[
1042a]
[3]
We must now draw our conclusions from
what has been said, and after summing up the result, bring our inquiry
to a close. We have said
1 that the objects of our inquiry are the causes and
principles and elements of substances. Now some substances are agreed
upon by all; but about others certain thinkers have stated individual
theories.Those about
which there is agreement are natural substances: e.g. fire, earth,
water, air and all the other simple bodies; next, plants and their
parts, and animals and the parts of animals; and finally the sensible
universe and its parts; and certain thinkers individually include as
substances the Forms and the objects of mathematics.
2And arguments show that there are yet other
substances: the essence and the substrate.
3 Again, from another point of view, the genus is
more nearly substance than the species, and the universal than the
particulars
4;
and there is a close connection between the universal and genus and
the Ideas, for they are thought to be substance on the same
grounds.
5And since the essence is substance, and definition is the formula of
the essence, we have therefore systematically examined definition and
essential predication.
6 And since
the definition is a formula, and the formula has parts,
[20]
we have been compelled to
investigate "parts," and to discover what things are parts of the
substance, and what are not; and whether the parts of the substance
are also parts of the definition.
7 Further, then, neither the universal nor the genus
is substance.
8As for the Ideas and the objects of
mathematics (for some say that these exist apart from sensible
substances) we must consider them later.
9 But now let us proceed to
discuss those substances which are generally accepted as
such.
Now these are the sensible
substances, and all sensible substances contain matter.And the substrate is substance;
in one sense matter (by matter I mean that which is not actually, but
is potentially, an individual thing); and in another the formula and
the specific shape (which is an individual thing and is theoretically
separable); and thirdly there is the combination of the two, which
alone admits of generation and destruction,
10
and is separable in an unqualified sense—for of substances
in the sense of formula some are separable
11 and some are not.
That matter is also substance is evident; for in all opposite
processes of change there is something that underlies those processes;
e.g., if the change is of
place , that which is now in
one place and subsequently in another; and if the change is of
magnitude , that which is now of such-and-such a
size, and subsequently smaller or greater; and if the change is of
quality , that which is now healthy and
subsequently diseased.
[
1042b]
[1]
Similarly, if the change is in respect of
being , there is something which is now in course
of generation, and subsequently in course of destruction, and which is
the underlying substrate, now as
this individual thing,
and subsequently as deprived of its individuality. In this last
process of change the others are involved, but in either one or
two
12
of the others it is not involved; for it does not necessarily follow
that if a thing contains matter that admits of change of place, it
also contains matter that is generable and destructible.
13
The difference between absolute and qualified generation has been
explained in the
Physics.
14Since
substance in the sense of substrate or matter is admittedly substance,
and this is potential substance, it remains to explain the nature of
the actual substance of sensible things. Now Democritus
15 apparently assumes three differences
in substance; for he says that the underlying body is one and the same
in material, but differs in figure, i.e. shape; or inclination, i.e.
position; or intercontact, i.e. arrangement.But evidently there are many differences; e.g.
some things are defined by the way in which their materials are
combined, as, for example, things which are unified by mixture, as
honey-water; or by ligature, as a faggot; or by glue, as a book; or by
clamping, as a chest; or by more than one of these methods. Other
things are defined by their position, e.g. threshold and lintel (for
these differ in being situated in a particular way);
[20]
and others by place <or
direction>, e.g. the winds; others by time, e.g. dinner and
breakfast; and others by the attributes peculiar to sensible things,
e.g. hardness and softness, density and rarity, dryness and humidity.
Some are distinguished by some of these differences, and others by all
of them; and in general some by excess and some by defect.
Hence it is clear that "is" has the same number of senses; for a
thing "is" a threshold because it is situated in a particular way, and
"to be a threshold" means to be situated in this particular way, and
"to be ice" means to be condensed in this particular way. Some things
have their being defined in all these ways: by being partly mixed,
partly blended, partly bound, partly condensed, and partly subjected
to all the other different processes; as, for example, a hand or a
foot.We must
therefore comprehend the various kinds of differences—for
these will be principles of being—i.e. the differences in
degree, or in density and rarity, and in other such modifications, for
they are all instances of excess and defect.And if anything differs in shape or in
smoothness or roughness, all these are differences in straightness and
curvature. For some things mixture will constitute being,
[
1043a]
[1]
and the opposite state not-being.
