Walter Stephens has added an important contribution, not just to witchcraft studies, but to late-medieval and early-modern studies as a whole. He opens with an account of demonic copulation from a witch trial in 1587 but then focuses almost exclusively on treatises and the "witchcraft theorists" who authored them. In his careful and wide-ranging reading of those sources, he follows the work of Stuart Clark (Thinking with Demons [Oxford, 1997]). But unlike Clark, who draws a firm line around 1500 and works to situate demonological literature amidst the larger intellectual currents of the early modern period, Stephens includes earlier treatises from the fifteenth century in his study. Moreover, he sets this literature in the context of intellectual developments stemming from the twelfth and thirteenth centuries and at the center of a general crisis of belief that he sees developing within later medieval Christianity.