arly. And
this is quite right, because they are opposite principles, and
therefore they are separable in thought. But they are never separable
in fact. There is no such thing as form without matter, or matter
without form. Every existent thing, that is, every individual object,
is a compound of matter and form. We may compare them in this respect
to the material and the shape of a thing, though we must be careful
not to think that form is merely shape. Geometry considers shapes as
if they existed by themselves. But, in fact, we know that there are no
such things as squares, circles, and triangles. There are only square
objects, circular objects, etc. And as there are no shapes without
objects, so there are no objects without shapes. We talk of things
being "shapeless," but this only means that their shape is irregular
or unusual. Some shape an object must have. Yet, though shape and
matter are inseparable in fact, they are opposite principles, and are
separable in thought. Geometry is quite right to treat shapes as if
they existed by themselves, but it is nevertheless dealing with mere
abstractions. Just in the same way, matter and form are never apart,
and to think of form by itself or matter by itself is a mere
abstraction. No such thing exists. In fact, to imagine that forms can
exist by themselves was just the mistake of which, as we have seen,
Aristotle accuses Plato. For the form is the Idea, and Plato imagined
that Ideas exist in a world of their own.

From this, too, we can see that the form is the universal, the matter
the particular. For the form is the Idea, and the Idea is the
universal. To say that form and {276} matter cannot exist apart is
thus the same as saying that the universal only exists in the
particular, which, as we have seen, is the fundamental note of
Aristotle's philosophy. But if we thus identify matter with the
particular element in things, we must be careful that we do not
confuse the particular with the individual. We often use these two
words as practically synonymous, and there is no harm in this, but
here we must be careful to separate them. For every individual is,
according to Aristotle, a compound of matter and form, of the
particular and the universal. And when we say that matter is the
particular, we mean, not that it is such a compound, but that it is
the absolutely particular which has no universal in it. But the
absolutely particular and isolated does not exist. A piece of gold