The article sets out a framework for analysing the way discourses construct legitimation for social practices in public communication as well as in everyday interaction. Four key categories of legitimation are distinguished: 1) ‘authorization’, legitimation by reference to the authority of tradition, custom and law, and of persons in whom institutional authority is vested; 2) ‘moral evaluation’, legitimation by reference to discourses of value; 3) rationalization, legitimation by reference to the goals and uses of institutionalized social action, and to the (...) social knowledges that endow them with cognitive validity; and 4) mythopoesis, legitimation conveyed through narratives whose outcomes reward legitimate actions and punish non-legitimate actions. Examples are drawn from texts legitimating or de-legitimating compulsory education, including children’s books, brochures for parents, teacher training texts, and media texts. (shrink)