Full Idea
Essences are supposed to do a lot of explanatory work: natural kinds can be identified in terms of their essences, metaphysical modality can be reduced to essence, the causal power of objects can be explained with the help of essence.
Gist of Idea
Essences are used to explain natural kinds, modality, and causal powers
Source
Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 1)
A Reaction
Natural kinds and modality are OK with me, but I'm dubious about the third one. If an essence explains something's causal powers, I have no idea what an essence might be. Essence are largely characterised in terms of causal powers.