four-dimensionalism

In philosophy, four-dimensionalism (sometimes called the doctrine of temporal parts) is a family of views about the ontology of time and persistence. Roughly, four-dimensionalists hold that persisting objects are extended in time in a way analogous to their extension in space, and that they are composed of distinct temporal parts located at different times, in addition to their spatial parts.

The label four-dimensionalism is used in more than one way in the literature. In a narrow sense it refers to theories of persistence—most prominently perdurantism and the closely related stage theory or exdurantism—according to which ordinary objects persist by having temporal parts. In a broader sense, the term is sometimes used for any view on which past, present and future times—and the objects located at them—are all equally real, in opposition to presentism. On this usage, "four-dimensionalism" functions as a label for non-presentist eternalist views of time rather than for a specific account of persistence.