In Ploughing the Clouds, Peter Lamborn Wilson suggests that the ancient Celts of Ireland may have possessed a "Soma" ceremony similar to one described in the Rig Veda, one of the oldest scriptures in the world. Written in India in 1500 BC, the Rig Veda praises a holy plant called Soma or "magic mushroom" that grants the drinker enlightenment and ecstasy. By comparing Celtic myth and folklore with the Rig Veda, he uncovers an Irish branch of the great Indo-European tradition of psychedelic (or "entheogenic") shamanism, and even reconstructs some of its secret rituals. He uses this comparative material to illuminate the deep meaning of the Soma-function in all cultures: the entheogenic origin of "poetic frenzy," the link between intoxication and inspiration. Peter Lamborn Wilson is a scholar, critic, poet, and visionary best known for Sacred Drift: Essays on the Margins of Islam (City Lights) and his radio commentaries on WBAI New York.