Others there are who, indeed, believe that chance is a cause, but
that it is inscrutable to human intelligence, as being a divine
thing and full of mystery.
Thus we must inquire what chance and spontaneity are, whether they
are the same or different, and how they fit into our division of
causes.
5
First then we observe that some things always come to pass in the
same way, and others for the most part. It is clearly of neither of
these that chance is said to be the cause, nor can the 'effect of
chance' be identified with any of the things that come to pass by
necessity and always, or for the most part. But as there is a third
class of events besides these two-events which all say are 'by
chance'-it is plain that there is such a thing as chance and
spontaneity; for we know that things of this kind are due to chance
and that things due to chance are of this kind.
But, secondly, some events are for the sake of something, others
not. Again, some of the former class are in accordance with deliberate
intention, others not, but both are in the class of things which are
for the sake of something. Hence it is clear that even among the
things which are outside the necessary and the normal, there are
some in connexion withwhich the phrase 'for the sake of something'
is applicable. (Events that are for the sake of something include
whatever may be done as a result of thought or of nature.) Things of
this kind, then, when they come to pass incidental are said to be
'by chance'. For just as a thing is something either in virtue of
itself or incidentally, so may it be a cause. For instance, the
housebuilding faculty is in virtue of itself the cause of a house,
whereas the pale or the musical is the incidental cause. That which is
per se cause of the effect is determinate, but the incidental cause is
indeterminable, for the possible attributes of an individual are
innumerable. To resume then; when a thing of this kind comes to pass
among events which are for the sake of something, it is said to be
spontaneous or by chance. (The distinction between the two must be
made later-for the present it is sufficient if it is plain that both
are in the sphere of things done for the sake of something.)
Example: A man is engaged in collecting subscriptions for a feast.
He would have gone to such and such a place for the purpose of getting
the money, if he had known. He actually went there for another purpose
and it was only incidentally that he got his money by going there; and
this was not due to the fact that he went there as a rule or
necessarily, nor is the end effected (getting the money) a cause
present in himself-it belongs to the class of things that are
intentional and the result of intelligent deliberation. It is when
these conditions are satisfied that the man is said to have gone 'by
chance'. If he had gone of deliberate purpose and for the sake of
this-if he always or normally went there when he was collecting
payments-he would not be said to have gone 'by chance'.
It is clear then that chance is an incidental cause in the sphere of
those actions for the sake of something which involve purpose.
Intelligent reflection, then, and chance are in the same sphere, for
purpose implies intelligent reflection.
It is necessary, no doubt, that the causes of what comes to pass
by chance be indefinite; and that is why chance is supposed to
belong to the class of the indefinite and to be inscrutable to man,
and why it might be thought that, in a way, nothing occurs by
chance. For all these statements are correct, because they are well
grounded. Things do, in a way, occur by chance, for they occur
incidentally and chance is an incidental cause. But strictly it is not
the cause-without qualification-of anything; for instance, a
housebuilder is the cause of a house; incidentally, a fluteplayer
may be so.
And the causes of the man's coming and getting the money (when he
did not come for the sake of that) are innumerable. He may have wished
to see somebody or been following somebody or avoiding somebody, or
may have gone to see a spectacle. Thus to say that chance is a thing
contrary to rule is correct. For 'rule' applies to what is always true
or true for the most part, whereas chance belongs to a third type of
event. Hence, to conclude, since causes of this kind are indefinite,
chance too is indefinite. (Yet in some cases one might raise the
question whether any incidental fact might be the cause of the
chance occurrence, e.g. of health the fresh air or the sun's heat
may be the cause, but having had one's hair cut cannot; for some
incidental causes are more relevant to the effect than others.)
Chance or fortune is called 'good' when the result is good, 'evil'
when it is evil. The terms 'good fortune' and 'ill fortune' are used
when either result is of considerable magnitude. Thus one who comes
within an ace of some great evil or great good is said to be fortunate
or unfortunate. The mind affirms the essence of the attribute,
ignoring the hair's breadth of difference. Further, it is with
reason that good fortune is regarded as unstable; for chance is
unstable, as none of the things which result from it can be invariable
or normal.
