We spend a third of our lives sleeping, with much of the night filled with dreams. Peculiarly vivid, disturbing dreams leave behind impressions that are hard to dismiss. But what are nightmares? And what significance do they have for the dreamer? Questions like these have been asked and answered in all time periods in all of the world's cultures. The Nightmare Encyclopedia examines ideas about bad dreams found in different parts of the world, in different periods of Western history, in recent clinical research, in current theories of the occult, and in popular films. Most of the world's traditional societies are taught that our souls leave our bodies and travel to other realms when we dream, so maybe nightmares are the result of getting lost in one of dreamland's bad neighborhoods. In medieval Europe, it was thought that demons could attack and rape human beings in their sleep. In contrast, modern psychologists tend to view nightmares as repressed conflicts that return from our unconscious to haunt us in our dreams. This book also includes interpretations of dream symbols found in nightmares.