Charles Travis presents a series of essays in which he has developed his distinctive view of the relation of thought to language. The key idea is 'occasion-sensitivity': what it is for words to express a given concept is for them to be apt for contributing to any of many different conditions of correctness (notably truth conditions). Since words mean what they do by expressing a given concept, it follows that meaning does not determine truth conditions. This view ties thoughts less tightly to the linguistic forms which express them than traditional views of the matter, and in two directions: a given linguistic form, meaning fixed, may express an indefinite variety of thoughts; one thought can be expressed in an indefinite number of syntactically and semantically distinct ways. Travis highlights the importance of this view for linguistic theory, and shows how it gives new form to a variety of traditional philosophical problems.