The Rig Veda, written in India about 1500BC, praises a holy plant called Soma, which is sacrificed and consumed, granting the drinker an experience of enlightenment and ecstasy. The late Gordon Wasson identified Soma as a "magic mushroom," Amanita muscaria, and he and his followers discovered that such Indo-Europeans as the ancient Greeks, Iranians and Norse had also used a Soma-type plant. In Ploughing the Clouds Peter Lamborn Wilson investigates...