The Psychedelic Experience: A Manual Based on the Tibetan Book of the Dead (Penguin Modern Classics)

Timothy Leary was one of the most famous countercultural icons of the 1960s. Labelled as the 'Most Dangerous Man in America', Leary had many run-ins with the law and served several prison sentences. He dies in 1996; the following year seven grams of his ashes were launched into space aboard a Pegasus rocket.

Ralph Metzner is a professor of psychology at the California Institute for Integral Studies and president of the Green earth Foundation.

RICHARD ALPERT is a former professor who conducted controversial LSD experiments with Leary at Harvard. He is considered one of the most important spiritual teachers of the 20th century.