A Semantics for Counterfactuals Based on Fuzzy Logic

Lewis–Stalnaker’s semantics for counterfactuals is based on the notion of similarity of possible worlds. Since the general notion of similarity is prominently studied in fuzzy mathematics, where it is modeled by fuzzy equivalence relations, it is natural to attempt at reconstructing Lewis’ and Stalnaker’s ideas in terms of fuzzy similarities. This paper sketches such a reconstruction; full details will be presented in an upcoming paper. We demonstrate that the approach is viable, adequate with respect to the expected properties of counterfactuals, and provides meaningful generalizations of the classical account.