by Aristotle
When the change from contrary to contrary is in quantity, it is growth and diminution; when it is in place, it is locomotion; when it is in property, i.e. in quality, it is alteration; but when nothing persists of which the resultant is a property (or an [320a1] accident in any sense of the term), it is coming-to-be, and the converse change is passing-away.
5 · Matter, in the most proper sense of the term, is to be identified with the substratum which is receptive of coming-to-be and passing-away; but the substratum of the remaining kinds of change is also, in a certain sense, matter, because all these substrata are receptive of contrarieties of some kind. So much, then, as an answer to the questions whether coming-to-be occurs or not, and how it occurs, and [5] what alteration is; but we have still to treat of growth. We must explain wherein growth differs from coming-to-be and from alteration, and what is the process of growing and the process of diminishing in each and all of the things that grow and diminish. [10]
Hence our first question is this: Do these changes differ from one another solely because of a difference in their respective spheres? In other words, do they differ because, while a change from this to that (viz. from potential substance to actual substance) is coming-to-be, a change in the sphere of magnitude is growth and one in the sphere of quality is alteration—both growth and alteration being changes from what is potentially to what is actually? Or is there also a difference in [15] the manner of the change, since it is evident that, whereas neither what is altering nor what is coming-to-be necessarily changes its place, what is growing or diminishing does, though in a different manner from that in which the moving thing does? For that which is being moved changes its place as a whole; but the growing [20] thing changes its place like a metal that is being beaten, retaining its position as a whole while its parts change their places. (But not in the same way as the parts of a sphere; for they change their places while the whole continues to occupy an equal place, but the parts of the growing thing change over an ever-increasing place and the parts of the diminishing thing over an ever-diminishing area.)
It is clear, then, that these changes—the changes of that which is coming-to-be, [25] of that which is altering, and of that which is growing—differ in manner as well as in sphere. But how are we to conceive the sphere of the change which is growth and diminution? The sphere of growing and diminishing is believed to be magnitude. Are we to suppose that body and magnitude come-to-be out of something which, though potentially magnitude and body, is actually incorporeal and devoid of magnitude? And since this description may be understood in two different ways, in which of these two ways are we to apply it to the process of [30] growth? Is the matter, out of which growth takes place, separate and existing alone by itself, or contained in another body?
Perhaps it is impossible for growth to take place in either of these ways. For since the matter is separate, either it will occupy no place (as if it were a point), or it [320b1] will be a void, i.e. a non-perceptible body. But the first of these is impossible, and in the second the matter must be in something. For since what comes-to-be out of it will always be somewhere, it too must be somewhere—either intrinsically or indirectly. But if it is to be in something and yet remains separate in such a way that [5] it is in no sense a part of that body (neither intrinsically nor accidentally, many impossibilities will result. It is as if we were to suppose that when, e.g., air comes-to-be out of water the process were due not to a change of the water, but to the matter of the air being contained in the water as in a vessel. For there is nothing [10] to prevent an indeterminate number of matters being thus contained in the water, so that they might come-to-be actually; and we do not in fact see air coming-to-be out of water in this fashion, viz. withdrawing out of it and leaving it to persist.
It is therefore better to suppose that in all instances of coming-to-be the matter is inseparable, being numerically identical and one, though not one in definition. [15] But the same reasons also forbid us to regard the matter of the body as points or lines. The matter is that of which points and lines are limits, and it is something that can never exist without quality and without form.
Now it is no doubt true, as we have also established elsewhere, that one thing comes-to-be (in the unqualified sense) out of another thing; and further it is true that the efficient cause of its coming-to-be is either an actual thing (which is the [20] same as the effect either generically or specifically, as e.g. fire is the efficient cause of fire or one man of another), or an actuality (for what is hard does not come-to-be through what is hard).6 Nevertheless, since there is also a matter out of which corporeal substance itself comes-to-be (corporeal substance, however, already characterized as such-and-such a determinate body, for there is no such thing as body in general), this same matter is also the matter of magnitude and quality—being separable from these matters in definition, but not separable in place unless [25] qualities are, in their turn, separable.
