophical Lessons of the Pole and Barn

Berit Brogaard 

Presentist Four-Dimensionalism

Kit Fine 

A Counterexample to Locke's Thesis

Mark Heller 

Temporal Overlap is Not Coincidence

Robin Le Poidevin 

Continuants and Continuity

Josh Parsons 

Must a Four-dimentionalist Believe in Temporal Parts?

Peter Simons 

How To Exist at a Time When You Have No Temporal Parts

Peter van Inwagen 

Temporal Parts and Identity Across Time