This fascinating book explores the evolution of religious dualism, the doctrine that man and cosmos are constant battlegrounds between forces of good and evil. It traces this evolution from late Egyptian religion and the revelations of Zoroaster and the Orphics in antiquity through the Dead Sea Scrolls, the Mithraic Mysteries, and the great Gnostic teachers to its revival in medieval Europe with the suppression of the Bogomils and the Cathars, heirs to the age-long teachings of dualism. Integrating political, cultural, and religious history, Yuri Stoyanov illuminates the dualist religious systems, recreating in vivid detail the diverse worlds of their striking ideas and beliefs, their convoluted mythologies and symbolism.