The Basic Works of Aristotle (Modern Library Classics) (89 page)

10
     Further, since the change which is motion has been proved
⁵⁸
to be eternal,
(15)
the continuity of the occurrence of coming-to-be follows necessarily from what we have established: for the eternal motion, by causing ‘the generator’
⁵⁹
to approach and retire, will produce coming-to-be uninterruptedly. At the same time it is clear that we were also right when, in an earlier work,
⁶⁰
we called motion (not coming-to-be) ‘the primary form of change’.
(20)
For it is far more reasonable that
what is
should cause the coming-to-be of
what is not
, than that
what is not
should cause the being of
what is.
Now that which is being moved
is
, but that which is coming-to-be
is not
: hence, also, motion is prior to coming-to-be.

We have assumed, and have proved,
⁶¹
that coming-to-be and passing-away happen to things continuously; and we assert that motion causes coming-to-be.
(25)
That being so, it is evident that, if the motion be single,
both
processes cannot occur since they are contrary to one another: for it is a law of nature that the same cause, provided it remain in the same condition, always produces the same effect, so that, from a
single motion, either coming-to-be or passing-away will always result. The movements must, on the contrary, be more than one,
(30)
and they must be contrasted with one another either by the sense of their motion
⁶²
or by its irregularity:
⁶³
for contrary effects demand contraries as their causes.

This explains why it is not the primary motion that causes coming-to-be and passing-away, but the motion along the inclined circle:
⁶⁴
for this motion not only possesses the necessary continuity, but includes a duality of movements as well.
[336b]
For if coming-to-be and passing-away are always to be continuous, there must be some body always being moved (in order that these changes may not fail) and moved with a duality of movements (in order that both changes, not one only, may result). Now the continuity of this movement is caused by the motion of the whole: but the approaching and retreating of the moving body are caused by the inclination.
⁶⁵
For the consequence of the inclination is that the body becomes alternately remote and near; and since its distance is thus unequal,
(5)
its movement will be irregular. Therefore, if it generates by approaching and by its proximity, it—this very same body—destroys by retreating and becoming remote: and if it generates by many successive approaches, its also destroys by many successive retirements.
(10)
For contrary effects demand contraries as their causes; and the natural processes of passing-away and coming-to-be occupy equal periods of time. Hence, too, the times—i. e the lives—of the several kinds of living things have a number by which they are distinguished: for there is an Order controlling all things, and every time (i. e. every life) is measured by a period. Not all of them, however, are measured by the same period, but some by a smaller and others by a greater one: for to some of them the period,
(15)
which is their measure, is a year, while to some it is longer and to others shorter.

And there are facts of observation in manifest agreement with our theories. Thus we see that coming-to-be occurs as the sun approaches and decay as it retreats; and we see that the two processes occupy equal times. For the durations of the natural processes of passing-away and coming-to-be are equal.
(20)
Nevertheless it often happens that things pass-away in too short a time. This is due to the ‘intermingling’ by which the things that come-to-be and pass-away are implicated with
one another. For their matter is ‘irregular’, i. e. is not everywhere the same: hence the processes by which they come-to-be must be ‘irregular’ too, i. e. some too quick and others too slow. Consequently the phenomenon in question occurs, because the ‘irregular’ coming-to-be of these things is the passing-away of other things.

Coming-to-be and passing-away will, as we have said,
(25)
always be continuous, and will never fail owing to the cause we stated.
⁶⁶
And this continuity has a sufficient reason on our theory. For in all things, as we affirm, Nature always strives after ‘the better’. Now ‘being’ (we have explained elsewhere
⁶⁷
the exact variety of meanings we recognize in this term) is better than ‘not-being’: but not all things can possess ‘being’,
(30)
since they are too far removed from the ‘originative source’. God therefore adopted the remaining alternative, and fulfilled the perfection of the universe by making coming-to-be uninterrupted: for the greatest possible coherence would thus be secured to existence, because that ‘coming-to-be should itself come-to-be perpetually’ is the closest approximation to eternal being.

The cause of this perpetuity of coming-to-be, as we have often said, is circular motion: for that is the only motion which is continuous.
[337a]
That, too, is why all the other things—the things, I mean, which are reciprocally transformed in virtue of their ‘passions’ and their ‘powers of action’, e. g. the ‘simple’ bodies—imitate circular motion. For when Water is transformed into Air, Air into Fire,
(5)
and the Fire back into Water, we say the coming-to-be ‘has completed the circle’, because it reverts again to the beginning. Hence it is by imitating circular motion that rectilinear motion too is continuous.

