Widely acclaimed philosopher and cognitive scientist Andy Clark unpacks this provocative new theory that the brain is a powerful, dynamic prediction engine, mediating our experience of both body and world. From the most mundane experiences to the most sublime, reality as we know it is the complex synthesis of sensory information and expectation. Exploring its fascinating mechanics and remarkable implications for our lives, mental health, and society, Clark nimbly illustrates how the predictive brain sculpts all human experience. Chronic pain and mental illness are shown to involve subtle malfunctions of our unconscious predictions, pointing the way towards more effective, targeted treatments. Under renewed scrutiny, the very boundary between ourselves and the outside world dissolves, showing that we are as entangled with our environments as we are with our onboard memories, thoughts, and feelings. And perception itself is revealed to be something of a controlled hallucination.