 One of our initial questions (Section 1 above) was whether a commitment to transworld identity—the view that an individual exists in more than one possible world—is an acceptable commitment for one who believes in possible worlds. The considerations of Sections 4–5 above suggest that this commitment does involve genuine (although perhaps not insuperable) problems, even for one who rejects David Lewis’s extreme realism about the nature of possible worlds. The problems do not arise directly from the notion of an individual’s existing in more than one possible world with different properties. Rather, they derive principally from the fact that it is hard to accommodate all that we want to say about the modal properties of ordinary individuals (including all the things we want to say about their essential and accidental properties) if de re modal statements about such individuals are characterized in terms of their existence or non-existence in other possible worlds.