From this it is evident that if substance is the
cause of the existence of each thing, we must look among these
"differences" for the cause of the being of each thing.No one of them, nor the
combination of any two of them, is substance, but nevertheless each
one of them contains something analogous to substance. And just as in
the case of substances that which is predicated of the matter is the
actuality itself, so in the other kinds of definition it is the
nearest approximation to actuality. E.g., if we have to define a
threshold, we shall call it "a piece of wood or stone placed in
such-and-such a way"; and we should define a house as "bricks and
timber arranged in such-and-such a way";or again in some cases there is the final
cause as well. And if we are defining ice, we shall describe it as
"water congealed or condensed in such-and-such a way"; and a harmony
is "such-and-such a combination of high and low"; and similarly in the
other cases.
From this it is evident
that the actuality or formula is different in the case of different
matter; for in some cases it is a combination, in others a mixture,
and in others some other of the modes which we have
described.Hence in
defining the nature of a house, those who describe it as stones,
bricks and wood, describe the potential house, since these things are
its matter; those who describe it as "a receptacle for containing
goods and bodies," or something else to the same effect, describe its
actuality; but those who combine these two definitions describe the
third kind of substance, that which is composed of matter and
form.For it would
seem that the formula which involves the differentiae is that of the
form and the actuality,
[20]
while that which involves the constituent parts is rather that of
the matter. The same is true of the kind of definitions which
Archytas
16 used to accept; for
they are definitions of the combined matter and form. E.g., what is
"windlessness?" Stillness in a large extent of air; for the air is the
matter, and the stillness is the actuality and substance.What is a calm? Levelness of
sea. The sea is the material substrate, and the levelness is the
actuality or form.
From the foregoing
account it is clear what sensible substance is, and in what sense it
exists; either as matter, or as form and actuality, or thirdly as the
combination of the two.
We must not fail to realize
that sometimes it is doubtful whether a name denotes the composite
substance or the actuality and the form—e.g. whether "house"
denotes the composite thing, "a covering made of bricks and stones
arranged in such-and-such a way," or the actuality and form, "a
covering"; and whether "line" means "duality in length" or
"duality"
17; and whether "animal"
means "a soul in a body" or "a soul"; for the soul is the substance
and actuality of some body.The term "animal" would be applicable to both cases; not as being
defined by one formula, but as relating to one concept. These
distinctions are of importance from another point of view, but
unimportant for the investigation of sensible substance;
[
1043b]
[1]
because the essence belongs to the form and the
actualization.Soul
and essence of soul are the same, but man and essence of man are not,
unless the soul is also to be called man; and although this is so in
one sense, it is not so in another.
It
appears, then, upon inquiry into the matter,
18 that a syllable is not derived from the phonetic
elements plus combination, nor is a house bricks plus combination. And
this is true; for the combination or mixture is not derived from the
things of which it is a combination or mixture,nor, similarly, is any other of the
"differences." E.g., if the threshold is defined by its position, the
position is not derived from the threshold, but rather vice versa.
Nor, indeed, is man "animal"
plus "two-footed"; there
must be something which exists besides these, if they are matter; but
it is neither an element nor derived from an element, but the
substance; and those who offer the definition given above are omitting
this and describing the matter.If, then, this something else is the cause of
a man's being, and this is his substance, they will not be stating his
actual substance.
Now the substance must
be either eternal or perishable without ever being in process of
perishing, and generated without ever being in process of generation.
It has been clearly demonstrated elsewhere
19 that no one generates or creates the form; it
is the individual thing that is created, and the compound that is
generated.But
whether the substances of perishable things are separable or not is
not yet at all clear
20; only
it is clear that this is impossible in some cases,
[20]
i.e. in the case of all things which
cannot exist apart from the particular instances; e.g. house or
implement.
21 Probably, then,
neither these things themselves, nor anything else which is not
naturally composed, are substances; for their nature is the only
substance which one can assume in the case of perishable
things.Hence the
difficulty which perplexed the followers of Antisthenes
22 and others similarly unlearned has a
certain application; I mean the difficulty that it is impossible to
define
what a thing is (for the definition, they say, is
a lengthy formula), but it
is possible actually to teach
others what a thing
is like; e.g., we cannot say
what silver is, but we can say that it is like
tin.Hence there can
be definition and formula of one kind of substance, i.e. the
composite, whether it is sensible or intelligible; but not of its
primary constituents, since the defining formula denotes something
predicated of something, and this must be partly of the nature of
matter and partly of the nature of form.
