Abstract
Suppose that wc identify physical objccts, in thc first instance, by extension, as things like stones, tables, trees, people and other animals: the persisting macroscopic constituents of the world in which we live. Of course, there is a substantive question of what it is to be y such things in the way relevant to categorization as a physical object. So this can hardly be the final word on the matter. Still, it is equally clear that this gives us all a perfectly respectable initial conception of what we are talking about; and it is an entirely adequate starting point for what follows.