In this fascinating new work, neuroscientist Anil Seth explores the answer to an age-old question: what creates consciousness, your awareness of yourself and the world around you? Delving into a host of competing theories, Seth ultimately argues that “[w]e perceive the world not as it is, but as it is useful to us”—that we actually live in a “controlled hallucination” that results from our brain’s best guesses of what is happening, rather than an objective reality.