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Physics
By Aristotle
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Physics
By Aristotle
Written 350 B.C.E
Translated by R. P. Hardie and R. K. Gaye
Part 1
When the objects of an inquiry, in any department, have principles, conditions,
or elements, it is through acquaintance with these that knowledge, that
is to say scientific knowledge, is attained. For we do not think that we
know a thing until we are acquainted with its primary conditions or first
principles, and have carried our analysis as far as its simplest elements.
Plainly therefore in the science of Nature, as in other branches of study,
our first task will be to try to determine what relates to its
principles.
The natural way of doing this is to start from the things which
are more knowable and obvious to us and proceed towards those which are
clearer and more knowable by nature; for the same things are not 'knowable
relatively to us' and 'knowable' without qualification. So in the present
inquiry we must follow this method and advance from what is more obscure
by nature, but clearer to us, towards what is more clear and more knowable
by nature.
Now what is to us plain and obvious at first is rather confused
masses, the elements and principles of which become known to us later by
analysis. Thus we must advance from generalities to particulars; for it
is a whole that is best known to sense-perception, and a generality is
a kind of whole, comprehending many things within it, like parts. Much
the same thing happens in the relation of the name to the formula. A name,
e.g. 'round', means vaguely a sort of whole: its definition analyses this
into its particular senses. Similarly a child begins by calling all men
'father', and all women 'mother', but later on distinguishes each of
them.
Part 2
The principles in question must be either (a) one or (b) more than
one. If (a) one, it must be either (i) motionless, as Parmenides and Melissus
assert, or (ii) in motion, as the physicists hold, some declaring air to
be the first principle, others water. If (b) more than one, then either
(i) a finite or (ii) an infinite plurality. If (i) finite (but more than
one), then either two or three or four or some other number. If (ii) infinite,
then either as Democritus believed one in kind, but differing in shape
or form; or different in kind and even contrary.
A similar inquiry is made by those who inquire into the number
of existents: for they inquire whether the ultimate constituents of existing
things are one or many, and if many, whether a finite or an infinite plurality.
So they too are inquiring whether the principle or element is one or
many.
Now to investigate whether Being is one and motionless is not a
contribution to the science of Nature. For just as the geometer has nothing
more to say to one who denies the principles of his science-this being
a question for a different science or for or common to all-so a man investigating
principles cannot argue with one who denies their existence. For if Being
is just one, and one in the way mentioned, there is a principle no longer,
since a principle must be the principle of some thing or
things.
To inquire therefore whether Being is one in this sense would be
like arguing against any other position maintained for the sake of argument
(such as the Heraclitean thesis, or such a thesis as that Being is one
man) or like refuting a merely contentious argument-a description which
applies to the arguments both of Melissus and of Parmenides: their premisses
are false and their conclusions do not follow. Or rather the argument of
Melissus is gross and palpable and offers no difficulty at all: accept
one ridiculous proposition and the rest follows-a simple enough
proceeding.
We physicists, on the other hand, must take for granted that the
things that exist by nature are, either all or some of them, in motion
which is indeed made plain by induction. Moreover, no man of science is
bound to solve every kind of difficulty that may be raised, but only as
many as are drawn falsely from the principles of the science: it is not
our business to refute those that do not arise in this way: just as it
is the duty of the geometer to refute the squaring of the circle by means
of segments, but it is not his duty to refute Antiphon's proof. At the
same time the holders of the theory of which we are speaking do incidentally
raise physical questions, though Nature is not their subject: so it will
perhaps be as well to spend a few words on them, especially as the inquiry
is not without scientific interest.
The most pertinent question with which to begin will be this: In
what sense is it asserted that all things are one? For 'is' is used in
many senses. Do they mean that all things 'are' substance or quantities
or qualities? And, further, are all things one substance-one man, one horse,
or one soul-or quality and that one and the same-white or hot or something
of the kind? These are all very different doctrines and all impossible
to maintain.
For if both substance and quantity and quality are, then, whether
these exist independently of each other or not, Being will be
many.
If on the other hand it is asserted that all things are quality
or quantity, then, whether substance exists or not, an absurdity results,
if the impossible can properly be called absurd. For none of the others
can exist independently: substance alone is independent: for everything
is predicated of substance as subject. Now Melissus says that Being is
infinite. It is then a quantity. For the infinite is in the category of
quantity, whereas substance or quality or affection cannot be infinite
except through a concomitant attribute, that is, if at the same time they
are also quantities. For to define the infinite you must use quantity in
your formula, but not substance or quality. If then Being is both substance
and quantity, it is two, not one: if only substance, it is not infinite
and has no magnitude; for to have that it will have to be a
quantity.
