The Complete Aristotle (eng.)

substances
which are more in number and more real; e.g. Plato posited two
kinds of substance-the Forms and objects of mathematics-as well as
a third kind, viz. the substance of sensible bodies. And Speusippus
made still more kinds of substance, beginning with the One, and
assuming principles for each kind of substance, one for numbers,
another for spatial magnitudes, and then another for the soul; and
by going on in this way he multiplies the kinds of substance. And
some say Forms and numbers have the same nature, and the other
things come after them-lines and planes-until we come to the
substance of the material universe and to sensible bodies.
    Regarding these matters, then, we must inquire which of the
common statements are right and which are not right, and what
substances there are, and whether there are or are not any besides
sensible substances, and how sensible substances exist, and whether
there is a substance capable of separate existence (and if so why
and how) or no such substance, apart from sensible substances; and
we must first sketch the nature of substance.
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3
    The word ‘substance’ is applied, if not in more senses, still at
least to four main objects; for both the essence and the universal
and the genus, are thought to be the substance of each thing, and
fourthly the substratum. Now the substratum is that of which
everything else is predicated, while it is itself not predicated of
anything else. And so we must first determine the nature of this;
for that which underlies a thing primarily is thought to be in the
truest sense its substance. And in one sense matter is said to be
of the nature of substratum, in another, shape, and in a third, the
compound of these. (By the matter I mean, for instance, the bronze,
by the shape the pattern of its form, and by the compound of these
the statue, the concrete whole.) Therefore if the form is prior to
the matter and more real, it will be prior also to the compound of
both, for the same reason.
    We have now outlined the nature of substance, showing that it is
that which is not predicated of a stratum, but of which all else is
predicated. But we must not merely state the matter thus; for this
is not enough. The statement itself is obscure, and further, on
this view, matter becomes substance. For if this is not substance,
it baffles us to say what else is. When all else is stripped off
evidently nothing but matter remains. For while the rest are
affections, products, and potencies of bodies, length, breadth, and
depth are quantities and not substances (for a quantity is not a
substance), but the substance is rather that to which these belong
primarily. But when length and breadth and depth are taken away we
see nothing left unless there is something that is bounded by
these; so that to those who consider the question thus matter alone
must seem to be substance. By matter I mean that which in itself is
neither a particular thing nor of a certain quantity nor assigned
to any other of the categories by which being is determined. For
there is something of which each of these is predicated, whose
being is different from that of each of the predicates (for the
predicates other than substance are predicated of substance, while
substance is predicated of matter). Therefore the ultimate
substratum is of itself neither a particular thing nor of a
particular quantity nor otherwise positively characterized; nor yet
is it the negations of these, for negations also will belong to it
only by accident.
    If we adopt this point of view, then, it follows that matter is
substance. But this is impossible; for both separability and
‘thisness’ are thought to belong chiefly to substance. And so form
and the compound of form and matter would be thought to be
substance, rather than matter. The substance compounded of both,
i.e. of matter and shape, may be dismissed; for it is posterior and
its nature is obvious. And matter also is in a sense manifest. But
we must inquire into the third kind of substance; for this is the
most perplexing.
    Some of the sensible substances are generally admitted to be
substances, so that we must look first among these. For it is an
advantage to advance to that which is more knowable. For learning
proceeds for all in this way-through that which is less knowable by
nature to that which is more knowable; and just as in conduct our
task is to start from what is good for each and make what is
without