This course will introduce and investigate dynamic semantics. Very roughly, this is an approach to semantics on which meanings are identified with incremental changes to a body of information. This is meant to contrast with, or perhaps generalize, 'static' approaches on which meanings are supplied by referents, concepts, or truth-conditions. A special focus of the course will be on foundational questions about dynamic theories. What makes a theory dynamic, and not static? What kind of evidence could there be for a distinctively dynamic (or static) theory? Though these foundational questions will be our focus, we will keep them grounded through a number of case studies drawn from anaphora, presupposition projection, and epistemic modality.