ABSTRACT
Essentialism as applied to individuals is the claim that for at least some individuals there are properties that those individuals possess essentially. The fact that essentialism renders fairy tales and dreams of transmutation impossible is no objection, since the denial of an essential truth need not be incoherent. Biological species were, until Darwin, the paradigm of a natural kind. However, deeper understanding of species, especially in the light of evolution, has cast doubt, for many philosophers of biology, on the claim that species are natural kinds. Natural kind essentialism may be understood in a stronger form that implies strong realism about kinds; there are entities that are natural kinds having essential properties. Kripke’s diagnosis of the failure of candidate meanings to pass the test of necessity is not simply that a proper name has no meaning but also, more positively, that a proper name functions so as to designate the same individual in every possible world where that individual exists.
