What's So Different about a Counterfactual?

The author contends that the difference between so-called factual and counterfactual arguments is greatly exaggerated; it is one of degree, not of kind. Both arguments ultimately rest on the quality of their assumptions, the chain of logic linking causes to outcomes, and their consistency with available evidence. He critiques two recent historical works that make extensive use of counterfactuals and finds them seriously deficient in method and argument. He then reviews the criteria for counterfactual experimentation proposed by social scientists who have addressed this problem and finds many of their criteria unrealistic and overly restrictive. The methods of counterfactual experimentation need to be commensurate with the purposes for which it is used. The author discusses three uses for counterfactual arguments and thought experiments and proposes eight criteria appropriate to plausible-world counterfactuals.