Again, 'one' itself, no less than 'being', is used in many senses,
so we must consider in what sense the word is used when it is said that
the All is one.
Now we say that (a) the continuous is one or that (b) the indivisible
is one, or (c) things are said to be 'one', when their essence is one and
the same, as 'liquor' and 'drink'.
If (a) their One is one in the sense of continuous, it is many,
for the continuous is divisible ad infinitum.
There is, indeed, a difficulty about part and whole, perhaps not
relevant to the present argument, yet deserving consideration on its own
account-namely, whether the part and the whole are one or more than one,
and how they can be one or many, and, if they are more than one, in what
sense they are more than one. (Similarly with the parts of wholes which
are not continuous.) Further, if each of the two parts is indivisibly one
with the whole, the difficulty arises that they will be indivisibly one
with each other also.
But to proceed: If (b) their One is one as indivisible, nothing
will have quantity or quality, and so the one will not be infinite, as
Melissus says-nor, indeed, limited, as Parmenides says, for though the
limit is indivisible, the limited is not.
But if (c) all things are one in the sense of having the same definition,
like 'raiment' and 'dress', then it turns out that they are maintaining
the Heraclitean doctrine, for it will be the same thing 'to be good' and
'to be bad', and 'to be good' and 'to be not good', and so the same thing
will be 'good' and 'not good', and man and horse; in fact, their view will
be, not that all things are one, but that they are nothing; and that 'to
be of such-and-such a quality' is the same as 'to be of such-and-such a
size'.
Even the more recent of the ancient thinkers were in a pother lest
the same thing should turn out in their hands both one and many. So some,
like Lycophron, were led to omit 'is', others to change the mode of expression
and say 'the man has been whitened' instead of 'is white', and 'walks'
instead of 'is walking', for fear that if they added the word 'is' they
should be making the one to be many-as if 'one' and 'being' were always
used in one and the same sense. What 'is' may be many either in definition
(for example 'to be white' is one thing, 'to be musical' another, yet the
same thing be both, so the one is many) or by division, as the whole and
its parts. On this point, indeed, they were already getting into difficulties
and admitted that the one was many-as if there was any difficulty about
the same thing being both one and many, provided that these are not opposites;
for 'one' may mean either 'potentially one' or 'actually
one'.
Part 3
If, then, we approach the thesis in this way it seems impossible
for all things to be one. Further, the arguments they use to prove their
position are not difficult to expose. For both of them reason contentiously-I
mean both Melissus and Parmenides. [Their premisses are false and their
conclusions do not follow. Or rather the argument of Melissus is gross
and palpable and offers no difficulty at all: admit one ridiculous proposition
and the rest follows-a simple enough proceeding.] The fallacy of Melissus
is obvious. For he supposes that the assumption 'what has come into being
always has a beginning' justifies the assumption 'what has not come into
being has no beginning'. Then this also is absurd, that in every case there
should be a beginning of the thing-not of the time and not only in the
case of coming to be in the full sense but also in the case of coming to
have a quality-as if change never took place suddenly. Again, does it follow
that Being, if one, is motionless? Why should it not move, the whole of
it within itself, as parts of it do which are unities, e.g. this water?
Again, why is qualitative change impossible? But, further, Being cannot
be one in form, though it may be in what it is made of. (Even some of the
physicists hold it to be one in the latter way, though not in the former.)
Man obviously differs from horse in form, and contraries from each
other.
The same kind of argument holds good against Parmenides also, besides
any that may apply specially to his view: the answer to him being that
'this is not true' and 'that does not follow'. His assumption that one
is used in a single sense only is false, because it is used in several.
His conclusion does not follow, because if we take only white things, and
if 'white' has a single meaning, none the less what is white will be many
and not one. For what is white will not be one either in the sense that
it is continuous or in the sense that it must be defined in only one way.
'Whiteness' will be different from 'what has whiteness'. Nor does this
mean that there is anything that can exist separately, over and above what
is white. For 'whiteness' and 'that which is white' differ in definition,
not in the sense that they are things which can exist apart from each other.
But Parmenides had not come in sight of this distinction.
It is necessary for him, then, to assume not only that 'being'
has the same meaning, of whatever it is predicated, but further that it
means (1) what just is and (2) what is just one.
