Is consciousness nothing more than the result of neurons firing through brain tissue? Or is it, as some claim, a fundamental reality like space, time and matter? In recent years the nature of consciousness - our immediately known experiences - has taken its place as the most profound problem in the scientific discourse. Now in this new book, Colin McGinn takes a provocative position on this perplexing problem. Arguing that we can never truly "know" consciousness - that the human intellect is simply not equipped to unravel this mystery - he demonstrates that accepting this limitation in fact opens up a whole new field of investigation. Indeed, he asserts, consciousness is the best place from which to begin to understand the internal make-up of human intelligence, to investigate our cognitive strengths and weaknesses, and to explore the possibility of machine minds.