Individualism,causal powers,and explanation

Versions of this paper were presented at the 17th Annual Meeting of the Society for Philosophy and Psychology in June 1991, at Cornell University in October 1991, and at Queen's University in January 1992; I thank Terence Horgan and Carl Ginet, respectively, for their comments on the first two of these occasions. I would also like to thank Terence Irwin, Sydney Shoemaker, Bob Stalnaker, Ed Stein, and J. D. Trout for comments on earlier versions of the paper, and Joe Moore, Dave Robb and Sergio Sismondo for useful discussion.