It must be so, for (1) an attribute is predicated of some subject,
so that the subject to which 'being' is attributed will not be, as it is
something different from 'being'. Something, therefore, which is not will
be. Hence 'substance' will not be a predicate of anything else. For the
subject cannot be a being, unless 'being' means several things, in such
a way that each is something. But ex hypothesi 'being' means only one
thing.
If, then, 'substance' is not attributed to anything, but other
things are attributed to it, how does 'substance' mean what is rather than
what is not? For suppose that 'substance' is also 'white'. Since the definition
of the latter is different (for being cannot even be attributed to white,
as nothing is which is not 'substance'), it follows that 'white' is not-being--and
that not in the sense of a particular not-being, but in the sense that
it is not at all. Hence 'substance' is not; for it is true to say that
it is white, which we found to mean not-being. If to avoid this we say
that even 'white' means substance, it follows that 'being' has more than
one meaning.
In particular, then, Being will not have magnitude, if it is substance.
For each of the two parts must he in a different sense.
(2) Substance is plainly divisible into other substances, if we
consider the mere nature of a definition. For instance, if 'man' is a substance,
'animal' and 'biped' must also be substances. For if not substances, they
must be attributes-and if attributes, attributes either of (a) man or of
(b) some other subject. But neither is possible.
(a) An attribute is either that which may or may not belong to
the subject or that in whose definition the subject of which it is an attribute
is involved. Thus 'sitting' is an example of a separable attribute, while
'snubness' contains the definition of 'nose', to which we attribute snubness.
Further, the definition of the whole is not contained in the definitions
of the contents or elements of the definitory formula; that of 'man' for
instance in 'biped', or that of 'white man' in 'white'. If then this is
so, and if 'biped' is supposed to be an attribute of 'man', it must be
either separable, so that 'man' might possibly not be 'biped', or the definition
of 'man' must come into the definition of 'biped'-which is impossible,
as the converse is the case.
(b) If, on the other hand, we suppose that 'biped' and 'animal'
are attributes not of man but of something else, and are not each of them
a substance, then 'man' too will be an attribute of something else. But
we must assume that substance is not the attribute of anything, that the
subject of which both 'biped' and 'animal' and each separately are predicated
is the subject also of the complex 'biped animal'.
Are we then to say that the All is composed of indivisible substances?
Some thinkers did, in point of fact, give way to both arguments. To the
argument that all things are one if being means one thing, they conceded
that not-being is; to that from bisection, they yielded by positing atomic
magnitudes. But obviously it is not true that if being means one thing,
and cannot at the same time mean the contradictory of this, there will
be nothing which is not, for even if what is not cannot be without qualification,
there is no reason why it should not be a particular not-being. To say
that all things will be one, if there is nothing besides Being itself,
is absurd. For who understands 'being itself' to be anything but a particular
substance? But if this is so, there is nothing to prevent there being many
beings, as has been said.
It is, then, clearly impossible for Being to be one in this
sense.
Part 4
The physicists on the other hand have two modes of
explanation.
The first set make the underlying body one either one of the three
or something else which is denser than fire and rarer than air then generate
everything else from this, and obtain multiplicity by condensation and
rarefaction. Now these are contraries, which may be generalized into 'excess
and defect'. (Compare Plato's 'Great and Small'-except that he make these
his matter, the one his form, while the others treat the one which underlies
as matter and the contraries as differentiae, i.e. forms).
The second set assert that the contrarieties are contained in the
one and emerge from it by segregation, for example Anaximander and also
all those who assert that 'what is' is one and many, like Empedocles and
Anaxagoras; for they too produce other things from their mixture by segregation.
These differ, however, from each other in that the former imagines a cycle
of such changes, the latter a single series. Anaxagoras again made both
his 'homceomerous' substances and his contraries infinite in multitude,
whereas Empedocles posits only the so-called elements.
The theory of Anaxagoras that the principles are infinite in multitude
was probably due to his acceptance of the common opinion of the physicists
that nothing comes into being from not-being. For this is the reason why
they use the phrase 'all things were together' and the coming into being
of such and such a kind of thing is reduced to change of quality, while
some spoke of combination and separation. Moreover, the fact that the contraries
proceed from each other led them to the conclusion. The one, they reasoned,
must have already existed in the other; for since everything that comes
into being must arise either from what is or from what is not, and it is
impossible for it to arise from what is not (on this point all the physicists
agree), they thought that the truth of the alternative necessarily followed,
namely that things come into being out of existent things, i.e. out of
things already present, but imperceptible to our senses because of the
smallness of their bulk. So they assert that everything has been mixed
in every. thing, because they saw everything arising out of everything.
