Abstract
Dispositional essentialists argue that physical properties have their causal roles essentially. This is typically taken to mean that physical properties are identical to dispositions. I argue that this is untenable, and that we must instead say that properties bestow dispositions. I explore what it is for a property to have such a role essentially. Dispositional essentialists argue for their view by citing certain epistemological and metaphysical implications, and I appeal to these implications to place desiderata on the concept of essence involved. I argue that the traditional modal theory of essence meets these desiderata, but that the resulting theory wrongly implies that certain dispositions essential to mass are essential to charge, thereby offering a new argument against modal theories of essence. I argue that dispositional essentialism requires a primitive notion of essence, and develop a primitivist theory based on Kit Fine's views. I show that the primitivist theory has all the virtues of the modal alternative, and none of the vices. I develop a novel way of thinking about the relationship between properties, laws and dispositions, and argue that it has distinct advantages over standard dispositional essentialist formulations.