to the phenomenon of sleep, just as
in connection with the etheric body attention was drawn to death. All
human work, so far as the manifested world is concerned, is dependent upon
activity during waking life. But that activity is possible only as long as
man is able to recuperate his exhausted forces by sleep. Action and
thought disappear, pain and pleasure fade away during sleep, and on
re-awaking, man's conscious powers ascend from the unconsciousness of
sleep as though from hidden mysterious sources of energy. It is the same
consciousness which sinks down into dim depths on falling asleep and
ascends from them again on re-awaking.

That which awakens life again out of this state of unconsciousness is,
according to occult science, the third principle of the human being. It is
called the astral body. Just as the physical body cannot keep its form by
means of the mineral substances and forces it contains, but must, in order
to be kept together, be interpenetrated by the etheric body, so is it
impossible for the forces of the etheric body to illuminate themselves
with the light of consciousness. An etheric body left to its own resources
would be in a permanent state of sleep.(1) An etheric body awake, is
illuminated by an astral body. This astral body seems to sense-observation
to disappear when man falls asleep; to clairvoyant observation it is still
present, with the difference that it appears separated from or drawn out
of the etheric body. Sense-observation has nothing to do with the astral
body itself, but only with its effects in the manifested world, and these
cease during sleep. In the same sense in which man possesses his physical
body in common with plants, he resembles animals as regards his astral
body.

Plants are in a permanent state of sleep. One who does not judge
accurately in these matters may easily make the mistake of attributing to
plants the same kind of consciousness as that of animals and human beings
in the waking state; but this assumption can only be due to an inaccurate
conception of consciousness. In that case it is said that, if an external
stimulus is applied to a plant, it responds by certain movements, as would
an animal. The _sensitiveness_ of some plants is spoken of,--for example,
of those which contract their leaves when certain external things act upon
them. But the characteristic mark of consciousness is not that a being
reacts in a certain way to an impression, but that it experi