This book uses Zen Buddhism as the opening wedge for an extraordinarily wide-ranging exploration of consciousness. In order to understand the brain mechanisms that produce Zen states, one needs some understanding of the anatomy, physiology, and chemistry of the brain. Austin, a neuroscientist and Zen practitioner, interweaves his teachings of the brain with his teachings/personal narrative of Zen. The science, which contains the latest relevant developments in brain research, is both inclsive and rigorous; the Zen sections are clear and evocative. Along the way, Austin covers such topics as similar states in other disciplines and religions, sleep and dreams, mental illness, consciousness-altering drugs, and the social consequences of advanced stages of enlightenment.