The secretive Mysteries conducted at Eleusis in Greece for nearly two millennia have long puzzled scholars with strange accounts of initiates experiencing otherworldly journeys. In this groundbreaking work, three experts a mycologist, a chemist, and a historian argue persuasively that the sacred potion given to participants in the course of the ritual contained a psychoactive entheogen. The authors then expand the discussion to show that natural psychedelic agents have been used in spiritual rituals across history and cultures. Although controversial when first published in 1978, the book s...