Aristotle

by Various Works [lit]

  and 'after' what is nearer, but in the future we call the nearer

  'before' and the farther 'after'. So that since the 'before' is in

  time, and every movement involves a 'before', evidently every change

  and every movement is in time.

  It is also worth considering how time can be related to the soul;

  and why time is thought to be in everything, both in earth and in

  sea and in heaven. Is because it is an attribute, or state, or

  movement (since it is the number of movement) and all these things are

  movable (for they are all in place), and time and movement are

  together, both in respect of potentiality and in respect of actuality?

  Whether if soul did not exist time would exist or not, is a question

  that may fairly be asked; for if there cannot be some one to count

  there cannot be anything that can be counted, so that evidently

  there cannot be number; for number is either what has been, or what

  can be, counted. But if nothing but soul, or in soul reason, is

  qualified to count, there would not be time unless there were soul,

  but only that of which time is an attribute, i.e. if movement can

  exist without soul, and the before and after are attributes of

  movement, and time is these qua numerable.

  One might also raise the question what sort of movement time is

  the number of. Must we not say 'of any kind'? For things both come

  into being in time and pass away, and grow, and are altered in time,

  and are moved locally; thus it is of each movement qua movement that

  time is the number. And so it is simply the number of continuous

  movement, not of any particular kind of it.

  But other things as well may have been moved now, and there would be

  a number of each of the two movements. Is there another time, then,

  and will there be two equal times at once? Surely not. For a time that

  is both equal and simultaneous is one and the same time, and even

  those that are not simultaneous are one in kind; for if there were

  dogs, and horses, and seven of each, it would be the same number.

  So, too, movements that have simultaneous limits have the same time,

  yet the one may in fact be fast and the other not, and one may be

  locomotion and the other alteration; still the time of the two changes

  is the same if their number also is equal and simultaneous; and for

  this reason, while the movements are different and separate, the

  time is everywhere the same, because the number of equal and

  simultaneous movements is everywhere one and the same.

  Now there is such a thing as locomotion, and in locomotion there

  is included circular movement, and everything is measured by some

  one thing homogeneous with it, units by a unit, horses by a horse, and

  similarly times by some definite time, and, as we said, time is

  measured by motion as well as motion by time (this being so because by

  a motion definite in time the quantity both of the motion and of the

  time is measured): if, then, what is first is the measure of

  everything homogeneous with it, regular circular motion is above all

  else the measure, because the number of this is the best known. Now

  neither alteration nor increase nor coming into being can be

  regular, but locomotion can be. This also is why time is thought to be

  the movement of the sphere, viz. because the other movements are

  measured by this, and time by this movement.

  This also explains the common saying that human affairs form a

  circle, and that there is a circle in all other things that have a

  natural movement and coming into being and passing away. This is

  because all other things are discriminated by time, and end and

  begin as though conforming to a cycle; for even time itself is thought

  to be a circle. And this opinion again is held because time is the

  measure of this kind of locomotion and is itself measured by such.

  So that to say that the things that come into being form a circle is

  to say that there is a circle of time; and this is to say that it is

  measured by the circular movement; for apart from the measure

  nothing else to be measured is observed; the whole is just a plurality

  of measures.

  It is said rightly, too, that the number of the sheep and of the

  dogs is the same number if the two numbers are equal, but not the same

  decad or the same ten; just as the equilateral and the scalene are not

  the same triangle, yet they are the same figure, because they are both

  triangles. For things are called the same so-and-so if they do not

  differ by a differentia of that thing, but not if they do; e.g.

  triangle differs from triangle by a differentia of triangle, therefore

  they are different triangles; but they do not differ by a

  differentia of figure, but are in one and the same division of it. For

  a figure of the one kind is a circle and a figure of another kind of

  triangle, and a triangle of one kind is equilateral and a triangle

  of another kind scalene. They are the same figure, then, that,

  triangle, but not the same triangle. Therefore the number of two

  groups also-is the same number (for their number does not differ by

  a differentia of number), but it is not the same decad; for the things

  of which it is asserted differ; one group are dogs, and the other

  horses.

  We have now discussed time-both time itself and the matters

  appropriate to the consideration of it.

