The Stage View and Temporary Intrinsics

Abstract

Four-dimensionalism, as I’ll use the term, is the doctrine that reality is spread out in time as well as space.1 Just as objects that are located at multiple regions of space contain parts con ned to those regions of space, so objects that are located at multiple regions of time contain parts — temporal parts — that are con ned to those regions of time. (Or better: an object that occupies an extended spatiotemporal region R has parts con ned to the various subregions of R; but I’ll ignore this complication henceforth.) Most who accept this ontology of perduring objects, as they are often called, identify the continuants of our everyday ontology with “space-time worms” — mereological sums of stages from different times. Elsewhere (1996) I have proposed a different version of four-dimensionalism, which identi es continuants with the stages themselves, and which analyses de re temporal predication with a temporal version of modal counterpart theory (Lewis, 1968, 1971). On this view, a current assertion of ‘Clinton was indiscreet’ is true iff the (current) referent of ‘Clinton’ — a stage — has an indiscreet temporal counterpart in the past. The temporal counterpart relation is the same “genidentity” or “unity” relation used by the worm theorist to unify the successive stages of continuing space-time worms. In my 1996 I supported this view by appeal to its ability to resolve various philosophical puzzles, including the paradoxes of material constitution and Derek Par t’s (1971) puzzle about identity and what matters; the purpose of the present note is to mention one other line of argument. A widely discussed contemporary argument for temporal parts is David Lewis’s argument from temporary intrinsics, according to which only the fourdimensionalist can explain the phenomenon of intrinsic change.2 I am now straight-shaped, but will fail to be straight-shaped in the future. There is an