This book challenges existing theories of conscious mental processes and proposes a new physicalist but not reductionist conception of consciousness  What is consciousness? How the physical processes in the brain can lead to the activity of a conscious mind? These questions raise the most heated debates in philosophy and current science. The philosopher David J. Chalmers offers here a concise analysis of this debate and outlines a new theory of consciousness that rejects reductionism, which is still compatible with the physicalist concepts, but goes beyond them.  In a rigorous and stimulating style, the author takes us on a powerful journey through the branches of philosophical conceptions of consciousness. Unlike the contemporary cognitive science and neuroscience, Chalmers proposes to understand the conscious experience as an irreducible entity-like physical properties of time, mass and space, which would be in very deep levels that can not be understood as the sum of simpler hardware.  In the second half of the book, the author builds a fundamental theory about the basic laws governing the structure and character of conscious experiences, showing how this reconceptualization of mind could lead to a new science of consciousness.  Throughout the book, Chalmers provides fascinating thought experiments, suggesting, for example, what if a brain gradually replace neurons by silicon chips. To the extent that replace neurons, Did it gradually disappear consciousness?  Throughout the text also find suggestions for how the author's ideas could be applied to issues related to artificial intelligence or interpretation of quantum mechanics