The controversy between action and system-theoretical approaches marks one of the central dividing lines in the discussion of sociological theory, which also includes the level of methods. Habermas has articulated this dividing line in a widely recognized formula: action theories primarily rely on hermeneutic understanding of meaning, while system-theoretical approaches focus solely on functional analysis; bound to the perspective of the functionalist observer, system theory cannot find an adequate approach to the problem of intersubjectivity. The third volume of the successful textbook "Foundations of Sociological Theory" aims to revise this assessment and its underlying assumptions.