Aristotle wrote about lucid dreaming -- when he wasn't busy with metaphysics.

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Background of Lucid Dreams

Dreams have been of paramount importance to cultures throughout the ages. Native Americans viewed dreams as portals to the spirit world, paths to prophecy and quests. The Aborigines refer to the stories of the world's very beginning as their dreamings.

Lucid dreaming isn't new, either. Aristotle may have been the first to write about lucid dreaming, although he didn't have a term for it. And some Tibetan Buddhists have been practicing something like lucid dreaming for a very long time: dream yoga.

The objective of dream yoga is to probe your consciousness and bring you to a constant state of awareness. A big part of the belief system of Buddhism is recognizing the world for what it is, free from illusion. A lucid dreamer recognizes the dream world for what it is -- a dream. As you're dreaming, you follow along the winding pathways of your own mind, making discoveries about the way you think and the obstacles your mind puts in the way of achieving clarity. Mystics have their own name for this altered state of consciousness: nondual awareness.

Yoga can bring about a new kind of awareness.

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A Dutch psychiatrist named Frederik van Eeden came up with the term for lucid dreams in 1913. He claimed that there are nine well-defined types of dreams in all, including ordinary, symbolic and vivid dreams. He recorded several of his own lucid dreams, and his thoughts during them and upon awakening. He remarked that they often involved flying. Many lucid dreamers report pleasurable erotic dreams -- though van Eeden missed out.

Nowadays, many people have heard of lucid dreaming because of a man named Stephen Laberge, a psychophysiologist with a Stanford degree who heads up the Lucidity Institute, which is dedicated to the study of lucid dreams and their application to daily life. LaBerge calls himself a dream sailor. He runs workshops that aren't cheap (upward of a few grand) to teach people how to have lucid dreams. He claims that lucid dreams can do everything from making you more creative to helping with grief.

So what's it like to have a lucid dream? If lucid dreaming occurs when we're asleep, how could we possibly know we're dreaming? Read on to find out some theories about lucid dreaming.