ABSTRACT
In this chapter, the highlights of the history of the ritual use of psychedelic substances are reviewed and the most common ones are briefly sketched as a preparation for subsequent discussion of the neurochemical correlates of mystical states. Specifically, the use of psychedelics among the ancient Hindus, mentioned extensively in the Vedas; among the members of the Native American Church and among the ancient Greeks, in their annual celebration of the Mysteries of Eleusis is described as well as the phenomenology of the experiences and their meaning to the mystics of these cultures. Moreover, the recent history and the current research in the long-term therapeutic effects of some psychedelics, especially psilocybin, is surveyed, rendering clear to the reader the fundamental similarity of the drug-facilitated mystical states and their effects, to those attained through meditation and other psychophysiological techniques.
