 Finally, it can be noted that the problems concerning transworld identity discussed here arise only because it is assumed that not all of an individual’s properties are essential to it (and hence that, if it exists in more than one possible world, it has different properties in different worlds). If, instead, one were to hold that all of an individual’s properties are essential properties—and hence, for example, that George Eliot could not have existed with properties in any way different from her actual ones—then no such problems would arise. Moreover, this suggestion, implausible though it may be, is of some historical interest. For, according to a standard interpretation of the views of Gottfried Leibniz, the philosopher who is the father of theories of possible worlds, Leibniz’s theory of ‘complete individual notions’ commits him to the thesis that an individual such as George Eliot does have all her properties essentially (cf. Leibniz, Discourse on Metaphysics (1687), Sections 8 and 13; printed in Leibniz 1973 and elsewhere). According to the ‘hyper-essentialist’ view to which Leibniz appears to be committed, any individual, in any possible world, whose properties in that world differ from the actual properties of George Eliot is not, strictly speaking, identical with Eliot. However, it also seems clear that this does not represent a way of saving a transworld identity interpretation of de re modality. On the contrary: if there is no possible world in which George Eliot exists with properties different from her actual properties, then it is plausible to conclude that there is no possible world, other than the actual world, in which she exists at all. For unless possible worlds can be exact duplicates (something that Leibniz himself would deny), any merely possible world must differ from the actual world in some respect. If so, then the properties of any individual in another possible world must differ in some respect from the actual properties of Eliot (even if the difference is only a difference in relational properties), in which case, if all Eliot’s properties are essential to her, that individual is not Eliot. (Leibniz’s views may, however, be seen as a partial anticipation of counterpart theory, which attempts to save the truth of the claim that George Eliot could have been different in some respects (thus denying ‘hyper-essentialism’) while preserving the metaphysical thesis that no individual who is, strictly speaking, identical with Eliot exists in any other possible world (cf. Kripke 1980, 45, note 13).)