Magic and Mysticism: An Introduction to Western Esoteric Traditions is an ambitious recasting of the gnostic insight that has inspired and influenced countless writers through the ages. Arthur Versluis, one of the generation's more prolific scholars of esotericism, has produced a volume that is both comprehensive in scope and exacting in detail. Moving beyond previous studies that separate mysticism and magic, Versluis argues that these two products of human imagination, which are not entirely reducible to rational analysis, need to be juxtaposed, as they help us define the larger spectrum of the esoteric. I have little doubt that this work will be of great interest to specialist and non-specialist alike, to historians of mysticism and esotericism in particular, and to students of comparative religion more generally.