7Once we came out of the jungle and found time to think of something besides food, sex, and shelter, we confronted the fundamental questions: what are we? Who are we? Is a person a body, a soul? How do we access the external world if we are nothing but brains encased in bodies?

As neuroscientists map the most detailed aspects of the human brain and its interplay with the rest of the body, they remain baffled by what is essentially human: our selves. In most of the existing scientific literature, information processing has taken the place of the soul. Yet thus far, no convincing account has been presented of exactly where and how consciousness is stored in our bodies.

In The Spread Mind, Riccardo Manzotti convincingly argues that our bodies do not contain subjective experience. Yet consciousness is real, and, like any other real phenomenon, is physical. Where is it, then? Manzotti's radical hypothesis is that consciousness is one and the same as the physical world surrounding us.

Drawing on Einstein's theories of relativity, evidence about dreams and hallucination, and the geometry of light in perception, and using vivid, real-world examples to illustrate his ideas, Manzotti argues that consciousness is not a ''movie in the head.'' Experience is not in our head: it is the actual world we move in.