Abstract

Lewis' argument against the Limit Assumption and Pollock's Generalized Consequence Principle together suggest that "minimal-change" theories of counterfactuals are wrong. The "small-change" theories presented by Nute do not say enough. While these theories rely on closeness between possible worlds, I base an alternative on the ceteris paribus concept. My theory solves a problem that the above cannot, and is more relevant to the philosophy of science. Ceteris paribus conditions should normally include the causes, but exclude the effects, of the negated antecedent. An example from community ecology, the debate over null models in island-biogeographical studies of competition, supports these arguments