Chapter II: The Nature of Humanity

As the physical body cannot maintain its form through the mineral substances and forces it contains, but needs to be permeated by the etheric body, so too the forces of the etheric body cannot of themselves become illumined with the light of consciousness. Left to itself, an etheric body would of necessity be in a perpetual state of sleep—or, we may also say, could only maintain in the physical body a vegetable form of life. An etheric body that is awake is illumined by an astral body. For outer observation the effect of the astral body disappears when man falls asleep. For supersensible observation however, the astral body still remains, but it is now seen to be separated from the etheric body, or lifted out of it. Sensory observation is in fact concerned, not with the astral body itself, but only with its effects within the manifest world, and these are not immediately present during sleep.