. The changes thus produced in the soul constitute ideas; but, with
a prophetic inspiration, he complained that man will never know the true
essence of things.

[Sidenote: The Physics of Zeno.]

In his Physics Zeno adopted the doctrine of Strato, that the world is a
living being. He believed that nothing incorporeal can produce an
effect, and hence that the soul is corporeal. Matter and its properties
he considered to be absolutely inseparable, a property being actually a
body. In the world there are two things, matter and God, who is the
Reason of the world. Essentially, however, God and matter are the same
thing, which assumes the aspect of matter from the passive point of
view, and God from the active; he is, moreover, the prime moving force,
Destiny, Necessity, a life-giving Soul, evolving things as the vital
force evolves a plant out of a seed; the visible world is thus to be
regarded as the material manifestation of God. The transitory objects
which it on all sides presents will be reabsorbed after a season of
time, and reunited in him. The Stoics pretended to indicate, even in a
more definite manner, the process by which the world has arisen, and
also its future destiny; for, regarding the Supreme as a vital heat,
they supposed that a portion of that fire, declining in energy, became
transmuted into matter, and hence the origin of the world; but that that
fire, hereafter resuming its activity, would cause a universal
conflagration, the end of things. During the present state everything
is in a condition of uncertain mutation, decays being followed by
reproductions, and reproductions by decays; and, as a cataract shows
from year to year an invariable form, though the water composing it is
perpetually changing, so the objects around us are nothing more than a
flux of matter offering a permanent form. Thus the visible world is only
a moment in the life of God, and after it has vanished away like a
scroll that is burned, a new period shall be ushered in, and a new
heaven and a new earth, exactly like the ancient ones, shall arise.
Since nothing can exist without its contrary, no injustice unless there
was justice, no cowardice unless there was courage, no lie unless there
was truth, no shadow unless there was light, so the existence of good
necessitates that of evil. The Stoics believed that the development of
the world is under the dominion of paramount law, supreme law, Destiny,
to which God himself is subject, an