The Causal Theory of Properties and the Causal Theory of Reference , or How to Name Properties and Why It Matters ∗

The Causal Theory of Properties (CTP) (Shoemaker, 1980a, 1980b, 1998) presents a striking picture: although a property might ultimately be distinct from the causal powers it confers on its instantiations (Shoemaker, 1998, p. 64), those causal powers limn the property’s identity. In the words of CTP’s leading proponent, Sydney Shoemaker, “The formulation of the causal theory of properties I now favor...says that the causal features of a property, both forward-looking and backward-looking, are essential to it. And it says that properties having the same causal features are identical” (1998, p. 64). Thus, as Shoemaker presents it, CTP is the conjunction of two metaphysical theses: an essentialist thesis and an individuation thesis. The former asserts that whatever causal relations a property enters into are essential to that property: if a property enters into a given causal relation in any possible world, the property enters into that causal relation in every possible world in which the property exists. The latter asserts that for any properties P and Q, P is identical to Q if and only if P and Q enter into all of the same causal relations.