  Book V

  1

  EVERYTHING which changes does so in one of three senses. It may

  change (1) accidentally, as for instance when we say that something

  musical walks, that which walks being something in which aptitude

  for music is an accident. Again (2) a thing is said without

  qualification to change because something belonging to it changes,

  i.e. in statements which refer to part of the thing in question:

  thus the body is restored to health because the eye or the chest, that

  is to say a part of the whole body, is restored to health. And above

  all there is (3) the case of a thing which is in motion neither

  accidentally nor in respect of something else belonging to it, but

  in virtue of being itself directly in motion. Here we have a thing

  which is essentially movable: and that which is so is a different

  thing according to the particular variety of motion: for instance it

  may be a thing capable of alteration: and within the sphere of

  alteration it is again a different thing according as it is capable of

  being restored to health or capable of being heated. And there are the

  same distinctions in the case of the mover: (1) one thing causes

  motion accidentally, (2) another partially (because something

  belonging to it causes motion), (3) another of itself directly, as,

  for instance, the physician heals, the hand strikes. We have, then,

  the following factors: (a) on the one hand that which directly

  causes motion, and (b) on the other hand that which is in motion:

  further, we have (c) that in which motion takes place, namely time,

  and (distinct from these three) (d) that from which and (e) that to

  which it proceeds: for every motion proceeds from something and to

  something, th
at which is directly in motion being distinct from that

  to which it is in motion and that from which it is in motion: for

  instance, we may take the three things 'wood', 'hot', and 'cold', of

  which the first is that which is in motion, the second is that to

  which the motion proceeds, and the third is that from which it

  proceeds. This being so, it is clear that the motion is in the wood,

  not in its form: for the motion is neither caused nor experienced by

  the form or the place or the quantity. So we are left with a mover,

  a moved, and a goal of motion. I do not include the starting-point

  of motion: for it is the goal rather than the starting-point of motion

  that gives its name to a particular process of change. Thus

  'perishing' is change to not-being, though it is also true that that

  that which perishes changes from being: and 'becoming' is change to

  being, though it is also change from not-being.

  Now a definition of motion has been given above, from which it

  will be seen that every goal of motion, whether it be a form, an

  affection, or a place, is immovable, as, for instance, knowledge and

  heat. Here, however, a difficulty may be raised. Affections, it may be

  said, are motions, and whiteness is an affection: thus there may be

  change to a motion. To this we may reply that it is not whiteness

  but whitening that is a motion. Here also the same distinctions are to

  be observed: a goal of motion may be so accidentally, or partially and

  with reference to something other than itself, or directly and with no

  reference to anything else: for instance, a thing which is becoming

  white changes accidentally to an object of thought, the colour being

  only accidentally the object of thought; it changes to colour, because

  white is a part of colour, or to Europe, because Athens is a part of

  Europe; but it changes essentially to white colour. It is now clear in

  what sense a thing is in motion essentially, accidentally, or in

  respect of something other than itself, and in what sense the phrase

  'itself directly' is used in the case both of the mover and of the

  moved: and it is also clear that the motion is not in the form but

  in that which is in motion, that is to say 'the movable in

  activity'. Now accidental change we may leave out of account: for it

  is to be found in everything, at any time, and in any respect.

  Change which is not accidental on the other hand is not to be found in

  everything, but only in contraries, in things intermediate contraries,

  and in contradictories, as may be proved by induction. An intermediate

  may be a starting-point of change, since for the purposes of the

  change it serves as contrary to either of two contraries: for the

  intermediate is in a sense the extremes. Hence we speak of the

  intermediate as in a sense a contrary relatively to the extremes and

  of either extreme as a contrary relatively to the intermediate: for

  instance, the central note is low relatively-to the highest and high

  relatively to the lowest, and grey is light relatively to black and

  dark relatively to white.

  And since every change is from something to something-as the word

  itself (metabole) indicates, implying something 'after' (meta)

  something else, that is to say something earlier and something

  later-that which changes must change in one of four ways: from subject

  to subject, from subject to nonsubject, from non-subject to subject,

  or from non-subject to non-subject, where by 'subject' I mean what

  is affirmatively expressed. So it follows necessarily from what has

  been said above that there are only three kinds of change, that from

  subject to subject, that from subject to non-subject, and that from

  non-subject to subject: for the fourth conceivable kind, that from

  non-subject to nonsubject, is not change, as in that case there is

  no opposition either of contraries or of contradictories.

