 Young Oscar and old Oscar are the same dog but absolutely different things, i.e., different logical objects. The material conditions rendering young Oscar and old Oscar the same dog (and the same Dalmatian) are precisely the same as the material conditions under which young Oscar and old Oscar would qualify as temporal parts of the same dog. The only difference is logical. The identity relation between young Oscar and old Oscar can be formalized in an extensional logic (Deutsch 1997), but a theory of temporal parts requires a modal/temporal apparatus. Young Oscar is wholly present during his youth and possesses the simple, non-relational, property of not having a gray muzzle.