The Kykeon and the Ergot Hypothesis
Two of the theory's three authors, Carl Ruck and R. Gordon Wasson, were among the group of scholars who coined the word 'entheogen' the following year, giving the modern psychedelic-spirituality field its central vocabulary. The ergot theory remains chemically plausible but is not directly confirmed by any surviving ancient text.
R. Gordon Wasson, Albert Hofmann & Carl Ruck, The Road to Eleusis (1978); Ruck, Bigwood, Staples, Ott & Wasson, 'Entheogens', Journal of Psychedelic Drugs 11 (1979)
The theory that the sacred drink at the heart of the ancient Eleusinian Mysteries was a psychoactive preparation made from a grain fungus.