Discusses the extensionality and determination problems for truth-theoretic semantics. The extensionality problem is how to impose a constraint on a truth theory that guarantees that it meets Tarski’s Convention T. The determination problem is the problem of specifying for a theory that meets Tarski’s Convention T which theorems can be used to interpret the sentences of the object language. Argues that nothing the theory states can solve the extensionality problem, but that one can state a condition on the theory that will solve the problem, and that the determination problem can be solved by specifying a canonical proof procedure for the theory.
Keywords: canonical proof, intensional contexts, determination problem, extensionality problem