In this foundational theoretical work, the contours of a contemporary, interdisciplinary and action-theoretically oriented cultural psychology are unfolded. The monograph is one of the rare attempts to provide a detailed theoretical and methodological foundation for today's internationally established cultural psychology. Similar to Ernst Boesch's or Jerome Bruner's approach, the conception of cultural psychological thinking presented here is also based on action theory. In empirical research, it focuses on the methodologically controlled, interpretative analysis of texts. It thus joins the broad stream of hermeneutic, qualitative approaches to subject and social research that have been developed in psychology and sociology following the interpretative and cultural turn. In addition to the typologically differentiated, action- and interpretation-theoretical considerations, some systematic reflections on the normative foundations of cultural psychology are particularly important. There are good reasons for entrusting a social and cultural science-based, interpretative psychology not least with the task of criticising forms of action, life and self. The fact that science is committed to reason means more than methodological rationality. Its practice should also contribute to the establishment and cultivation of rational forms of life - even if this is only possible in a dialogue in which the dispute about the best arguments for a fulfilling, thriving life is indispensable.