Both are then, as I have said, incidental causes-both chance and
spontaneity-in the sphere of things which are capable of coming to
pass not necessarily, nor normally, and with reference to such of
these as might come to pass for the sake of something.
6
They differ in that 'spontaneity' is the wider term. Every result of
chance is from what is spontaneous, but not everything that is from
what is spontaneous is from chance.
Chance and what results from chance are appropriate to agents that
are capable of good fortune and of moral action generally. Therefore
necessarily chance is in the sphere of moral actions. This is
indicated by the fact that good fortune is thought to be the same,
or nearly the same, as happiness, and happiness to be a kind of
moral action, since it is well-doing. Hence what is not capable of
moral action cannot do anything by chance. Thus an inanimate thing
or a lower animal or a child cannot do anything by chance, because
it is incapable of deliberate intention; nor can 'good fortune' or
'ill fortune' be ascribed to them, except metaphorically, as
Protarchus, for example, said that the stones of which altars are made
are fortunate because they are held in honour, while their fellows are
trodden under foot. Even these things, however, can in a way be
affected by chance, when one who is dealing with them does something
to them by chance, but not otherwise.
The spontaneous on the other hand is found both in the lower animals
and in many inanimate objects. We say, for example, that the horse
came 'spontaneously', because, though his coming saved him, he did not
come for the sake of safety. Again, the tripod fell 'of itself',
because, though when it
fell it stood on its feet so as to serve for a
seat, it did not fall for the sake of that.
Hence it is clear that events which (1) belong to the general
class of things that may come to pass for the sake of something, (2)
do not come to pass for the sake of what actually results, and (3)
have an external cause, may be described by the phrase 'from
spontaneity'. These 'spontaneous' events are said to be 'from
chance' if they have the further characteristics of being the
objects of deliberate intention and due to agents capable of that mode
of action. This is indicated by the phrase 'in vain', which is used
when A which is for the sake of B, does not result in B. For instance,
taking a walk is for the sake of evacuation of the bowels; if this
does not follow after walking, we say that we have walked 'in vain'
and that the walking was 'vain'. This implies that what is naturally
the means to an end is 'in vain', when it does not effect the end
towards which it was the natural means-for it would be absurd for a
man to say that he had bathed in vain because the sun was not
eclipsed, since the one was not done with a view to the other. Thus
the spontaneous is even according to its derivation the case in
which the thing itself happens in vain. The stone that struck the
man did not fall for the purpose of striking him; therefore it fell
spontaneously, because it might have fallen by the action of an
agent and for the purpose of striking. The difference between
spontaneity and what results by chance is greatest in things that come
to be by nature; for when anything comes to be contrary to nature,
we do not say that it came to be by chance, but by spontaneity. Yet
strictly this too is different from the spontaneous proper; for the
cause of the latter is external, that of the former internal.
We have now explained what chance is and what spontaneity is, and in
what they differ from each other. Both belong to the mode of causation
'source of change', for either some natural or some intelligent
agent is always the cause; but in this sort of causation the number of
possible causes is infinite.
Spontaneity and chance are causes of effects which though they might
result from intelligence or nature, have in fact been caused by
something incidentally. Now since nothing which is incidental is prior
to what is per se, it is clear that no incidental cause can be prior
to a cause per se. Spontaneity and chance, therefore, are posterior to
intelligence and nature. Hence, however true it may be that the
heavens are due to spontaneity, it will still be true that
intelligence and nature will be prior causes of this All and of many
things in it besides.
7
It is clear then that there are causes, and that the number of
them is what we have stated. The number is the same as that of the
things comprehended under the question 'why'. The 'why' is referred
ultimately either (1), in things which do not involve motion, e.g.
in mathematics, to the 'what' (to the definition of 'straight line' or
'commensurable', c.), or (2) to what initiated a motion, e.g. 'why
did they go to war?-because there had been a raid'; or (3) we are
inquiring 'for the sake of what?'-'that they may rule'; or (4), in the
case of things that come into being, we are looking for the matter.
The causes, therefore, are these and so many in number.
