Various Works

  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