Full Idea
Without the explanatory role of essence, the underlying epistemic picture would be jeopardised, because there would no longer be any causal route by which we might get from accidents to essence.
Gist of Idea
Essences must explain, so we can infer them causally from the accidents
Source
Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 27.5)
Book Reference
Pasnau,Robert: 'Metaphysical Themes 1274-1671' [OUP 2011], p.648
A Reaction
There is a slight whiff of circularity here. It could be that we are psychologically desperate for essences, and so we invent bogus causal routes from the accidents to get at them. Can we know there are essences awaiting us, on independent grounds?