Abstract
According to perdurantism, objects persist by being spread out over time, just as composite three-dimensional objects are spread out over space. Just as a composite three-dimensional object is spread out over space by having spatial parts, objects persist, according to perdurantism, by having temporal parts. Perdurantism can be stated more precisely by saying what exactly a temporal part is. In the sequel, Theodore Sider's definition of "instantaneous temporal part" shall be assumed: x is an instantaneous temporal part of y at instant t =df. x exists at, but only at, t; x is part of y at t; and x overlaps at t everything that is part of y at t. Much more could be and has been said about how perdurantism should be formulated. Though interesting in their own right, nothing of importance here turns on these matters of formulation