V. Higher Worlds and Their Connection with Ours

What, then, is the significance of sleep for man? What happens to him? Why does he leave his body? And how can the latter live without him? - The real, inner man, whose material expression and tool is the outer, physical body, notices when he falls asleep, how the whole outside world fades from his perception, how he gradually becomes insensitive to all the sense impressions he has received during the day, and how all mental sensations, joy and pain, completely fade. We must realize that the inner man, who perceives by means of the physical senses, is at the same time the bearer of pleasure and pain, of hate and love, and not the physical body. We might now object: If that is the case, how is it that this inner man, when leaving the body, does not retain the sensations of pain or joy in the astral world? The reason for this is that it must be in the physical body to perceive the facts of its inner life, which, like a mirror, reflects its emotions and brings them to consciousness. When the mirror is left, the image of the impressions fades and the person does not become aware of them again until he has retreated back into the body. There is thus a constant interaction between the inner and outer man.