It is also obvious
that, if numbers are in any sense substances, they are such in this
sense, and not, as some
23 describe them, aggregates
of units. For (a) the definition is a kind of number, since it is
divisible, and divisible into indivisible parts (for formulae are not
infinite); and number is of this nature.And (b) just as when any element which
composes the number is subtracted or added, it is no longer the same
number but a different one, however small the subtraction or addition
is;
[
1044a]
[1]
so neither the definition nor the essence will
continue to exist if something is subtracted from or added to it. And
(c) a number must be something in virtue of which it is a unity
(whereas our opponents cannot say what makes it one); that is, if it
is a unity.For either it
is not a unity but a kind of aggregate, or if it is a unity, we must
explain what makes a unity out of a plurality. And the definition is a
unity; but similarly they cannot explain the definition either. This
is a natural consequence, for the same reason applies to both, and
substance is a unity in the way which we have explained, and not as
some thinkers say: e.g. because it is a kind of unit or point; but
each substance is a kind of actuality and nature.Also (d) just as a number does not
admit of variation in degree, so neither does substance in the sense
of form; if any substance does admit of this, it is substance in
combination with matter.
24Let this suffice as a detailed account of the
generation and destruction of so-called substances, in what sense they
are possible and in what sense they are not; and of the reference of
things to number.
As regards material substance, we must
not fail to realize that even if all things are derived from the same
primary cause, or from the same things as primary causes
25; i.e. even if all things that are
generated have the same matter for their first principle, nevertheless
each thing has some matter peculiar to it; e.g., "the sweet" or "the
viscous" is the proximate matter of mucus, and "the bitter" or some
such thing is that of bile—
[20]
although probably mucus and bile are derived from
the same ultimate matter.The result is that there is more than one matter of the same thing,
when one thing is the matter of the other; e.g., mucus is derived from
"the viscous"; and from "the sweet," if "the viscous" is derived from
"the sweet"; and from bile, by the analysis of bile into its ultimate
matter. For there are two senses in which X comes from Y; either
because X will be found further on than Y in the process of
development, or because X is produced when Y is analyzed into its
original constituents.And
different things can be generated by the moving cause when the matter
is one and the same, e.g. a chest and a bed from wood. But some
different things must necessarily have different matter; e.g., a saw
cannot be generated from wood, nor does this lie in the power of the
moving cause, for it cannot make a saw of wool or wood.
If, then, it is possible to make the same thing from different
matter, clearly the art, i.e. the moving principle, is the same; for
if both the matter and the mover are different, so too is the
product.
So whenever we inquire
what the cause is, since there are causes in several senses, we must
state all the possible causes.E.g., what is the material cause of a man? The
menses. What is the moving cause? The semen. What is the formal cause?
The essence. What is the final cause? The end.
[
1044b]
[1]
(But
perhaps both the latter are the same.) We must, however, state the
most proximate causes. What is the matter? Not fire or earth, but the
matter proper to man.
Thus as regards generable natural
substances we must proceed in this manner, if we are to proceed
correctly; that is, if the causes are these and of this number, and it
is necessary to know the causes. But in the case of substances which
though natural are eternal the principle is different. For presumably
some of them have no matter; or no matter of this kind, but only such
as is spatially mobile.
26Moreover, things which exist by
nature but are not substances have no matter; their substrate is their
substance. E.g., what is the cause of an eclipse; what is its matter?
It has none; it is the moon which is affected. What is the moving
cause which destroys the light? The earth. There is probably no final
cause. The formal cause is the formula; but this is obscure unless it
includes the efficient cause.E.g., what is an eclipse? A privation of
light; and if we add "caused by the earth's intervention," this is the
definition which includes the <efficient> cause. In the
case of sleep it is not clear what it is that is proximately affected.
Is it the animal? Yes; but in respect of what, and of what
proximately? The heart, or some other part. Again, by what is it
affected? Again, what is the affection which affects that part, and
not the whole animal? A particular kind of immobility?
[20]
Yes; but in virtue of what
affection of the proximate subject is it this?
Since
some things both are and are not, without being liable to generation
and destruction
27—e.g. points,
28 if they exist at all; and in
general the forms and shapes of things (because white does not come to
be, but the wood becomes white, since everything which comes into
being comes from something and becomes something)—not all
the contraries
29 can be generated from each other.