But things, as they say, appear different from one another and receive
different names according to the nature of the particles which are numerically
predominant among the innumerable constituents of the mixture. For nothing,
they say, is purely and entirely white or black or sweet, bone or flesh,
but the nature of a thing is held to be that of which it contains the
most.
Now (1) the infinite qua infinite is unknowable, so that what is
infinite in multitude or size is unknowable in quantity, and what is infinite
in variety of kind is unknowable in quality. But the principles in question
are infinite both in multitude and in kind. Therefore it is impossible
to know things which are composed of them; for it is when we know the nature
and quantity of its components that we suppose we know a
complex.
Further (2) if the parts of a whole may be of any size in the direction
either of greatness or of smallness (by 'parts' I mean components into
which a whole can be divided and which are actually present in it), it
is necessary that the whole thing itself may be of any size. Clearly, therefore,
since it is impossible for an animal or plant to be indefinitely big or
small, neither can its parts be such, or the whole will be the same. But
flesh, bone, and the like are the parts of animals, and the fruits are
the parts of plants. Hence it is obvious that neither flesh, bone, nor
any such thing can be of indefinite size in the direction either of the
greater or of the less.
Again (3) according to the theory all such things are already present
in one another and do not come into being but are constituents which are
separated out, and a thing receives its designation from its chief constituent.
Further, anything may come out of anything-water by segregation from flesh
and flesh from water. Hence, since every finite body is exhausted by the
repeated abstraction of a finite body, it seems obviously to follow that
everything cannot subsist in everything else. For let flesh be extracted
from water and again more flesh be produced from the remainder by repeating
the process of separation: then, even though the quantity separated out
will continually decrease, still it will not fall below a certain magnitude.
If, therefore, the process comes to an end, everything will not be in everything
else (for there will be no flesh in the remaining water); if on the other
hand it does not, and further extraction is always possible, there will
be an infinite multitude of finite equal particles in a finite quantity-which
is impossible. Another proof may be added: Since every body must diminish
in size when something is taken from it, and flesh is quantitatively definite
in respect both of greatness and smallness, it is clear that from the minimum
quantity of flesh no body can be separated out; for the flesh left would
be less than the minimum of flesh.
Lastly (4) in each of his infinite bodies there would be already
present infinite flesh and blood and brain- having a distinct existence,
however, from one another, and no less real than the infinite bodies, and
each infinite: which is contrary to reason.
The statement that complete separation never will take place is
correct enough, though Anaxagoras is not fully aware of what it means.
For affections are indeed inseparable. If then colours and states had entered
into the mixture, and if separation took place, there would be a 'white'
or a 'healthy' which was nothing but white or healthy, i.e. was not the
predicate of a subject. So his 'Mind' is an absurd person aiming at the
impossible, if he is supposed to wish to separate them, and it is impossible
to do so, both in respect of quantity and of quality- of quantity, because
there is no minimum magnitude, and of quality, because affections are
inseparable.
Nor is Anaxagoras right about the coming to be of homogeneous bodies.
It is true there is a sense in which clay is divided into pieces of clay,
but there is another in which it is not. Water and air are, and are generated
'from' each other, but not in the way in which bricks come 'from' a house
and again a house 'from' bricks; and it is better to assume a smaller and
finite number of principles, as Empedocles does.
Part 5
All thinkers then agree in making the contraries principles, both
those who describe the All as one and unmoved (for even Parmenides treats
hot and cold as principles under the names of fire and earth) and those
too who use the rare and the dense. The same is true of Democritus also,
with his plenum and void, both of which exist, be says, the one as being,
the other as not-being. Again he speaks of differences in position, shape,
and order, and these are genera of which the species are contraries, namely,
of position, above and below, before and behind; of shape, angular and
angle-less, straight and round.
It is plain then that they all in one way or another identify the
contraries with the principles. And with good reason. For first principles
must not be derived from one another nor from anything else, while everything
has to be derived from them. But these conditions are fulfilled by the
primary contraries, which are not derived from anything else because they
are primary, nor from each other because they are contraries.
But we must see how this can be arrived at as a reasoned result,
as well as in the way just indicated.
