In this book Zen Buddhism becomes the opening wedge for an extraordinarily wide-ranging exploration of consciousness. In order to understand which brain mechanisms produce Zen states, one needs some understanding of the anatomy, physiology, and chemistry of the brain. Austin, both a neurologist and a Zen practitioner, interweaves the most recent brain research with the personal narrative of his Zen experiences. The science is both inclusive and rigorous; the Zen sections are clear and evocative.

Along the way, Austin examines such topics as similar states in other disciplines and religions, sleep and dreams, mental illness, consciousness-altering drugs, and the social consequences of the advanced stage of ongoing enlightenment.