shows that Anaximenes compared the breath of life to the air,
and regarded the two as essentially related--indeed as identical.
For the breath, he thought, holds together both animal and
human life; and so the air holds together the whole world in a
complex unity. He reached the wider doctrine by observing that
the air is, to all appearance, infinitely extended, and that earth,
water, and fire seem to be but islands in an ocean which spreads
around them on all sides, penetrating their inmost pores, and
bathing their smallest atoms. It was on such facts and
appearances that he based his main doctrine. If we think of the
modern theory of the luminiferous ether, we shall not be far
from his view-point. But the simpler and more obvious qualities
of the air would of course not be without their influence--its
mobility and incessant motion; its immateriality; its
inexhaustibility; its seeming eternity. It is, therefore, not
astonishing that with his attention thus focussed on a group of
truly wonderful phenomena, the old nature-philosopher should
have selected air as his primary substance--as the universal
vehicle of vital and psychic force.

It is of especial interest to the nature-mystic to find that
Anaximenes was faithful to the doctrine that the primary
substance must contain in itself the cause of its own motion.
And the interest is intensified in view of the fact that his
insistence on the life-giving properties of air rests on a widely
spread group of animistic notions which have exercised an
extraordinary influence on the world at large. Let Tylor furnish
a summary. "Hebrew shows _nephesh_, 'breath,' passing into all
the meanings of life, soul, mind, animal, while _ruach_ and
_neshamah_ make the like transition from 'breath' to 'spirit'; and