The term ''mysticism'' has never been consistently defined or employed, either in religious traditions or in academic discourse. The essays in this volume offer ways of defining what mysticism is, as well as methods for grappling with its complexity in a classroom. Parsons has succeeded to bring together some of the most important established authorities on mystical traditions, together with emerging authorities, and cover an impressively varied and broad range of subfields within the study of mysticism, esotericism, and Gnosticism.