Three scientific titans join forces to completely revise the classic text on the ritual uses of psychoactive plants. They provide a fascinating testimony of these plants of the gods, tracing their uses throughout the world and their significance in shaping culture and history. In the traditions of every culture, plants have been highly valued for their nourishing, healing, and transformative properties. The most powerful of those plants, which are known to transport the human mind into other dimensions of consciousness, have always been regarded as sacred. The authors detail the uses of hallucinogens in sacred shamanic rites while providing lucid explanations of the biochemistry of these plants and the cultural prayers, songs, and dances associated with them. The text is lavishly illustrated with 400 rare photographs of plants, people, ceremonies, and art related to the ritual use of the world's sacred psychoactive flora.