Our first presupposition must be that in nature nothing acts on,
or is acted on by, any other thing at random, nor may anything come from
anything else, unless we mean that it does so in virtue of a concomitant
attribute. For how could 'white' come from 'musical', unless 'musical'
happened to be an attribute of the not-white or of the black? No, 'white'
comes from 'not-white'-and not from any 'not-white', but from black or
some intermediate colour. Similarly, 'musical' comes to be from 'not-musical',
but not from any thing other than musical, but from 'unmusical' or any
intermediate state there may be.
Nor again do things pass into the first chance thing; 'white' does
not pass into 'musical' (except, it may be, in virtue of a concomitant
attribute), but into 'not-white'-and not into any chance thing which is
not white, but into black or an intermediate colour; 'musical' passes into
'not-musical'-and not into any chance thing other than musical, but into
'unmusical' or any intermediate state there may be.
The same holds of other things also: even things which are not
simple but complex follow the same principle, but the opposite state has
not received a name, so we fail to notice the fact. What is in tune must
come from what is not in tune, and vice versa; the tuned passes into untunedness-and
not into any untunedness, but into the corresponding opposite. It does
not matter whether we take attunement, order, or composition for our illustration;
the principle is obviously the same in all, and in fact applies equally
to the production of a house, a statue, or any other complex. A house comes
from certain things in a certain state of separation instead of conjunction,
a statue (or any other thing that has been shaped) from shapelessness-each
of these objects being partly order and partly composition.
If then this is true, everything that comes to be or passes away
from, or passes into, its contrary or an intermediate state. But the intermediates
are derived from the contraries-colours, for instance, from black and white.
Everything, therefore, that comes to be by a natural process is either
a contrary or a product of contraries.
Up to this point we have practically had most of the other writers
on the subject with us, as I have said already: for all of them identify
their elements, and what they call their principles, with the contraries,
giving no reason indeed for the theory, but contrained as it were by the
truth itself. They differ, however, from one another in that some assume
contraries which are more primary, others contraries which are less so:
some those more knowable in the order of explanation, others those more
familiar to sense. For some make hot and cold, or again moist and dry,
the conditions of becoming; while others make odd and even, or again Love
and Strife; and these differ from each other in the way
mentioned.
Hence their principles are in one sense the same, in another different;
different certainly, as indeed most people think, but the same inasmuch
as they are analogous; for all are taken from the same table of columns,
some of the pairs being wider, others narrower in extent. In this way then
their theories are both the same and different, some better, some worse;
some, as I have said, take as their contraries what is more knowable in
the order of explanation, others what is more familiar to sense. (The universal
is more knowable in the order of explanation, the particular in the order
of sense: for explanation has to do with the universal, sense with the
particular.) 'The great and the small', for example, belong to the former
class, 'the dense and the rare' to the latter.
It is clear then that our principles must be
contraries.
Part 6
The next question is whether the principles are two or three or
more in number.
One they cannot be, for there cannot be one contrary. Nor can they
be innumerable, because, if so, Being will not be knowable: and in any
one genus there is only one contrariety, and substance is one genus: also
a finite number is sufficient, and a finite number, such as the principles
of Empedocles, is better than an infinite multitude; for Empedocles professes
to obtain from his principles all that Anaxagoras obtains from his innumerable
principles. Lastly, some contraries are more primary than others, and some
arise from others-for example sweet and bitter, white and black-whereas
the principles must always remain principles.
This will suffice to show that the principles are neither one nor
innumerable.
Granted, then, that they are a limited number, it is plausible
to suppose them more than two. For it is difficult to see how either density
should be of such a nature as to act in any way on rarity or rarity on
density. The same is true of any other pair of contraries; for Love does
not gather Strife together and make things out of it, nor does Strife make
anything out of Love, but both act on a third thing different from both.
Some indeed assume more than one such thing from which they construct the
world of nature.
Other objections to the view that it is not necessary to assume
a third principle as a substratum may be added. (1) We do not find that
the contraries constitute the substance of any thing. But what is a first
principle ought not to be the predicate of any subject. If it were, there
would be a principle of the supposed principle: for the subject is a principle,
and prior presumably to what is predicated of it. Again (2) we hold that
a substance is not contrary to another substance. How then can substance
be derived from what are not substances? Or how can non-substances be prior
to substance?
