endurantism or endurance theory is a philosophical theory of persistence and identity. according to the endurantist view, material objects are persisting three-dimensional individuals wholly present at every moment of their existence, which goes with an a-theory of time. this conception of an individual as always present is opposed to perdurantism or four-dimensionalism, which maintains that an object is a series of temporal parts or stages, requiring a b-theory of time. the use of "endure" and "perdure" to distinguish two ways in which an object can be thought to persist can be traced to david lewis.