exists is an individual thing. Again, he tells us that the
Idea is outside time. But whatever exists must exist at
some time. Here then this central idealistic thought seems
well fixed in Plato’s mind. But when he goes on to speak
of recollection and reincarnation, when he tells us that the
soul before birth dwelt apart in the world of Ideas, to which
after death it may hope to return, it is clear that Plato has
forgotten his own philosophy, that he is now thinking of
the Ideas as individual existences in a world of their own.
This is a world of Ideas having a separate existence and
place of its own. It is not this world. It is a world beyond.
Thus the Platonic philosophy which began on a high level
of idealistic thinking, proclaiming the sole reality of the
universal, ends by turning the universal itself into nothing
but an existent particular. It is the old old story of trying to
form mental pictures of that which no picture is adequate to
comprehend. Since all pictures are formed out of sensuous
materials, and since we can form no picture of anything
that is not an individual thing, to form a picture of the
universal necessarily means thinking of it as just what it is
not, an individual. So Plato commits the greatest sin that
can be ascribed to a philosopher. He treats thought as a
thing.
To sum up. Plato is the great founder of idealism, the
initiator of all subsequent truths in philosophy. {248} But,
as always with pioneers, his idealism is crude. It cannot
explain the world; it cannot explain itself. It cannot even
keep true to its own principles, because, having for the first
time in history definitely enunciated the truth that reality
is the universal, it straightway forgets its own creed and
plunges back into a particularism which regards the Ideas
as existent individuals. It was these defects which Aristotle
set himself to rectify in a purer idealism, shorn of Plato’s
impurities.
{249}