If then we accept both the former argument and this one, we must,
to preserve both, assume a third somewhat as the substratum of the contraries,
such as is spoken of by those who describe the All as one nature-water
or fire or what is intermediate between them. What is intermediate seems
preferable; for fire, earth, air, and water are already involved with pairs
of contraries. There is, therefore, much to be said for those who make
the underlying substance different from these four; of the rest, the next
best choice is air, as presenting sensible differences in a less degree
than the others; and after air, water. All, however, agree in this, that
they differentiate their One by means of the contraries, such as density
and rarity and more and less, which may of course be generalized, as has
already been said into excess and defect. Indeed this doctrine too (that
the One and excess and defect are the principles of things) would appear
to be of old standing, though in different forms; for the early thinkers
made the two the active and the one the passive principle, whereas some
of the more recent maintain the reverse.
To suppose then that the elements are three in number would seem,
from these and similar considerations, a plausible view, as I said before.
On the other hand, the view that they are more than three in number would
seem to be untenable.
For the one substratum is sufficient to be acted on; but if we
have four contraries, there will be two contrarieties, and we shall have
to suppose an intermediate nature for each pair separately. If, on the
other hand, the contrarieties, being two, can generate from each other,
the second contrariety will be superfluous. Moreover, it is impossible
that there should be more than one primary contrariety. For substance is
a single genus of being, so that the principles can differ only as prior
and posterior, not in genus; in a single genus there is always a single
contrariety, all the other contrarieties in it being held to be reducible
to one.
It is clear then that the number of elements is neither one nor
more than two or three; but whether two or three is, as I said, a question
of considerable difficulty.
Part 7
We will now give our own account, approaching the question first
with reference to becoming in its widest sense: for we shall be following
the natural order of inquiry if we speak first of common characteristics,
and then investigate the characteristics of special
cases.
We say that one thing comes to be from another thing, and one sort
of thing from another sort of thing, both in the case of simple and of
complex things. I mean the following. We can say (1) 'man becomes musical',
(2) what is 'not-musical becomes musical', or (3), the 'not-musical man
becomes a musical man'. Now what becomes in (1) and (2)-'man' and 'not
musical'-I call simple, and what each becomes-'musical'-simple also. But
when (3) we say the 'not-musical man becomes a musical man', both what
becomes and what it becomes are complex.
As regards one of these simple 'things that become' we say not
only 'this becomes so-and-so', but also 'from being this, comes to be so-and-so',
as 'from being not-musical comes to be musical'; as regards the other we
do not say this in all cases, as we do not say (1) 'from being a man he
came to be musical' but only 'the man became musical'.
When a 'simple' thing is said to become something, in one case
(1) it survives through the process, in the other (2) it does not. For
man remains a man and is such even when he becomes musical, whereas what
is not musical or is unmusical does not continue to exist, either simply
or combined with the subject.
These distinctions drawn, one can gather from surveying the various
cases of becoming in the way we are describing that, as we say, there must
always be an underlying something, namely that which becomes, and that
this, though always one numerically, in form at least is not one. (By that
I mean that it can be described in different ways.) For 'to be man' is
not the same as 'to be unmusical'. One part survives, the other does not:
what is not an opposite survives (for 'man' survives), but 'not-musical'
or 'unmusical' does not survive, nor does the compound of the two, namely
'unmusical man'.
We speak of 'becoming that from this' instead of 'this becoming
that' more in the case of what does not survive the change-'becoming musical
from unmusical', not 'from man'-but there are exceptions, as we sometimes
use the latter form of expression even of what survives; we speak of 'a
statue coming to be from bronze', not of the 'bronze becoming a statue'.
The change, however, from an opposite which does not survive is described
indifferently in both ways, 'becoming that from this' or 'this becoming
that'. We say both that 'the unmusical becomes musical', and that 'from
unmusical he becomes musical'. And so both forms are used of the complex,
'becoming a musical man from an unmusical man', and unmusical man becoming
a musical man'.
But there are different senses of 'coming to be'. In some cases
we do not use the expression 'come to be', but 'come to be so-and-so'.
Only substances are said to 'come to be' in the unqualified
sense.
Now in all cases other than substance it is plain that there must
be some subject, namely, that which becomes. For we know that when a thing
comes to be of such a quantity or quality or in such a relation, time,
or place, a subject is always presupposed, since substance alone is not
predicated of another subject, but everything else of
substance.
But that substances too, and anything else that can be said 'to
be' without qualification, come to be from some substratum, will appear
on examination. For we find in every case something that underlies from
which proceeds that which comes to be; for instance, animals and plants
from seed.
