by Aristotle
12 · If the categories are classified as substance, quality, place, acting or being acted on, relation, quantity, there must be three kinds of movement—of quality, of quantity, of place. There is no movement in respect of substance [10] (because there is nothing contrary to substance), nor in respect of relation (for it is possible that if one of two things changes, the other ceases to be true, though it does not change at all,—so that their movement is accidental), nor of agent and patient, nor of mover and moved, because there is no movement of movement nor generation [15] of generation, nor, in general, change of change. For there might be movement of movement in two senses; (1) movement may be the subject moved, as a man is moved because he changes from white to black,—so that in this way movement might be either heated or cooled or change its place or increase. But this is impossible; for change is not a subject. Or (2) some other subject may change from [20] a change into some other species of change (as a man changes from disease into health). But this also is not possible except incidentally. For every movement is change from something into something. (And so are generation and destruction; but they are changes into things opposed in one way, while movements are changes into [25] things opposed in another way.) A thing changes, then, at the same time from health into illness, and from this change itself into another. Clearly, then, if it has become ill, it will have changed into some change or other (for it may be at rest), and, further, into a determinate change each time; and that new change will be from something into something; therefore it will be the opposite change, that of growing [30] well. But this happens only incidentally, e.g. there is a change from the process of recollection to that of forgetting, only because that to which the process attaches is changing, now into a state of knowledge, now into one of ignorance.
Further, the process will go on to infinity, if there is to be change of change and generation of generation. For if the later is, so too must the earlier be—e.g. if the simple coming to be was once coming to be, that which was coming to be it was also [1068b1] once coming to be; therefore that which was simply coming to be it was not yet in existence, but something which was coming to be coming to be it was already in existence. And this was once coming to be, so that then it was not yet coming to be. Now since of an infinite number of terms there is not a first, the first in this series will not exist, and therefore no following term will exist. Nothing, then, can either [5] come to be or move or change. Further, that which has a movement has also the contrary movement and rest, and that which comes to be also ceases to be. Therefore that which is coming to be is ceasing to be when it has come to be coming to be; for it cannot cease to be at the very time at which it is coming to be coming to be, nor after it has come to be; for that which is ceasing to be must be. Further, there must be a matter underlying that which comes to be and changes. What will it be, [10] then, that becomes movement or generation, as body or soul is that which suffers alteration? And what is it that they move into? For their movement must be the movement or coming to be of this from that to the other. How, then, can this condition be fulfilled? There can be no learning of learning, and therefore no [15] generation of generation.
Since there is not movement either of substance or of relation or of activity and passivity, it remains that movement is in respect of quality and quantity and place; for each of these admits of contrariety. By quality I mean not that which is in the substance (for even the differentia is a quality), but the passive quality, in virtue of [20] which a thing is said to be acted on or to be incapable of being acted on. The unmovable is either that which is wholly incapable of being moved, or that which is moved with difficulty in a long time or begins slowly, or that which would naturally be moved and can be moved, but is not moving when and where and as it would naturally be moved. This alone among unmovables I describe as being at rest; for [25] rest is contrary to movement, so that it must be a privation in that which is receptive of movement.
Things which are in one primary place are together, and things which are in different places are apart. Things whose extremes are together touch. That at which the changing thing, if it changes continuously according to its nature, naturally arrives before it arrives at the extreme into which it is changing, is [30] between. That which is most distant in a straight line is contrary in place. That is successive which is after the beginning (the order being determined by position or form or in some other way) and has nothing of the same class between it and that which it succeeds, e.g. lines succeed a line, units a unit, or one house another house. (There is nothing to prevent a thing of some other class from being between.) For the successive succeeds something and is something later; one does not succeed two, [1069a1] nor the first day of the month the second. That which, being successive, touches, is contiguous. Since all change is between opposites, and these are either contraries or contradictories, and there is no middle term for contradictories, clearly that which [5] is between is between contraries. The continuous is a species of the contiguous; two things are called continuous when the limits of each, with which they touch and are kept together, become one and the same, so that plainly the continuous is found in the things out of which a unity naturally arises in virtue of their contact. And plainly the successive is primary for the successive does not necessarily touch, but [10] that which touches is successive. And if a thing is continuous, it touches, but if it touches, it is not necessarily continuous; and in things in which there is no touching, there is no organic unity. Therefore a point is not the same as a unit; for contact belongs to points, but not to units, which have only succession; and there is something between two of the former but not between two of the latter.
