Aristotle uses the concept of catharsis at various points in his writings–in his works on reproduction, on zoology, on physics, and on politics. In his Poetics, the concept is deployed metaphorically in order to determine the purpose of tragedy. Which models of catharsis was Aristotle acquainted with, and what was the relationship between them? Proceeding from a detailed foreword, the specialist papers provide an overview of the use of the term in the different areas of biology, medicine, ritual, cult, music theory, psychology and philosophy. Working on a broad collaborative interdisciplinary basis, the authors determine the specific functions of the various conceptions of catharsis and thus clarify the foundations for the concept in poetology.