Generally things which come to be, come to be in different ways:
(1) by change of shape, as a statue; (2) by addition, as things which grow;
(3) by taking away, as the Hermes from the stone; (4) by putting together,
as a house; (5) by alteration, as things which 'turn' in respect of their
material substance.
It is plain that these are all cases of coming to be from a
substratum.
Thus, clearly, from what has been said, whatever comes to be is
always complex. There is, on the one hand, (a) something which comes into
existence, and again (b) something which becomes that-the latter (b) in
two senses, either the subject or the opposite. By the 'opposite' I mean
the 'unmusical', by the 'subject' 'man', and similarly I call the absence
of shape or form or order the 'opposite', and the bronze or stone or gold
the 'subject'.
Plainly then, if there are conditions and principles which constitute
natural objects and from which they primarily are or have come to be-have
come to be, I mean, what each is said to be in its essential nature, not
what each is in respect of a concomitant attribute-plainly, I say, everything
comes to be from both subject and form. For 'musical man' is composed (in
a way) of 'man' and 'musical': you can analyse it into the definitions
of its elements. It is clear then that what comes to be will come to be
from these elements.
Now the subject is one numerically, though it is two in form. (For
it is the man, the gold-the 'matter' generally-that is counted, for it
is more of the nature of a 'this', and what comes to be does not come from
it in virtue of a concomitant attribute; the privation, on the other hand,
and the contrary are incidental in the process.) And the positive form
is one-the order, the acquired art of music, or any similar
predicate.
There is a sense, therefore, in which we must declare the principles
to be two, and a sense in which they are three; a sense in which the contraries
are the principles-say for example the musical and the unmusical, the hot
and the cold, the tuned and the untuned-and a sense in which they are not,
since it is impossible for the contraries to be acted on by each other.
But this difficulty also is solved by the fact that the substratum is different
from the contraries, for it is itself not a contrary. The principles therefore
are, in a way, not more in number than the contraries, but as it were two,
nor yet precisely two, since there is a difference of essential nature,
but three. For 'to be man' is different from 'to be unmusical', and 'to
be unformed' from 'to be bronze'.
We have now stated the number of the principles of natural objects
which are subject to generation, and how the number is reached: and it
is clear that there must be a substratum for the contraries, and that the
contraries must be two. (Yet in another way of putting it this is not necessary,
as one of the contraries will serve to effect the change by its successive
absence and presence.)
The underlying nature is an object of scientific knowledge, by
an analogy. For as the bronze is to the statue, the wood to the bed, or
the matter and the formless before receiving form to any thing which has
form, so is the underlying nature to substance, i.e. the 'this' or
existent.
This then is one principle (though not one or existent in the same
sense as the 'this'), and the definition was one as we agreed; then further
there is its contrary, the privation. In what sense these are two, and
in what sense more, has been stated above. Briefly, we explained first
that only the contraries were principles, and later that a substratum was
indispensable, and that the principles were three; our last statement has
elucidated the difference between the contraries, the mutual relation of
the principles, and the nature of the substratum. Whether the form or the
substratum is the essential nature of a physical object is not yet clear.
But that the principles are three, and in what sense, and the way in which
each is a principle, is clear.
So much then for the question of the number and the nature of the
principles.
Part 8
We will now proceed to show that the difficulty of the early thinkers,
as well as our own, is solved in this way alone.
The first of those who studied science were misled in their search
for truth and the nature of things by their inexperience, which as it were
thrust them into another path. So they say that none of the things that
are either comes to be or passes out of existence, because what comes to
be must do so either from what is or from what is not, both of which are
impossible. For what is cannot come to be (because it is already), and
from what is not nothing could have come to be (because something must
be present as a substratum). So too they exaggerated the consequence of
this, and went so far as to deny even the existence of a plurality of things,
maintaining that only Being itself is. Such then was their opinion, and
such the reason for its adoption.
Our explanation on the other hand is that the phrases 'something
comes to be from what is or from what is not', 'what is not or what is
does something or has something done to it or becomes some particular thing',
are to be taken (in the first way of putting our explanation) in the same
sense as 'a doctor does something or has something done to him', 'is or
becomes something from being a doctor.' These expressions may be taken
in two senses, and so too, clearly, may 'from being', and 'being acts or
is acted on'. A doctor builds a house, not qua doctor, but qua housebuilder,
and turns gray, not qua doctor, but qua dark-haired. On the other hand
he doctors or fails to doctor qua doctor. But we are using words most appropriately
when we say that a doctor does something or undergoes something, or becomes
something from being a doctor, if he does, undergoes, or becomes qua doctor.
