A new revised edition of the classic study takes a fresh look at human consciousness and an exciting new view of the untapped potential of the human mind What is consciousness and why do we need to know? In this new fourth edition of his revolutionary study, Robert Ornstein reexamines what is known about consciousness and why this understanding is so important at this time of enormous challenge, change and potential. He begins with an exploration of how the human brain evolved as a complex system for limiting what we "pick up" from the vast external environment to just the information we need to survive. We fill in the gaps with "unconscious inferences" - assumptions, categorizations, expectations and habituations that allow us to operate in the world, but that limit our perception of what is, and what is possible. Going beyond the theory that creative impulses originate in the right side of the brain and rational impulses in the left, he shows how a synthesis of these two functions can bring about "a more complete science of human consciousness with an extended conception of our own capabilities." Ornstein proposes that education at all levels should now include learning and teaching about our human nature - the nature of the person being taught. Offering far more than scholarly discourse, he enriches his presentation with thought-provoking illustrations and traditional teachings stories that bring the science to life, giving readers a first-hand taste of what such education might be like. Only with the development of self-knowledge and the cultivation of a comprehensive, expanded consciousness, he says, will humanity be able to perceive and take the "selfless" steps necessary to solve our collective problems. This new edition comes at a time when on a global scale we need this type of thinking more than ever.