The road to Eleusis: Unveiling the secret of the mysteries.

Argues that the psycho-active ingredient in the secret kykeion potion used in the Eleusinian mysteries was most likely the ergotism causing fungus Claviceps purpurea. Furthermore the book introduced the term "entheogen" as an alternative for terms such as "psychedelic", "hallucinogen" and "drug" that can be misleading in certain contexts.