Thoughts on dreams, borrowed from James Hughes' Altered States:
The Greeks built temples to Hypnos, the god of sleep, where sick people would sleep, hoping to be cured by dreams.
The Romantics fed on the irrational dreamworld for their art, preferring it to the certain rationality of the Enlightenment. Some used drugs such as laudanum, opium, and hashish to bring them to these places when their rational minds could not.
Freud said that dreams are our repressed sexual and aggressive urges. In most of us, the ego censors these urges during conscious states. Since the ego loses much of its control during sleep and thus cannot block these urges, it must make them “acceptable” by disguising and distorting them.
Carl Jung saw parallels between psychotic delusions and ancient myth and theorized that below the personal unconscious in all of us lies a collective unconscious, shared by all of humanity. This could explain why many of the same dreams and mythological themes appear in otherwise unconnected cultures. He viewed dreams as gateways to this collective unconscious.
Shamans and yogis act consciously in “dream bodies” which can take them to other locations and other worlds.
Dutch physician Frederik van Eeden was one of the first in the Western world to record an account of lucid dreaming, noting that the dream worlds in which he traveled “cleverly imitated” the real world but with “small failures.” Like shamans, he described being able to slip into his “dreaming body” and believed that flying in a dream often indicated the onset of a lucid dream.
While for most people, dreams are considered an altered state of consciousness that is different from a normal conscious state, in some people the line is blurred. Psychotics do not appear to need to dream during sleep to the extent that non-psychotics do. It is believed that this is because psychotics dream while being awake.