Institutions usually do not come into view when it comes to processes of knowledge change. Rather, it is a widely shared belief that change happens when and only outside of these creativity blockers. Now, however, even where it is supposedly rigidly and stubbornly adhering to the traditional, change is always noticeable. Obviously, practices that are poled up for repetition and thus stabilize institutional relationships also bring about change. This interplay of repetition and change is summarized in this anthology with the term 'iteration'. Using a wide range of historical case studies, the authors show which variants of the interplay of repetition and change can be observed and which findings result for a transdisciplinary history of knowledge. The volume opens the series "Episteme in motion. Contributions to a Transdisciplinary History of Knowledge ", in which the results of the cooperation in the Collaborative Research Center 980, located at the Freie Universität Berlin, are presented.