quantities in the world, and there is a common element
in all the various pieces of iron, by virtue of which all are
classed together, there must be a concept of iron. There is,
therefore, an Idea of iron in the world of Ideas. And the iron
which we find in the earth must be matter which is already
formed into a copy of this Idea. It participates in the Idea
of iron. The same remarks apply to any other particular
kind of matter. In fact, all form, all the specific characters
and {209} features of matter, as we know it, are due to
the operation of the Ideas. Hence matter as it is in itself,
before the image of the Ideas is stamped upon it, must be
absolutely without quality, featureless, formless. But to be
absolutely without any quality is to be simply nothing at
all. This matter is, therefore, as Plato says, absolute not-
being. Zeller conjectures, probably rightly, that what Plato
meant was simply empty space. [Footnote 14] Empty space
is an existent not-being, and it is totally indeterminate and
formless. It accords with this view that Plato adopted the
Pythagorean tenet that the differential qualities of material
substances are due to their smallest particles being regular
geometrical figures limited out of the unlimited, that is,
out of space. Thus earth is composed of cubes. That is
to say, empty space when bound into cubes (the limiting
of the unlimited) becomes earth. The smallest particles of
fire aretetrahedra, of airoctahedra, of watericosahedra.
[Footnote 14:Plato and the Older Academy, chap. vii. ]
We have, then, on the one hand, the world of Ideas, on the
other, matter, an absolutely formless, chaotic, mass. By
impressing the images of the Ideas upon this mass, “things”
arise, that is to say, the specific objects of sense. They thus
participate both in Being and in not-being. But how is this
mixing of Being and not-being brought about? How do the
Ideas come to have their images stamped upon matter? It
is at this point that we enter upon the region of myth. Up
to this point Plato is certainly to be taken literally. He of
course believed in the reality of the world of Ideas, and he
no doubt also believed in his principle of matter. And he
thought that the objects of sense are to be {210} explained
as copies of the Ideas impressed upon matter. But now,
with the problem how this copying is brought about, Plato
leaves the method of scientific explanation behind. If the
Ideas are the absolute ground of all things, then the copy-
ing process must be done by the Ideas themselves. They
must themselves be made the principles for the production
of things. But this is, for Plato, impossible. For produc-
tion involves change. If the Ideas produce things out of
themselves, the Ideas must in the process undergo change.
But Plato has declared them to be absolutely unchange-
able, and to be thus immutable is to be sterile. Hence the
Ideas have within themselves no principle for the produc-
tion of things, and the scientific explanation of things by
this means becomes impossible. Hence there is nothing for
it but to have recourse to myth. Plato can only imagine
that things are produced by a world-former, or designer,
who, like a human artist, fashions the plastic matter into
images of the Ideas.God, the Creator, the world-designer, finds beside him, on
the one hand, the Ideas, on the other, formless matter.
First, he creates the World-Soul. This is incorporeal, but
occupies space. He spreads it out like a huge net in empty