  We are attuned in everyday conversation not primarily to the sentences we utter to one another, but to the speech acts that those utterances are used to perform: requests, warnings, invitations, promises, apologies, predictions, and the like. Such acts are staples of communicative life, but only became a topic of sustained investigation, at least in the English-speaking world, in the middle of the twentieth  century.[1]  Since that time “speech act theory” has become influential not only within philosophy, but also in linguistics, psychology, legal theory, artificial intelligence, literary theory, and feminist thought among other scholarly   disciplines.[2]  Recognition of the significance of speech acts has illuminated the ability of language to do other things than describe reality. In the process the boundaries among the philosophy of language, the philosophy of action, aesthetics, the philosophy of mind, political philosophy, and ethics have become less sharp. In addition, an appreciation of speech acts has helped lay bare a normative structure implicit in linguistic practice, including even that part of this practice concerned with describing reality. Much recent research aims at an accurate characterization of this normative structure underlying linguistic practice.