may be compared with the modern conception of laws of
nature. They are in space, but not in time, and they are the makers
of time. They are represented as constantly thinking of the same; for
thought in the view of Plato is equivalent to truth or law, and need not
imply a human consciousness, a conception which is familiar enough to
us, but has no place, hardly even a name, in ancient Greek philosophy.
To this principle of the same is opposed the principle of the other--the
principle of irregularity and disorder, of necessity and chance, which
is only partially impressed by mathematical laws and figures. (We
may observe by the way, that the principle of the other, which is the
principle of plurality and variation in the Timaeus, has nothing in
common with the 'other' of the Sophist, which is the principle of
determination.) The element of the same dominates to a certain extent
over the other--the fixed stars keep the 'wanderers' of the inner circle
in their courses, and a similar principle of fixedness or order appears
to regulate the bodily constitution of man. But there still remains a
rebellious seed of evil derived from the original chaos, which is the
source of disorder in the world, and of vice and disease in man.

But what did Plato mean by essence, (Greek), which is the intermediate
nature compounded of the Same and the Other, and out of which, together
with these two, the soul of the world is created? It is difficult to
explain a process of thought so strange and unaccustomed to us, in which
modern distinctions run into one another and are lost sight of. First,
let us consider once more the meaning of the Same and the Other. The
Same is the unchanging and indivisible, the heaven of the fixed stars,
partaking of the divine nature, which, having law in itself, gives law
to all besides and is the element of order and permanence in man and
on the earth. It is the rational principle, mind regarded as a work, as
creation--not as the creator. The old tradition of Parmenides and of the
Eleatic Being, the foundation of so much in the philosophy of Greece and
of the world, was lingering in Plato's mind. The Other is the variable
or changing element, the residuum of disorder or chaos, which cannot be
reduced to order, nor altogether banished, the source of evil, seen in
the errors of man and also in the wanderings of the planets, a necessity
which protrudes through nature. Of this too there was a shadow in the
Eleatic phil