Hallucinations, by no means, are insane. They are more commonly associated with sensory deprivation, intoxication, or as a result of illness or injury. Hallucinations can also occur as a result of a mild fever, or even before sleep or upon awakening. When this happens, a person may see visions ranging from luminous colored dots to astonishingly detailed faces or terrifying monsters. In some cases, hallucinations may lead to religious epiphanies and revelations, or even an out-of-body sensation. In this book, "Hallucinations," written with his usual elegant style, curiosity, and compassion, Dr. Sacks weaves together stories of his patients and his own experiences. This book aims to shed light on hallucinations, what they tell us about the organization and structure of our brains, how they have influenced the folklore and art of every culture, and why hallucinations can occur to any of us as a vital part of human nature.