Propositions: Individuation and Invirtuation Forthcoming in Australasian Journal of Philosophy

The pressure to individuate propositions more finely than intensionally – that is hyperintensionally – has two distinct sources. One source is the philosophy of mind: one can believe a proposition without believing an intensionally equivalent proposition. The second source is metaphysics: there are intensionally equivalent propositions such that one proposition is true in virtue of the other but not vice-versa. I focus on what our theory of propositions should look like when it’s guided by metaphysical concerns about what is true in virtue of what. In this paper I articulate and defend a metaphysical theory of the individuation of propositions, according to which two propositions are identical just in case they occupy the same nodes in a network of invirtuation relations. Invirtuation is here taken to be a primitive relation of metaphysical explanation exemplified by propositions that, in conjunction with truth, defines the notion of true in virtue of. After formulating the theory, I compare it with a view that individuates propositions by cognitive equivalence, and then defend the theory from objections.