perdurantism

Perdurantism or perdurance theory is a philosophical theory of persistence and identity. In metaphysics the debate over persistence currently involves three competing theories—one three-dimensionalist theory called "endurantism" and two four-dimensionalist theories called "perdurantism" and "exdurantism". For a perdurantist, all objects are considered to be four-dimensional "worms" that make up the different regions of spacetime. It is a fusion of all the perdurant's instantaneous time slices compiled and blended into a complete mereological whole. Perdurantism posits that temporal parts alone are what ultimately change. Katherine Hawley in How Things Persist states that change is "the possession of different properties by different temporal parts of an object".

Take any perdurant and isolate a part of its spatial region. That isolated spatial part has a corresponding temporal part to match it. We can imagine an object, or four-dimensional worm: an apple. This object is not just spatially extended but temporally extended. The complete view of the apple includes its coming to be from the blossom, its development, and its final decay. Each of these stages is a temporal time slice of the apple, but by viewing an object as temporally extended, perdurantism views the object in its entirety.