Kinds, Essence, and Natural Necessity

Abstract

It is commonly assumed that there is a kind of necessity, natural or physical necessity, that is in some sense “weaker” than logical necessity and is somehow related to natural laws, or, more specifically, to causal laws — whence this supposed kind of necessity is often also called ‘nomic’ or ‘causal’ necessity. Of course, many empiricist philosophers have followed David Hume in being sceptical either about the existence or, less radically, at least about our epistemic access to any such species of necessity.1 But in recent years the foregoing concept of natural necessity has come under attack from another quarter, namely, from certain philosophers — some of whom describe themselves as ‘scientific essentialists’ — who hold that natural laws are in fact necessary in the strongest possible sense: that is, who hold that the necessity of such laws is no weaker than, and just as “absolute” as, the necessity of logical truths.2