Chapter 3 examines the core creative practice at the heart of the institution and tradition of the Theater an der Ruhr and most public theatres in Germany: the rehearsal. Rehearsals are not merely the most significant spaces for the training of the body and elaboration of a play. They are also practices for the cultivation of a particular form of comportment described by actors and directors as Haltung. The rehearsing of Haltung, which is discussed as an example of an ethnographic concept, that is, one stemming from the theorising of my interlocutors, constitutes the fundamental ethical practice and internal good facilitated by the institutional tradition of the Theater an der Ruhr. This chapter examines the broader significance of studying the learning of conduct during rehearsals and makes a case for their study as foundational to an understanding of creativity and self-formation in theatre. It also investigates issues of authority and discipline, thinking about rehearsals as a form of social practice rather than an artistic means to create a staging.