White is not generated from black in the same way as a white man is
generated from a black man; nor does everything contain matter, but
only such things as admit of generation and transformation into each
other.And such
things as, without undergoing a process of change, both are and are
not, have no matter.
There is a
difficulty in the question how the matter of the individual is related
to the contraries. E.g., if the body is potentially healthy, and the
contrary of health is disease, is the body potentially both healthy
and diseased? And is water potentially wine and vinegar? Probably in
the one case it is the matter in respect of the positive state and
form, and in the other case in respect of privation and degeneration
which is contrary to its proper nature.
There is also a
difficulty as to why wine is not the matter of vinegar, nor
potentially vinegar (though vinegar comes from it), and why the living
man is not potentially dead. In point of fact they are not; their
degeneration is accidental,
[
1045a]
[1]
and the actual
matter of the living body becomes by degeneration the potentiality and
matter of the dead body, and water the matter of vinegar; for the one
becomes the other just as day becomes night.All things which change reciprocally in this
way must return into the matter; e.g., if a living thing is generated
from a dead one, it must first become the matter, and then a living
thing; and vinegar must first become water, and then wine.
With regard to the difficulty which we have described
30 in
connection with definitions and numbers, what is the cause of the
unification? In all things which have a plurality of parts, and which
are not a total aggregate but a whole of some sort distinct from the
parts, there is some
cause ; inasmuch as even in bodies
sometimes contact is the cause of their unity, and sometimes viscosity
or some other such quality.But a definition is
one account, not by connection,
like the
Iliad
, but because it is a definition of one thing.
What is it, then, that makes "man" one
thing, and why does it make him one thing and not many, e.g. "animal"
and "two-footed," especially if, as some say, there is an Idea of
"animal" and an Idea of "two-footed"?Why are not these Ideas "man," and why should
not man exist by participation, not in any "man," but in two Ideas,
those of "animal" and "two-footed"?
[20]
And in general "man" will be not one, but two
things—"animal" and "two-footed." Evidently if we proceed in
this way, as it is usual to define and explain, it will be impossible
to answer and solve the difficulty.But if, as we maintain, man is part matter and
part form—the matter being potentially, and the form
actually man—, the point which we are investigating will no
longer seem to be a difficulty. For this difficulty is just the same
as we should have if the definition of X
31 were "round bronze"; for this name
would give a clue to the formula, so that the question becomes "what
is the cause of the unification of 'round' and 'bronze'?"The difficulty is no longer
apparent, because the one is matter and the other form. What then is
it (apart from the active cause) which causes that which exists
potentially to exist actually in things which admit of generation?
There
is no other cause of the potential sphere's being
an actual sphere; this was the essence of each.
32Some
matter is intelligible and some sensible, and part of the formula is
always matter and part actuality; e.g., the circle is a plane
figure.
33 But such thing
34 as have no matter, neither intelligible nor
sensible, are ipso facto each one of them essentially something one;
[
1045b]
[1]
just as they are essentially something
existent: an individual substance, a quality, or a quantity. Hence
neither "existent" nor "one" is present in their definitions. And
their essence is ipso facto something one, just as it is something
existent.Hence also
there is no other cause of the unity of any of these things, or of
their existence; for each one of them is one and "existent" not
because it is contained in the genus "being" or "unity," nor because
these genera exist separately apart from their particulars, but ipso
facto.
It is because of this difficulty that some
thinkers
35 speak of "participation," and raise the question of
what is the cause of participation, and what participation means; and
others speak of "communion"; e.g., Lycophron
36 says that
knowledge is a communion of the soul with "knowing"; and others call
life a combination or connection of soul with body.The same argument, however, applies in
every case; for "being healthy" will be the "communion" or
"connection" or "combination" of soul and health; and "being a bronze
triangle" a "combination" of bronze and triangle; and "being white" a
"combination" of surface and whiteness. The reason for this is that
people look for a unifying formula, and a difference, between
potentiality and actuality.But, as we have said,
37 the proximate matter and the shape are one
and the same; the one existing potentially, and the other
actually.
[20]
Therefore to
ask the cause of their unity is like asking the cause of unity in
general; for each individual thing is one, and the potential and the
actual are in a sense one. Thus there is no cause other than whatever
initiates the development from potentiality to actuality. And such
things as have no matter are all, without qualification, essential
unities.