Book excerpt: Films with dream sequences, or a dreamlike quality, allow directors to create their own rules of logic and nature to meet a variety of artistic needs. For instance, an opening dream immediately establishes what a character is feeling; a later dream--or series of them--provides viewers with a glimpse of the climax, and a concluding dream ties up loose ends. (In real life, of course, dreams do not occur at such convenient times or serve such useful purposes.) This book explores why science is lost or distorted in the process of representing dreams on film and why audiences prefer this figurative truth of art over the literal truth of science. Part One discusses changes in form and considers the history of dream theory. Additionally, the physiology of sleeping and dreaming, dream structure, sleep deprivation, dreams under the influence of drugs or alcohol, and waking up, as depicted on film, are examined. Part Two investigates changes in content, and delves into the psychology of sleeping and dreaming, dream interpretation, altered states of consciousness, visions and prophecies, dreams as wish fulfillment, sex and death, nightmares, and reality versus illusion. The author uses theories by Freud, Jung, and current experts in her analyses of dream sequences and their use in film.