The Basic Works of Aristotle (Modern Library Classics) (72 page)

10
     Having established these distinctions, we may now proceed to the question whether the heaven is ungenerated or generated,
(5)
indestructible or destructible. Let us start with a review of the theories of other thinkers; for the proofs of a theory are difficulties for the contrary theory. Besides, those who have first heard the pleas of our adversaries will be more likely to credit the assertions which we are going to make. We shall be less open to the charge of procuring judgement by default.
(10)
To give a satisfactory decision as to the truth it is necessary to be rather an arbitrator than a party to the dispute.

That the world was generated all are agreed, but, generation over, some say that it is eternal, others say that it is destructible like any other natural formation.
²¹
Others again,
(15)
with Empedocles of Acragas and Heraclitus of Ephesus, believe that there is alteration in the destructive process, which takes now this direction, now that, and continues without end.

Now to assert that it was generated and yet is eternal is to assert the impossible; for we cannot reasonably attribute to anything any characteristics but those which observation detects in many or all instances. But in this case the facts point the other way: generated things are seen always to be destroyed.
(20)
Further, a thing whose present state had no beginning and which could not have been other than it was at any previous moment throughout its entire duration, cannot possibly be changed. For there will have to be some cause of change, and if this had been present earlier it would have made possible another condition of that to which any other condition was impossible. Suppose that the world was formed out of elements which were formerly otherwise conditioned than as they are now.
(25)
Then (1)
if their condition was always so and could not have been otherwise, the world could never have come into being. And (2) if the world did come into being, then, clearly, their condition must have been capable of change and not eternal: after combination therefore they will be dispersed, just as in the past after dispersion they came into combination, and this process either has been, or could have been,
(30)
indefinitely repeated. But if this is so, the world cannot be indestructible, and it does not matter whether the change of condition has actually occurred or remains a possibility.

Some of those who hold that the world, though indestructible, was yet generated, try to support their case by a parallel which is illusory.
²²
They say that in their statements about its generation they are doing what geometricians do when they construct their figures,
(35)
not implying that the universe really had a beginning, but for didactic reasons facilitating understanding by exhibiting the object, like the figure, as in course of formation.
[280a]
The two cases, as we said, are not parallel; for, in the construction of the figure, when the various steps are completed the required figure forthwith results; but in these other demonstrations what results is not that which was required.
(5)
Indeed it cannot be so; for antecedent and consequent, as assumed, are in contradiction. The ordered, it is said,
²³
arose out of the unordered; and the same thing cannot be at the same time both ordered and unordered; there must be a process and a lapse of time separating the two states.
(10)
In the figure, on the other hand, there is no temporal separation. It is clear then that the universe cannot be at once eternal and generated.

To say that the universe alternately combines and dissolves is no more paradoxical than to make it eternal but varying in shape.
(15)
It is as if one were to think that there was now destruction and now existence when from a child a man is generated, and from a man a child. For it is clear that when the elements come together the result is not a chance system and combination, but the very same as before—especially on the view of those who hold this theory, since they say that the contrary is the cause of each state.
²⁴
So that if the totality of body,
(20)
which is a continuum, is now in this order or disposition and now in that, and if the combination of the whole is a world or heaven,
then it will not be the world that comes into being and is destroyed, but only its dispositions.

If the world is believed to be one, it is impossible to suppose that it should be, as a whole, first generated and then destroyed, never to reappear; since before it came into being there was always present the combination prior to it,
(25)
and that, we hold, could never change if it was never generated. If, on the other hand, the worlds are infinite in number the view is more plausible. But whether this is, or is not, impossible will be clear from what follows. For there are some who think it possible both for the ungenerated to be destroyed and for the generated to persist undestroyed. (This is held in the
Timaeus,
²⁵
where Plato says that the heaven,
(30)
though it was generated, will none the less exist to eternity.) So far as the heaven is concerned we have answered this view with arguments appropriate to the nature of the heaven: on the general question we shall attain clearness when we examine the matter universally.

11
     
[280b]
We must first distinguish the senses in which we use the words ‘ungenerated’ and ‘generated’, ‘destructible’ and ‘indestructible’. These have many meanings, and though it may make no difference to the argument, yet some confusion of mind must result from treating as uniform in its use a word which has several distinct applications.
(5)
The character which is the ground of the predication will always remain obscure.

