But as our understanding has advanced in the last few decades, we have discovered that the brain is not a passive receiver, but an ever-active predictor. Among the most stunning of these is the realization that experience itself, because it is guided by prior expectation, is a kind of controlled hallucination. We don't passively take in the world around us; instead our mind is constantly making and refining predictions about what we expect to see. This even applies to our bodies, as the way we experience pain and other states is shaped by our expectations, and this has broader implications for the understanding and treatment of conditions from PTSD to schizophrenia to medically unexplained symptoms. From the most mundane experiences to the most sublime, it is our predictions that sculpt our experience. A landmark study of cognitive science, this lays out the extraordinary explanatory power of the predictive brain for our lives, mental health and society.