BOOK XII (Λ)
1 · Substance is the subject of our inquiry; for the principles and the causes we are seeking are those of substances. For if the universe is of the nature of a whole, [20] substance is its first part; and if it coheres by virtue of succession, on this view also substance is first, and is succeeded by quality, and then by quantity. At the same time these latter are not even beings in the unqualified sense, but are quantities and movements—or else even the not-white and the not-straight would be; at least we say even these are, e.g. ‘there is a not-white’. Further, none of the others can exist apart. And the old philosophers also in effect testify to this; for it was of substance [25] that they sought the principles and elements and causes. The thinkers of the present day tend to rank universals as substances (for genera are universals, and these they tend to describe as principles and substances, owing to the abstract nature of their inquiry); but the old thinkers ranked particular things as substances, e.g. fire and earth, but not what is common to both, body.
There are three kinds of substance—one that is sensible (of which one [30] subdivision is eternal and another is perishable, and which all recognize, as comprising e.g. plants and animals),—of this we must grasp the elements, whether one or many; and another that is immovable, and this certain thinkers assert to be capable of existing apart, some dividing it into two, others combining the Forms and the objects of mathematics into one class, and others believing only in the [35] mathematical part of this class. The former two kinds of substance are the subject of natural science (for they imply movement); but the third kind belongs to another [1069b1] science, if there is no principle common to it and to the other kinds.
Sensible substance is changeable. Now if change proceeds from opposites or from intermediate points, and not from all opposites (for the voice is not-white) but [5] from the contrary, there must be something underlying which changes into the contrary state; for the contraries do not change.
2 · Further, something persists, but the contrary does not persist; there is, then, some third thing besides the contraries, viz. the matter. Now since changes are of four kinds—either in respect of the essence or of the quality or of the quantity or of the place, and change in respect of the ‘this’ is simple generation and destruction, [10] and change in quantity is increase and diminution, and change in
respect of an affection is alteration, and change in place is motion, changes will be from given states into those contrary to them in these several respects. The matter, then, which changes must be capable of both states. And since things are said to be in two ways, everything changes from that which is potentially to that which is actually, e.g. [15] from the potentially white to the actually white, and similarly in the case of increase and diminution. Therefore not only can a thing come to be, incidentally, out of that which is not, but also all things come to be out of that which is, but is potentially, [20] and is not actually. And this is the ‘One’ of Anaxagoras; for instead of ‘all things were together’ and the ‘Mixture’ of Empedocles and Anaximander and the account given by Democritus, it is better to say all things were together potentially but not actually. Therefore these thinkers seem to have had some notion of matter.
Now all things that change have matter, but different matter; and of eternal [25] things those which are not generable but are movable in space have matter—not matter for generation, however, but for motion from one place to another.
(One might raise the question from what sort of non-being generation proceeds; for things are said not to be in three ways.)
If, then, a thing exists potentially, still it is not potentially any and every thing, but different things come from different things; nor is it satisfactory to say that all [30] things were together; for they differ in their matter, since otherwise why did an infinity of things come to be, and not one thing? For Reason is one, so that if matter also is one, that must have come to be in actuality what the matter was in potentiality. The causes and the principles, then, are three, two being the pair of contraries of which one is formula and form and the other is privation, and the third being the matter.
[35] 3 · Next we must observe that neither the matter nor the form comes to be—i.e. the proximate matter and form. For everything that changes is something [1070a1] and is changed by something and into something. That by which it is changed is the primary mover; that which is changed, the matter; that into which it is changed, the form. The process, then, will go on to infinity, if not only the bronze comes to be round but also the round or the bronze comes to be; therefore there must be a stop at some point.
Next we must observe that each substance comes into being out of something [5] synonymous. (Natural objects and other things are substances.) For things come into being either by art or by nature or by chance or by spontaneity. Now art is a principle of movement in something other than the thing moved, nature is a principle in the thing itself (for man begets man), and the other causes are privations of these two.
