Categoricity and Negation. A Note on Kripke’s Affirmativism

The idea that an adequate language for science needs a negation operator was recently dismissed by Kripke as "yet another dogma of empiricism”. That a scientist could, and even should, drop negation implies at least three points: 1. negativist theories, i.e., theories formulated in languages that include negation, are conservative extensions of their affirmativist versions; 2. negativist theories have no serious advantages over their affirmativist versions; 3. negativist theories are dispensable and should better be replaced by their affirmativist versions. We argue that all three points are problematic.