»The Participatory State. Participation in Public, Administrative and Procedural Law«: More than fifty years have passed since the participation debate began, yet there is no overarching constitutional theory of participation that encompasses all three branches of government. Dominik Steiger fills this lacuna with his »theory of imperative participation« that is based on the separation of powers doctrine and shows how participation by the people and individuals must be conceptualised to enhance the legitimacy of public authority.