man would still be real even if all men were destroyed, and
it was real before any man existed, if there ever was such
a time. For the Ideas, being timeless, cannot be real now
and not then.
Of what kinds of things are there Ideas? That there are
moral Ideas, such as Justice, Goodness, and Beauty, Ideas
of corporeal things, such as horse, man, tree, star, river,
and Ideas of qualities, such as whiteness, heaviness, {195}
sweetness, we have already seen. But there are Ideas not
only of natural corporeal objects, but likewise of manufac-
tured articles; there are Ideas of beds, tables, clothes. And
there are Ideas not only of exalted moral entities, such as
Beauty and Justice. There are also the Ideal Ugliness, and
the Ideal Injustice. There are even Ideas of the positively
nauseating, such as hair, filth, and dirt. This is asserted
in the “Parmenides.” In that dialogue Plato’s teaching is
put into the mouth of Parmenides. He questions the young
Socrates whether there are Ideas of hair, filth, and dirt.
Socrates denies that there can be Ideas of such base things.
But Parmenides corrects him, and tells him that, when he
has attained the highest philosophy, he will no longer de-
spise such things. Moreover, these Ideas of base things are
just as much perfection in their kind as Beauty and Good-
ness are in theirs. In general, the principle is that there
must be an Idea wherever a concept can be formed; that
is, wherever there is a class of many things called by one
name.
We saw, in treating of the Eleatics, that for them the ab-
solute Being contained no not-being, and the absolute One
no multiplicity. And it was just because they denied all
not-being and multiplicity of the absolute reality that they
were unable to explain the world of existence, and were
forced to deny it altogether. The same problem arises for
Plato. Is Being absolutely excludent of not-being? Is the
Absolute an abstract One, utterly exclusive of the many?
Is his philosophy a pure monism? Is it a pluralism? Or is
it a combination of the two? These questions are discussed
in the “Sophist” and the “Parmenides.”{196}Plato investigates the relations of the One and the many,
Being and not-being, quite in the abstract. He decides the
principles involved, and leaves it to the reader to apply
them to the theory of Ideas. Whether the Absolute is one
or many, Being or not-being, can be decided independently
of any particular theory of the nature of the Absolute, and
therefore independently of Plato’s own theory, which was
that the Absolute consists of Ideas. Plato does not accept
the Eleatic abstraction. The One cannot be simply one, for
every unity must necessarily be a multiplicity. The many
and the One are correlative ideas which involve each other.
Neither is thinkable without the other. A One which is not
many is as absurd an abstraction as a whole which has no
parts. For the One can only be defined as that which is not
many, and the many can only be defined as the not-one.
The One is unthinkable except as standing out against a
background of the many. The idea of the One therefore in-
volves the idea of the many, and cannot be thought without
it. Moreover, an abstract One is unthinkable and unknow-
able, because all thought and knowledge consist in applying
predicates to subjects, and all predication involves the du-