The parallels between the human brain and computers are easy to see today. But in the 1950s, when John Lilly developed his theory of the human bio-computer, this was a dramatic new way of viewing humans. Rooted in his extensive knowledge of neurophysiology, neuroanatomy, and electronics, and developed through personal experimentation in the sensory isolation tank that he invented, Lilly's manual shows how to step out of the mind-body and find out who we really are.