In defense of the possibilism–actualism distinction

Abstract

In Modal Logic as Metaphysics, Timothy Williamson claims that the possibilism–actualism (P–A) distinction is badly muddled. In its place, he introduces a necessitism–contingentism (N–C) distinction that he claims is free of the confusions that purportedly plague the P–A distinction. In this paper I argue first that the P–A distinction, properly understood, is entirely coherent and historically well-grounded. I then look at the two arguments Williamson levels at the P–A distinction and find them wanting and show, moreover, that, when the N–C distinction is broadened (as per Williamson himself) so as to enable necessitists to fend off contingentist objections, the P–A distinction can be faithfully reconstructed in terms of the N–C distinction. However, Williamson’s critique does point to a genuine shortcoming in the common formulation of the P–A distinction. I propose a new definition of the distinction in terms of essential properties that avoids this shortcoming.