Persistence and Spacetime by Yuri Balashov (University of Georgia)
Material objects persist through time and survive change. How do they manage to do so? What are the underlying facts of persistence? Do objects persist by being wholly present at all moments of time at which they exist? Or do they persist by having distinct temporal segments confined to the corresponding times? Are objects three-dimensional entities extended in space, but not in time? Or are they four-dimensional spacetime worms? These are matters of intense debate, which is now driven by concerns about two major issues in fundamental ontology: parthood and location. It is in this context that broadly empirical considerations are increasingly brought to bear on the debate about persistence. Persistence and Spacetime pursues this empirically based approach to the questions. Yuri Balashov begins by setting out major rival views of persistence - endurance, perdurance, and exdurance - in a spacetime framework and proceeds to investigate the implications of Einstein's theory of relativity for the debate about persistence. His overall conclusion - that relativistic considerations favour four-dimensionalism over three-dimensionalism - is hardly surprising. It is, however, anything but trivial. Contrary to a common misconception, there is no straightforward argument from relativity to four-dimensionalism. The issues involved are complex, and the debate is closely entangled with a number of other philosophical disputes, including those about the nature and ontology of time, parts and wholes, material constitution, causation and properties, and vagueness.