What started as a two-part essay in the "New York Review of Books", this work discusses well-known thinkers, such as Francis Crick, Gerald Edelman, Roger Penrose, Daniel Dennett, Israel Rosenfeld and David Chalmers. The question of just how the brain works, and the mystery of human consciousness, are the most important issues in philosophy and science today. They affect every corner of human existence, from artificial intelligence to promises of an afterlife. Most people are attached to some degree to the idea that human consciousness consists of something over and above, something altogether more mysterious and probably more precious than ordinary physical functions. John R. Searle rejects any such dualism between the innner sentient awareness and the biological functioning of the brain. He maintains instead that conscious states are no more or less than features of the brain caused by neurological processes. This means that consciousness should be studied as if it were any other physical phenomenon in people's bodies - in the same way as digestion or growth is examined. The book challenges the claims of Dennett and others that features of the brain can be represented and reproduced by computer programs, and opposes the advocates of artificial intelligence who believe that consciousness can be reduced to algorithmic procedures. It describes how far the neurosciences have come in relation to solving the problem of consciousness, and suggests avenues of further research which should lead to a biographical explanation of how conscious states arise from the activities of neurons. John R. Searle is the author of "The Rediscover of the Mind" and "The Construction of Social Reality".