Can Metaphysical Modality Be Based on Essence?

In his hugely influential paper “Essence and Modality” (1994), Kit Fine argued that the then orthodox view that essence can be understood in terms of metaphysical modality is fundamentally flawed. He proposed, in its place, the view that all metaphysical modality has its source in the essences or natures of things, where the notion of a thing’s essence or nature can be understood in terms of a broadly Aristotelian notion of real definition. This theory appears to require that the relevant conception of real definition can itself be isolated without appeal to metaphysical modality. I argue that this requirement cannot be met. I then briefly consider the implications of my argument for the relation between essence and metaphysical modality.