There are three kinds of substance—the matter, which is a ‘this’ by being [10] perceived (for all things that are characterized by contact and not by organic unity are matter and substratum); the nature, a ‘this’ and a state that it moves towards; and again, thirdly, the particular substance which is composed of these two, e.g. Socrates or Callias. Now in some cases the ‘this’ does not exist apart from the composite substance, e.g. the form of house does not so exist, unless the art of [15] building exists apart (nor is there generation and destruction of these forms, but it is in another way that the house apart from its matter, and health, and all things of art, exist and do not exist); but if it does it is only in the case of natural objects. And so Plato was not far wrong when he said that there are as many Forms as there are kinds of natural things (if there are Forms at all),—though not of such things1 as [20] fire, flesh, head; for all these are matter, and the last matter is the matter of that which is in the fullest sense substance. The moving causes exist as things preceding the effects, but causes in the sense of formulae are simultaneous with their effects. For when a man is healthy, then health also exists; and the shape of a bronze sphere exists at the same time as the bronze sphere. But we must examine whether any [25] form also survives afterwards. For in some cases this may be so, e.g. the soul may be of this sort—not all soul but the reason; for doubtless it is impossible that all soul should survive. Evidently then there is no necessity, on this ground at least, for the existence of the Ideas. For man is begotten by man, each individual by an [30] individual; and similarly in the arts; for the medical art is the formula of health.
4 · The causes and the principles of different things are in a sense different, but in a sense, if one speaks universally and analogically, they are the same for all. For we might raise the question whether the principles and elements are different or the same for substances and for relatives, and similarly in the case of each of the categories. But it is paradoxical that they should be the same for all. For then from [35] the same elements will proceed relatives and substances. What then will this common element be? For there is nothing common to and distinct from substance [1070b1] and the other things which are predicated; but the element is prior to the things of which it is an element. But again substance is not an element of relatives, nor is any of these an element of substance. Further, how can all things have the same elements? For none of the elements can be the same as that which is composed of [5] the elements, e.g. b or a cannot be the same as ba. (None, therefore, of the intelligibles, e.g. unity or being, is an element; for these are predicable of each of the compounds as well.) None of the elements then would be either a substance or a relative; but it must be one or other. All things then have not the same elements.
Or, as we put it, in a sense they have and in a sense they have not; e.g. perhaps [10] the elements of perceptible bodies are, as form, the hot, and in another sense the cold, which is the privation; and, as matter, that which directly and of itself is potentially these; and both these are substances and also the things composed of these, of which these are the principles (i.e. any unity which is produced out of the hot and the cold, e.g. flesh or bone); for the product must be different from the [15] elements. These things then have the same elements and principles, but different things have different elements; and if we put the matter thus, all things have not the same elements, but analogically they have; i.e. one might say that there are three principles—the form, the privation, and the matter. But each of these is different for each class, e.g. in colour they are white, black, and surface. Again, there is light, [20] darkness, and air; and out of these are produced day and night.
Since not only the elements present in a thing are causes, but also something external, i.e. the moving cause, clearly while principle and element are different both are causes, and principle is divided into these two kinds; and that which moves a thing or makes it rest is a principle and a substance. Therefore analogically there [25] are three elements, and four causes and principles; but the elements are different in different things, and the primary moving cause is different for different things. Health, disease, body; the moving cause is the medical art. Form, disorder of a particular kind, bricks; the moving cause is the building art. And since the moving cause in the case of natural things is, for instance man, and in the products of [30] thought it is the form or its contrary, there are in a sense three causes, while in a sense there are four. For the medical art is in some sense health, and the building art is the form of the house, and man begets man; further, besides these there is that which as first of all things moves all things. [35]
5 · Some things can exist apart and some cannot, and it is the former that are substances. And therefore all things have the same causes, because, without [1071a1] substances, affections and movements do not exist. Further, these causes will probably be soul and body, or reason and desire and body.
And in yet another way, analogically identical things are principles, i.e., [5] actuality and potency; but these also are not only different for different things but also apply in different senses to them. For in some cases the same thing exists at one time actually and at another potentially, e.g. wine or flesh or man does so. (And these too fall under the above-named causes. For the form exists actually, if it can exist apart, and so does the complex of form and matter, and the privation, e.g. [10]
darkness or the diseased. But the matter exists potentially; for this is that which can become both the actual things.) But the distinction of actuality and potentiality applies differently to cases where the matter is not the same, in which cases the form also is not the same but different; e.g. the cause of man is the elements in man (viz. fire and earth as matter, and the peculiar form), and the external cause, whatever it [15] is, e.g. the father, and besides these the sun and its oblique course, which are neither matter nor form nor privation nor of the same species with man, but moving causes.