PSYCHEDELIC DRUGS. Psychedelic substances, derived from plants—and more recently, from chemical syntheses—have been used by human beings for thousands of years, mainly as facilitators for religious ecstasy and firsthand contact with spirit or divinity. In this essay, the term mysticism is used interchangeably with spiritual experience to refer to any person's direct, subjective communion with a deity, spirit, or ultimate reality. Anthropologists often make a distinction between mysticism, which they see as an individual's firsthand, direct encounter with deities or spirits, and religious experiences that are mediated through a church, temple or some type of formal ecclesiastic structure. In discussing psychedelics and religion, Houston Smith reports that while psychedelics have been said to provoke religious experiences, they are not necessarily able to promote religious lives.

Overall, religious behavior universally makes efforts to induce an ecstatic spiritual state by crudely and directly manipulating physiological processes...