It is evident, from the preceding discussion of difficulties, that growth is not a change out of something which, though potentially a magnitude, actually possesses no magnitude. For, if it were, the void would exist in separation; but we have explained in a former work7 that this is impossible. Moreover, a change of that kind is not peculiarly distinctive of growth, but characterizes coming-to-be in general. [30] For growth is an increase, and diminution is a lessening, of the magnitude which is there already—that, indeed, is why the growing thing must possess some magnitude. Hence growth must not be regarded as a process from a matter without magnitude to an actuality of magnitude; for this would be a body’s coming-to-be rather than its growth.
We must therefore come to closer quarters and as it were grapple with our [321a1] enquiry from its beginning to determine the precise character of the growing and diminishing whose causes we are investigating.
It is evident that any and every part of the growing thing has increased, and that similarly in diminution every part has become smaller; also that a thing grows by the accession, and diminishes by the departure, of something. Hence it must [5] grow by the accession either of something incorporeal or of a body. Now, if it grows by the accession of something incorporeal, there will exist separate a void; but (as we have stated before) it is impossible for a matter of magnitude to exist separate. If, on the other hand, it grows by the accession of a body, there will be two bodies—that which grows and that which increases it—in the same place; and this too is impossible.
But neither is it open to us to say that growth or diminution occurs in the way [10] in which e.g. air is generated from water. For, although the volume has then become greater, the change will not be growth, but a coming-to-be of the one—viz. of that into which the change is taking place—and a passing-away of the contrasted body. It is not a growth of either. Nothing grows in the process; unless indeed there be something common to both things (to that which is coming-to-be and to that which passed-away), e.g. body, and this grows. The water has not grown, nor has the air; [15] but the former has passed-away and the latter has come-to-be, and—if anything has grown—there has been a growth of body. Yet this too is impossible. For our account of growth must preserve the characteristics of that which is growing and diminishing. And these characteristics are three: any and every part of the growing magnitude is made bigger (e.g. if flesh grows, every particle of the flesh gets [20] bigger); by the accession of something; and thirdly in such a way that the growing thing is preserved and persists. For whereas a thing does not persist in the processes of unqualified coming-to-be or passing-away, that which grows or alters persists in its identity through the altering and through the growing or diminishing, though the quality (in alteration) and the size (in growth) do not remain the same. Now if [25] the generation of air from water is to be regarded as growth, a thing might grow without the accession (and without the persistence) of anything, and diminish without the departure of anything—and that which grows need not persist. But this characteristic must be preserved; for the growth we are discu
ssing has been assumed to be thus characterized.
One might raise a further difficulty. What is that which grows? Is it that to [30] which something is added? If, e.g., a man grows in his shin, is it the shin which is greater—but not that whereby he grows, viz. not the food? Then why have not both grown? For when A is added to B, both A and B are greater, as when you mix wine with water; for each ingredient is alike increased in volume. Perhaps the explanation is that the substance of the one remains unchanged, but the substance of the other (viz. of the food) does not. For indeed, even in the mixture of wine and water, it is the prevailing ingredient which is said to have increased in volume. We say, e.g., that the wine has increased, because the whole mixture acts as wine but not as [321b1] water. A similar principle applies also to alteration. Flesh is said to have been altered if, while its character and essence remain, some property which was not there before, now qualifies it in its own right; on the other hand, that whereby it has been altered may have undergone no change, though sometimes it too has been [5] affected. The altering agent, however, and the source of the process are in the growing thing and in that which is being altered; for the mover is in these. No doubt what has come in, may sometimes expand as well as the body that has consumed it (that is so, e.g., if, after having come in, it is converted into wind), but when it has undergone this change it has passed-away; and the mover is not in it. [10]
We have now developed the difficulties sufficiently and must therefore try to find a solution of the problem while preserving the theses that the growing thing persists, that it grows by the accession (and diminishes by the departure) of something, further that every perceptible particle of it has become either larger or [15] smaller, the growing body is not void and that yet there are not two magnitudes in the same place, and that it does not grow by the accession of something incorporeal.
We must grasp the cause after previously determining, first, that the non-homoeomerous parts grow by the growth of the homoeomerous parts (for every organ is composed of these); and secondly, that flesh, bone, and every such [20] part—like every other thing which has its form in matter—has a twofold nature; for the form as well as the matter is called flesh or bone.
Now, that any and every part should grow—and grow by the accession of something—is possible in respect of form, but not in respect of matter. For we must think of the process as being like what happens when a man measures water with [25] the same measure; for what comes-to-be is always different. And it is in this sense that the matter of the flesh grows, some flowing out and some flowing in; not in the sense that fresh matter accedes to every particle of it. There is, however, an accession to every part of its figure or form.