Now, the causes being four, it is the business of the physicist to
know about them all, and if he refers his problems back to all of
them, he will assign the 'why' in the way proper to his science-the
matter, the form, the mover, 'that for the sake of which'. The last
three often coincide; for the 'what' and 'that for the sake of
which' are one, while the primary source of motion is the same in
species as these (for man generates man), and so too, in general,
are all things which cause movement by being themselves moved; and
such as are not of this kind are no longer inside the province of
physics, for they cause motion not by possessing motion or a source of
motion in themselves, but being themselves incapable of motion.
Hence there are three branches of study, one of things which are
incapable of motion, the second of things in motion, but
indestructible, the third of destructible things.
The question 'why', then, is answered by reference to the matter, to
the form, and to the primary moving cause. For in respect of coming to
be it is mostly in this last way that causes are investigated-'what
comes to be after what? what was the primary agent or patient?' and so
at each step of the series.
Now the principles which cause motion in a physical way are two,
of which one is not physical, as it has no principle of motion in
itself. Of this kind is whatever causes movement, not being itself
moved, such as (1) that which is completely unchangeable, the
primary reality, and (2) the essence of that which is coming to be,
i.e. the form; for this is the end or 'that for the sake of which'.
Hence since nature is for the sake of something, we must know this
cause also. We must explain the 'why' in all the senses of the term,
namely, (1) that from this that will necessarily result ('from this'
either without qualification or in most cases); (2) that 'this must be
so if that is to be so' (as the conclusion presupposes the premisses);
(3) that this was the essence of the thing; and (4) because it is
better thus (not without qualification, but with reference to the
essential nature in each case).
8
We must explain then (1) that Nature belongs to the class of
causes which act for the sake of something; (2) about the necessary
and its place in physical problems, for all writers ascribe things
to this cause, arguing that since the hot and the cold, c., are of
such and such a kind, therefore certain things necessarily are and
come to be-and if they mention any other cause (one his 'friendship
and strife', another his 'mind'), it is only to touch on it, and
then good-bye to it.
A difficulty presents itself: why should not nature work, not for
the sake of something, nor because it is better so, but just as the
sky rains, not in order to make the corn grow, but of necessity?
What is drawn up must cool, and what has been cooled must become water
and descend, the result of this being that the corn grows. Similarly
if a man's crop is spoiled on the threshing-floor, the rain did not
fall for the sake of this-in order that the crop might be
spoiled-but that result just followed. Why then should it not be the
same with the parts in nature, e.g. that our teeth should come up of
necessity-the front teeth sharp, fitted for tearing, the molars
broad and useful for grinding down the food-since they did not arise
for this end, but it was merely a coincident result; and so with all
other parts in which we suppose that there is purpose? Wherever then
all the parts came about just what they would have been if they had
come be for an end, such things survived, b
eing organized
spontaneously in a fitting way; whereas those which grew otherwise
perished and continue to perish, as Empedocles says his 'man-faced
ox-progeny' did.
Such are the arguments (and others of the kind) which may cause
difficulty on this point. Yet it is impossible that this should be the
true view. For teeth and all other natural things either invariably or
normally come about in a given way; but of not one of the results of
chance or spontaneity is this true. We do not ascribe to chance or
mere coincidence the frequency of rain in winter, but frequent rain in
summer we do; nor heat in the dog-days, but only if we have it in
winter. If then, it is agreed that things are either the result of
coincidence or for an end, and these cannot be the result of
coincidence or spontaneity, it follows that they must be for an end;
and that such things are all due to nature even the champions of the
theory which is before us would agree. Therefore action for an end
is present in things which come to be and are by nature.
Further, where a series has a completion, all the preceding steps
are for the sake of that. Now surely as in intelligent action, so in
nature; and as in nature, so it is in each action, if nothing
interferes. Now intelligent action is for the sake of an end;
therefore the nature of things also is so. Thus if a house, e.g. had
been a thing made by nature, it would have been made in the same way
as it is now by art; and if things made by nature were made also by
art, they would come to be in the same way as by nature. Each step
then in the series is for the sake of the next; and generally art
partly completes what nature cannot bring to a finish, and partly
imitates her. If, therefore, artificial products are for the sake of
an end, so clearly also are natural products. The relation of the
later to the earlier terms of the series is the same in both. This
is most obvious in the animals other than man: they make things
neither by art nor after inquiry or deliberation. Wherefore people