A Counterfactual Theory of Causal Explanation

Abstract

We commonly explain certain occurrences in the natural world, on the basis of a shared stock of information available to the non-specialised layman as well as to the natural scientist. That shared stock of information is our folk physics. The snow melted because spring had finally come; the car was wrecked because it was hit by a bus; the match lit because it was struck. Such explanations are, or appear to be, causal explanations. Many of our other folk explanations may be noncausal explanations, but I consider only the former sort. I assume, following Davidson, that laws are strict, i.e., exceptionless. If it is a deterministic law that Fs are Gs, then every F without exception must be a G. If it is a stochastic law that Pr(G, F)=p, where O<p<1, then, for any finite sample, s, it may well be that the proportion of Fs in s which are Gs may not be exactly p. However, as one examines Fs indefinitely, the proportion which are found to be Gs will tend to p, and in the limit, the proportion of Fs which are Gs will be