The word ‘ungenerated’ then is used (
a
) in one sense whenever something now is which formerly was not, no process of becoming or change being involved. Such is the case, according to some, with contact and motion, since there is no process of coming to be in contact or in motion. (
b
) It is used in another sense, when something which is capable of coming to be, with or without process,
(10)
does not exist; such a thing is ungenerated in the sense that its generation is not a fact but a possibility. (
c
) It is also applied where there is general impossibility of any generation such that the thing now is which then was not. And ‘impossibility’ has two uses: first, where it is untrue to say that the thing can ever come into being, and secondly, where it cannot do so easily, quickly, or well. In the same way the word ‘generated’ is used,
(15)
(
a
) first, where what formerly was not afterwards is, whether a process of becoming was or was not involved, so long as that which then was not, now is; (
b
) secondly, of anything capable
of existing, ‘capable’ being defined with reference either to truth or to facility; (
c
) thirdly, of anything to which the passage from not being to being belongs, whether already actual,
(20)
if its existence is due to a past process of becoming, or not yet actual but only possible. The uses of the words ‘destructible’ and ‘indestructible’ are similar. ‘Destructible’ is applied (
a
) to that which formerly was and afterwards either is not or might not be, whether a period of being destroyed and changed intervenes or not; and (
b
) sometimes we apply the word to that which a process of destruction may cause not to be; and also (
c
) in a third sense, to that which is easily destructible,
(25)
to the ‘easily-destroyed’, so to speak. Of the indestructible the same account holds good. It is either (
a
) that which now is and now is not, without any process of destruction, like contact, which without being destroyed afterwards is not, though formerly it was; or (
b
) that which is but might not be, or which will at some time not be,
(30)
though it now is. For you exist now and so does the contact; yet both are destructible, because a time will come when it will not be true of you that you exist, nor of these things that they are in contact. Thirdly (
c
) in its most proper use, it is that which is, but is incapable of any destruction such that the thing which now is later ceases to be or might cease to be; or again, that which has not yet been destroyed, but in the future may cease to be.
[281a]
For indestructible is also used of that which is destroyed with difficulty.

This being so, we must ask what we mean by ‘possible’ and ‘impossible’. For in its most proper use the predicate ‘indestructible’ is given because it is impossible that the thing should be destroyed,
(5)
i. e. exist at one time and not at another. And ‘ungenerated’ also involves impossibility when used for that which cannot be generated, in such fashion that, while formerly it was not, later it is. An instance is a commensurable diagonal. Now when we speak of a power to move or to lift weights, we refer always to the maximum. We speak, for instance, of a power to lift a hundred talents or walk a hundred stades—though a power to effect the maximum is also a power to effect any part of the maximum—since we feel obliged in defining the power to give the limit or maximum.
(10)
A thing, then, which is capable of a certain amount as maximum must also be capable of that which lies within it. If, for example, a man can lift a hundred talents, he can also lift two, and if he can walk a hundred stades, he can also walk two.
(15)
But the power is of the maximum, and a thing said, with reference to its maximum, to be incapable of so much is also incapable of any greater amount. It is, for instance, clear that a person who cannot walk a thousand stades will also be unable to walk a thousand and
one. This point need not trouble us, for we may take it as settled that what is, in the strict sense, possible is determined by a limiting maximum. Now perhaps the objection might be raised that there is no necessity in this,
(20)
since he who sees a stade need not see the smaller measures contained in it, while, on the contrary, he who can see a dot or hear a small sound will perceive what is greater. This, however, does not touch our argument. The maximum may be determined either in the power or in its object. The application of this is plain.
(25)
Superior sight is sight of the smaller body, but superior speed is that of the greater body.

12
     Having established these distinctions we can now proceed to the sequel. If there are things capable both of being and of not being, there must be some definite maximum time of their being and not being; a time, I mean, during which continued existence is possible to them and a time during which continued non-existence is possible.
(30)
And this is true in every category, whether the thing is, for example, ‘man’, or ‘white’, or ‘three cubits long’, or whatever it may be. For if the time is not definite in quantity, but longer than any that can be suggested and shorter than none, then it will be possible for one and the same thing to exist for infinite time and not to exist for another infinity.
[281b]
This, however, is impossible.

