Lecture XXI
In those olden times something else—a third condition—came as naturally to the human soul as waking and sleeping do today. In today's state of being awake, human beings are restricted entirely to the physical world which they can perceive with their senses; they live between birth and death in a world which they can experience through their senses and through their understanding which is bounded by the brain. And in sleep they are unconscious. The entities of ego and astral body in which they live between falling asleep and waking up are not yet strong enough to supply them with a comparable consciousness. We know that the astral body has only been developing since the time of ancient Moon and the ego only since the beginning of Earth evolution. Both are young measured against cosmic evolution and they are not yet strong enough to achieve consciousness when left to themselves between going to sleep and waking up.
Cite:
GA 173c/1917-01-20/p007 · edition English