Abstract

Eric T. Olson has argued that those who hold that two material objects can exactly coincide at a moment of time, with one of these objects constituting the other, face an insuperable difficulty in accounting for the alleged differences between the objects, such as their being of different kinds and possessing different persistence-conditions. The differences, he suggests, are inexplicable, given that the objects in question are composed of the same particles related in precisely the same way. In response, I show that the differences are not at all inexplicable once it is recognized that the conditions for a persisting object to be composed by certain particles at a moment of time must involve facts concerning other moments of time, and that the relevant facts are different for persisting objects of different kinds. Philosophers who neglect this sort of constraint on composition principles may be said to be victims of the 'cinematographic fallacy'