 Suppose that we combine transworld identity with the claim (without which the introduction of transworld identity seems pointless) that a transworld identity can hold between A in w1 and B in w2 even though the properties that B has in w2 are somewhat different from the properties that A has in w1 (or, to put it more simply, suppose that we combine the claim that there are transworld identities with the claim that not all of a thing’s properties are essential to it). Then, it can be argued, unless there are non-trivial individual essences, we are in danger of having to admit the existence of possible worlds that differ from one another only in the identities of some of the individuals that they contain.