These considerations serve at the same time to explain what is to some people a baffling problem—viz. why the ‘simple’ bodies, since each of them is travelling towards its own place, have not become dissevered from one another in the infinite lapse of time.
(10)
The reason is their reciprocal transformation. For, had each of them persisted in its own place instead of being transformed by its neighbour, they would have got dissevered long ago. They are transformed, however, owing to the motion with its dual character:
⁶⁸
and because they are transformed, none of them is able to persist in any place allotted to it by the Order.
⁶⁹

It is clear from what has been said (i) that coming-to-be and
passing-away actually occur,
(15)
(ii) what causes them, and (iii) what subject undergoes them. But (
a
) if there is to be movement (as we have explained elsewhere, in an earlier work
⁷⁰
) there must be something which initiates it; if there is to be movement always, there must always be something which initiates it; if the movement is to be continuous,
(20)
what initiates it must be single, unmoved, ungenerated, and incapable of ‘alteration’; and if the circular
⁷¹
movements are more than one, their initiating causes must all of them, in spite of their plurality, be in some way subordinated to a single ‘originative source’. Further (
b
) since time is continuous, movement must be continuous, inasmuch as there can be no time without movement. Time, therefore, is a ‘number’
⁷²
of some continuous movement—a ‘number’,
(25)
therefore, of the circular movement, as was established in the discussions at the beginning.
⁷³
But (
c
) is movement continuous because of the continuity of that which is moved, or because that in which the movement occurs (I mean, e. g., the place or the quality) is continuous? The answer must clearly be ‘because that which is moved is continuous’. (For how can the quality be continuous except in virtue of the continuity of the thing to which it belongs? But if the continuity of ‘that in which’ contributes to make the movement continuous,
(30)
this is true only of ‘the place in which’; for that has ‘magnitude’ in a sense.) But (
d
) amongst continuous bodies which are moved, only that which is moved in a circle is ‘continuous’ in such a way that it preserves its continuity with itself throughout the movement. The conclusion therefore is that
this
is what produces continuous movement, viz. the body which is being moved in a circle; and its movement makes time continuous.

11
     Wherever there is continuity in any process (coming-to-be or ‘alteration’ or any kind of change whatever) we observe ‘consecutiveness’,
(35)
i. e.
this
coming-to-be after
that
without any interval.
[337b]
Hence we must investigate whether, amongst the consecutive members, there is any whose future being is necessary; or whether, on the contrary, every one of them may fail to come-to-be. For that some of them may fail to occur, is clear. (
a
) We need only appeal to the
distinction between the statements ‘
x
will be’ and ‘
x
is about to …’, which depends upon this fact. For if it be true to say of
x
that it ‘will be’, it must at some time be true to say of it that ‘it is’: whereas,
(5)
though it be true to say of
x now
that ‘it is about to occur’, it is quite possible for it not to come-to-be—thus a man might not walk, though he is now ‘about to’ walk. And (
b
) since (to appeal to a general principle) amongst the things which ‘are’ some are capable also of ‘not-being’, it is clear that the same ambiguous character will attach to them no less when they are coming-to-be: in other words, their coming-to-be will not be necessary.

Then are all the things that come-to-be of this contingent character? Or,
(10)
on the contrary, is it absolutely necessary for some of them to come-to-be? Is there, in fact, a distinction in the field of ‘coming-to-be’ corresponding to the distinction, within the field of ‘being’, between things that cannot possibly ‘not-be’ and things that can ‘not-be’? For instance, is it necessary that solstices shall come-to-be, i. e. impossible that they should fail to be able to occur?

Assuming that the antecedent must have come-to-be if the consequent is to be (e. g. that foundations must have come-to-be if there is to be a house: clay,
(15)
if there are to be foundations), is the converse also true? If foundations have come-to-be, must a house come-to-be? The answer seems to be that the necessary
nexus
no longer holds, unless it is ‘necessary’ for the consequent (as well as for the antecedent)
⁷⁴
to come-to-be—‘necessary’
absolutely
. If that be the case, however, ‘a house must come-to-be if foundations have come-to-be’, as well as
vice versa.
For the antecedent was assumed to be so related to the consequent that, if the latter is to be, the antecedent must have come-to-be before it. If,
(20)
therefore, it is necessary that the consequent should come-to-be, the antecedent also must have come-to-be: and if the antecedent has come-to-be, then the consequent also must come-to-be—not, however, because of the antecedent, but because the future being of the consequent was assumed as necessary. Hence, in any sequence, when the being of the consequent is necessary, the
nexus
is reciprocal—in other words, when the antecedent has come-to-be the consequent must always come-to-be too.
(25)

