An introduction to the twentieth century's major psychological theories about dreams and dreaming, this work offers a detailed historical overview of how these theories have developed from 1900 to the present. To help readers understand the many different approaches modern psychologists have taken, the book examines each approach in terms of three basic questions: How are dreams formed? What functions do dreams serve? How can dreams be interpreted? The book begins with a brief historical review of the most important ideas about dreams proposed in Western antiquity. It then presents comprehensive descriptions of the dream theories of Sigmund Freud, Carl Jung, and other clinical psychologists. It further discusses the revolutionary discoveries of the modern sleep laboratory and the most important research findings of experimental psychologists. The book concludes with an examination of dreams in contemporary "popular" psychology, a multifaceted analysis of a sample dream, and an extensive bibliography on dream research.