Let us take our start from this point. The impossible and the false have not the same significance. One use of ‘impossible’ and ‘possible’, and ‘false’ and ‘true’, is hypothetical. It is impossible, for instance,
(5)
on a certain hypothesis that the triangle should have its angles equal to two right angles, and on another the diagonal is commensurable. But there are also things possible and impossible, false and true, absolutely. Now it is one thing to be absolutely false, and another thing to be absolutely impossible. To say that you are standing when you are not standing is to assert a falsehood, but not an impossibility.
(10)
Similarly to say that a man who is playing the harp, but not singing, is singing, is to say what is false but not impossible. To say, however, that you are at once standing and sitting, or that the diagonal is commensurable, is to say what is not only false but also impossible. Thus it is not the same thing to make a false and to make an impossible hypothesis; and from the impossible hypothesis impossible results follow.
(15)
A man has, it is true, the capacity at once of sitting and of standing, because when he possesses the one he also possesses the other; but it does not follow that he can at once sit and stand, only that at another time he can do the other also. But if a thing has for infinite time more than one capacity, another time is impossible and
the times must coincide.
(20)
Thus if anything which exists for infinite time is destructible, it will have the capacity of not being. Now if it exists for infinite time let this capacity be actualized; and it will be in actuality at once existent and non-existent. Thus a false conclusion would follow because a false assumption was made,
(25)
but if what was assumed had not been impossible its consequence would not have been impossible.

Anything then which always exists is absolutely imperishable. It is also ungenerated, since if it was generated it will have the power for some time of not being. For as that which formerly was, but now is not, or is capable at some future time of not being, is destructible, so that which is capable of formerly not having been is generated. But in the case of that which always is, there is no time for such a capacity of not being,
(30)
whether the supposed time is finite or infinite; for its capacity of being must include the finite time since it covers infinite time.

It is therefore impossible that one and the same thing should be capable of always existing and of always not-existing. And ‘not always existing’, the contradictory, is also excluded.
[282a]
Thus it is impossible for a thing always to exist and yet to be destructible. Nor, similarly, can it be generated. For of two attributes if
B
cannot be present without
A,
the impossibility of
A
proves the impossibility of
B.
What always is, then, since it is incapable of ever not being, cannot possibly be generated. But since the contradictory of ‘that which is always capable of being’ is ‘that which is not always capable of being’; while ‘that which is always capable of not being’ is the contrary,
(5)
whose contradictory in turn is ‘that which is not always capable of not being’, it is necessary that the contradictories of both terms should be predicable of one and the same thing, and thus that, intermediate between what always is and what always is not,
(10)
there should be that to which being and not-being are both possible; for the contradictory of each will at times be true of it unless it always exists. Hence that which not always is not will sometimes be and sometimes not be; and it is clear that this is true also of that which cannot always be but sometimes is and therefore sometimes is not. One thing, then, will have the power of being and of not being, and will thus be intermediate between the other two.

Expressed universally our argument is as follows. Let there be two attributes,
(15)
A
and
B,
not capable of being present in any one thing together, while either
A
or
C
and either
B
or
D
are capable of being present in everything. Then
C
and
D
must be predicated of everything of which neither
A
nor
B
is predicated. Let
E
lie between
A
and
B;
for that which is neither of two contraries is a mean between them. In
E
both
C
and
D
must be present, for either
A
or
C
is present everywhere and therefore in
E.
Since then
A
is impossible,
(20)
C
must be present, and the same argument holds of
D.
²⁶

Neither that which always is, therefore, nor that which always is not is either generated or destructible. And clearly whatever is generated or destructible is not eternal. If it were, it would be at once capable of always being and capable of not always being,
(25)
but it has already been shown
²⁷
that this is impossible. Surely then whatever is ungenerated and in being must be eternal, and whatever is indestructible and in being must equally be so. (I use the words ‘ungenerated’ and ‘indestructible’ in their proper sense, ‘ungenerated’ for that which now is and could not at any previous time have been truly said not to be; ‘indestructible’ for that which now is and cannot at any future time be truly said not to be.) If, again, the two terms are coincident,
(30)
if the ungenerated is indestructible, and the indestructible ungenerated, then each of them is coincident with ‘eternal’; anything ungenerated is eternal and anything indestructible is eternal.
[282b]
This is clear too from the definition of the terms. Whatever is destructible must be generated; for it is either ungenerated or generated, but, if ungenerated, it is by hypothesis indestructible. Whatever, further, is generated must be destructible. For it is either destructible or indestructible, but, if indestructible, it is by hypothesis ungenerated.
(5)
If, however, ‘indestructible’ and ‘ungenerated’ are not coincident, there is no necessity that either the ungenerated or the indestructible should be eternal. But they must be coincident, for the following reasons. The terms ‘generated’ and ‘destructible’ are coincident; this is obvious from our former remarks, since between what always is and what always is not there is an intermediate which is neither,
(10)
and that intermediate is the generated and destructible. For whatever is either of these is capable both of being and of not being for a definite time: in either case, I mean, there is a certain period of time during which the thing is and another during which it is not. Anything therefore which is generated or destructible must be intermediate.
(15)
Now let
A
be that which always is and
B
that which always is not,
C
the generated, and
D
the destructible. Then
C
must be intermediate
between
A
and
B.
For in their case there is no time in the direction of either limit, in which either
A
is not or
B
is.
(20)
But for the generated there must be such a time either actually or potentially, though not for
A
and
B
in either way.
C
then will be, and also not be, for a limited length of time, and this is true also of
D,
the destructible. Therefore each is both generated and destructible. Therefore ‘generated’ and ‘destructible’ are coincident. Now let
E
stand for the ungenerated,
(25)
F
for the generated,
G
for the indestructible, and
H
for the destructible. As for
F
and
H,
it has been shown that they are coincident. But when terms stand to one another as these do,
F
and
H
coincident,
E
and
F
never predicated of the same thing but one or other of everything,
(30)
and
G
and
H
likewise, then
E
and
G
must needs be coincident. For suppose that
E
is not coincident with
G,
then
F
will be, since either
E
or
F
is predicable of everything. But of that of which
F
is predicated
H
will be predicable also.
[283a]
H
will then be coincident with
G,
but this we saw to be impossible. And the same argument shows that
G
is coincident with
E.

