bility of external observation and occult science must trace it
in its hidden life, until it again takes possession of its physical and
etheric bodies on waking.

As in all cases when knowledge of the hidden things and events of life
have to be dealt with, clairvoyant observation is necessary for the
discovery of the real facts of the sleep state in its true nature, but if
that which may be discovered by this means has once been made clear, it is
comprehensible to really unprejudiced thought without further
demonstration. For events in the unseen world show themselves by their
effects in the manifested world. If what is revealed by clairvoyant vision
is an explanation of visible events, such a confirmation by life itself is
the proof which may rightly be demanded. Even one who will not use the
means to be given later for the attainment of clairvoyant vision, may have
the following experience: he may, in the first place, take the statements
of the clairvoyant for granted, and then apply them to the material events
within his experience. He will then find that life thereby becomes clear
and comprehensible; and the more exact and minute his observations of
ordinary life, the more readily will he come to this conclusion.

Even though the astral body during sleep passes through no experiences,
though it is not conscious of pleasure, pain, and the like, it does not
remain inactive. On the contrary, it is a fact that active work is its
function in the sleep state. For it is the astral body which strengthens
and recuperates man's forces, exhausted during waking life. As long as the
astral body is united with the physical and etheric bodies it is related
to the outer world through these two bodies. They convey to it perceptions
and representations. Through the impressions which they receive from their
surroundings, it experiences pleasure and pain. Now the physical body can
be preserved in the form and shape suitable to the individual only by
means of the human etheric body. But this human form can be preserved only
by an etheric body which on its part receives corresponding forces from
the astral body. The etheric body is the builder, the architect, of the
physical body. It can, however, construct in the true sense only when it
receives from the astral body the impulse as to the manner in which it
must build. In this latter are contained the models, according to which
the etheric body gives the physical body its form. During our