This volume deals with the ancient and medieval 'pre-history' of an enigmatic term which is used in a variety of contexts: 'Wahnsinn' (insanity/craziness/folly), or particularly the respective adjective 'wahnsinnig' (insane/crazy/foolish) which is used almost ubiquitously, both have a variety of meanings. This variety ranges from labelling mental illnesses or behaviour which is incomprehensible, unreliable or dangerous, to positive attributes (»wahnsinnig gut« i.e. »extremely great«). In order for the humanities or cultural studies to examine 'Wahnsinn', Michel Foucault's pioneering study Folie et déraison. Histoire de la folie à l'âge classique (1961) constitutes a central starting point. What is primarily important here, is Foucault's explicit classification of the 'normal' and the 'other'. However, Foucault pays little attention to how 'Wahnsinn' is attributed to persons and does not consider the role played by literature and science or by the arts. Furthermore, due to its various forms of appearance, 'Wahnsinn' has to be regarded in binary relation to reason. After all, different discourses on 'Wahnsinn' have been shaping the culture of the Occident since way before the Enlightenment. This is shown in a decidedly interdisciplinary access offered by the essays in this volume, which is based on the platonic term mania. The term's advantage is that it does not have a sole negative connotation; thus, it includes other forms of 'being beside oneself' (ekstasis), for example divine inspiration, apart from abnormal mental disorders. In case studies, the contributions in this volume examine how texts from the Christian Ancient World and the Middle Ages stage abnormal behavior which can be traced back to perception disorder or mental disorientation, or how this behavior is attributed to certain persons. Thus, the prime focus of this examination tackles the question how 'Wahnsinn' is instrumentalised, and also analyses the role which is played by the socio-cultural backgrounds as well as the philosophical and theological context, and the context of medical history. The spectrum ranges from approaches which have been ignoring medical implications, to those which are being mixed with divine or demonological explanatory attempts by medical-dietary knowledge. It also focuses on those approaches which completely do without a demonological explanation for 'Wahnsinn' or ekstasis, and simply focus on outside impulses and physical factors in order to diagnose or treat different forms of 'Wahnsinn'.