In the summer of 2000 I held a seminar on the myth–ritual theory at Heidelberg University where I used Robert Segal's excellent reader The Myth–Ritual Theory. Later that year I gave a seminar on critical terms in the study of religions. Bernd-Christian Otto attended both classes. Now, twelve years later, these two courses have jointly come full circle: as we argue in the Introduction, “magic” is a key critical term in the study of religions and when discussing the shape of the present volume, Robert Segal's reader was an inspiration (even if not serving as a template). In the years following these classes, when I had moved to Norway and Bernd to Spain, we occasionally remained in touch. In 2009, following the defence of his massive doctoral thesis (a revised version is now published by de Gruyter), where I was one of the examiners, we started to discuss a future collaboration that would fuse Bernd's expertise on the conceptual history of magic with my interests in theories (of ritual and religion) and in the history of the study of religions. The Equinox Critical Categories in the Study of Religion seemed like the right venue and we wish to thank Janet Joyce for her enthusiasm for this project. In 2011, sponsored by a Yggdrasil Mobility Grant awarded by the Norwegian Research Council, Bernd spent six months at my department at the University of Bergen.