Lewisian counterpart theory

Lewisian counterpart theory suggests that when we talk about individuals across different possible worlds (ways things could be), we're not necessarily referring to the same person in each world. Instead, each person has counterparts—similar beings—in other worlds. These counterparts are not identical but are close enough in features or behavior to stand in for the original individual within that specific possible world. This approach helps explain how objects and persons can "exist" in multiple scenarios without implying they are the same in each. Essentially, it views identity across possible worlds as a matter of related, comparable counterparts rather than strict sameness.