In 1964, psychologists Timothy Leary, Ralph Metzner, and Richard Alpert published The Psychedelic Experience, a manual intended to prepare the users of psychedelic drugs for sessions. The authors had researched the therapeutic aspects of psychedelic substances, as well as their religious possibilities. The book is heavily influenced by the Tibetan Book of the Dead, (also known as Bardo Thodol) a funerary...