Abstract

Consider a language incorporating a mirror-image form of assertion, where the norm is to express what you take to be false rather than what you take to be true. Why aren’t ordinary languages like that? Why do we generally assert what we take to be true rather than what we take to be false? If Lewis and Massey are right, there is a sense in which the question is based on a mistake, and in which English could be described either way. I explore that idea, which centers on the role of duality in language. One of the main questions in the air is whether the symmetry of duality can be used as a guide to ‘real structure’ in semantics and pragmatics. I try to think through it with an analogy to relationism about space.