includes the final cause. Now the function of a thing is just what the
thing is for. And what it is for is the same as its end, or final
cause. {278} Therefore function is included in form. For example, the
function of a hand, its power of gripping, is part of its form. And
therefore, if it loses its function by being cut off from the arm, it
likewise loses its form. Even the dead hand, of course, has some form,
for every individual object is a compound of matter and form. But it
has lost the highest part of its form, and relatively to the living
hand it is mere matter, although, relatively to the flesh and bones of
which it is composed, it is still form. Clearly, then, form is not
merely shape. For the hand cut off does not lose its shape.

The form includes all the qualities of the thing. The matter is what
has the qualities. For the qualities are all universals. A piece of
gold is yellow, and this means simply that it has this in common with
other pieces of gold, and other yellow objects. To say that anything
has a quality is immediately to place it in a class. And what the
class has in common is a universal. A thing without qualities cannot
exist, nor qualities without a thing. And this is the same as saying
that form and matter cannot exist separately.

The matter, then, is the absolutely formless. It is the substratum
which underlies everything. It has, in itself, no character. It is
absolutely featureless, indefinite, without any quality. Whatever
gives a thing definiteness, character, quality, whatever makes it a
this or that, is its form. Consequently, there are no differences
within matter. One thing can only differ from another by having
different qualities. And as matter has no qualities, it has no
difference. And this in itself shows that the Aristotelian notion of
matter is not the same as our notion of physical substance. For,
according {279} to our modern usage, one kind of matter differs from
another, as brass from iron. But this is a difference of quality, and
for Aristotle all quality is part of the form. So in his view the
difference of brass from iron is not a difference of matter, but a
difference of form. Consequently, matter may become anything,
according to the form impressed upon it. It is thus the possibility of
everything, though it is actually nothing. It only becomes something
by the acquisition of form. And this leads directly to a most
important Aristotelian antithesis, that between po