The source records for "Plants, Stars, and the Origins of Religion" cover the origins of religion in the Middle East and Europe from prehistoric times to the fall of the Roman Empire. One of these records was the Phaistos Disk from Crete, which may have been intended to serve as a solar calendar, and a decipherment of the Phaistos Disk is included within this book. Author Mary Kilbourne Matossian has given particular attention to evidence for the possible role of psychoactive plants by people in prehistoric and ancient times. At the same time, "Plants, Stars, and the Origins of Religion" explores some prehistoric and ancient beliefs about stars.