Counterfactual Historical Reasoning

Counterfactual historical reasoning is the disciplined practice of asking what would have happened had some past condition been different, in order to assess whether that condition truly mattered. Every causal claim in history, that a railway, a war, an institution, or an idea made a difference, implicitly compares the actual world to a counterfactual one in which the supposed cause is absent. Counterfactual reasoning makes that comparison explicit and subjects it to rules: alter the antecedent minimally, keep the rest of the world as it plausibly would have been, and reason carefully toward the likely consequent. In its rigorous cliometric form, exemplified by Fogel's railroads study, the consequent is quantified as a social saving. But the general method is broader and conceptual, governed by criteria of minimal rewrite, plausibility, and explicit antecedent-consequent structure, and it underwrites causal inference throughout history, not only in its quantitative, economic variant.