Defining Rules, Proofs and Counterexamples

Abstract: In this talk, I will present an account of defining rules, with the aim of explaining these rules they play a central role in analytic proofs. Along the way, I’ll explain how Kreisel’s squeezing argument helps us understand the connection between an informal notion of validity and the notions formalised in our accounts of proofs and models, and the relationship between proof-theoretic and model- theoretic analyses of logical consequence.

• This is a talk for the VII Workshop on Philosophical Logic.

• The slides for the talk are available here, and the handout is here.