Clearly then also 'to come to be so-and-so from not-being' means 'qua
not-being'.
It was through failure to make this distinction that those thinkers
gave the matter up, and through this error that they went so much farther
astray as to suppose that nothing else comes to be or exists apart from
Being itself, thus doing away with all becoming.
We ourselves are in agreement with them in holding that nothing
can be said without qualification to come from what is not. But nevertheless
we maintain that a thing may 'come to be from what is not'-that is, in
a qualified sense. For a thing comes to be from the privation, which in
its own nature is not-being,-this not surviving as a constituent of the
result. Yet this causes surprise, and it is thought impossible that something
should come to be in the way described from what is
not.
In the same way we maintain that nothing comes to be from being,
and that being does not come to be except in a qualified sense. In that
way, however, it does, just as animal might come to be from animal, and
an animal of a certain kind from an animal of a certain kind. Thus, suppose
a dog to come to be from a horse. The dog would then, it is true, come
to be from animal (as well as from an animal of a certain kind) but not
as animal, for that is already there. But if anything is to become an animal,
not in a qualified sense, it will not be from animal: and if being, not
from being-nor from not-being either, for it has been explained that by
'from not being' we mean from not-being qua not-being.
Note further that we do not subvert the principle that everything
either is or is not.
This then is one way of solving the difficulty. Another consists
in pointing out that the same things can be explained in terms of potentiality
and actuality. But this has been done with greater precision elsewhere.
So, as we said, the difficulties which constrain people to deny the existence
of some of the things we mentioned are now solved. For it was this reason
which also caused some of the earlier thinkers to turn so far aside from
the road which leads to coming to be and passing away and change generally.
If they had come in sight of this nature, all their ignorance would have
been dispelled.
Part 9
Others, indeed, have apprehended the nature in question, but not
adequately.
In the first place they allow that a thing may come to be without
qualification from not being, accepting on this point the statement of
Parmenides. Secondly, they think that if the substratum is one numerically,
it must have also only a single potentiality-which is a very different
thing.
Now we distinguish matter and privation, and hold that one of these,
namely the matter, is not-being only in virtue of an attribute which it
has, while the privation in its own nature is not-being; and that the matter
is nearly, in a sense is, substance, while the privation in no sense is.
They, on the other hand, identify their Great and Small alike with not
being, and that whether they are taken together as one or separately. Their
triad is therefore of quite a different kind from ours. For they got so
far as to see that there must be some underlying nature, but they make
it one-for even if one philosopher makes a dyad of it, which he calls Great
and Small, the effect is the same, for he overlooked the other nature.
For the one which persists is a joint cause, with the form, of what comes
to be-a mother, as it were. But the negative part of the contrariety may
often seem, if you concentrate your attention on it as an evil agent, not
to exist at all.
For admitting with them that there is something divine, good, and
desirable, we hold that there are two other principles, the one contrary
to it, the other such as of its own nature to desire and yearn for it.
But the consequence of their view is that the contrary desires its wtextinction.
Yet the form cannot desire itself, for it is not defective; nor can the
contrary desire it, for contraries are mutually destructive. The truth
is that what desires the form is matter, as the female desires the male
and the ugly the beautiful-only the ugly or the female not per se but per
accidens.
The matter comes to be and ceases to be in one sense, while in
another it does not. As that which contains the privation, it ceases to
be in its own nature, for what ceases to be-the privation-is contained
within it. But as potentiality it does not cease to be in its own nature,
but is necessarily outside the sphere of becoming and ceasing to be. For
if it came to be, something must have existed as a primary substratum from
which it should come and which should persist in it; but this is its own
special nature, so that it will be before coming to be. (For my definition
of matter is just this-the primary substratum of each thing, from which
it comes to be without qualification, and which persists in the result.)
And if it ceases to be it will pass into that at the last, so it will have
ceased to be before ceasing to be.
The accurate determination of the first principle in respect of
form, whether it is one or many and what it is or what they are, is the
province of the primary type of science; so these questions may stand over
till then. But of the natural, i.e. perishable, forms we shall speak in
the expositions which follow.
The above, then, may be taken as sufficient to establish that there
are principles and what they are and how many there are. Now let us make
a fresh start and proceed.