Occult knowledge and practice can be divided into three main branches: Astrology, which aims to guide human fortune by means of foreknowledge; Alchemy, which tries to secure power through the agency of the philosopher's stone; and Ritual Magic, which seen to control the spirit world. In this classic book (first published in 1949), Butler explores ritual magic ming a wide range of texts from the pre-Christian rites of the Akkadians and Chaldeans to the Solomonic Clavicles of medieval Europe. Throughout, there is extensive quotation from the documents themselves, providing the reader with an authentic sense of the richness and power of these texts.