Philosophers often exploit context-sensitivity of theoretically interesting expressions like “know”, “good”, “truth”, “necessary”, “ought”, or vague expression to support theories about knowledge, goodness, truth, modality, obligation, vagueness. They also appeal to context in explaining various social practices. The details of such arguments rely on particular assumptions about what context is, and how it interacts with meaning. In this course, we will examine these assumptions by drawing on research in philosophy, linguistics and cognitive science, questioning how such research informs or constrains philosophers’ exploitation of context.