The paper describes the role of teachers as mediators of the social studies curriculum. The first section summarizes the literature on teacher cognition and describes the hermeneutic, or methodological, turn in that literature. The second section describes teachers as curriculum agents--that is, as professionals who bring intellectual and moral agency to their work with children, social studies, and schooling. This description is largely historical, emphasizing the rise of the technical idea of practice against which the notion of teacher-as-agent is clearly brought to light. The third section provides three examples of inquiry on teachers' mediation. These include ethnography, phenomenology, and critical analysis. An extensive reference section is included. (TRS)