The discovery of the true self is the recovery of union with our own being …. “Aum is the sound value of that union. We remember that the first sound in aum, “a,” is associated with what is called “waking consciousness.” That is the state of most of us throughout our lives. When consciousness is awake, what one sees seems to be separate from oneself — subject and object are separate from each other. On this level, Aristotelian logic prevails: a is not b. “U” is associated with dream consciousness. When you move into the level of of dream consciousness, all the laws of logic change. There, although you think you are seeing something that is not you, it is actually you that you are seeing, because the dream is simply a manifestation of your own will and energy — you created the dream and yet you are surprised by it. So the duality there is illustory. There, subject and object, though apparently separate, are the same.” The final audible sound in aum “m”, brings us to the level of deep, dreamless sleep. This is the realm out of which consciousness then will reappear.

– Joseph Campbell, Myths of Light