Now the relation of the ungenerated (
E
) to the generated (
F
) is the same as that of the indestructible (
G
) to the destructible (
H
). To say then that there is no reason why anything should not be generated and yet indestructible or ungenerated and yet destroyed,
(5)
to imagine that in the one case generation and in the other case destruction occurs once for all, is to destroy part of the data.
²⁸
For (1) everything is capable of acting or being acted upon, of being or not being, either for an infinite, or for a definitely limited space of time; and the infinite time is only a possible alternative because it is after a fashion defined,
(10)
as a length of time which cannot be exceeded. But infinity in one direction is neither infinite nor finite. (2) Further, why, after always existing, was the thing destroyed, why, after an infinity of not being, was it generated, at one moment rather than another? If every moment is alike and the moments are infinite in number, it is clear that a generated or destructible thing existed for an infinite time. It has therefore for an infinite time the capacity of not being (since the capacity of being and the capacity of not being will be present together),
(15)
if destructible, in the time before destruction, if generated, in the time after generation. If then we assume the two capacities to be actualized, opposites will be present together. (3)
Further, this second capacity will be present like the first at every moment, so that the thing will have for an infinite time the capacity both of being and of not being; but this has been shown to be impossible. (4) Again, if the capacity is present prior to the activity,
(20)
it will be present for all time, even while the thing was as yet un-generated and non-existent, throughout the infinite time in which it was capable of being generated. At the time, then, when it was not, at that same time it had the capacity of being, both of being then and of being thereafter, and therefore for an infinity of time.

It is clear also on other grounds that it is impossible that the destructible should not at some time be destroyed.
(25)
For otherwise it will always be at once destructible and in actuality indestructible, so that it will be at the same time capable of always existing and of not always existing. Thus the destructible is at some time actually destroyed. The generable, similarly, has been generated, for it is capable of having been generated and thus also of not always existing.

We may also see in the following way how impossible it is either for a thing which is generated to be thenceforward indestructible,
(30)
or for a thing which is ungenerated and has always hitherto existed to be destroyed. Nothing that is by chance can be indestructible or ungenerated, since the products of chance and fortune are opposed to what is, or comes to be, always or usually, while anything which exists for a time infinite either absolutely or in one direction, is in existence either always or usually.
[283b]
That which is by chance, then, is by nature such as to exist at one time and not at another. But in things of that character the contradictory states proceed from one and the same capacity, the matter of the thing being the cause equally of its existence and of its non-existence.
(5)
Hence contradictories would be present together in actuality.

Further, it cannot truly be said of a thing now that it exists last year, nor could it be said last year that it exists now. It is therefore impossible for what once did not exist later to be eternal. For in its later state it will possess the capacity of not existing, only not of not existing at a time when it exists—since then it exists in actuality—but of not existing last year or in the past.
(10)
Now suppose it to be in actuality what it is capable of being. It will then be true to say now that it does not exist last year. But this is impossible. No capacity relates to being in the past, but always to being in the present or future. It is the same with the notion of an eternity of existence followed later by non-existence. In the later state the capacity will be present for that which is not there in actuality.
(15)
Actualize, then, the
capacity. It will be true to say now that this exists last year or in the past generally.

Considerations also not general like these but proper to the subject show it to be impossible that what was formerly eternal should later be destroyed or that what formerly was not should later be eternal.
(20)
Whatever is destructible or generated is always alterable. Now alteration is due to contraries, and the things which compose the natural body are the very same that destroy it.…