Now (i) if the sequence of occurrences is to proceed
ad infinitum
‘downwards’,
⁷⁵
the coming-to-be of any determinate ‘this’ amongst the later members of the sequence will not be
absolutely
, but only
conditionally
, necessary. For it will always be necessary that some
other
⁷⁶
member shall have come-to-be before ‘this’ as the presupposed condition of the necessity that ‘this’ should come-to-be: consequently, since what is ‘infinite’ has no ‘originative source’, neither will there be in the infinite sequence any ‘primary’ member which will make it ‘necessary’ for the remaining members to come-to-be.
(30)

Nor again (ii) will it be possible to say with truth, even in regard to the members of a limited sequence, that it is ‘absolutely necessary’ for any one of them to come-to-be. We cannot truly say, e. g., that ‘it is absolutely necessary for a house to come-to-be when foundations have been laid’: for (unless it is
always
necessary for a house to be coming-to-be) we should be faced with the consequence that, when foundations have been laid, a thing which need not always be, must always be. No: if its coming-to-be is to be ‘necessary’,
(35)
it must be ‘always’ in its coming-to-be. For what is ‘of necessity’ coincides with what is ‘always’, since that which ‘must be’ cannot possibly ‘not-be’.
[338a]
Hence a thing is eternal if its ‘being’ is necessary: and if it is eternal, its ‘being’ is necessary. And if, therefore, the ‘coming-to-be’ of a thing is necessary, its ‘coming-to-be’ is eternal; and if eternal, necessary.

It follows that the coming-to-be of anything, if it is absolutely necessary,
(5)
must be cyclical—i. e. must return upon itself. For coming-to-be must either be limited or not limited: and if not limited, it must be either rectilinear or cyclical. But the first of these last two alternatives is impossible if coming-to-be is to be eternal, because there could not be any ‘originative source’ whatever in an infinite rectilinear sequence, whether its members be taken ‘downwards’ (as future events) or ‘upwards’ (as past events). Yet coming-to-be must have an ‘originative source’ ,
(10)
nor can it be eternal if it is limited. Consequently it must be cyclical. Hence the
nexus
must be reciprocal. By this I mean that the necessary occurrence of ‘this’ involves the necessary occurrence of its antecedent: and conversely that, given the antecedent, it is also necessary for the consequent to come-to-be. And this reciprocal
nexus
will hold continuously throughout the sequence: for it makes no difference whether the reciprocal
nexus
, of which we are speaking, is mediated by two, or by many, members.
(15)

It is in circular movement; therefore, and in cyclical coming-to-be that the ‘absolutely necessary’ is to be found. In other words, if the coming-to-be of any things is cyclical, it is ‘necessary’ that each of them is coming-to-be and has come-to-be: and if the coming-to-be of any things is ‘necessary’, their coming-to-be is cyclical.

The result we have reached is logically concordant with the eternity of circular motion, i. e. the eternity of the revolution of the heavens (a fact which approved itself on other and independent evidence),
⁷⁷
since precisely those movements which belong to, and depend upon, this eternal revolution ‘come-to-be’ of necessity, and of necessity ‘will be’.
[338b]
For since the revolving body is always setting something else in motion, the movement of the things it moves must also be circular. Thus, from the being of the ‘upper revolution’ it follows that the sun revolves in this determinate manner; and since the sun revolves
thus
, the seasons in consequence come-to-be in a cycle, i. e. return upon themselves; and since they come-to-be-cyclically,
(5)
so in their turn do the things whose coming-to-be the seasons initiate.

Then why do some things manifestly come-to-be in this cyclical fashion (as, e. g., showers and air, so that it must rain if there is to be a cloud and, conversely, there must be a cloud if it is to rain), while men and animals do not ‘return upon themselves’ so that the same individual comes-to-be a second time (for though your coming-to-be presupposes your father’s,
(10)
his coming-to-be does not presuppose yours) ? Why, on the contrary, does this coming-to-be seem to constitute a rectilinear sequence?

In discussing this new problem, we must begin by inquiring whether all things ‘return upon themselves’ in a uniform manner; or whether, on the contrary, though in some sequences what recurs is
numerically
the same, in other sequences it is the same
only in species.
⁷⁸
In consequence of this distinction, it is evident that those things, whose ‘substance’—that which is undergoing the process—is imperishable, will be numerically, as well as specifically,
(15)
the same in their recurrence: for the character of the process is determined by the character of that which undergoes it. Those things, on the other hand, whose ‘substance’ is perishable (not imperishable) must ‘return upon themselves’ in the sense that what recurs, though specifically the same, is not the same numerically. That is why, when Water comes-to-be from Air and Air from Water, the Air is the same ‘specifically’, not ‘numerically’: and if these too recur numerically the same,
⁷⁹
at any rate this does not happen with things whose ‘substance’ comes-to-be—whose ‘substance’ is such that it is essentially capable of not-being.