  Now change from non-subject to subject, the relation being that of

  contradiction, is 'coming to be'-'unqualified coming to be' when the

  change takes place in an unqualified way, 'particular coming to be'

  when the change is change in a particular character: for instance, a

  change from not-white to white is a coming to be of the particular

  thing, white, while change from unqualified not-being to being is

  coming to be in an unqualified way, in respect of which we say that

  a thing 'comes to be' without qualification, not that it 'comes to be'

  some particular thing. Change from subject to non-subject is

  'perishing'-'unqualified perishing' when the change is from being to

  not-being, 'particular perishing' when the change is to the opposite

  negation, the distinction being the same as that made in the case of

  coming to be.

  Now the expression 'not-being' is used in several senses: and

  there can be motion neither of that which 'is not' in respect of the

  affirmation or negation of a predicate, nor of that which 'is not'

  in the sense that it only potentially 'is', that is to say the

  opposite of that which actually 'is' in an unqualified sense: for

  although that which is 'not-white' or 'not-good' may nevertheless he

  in motion accidentally (for example that which is 'not-white' might be

  a man), yet that which is without qualification 'not-so-and-so' cannot

  in any sense be in motion: therefore it is impossible for that which

  is not to be in motion. This being so, it follows that 'becoming'

  cannot be a motion: for it is that which 'is not' that 'becomes'.

  For however true it may be that it accidentally 'becomes', it is

  nevertheless correct to say that it is that which 'is not' that in

  an unqualified sense 'becomes'. And similarly it is impossible for

  that which 'is not' to be at rest.

  There are these difficulties, then, in the way of the assumption

  that that which 'is not' can be in motion: and it may be further

  objected that, whereas everything which is in motion is in space, that

  which 'is not' is not in space: for then it would be somewhere.

  So, too, 'perishing' is not a motion: for a motion has for its

  contrary either another motion or rest, whereas 'perishing' is the

  contrary of 'becoming'.

  Since, then, every motion is a kind of change, and there are only

  the three kinds of change mentioned above, and since of these three

  those which take the form of 'becoming' and 'perishing', that is to

  say those which imply a relation of contradiction, are not motions: it

  necessarily follows that only change from subject to subject is

  motion. And every such subject is either a contrary or an intermediate

  (for a privation may be allowed to rank as a contrary) and can be

  affirmatively expressed, as naked, toothless, or black. If, then,

  the categories are severally distinguished as Being, Quality, Place,

  Time, Relation, Quantity, and Activity or Passivity, it necessarily

  follows that there are three kinds of motion-qualitative,

  quantitative, and local.

  2

  In respect of Substance there is no motion, because Substance has no

  contrary among things that are. Nor is there motion in respect of

 
; Relation: for it may happen that when one correlative changes, the

  other, although this does not itself change, is no longer

  applicable, so that in these cases the motion is accidental. Nor is

  there motion in respect of Agent and Patient-in fact there can never

  be motion of mover and moved, because there cannot be motion of motion

  or becoming of becoming or in general change of change.

  For in the first place there are two senses in which motion of

  motion is conceivable. (1) The motion of which there is motion might

  be conceived as subject; e.g. a man is in motion because he changes

  from fair to dark. Can it be that in this sense motion grows hot or

  cold, or changes place, or increases or decreases? Impossible: for

  change is not a subject. Or (2) can there be motion of motion in the

  sense that some other subject changes from a change to another mode of

  being, as e.g. a man changes from falling ill to getting well? Even

  this is possible only in an accidental sense. For, whatever the

  subject may be, movement is change from one form to another. (And

  the same holds good of becoming and perishing, except that in these

  processes we have a change to a particular kind of opposite, while the

  other, motion, is a change to a different kind.) So, if there is to be

  motion of motion, that which is changing from health to sickness

  must simultaneously be changing from this very change to another. It

  is clear, then, that by the time that it has become sick, it must also

  have changed to whatever may be the other change concerned (for that

  it should be at rest, though logically possible, is excluded by the

  theory). Moreover this other can never be any casual change, but

  must be a change from something definite to some other definite thing.

  So in this case it must be the opposite change, viz. convalescence. It

  is only accidentally that there can be change of change, e.g. there is

  a change from remembering to forgetting only because the subject of

  this change changes at one time to knowledge, at another to ignorance.

  In the second place, if there is to be change of change and becoming