This book concerns your nature as a human being. It is about the connection of your mind to your body. You may imagine that your mind – your stream of conscious thoughts,ideas,andfeelings–in?uencesyouractions.Youmaybelieve that what you think a?ects what you do. You could be right. However, the scienti?c ideas that prevailed from the time of Isaac Newton to the beginningofthetwentiethcenturyproclaimedyourphysicalactionsto becompletelydeterminedbyprocessesthataredescribableinphysical terms alone. Any notion that your conscious choices make a di?erence in how you behave was branded an illusion: you were asserted to be causally equivalent to a mindless automaton. We now know that that earlier form of science is fundamentally incorrect. During the ?rst part of the twentieth century, that classic- physics-based conception of nature was replaced by a new theory that reproduces all of the successful predictions of its predecessor, while providing also valid predictions about a host of phenomena that are strictly incompatible with the precepts of eighteenth and nineteenth century physics. No prediction of the new theory has been shown to be false.