All things that we consider to be essences are composites; nothing
is simple or single, either in works of art, or in the products of
nature.[113] Works of art, indeed, contain metal, wood, stone, and are
derived from these substances only by the labor of the artist, who, by
giving matter its form makes of it a statue, or bed, or house. Among
the products of nature, those that are compounds or mixtures may be
analyzed into the form impressed on the elements of the compound; so,
for instance, we may in a man, distinguish a soul and body, and in the
body four elements. Since the very matter of the elements, taken in
itself, has no form, every object seems composed of matter and of some
principle that supplies it with form.[114] So we are led to ask whence
matter derives its form, and to seek whether the soul is simple, or
whether it contains two parts, one of which plays the parts of matter,
and the other of form,[115] so that the first part would be similar
to the form received by the metal of a statue, and the latter to the
principle which produces the form itself.