That growth has taken place proportionally, is more manifest in the non-homoeomerous parts—e.g. in the hand. For there the fact that the matter is distinct [30] from the form is more manifest than in flesh and the homoeomeries. That is why there is a greater tendency to suppose that a corpse still possesses flesh and bone than that it still has a hand or an arm.
Hence in one sense it is true that any and every part of the flesh has grown; but in another sense it is false. For there has been an accession to every part of the flesh in respect to its form, but not in respect to its matter. The whole, however, has [322a1] become larger because of the accession of something, which is called food and is contrary to flesh, and the transformation of this food into the same form as that of flesh—as if, e.g., moist were to accede to dry and, having acceded, were to be transformed and to become dry. For in one sense like grows by like, but in another sense by unlike.
One might discuss what must be the character of that whereby a thing grows. [5] Clearly it must be potentially that which is growing—potentially flesh, e.g., if it is flesh that is growing. Actually, therefore, it must be other than the growing thing. This, then, has passed-away and come-to-be flesh. But it has not been transformed into flesh alone by itself (for that would have been a coming-to-be, not a growth); rather, the growing thing has done so by the food. In what way, then, has the food been modified by the growing thing? Perhaps we should say that it has been mixed with it, as if one were to pour water into wine and the wine were able to convert the [10] new ingredient into wine. And as fire lays hold of the inflammable, so the active principle of growth, dwelling in the growing thing (i.e. in that which is actually flesh), lays hold of an acceding food which is potentially flesh and converts it into actual flesh. The acceding food, therefore, must be together with the growing thing; for if it were apart from it, the change would be a coming-to-be. For it is possible to [15] produce fire by piling logs on to the already burning fire. That is growth. But when the logs themselves are set on fire, that is coming-to-be.
Quantity in general does not come-to-be any more than animal which is neither man nor any other of the specific forms of animal—the universal in this case corresponds to the quantity in that. But what does come-to-be in growth is flesh or bone—or a hand or arm and their homoeomeries. Such things come-to-be, then, by the accession not of a quantity of flesh but of a quantity of something. In so far as [20] this acceding food is potentially the double result—e.g. is potentially a quantity of flesh—it produces growth; for it is bound to become actually both a quantity and flesh. But in so far as it is potentially flesh only, it nourishes; for it is thus that nutrition and growth differ by their definition. That is why a body’s nutrition continues so long as it is kept alive (even when it is diminishing), though not its growth; and why nutrition, though the same as growth, is yet different from it in its [25] being. For in so far as that which accedes is potentially a quantity of flesh it tends to increase flesh; whereas, in so far as it is potentially flesh only, it is nourishment.
The form is a kind of power in matter—a duct, as it were. If, then, a matter accedes which is potentially a duct and also potentially possesses determinate [30] quantity, then these ducts will become bigger. But if it is no longer able to act just as water, continually mixed in greater and greater quantity with wine, in the end makes the wine watery and converts it into water—then it will cause a diminution of the quantum; though still the form persists.
6 · We must first investigate the matter, i.e. the so-called elements. We must [322b1] ask whether they really are elements or not, i.e. whether each of them is eternal or whether there is a sense in which they come-to-be; and, if they do come-to-be, whether all of them come-to-be in the same manner, reciprocally out of one another, or whether one amongst them is something primary. Hence we must begin by explaining certain matters about which the statements now current are vague. [5]
For all those who generate the elements as well as those who generate the bodies that are compounded of the elements—make use of dissociation and association, and of action and passion. Now association is combination; but the meaning of combining has not been clearly explained. Again, without an agent and a patient there cannot be altering any more than there can be dissociating and [10] associating. For not only those who postulate a plurality of elements employ their reciprocal action and passion to generate the compounds: those who derive things from a single element are equally compelled to introduce acting. And in this respect Diogenes is right when he argues that unless all things were derived from one, reciprocal action and passion could not occur. The hot thing, e.g., would not be [15] cooled and the cold thing in turn be warmed; for heat and cold do not change reciprocally into one another, but what changes (it is clear) is the substratum. Hence, whenever there is action and passion between things, that which underlies them must be a single something. No doubt, it is not true to say that all things are of [20] this character; but it is true of all things between which there is reciprocal action and passion.
But if we must investigate action and passion and combination, we must also investigate contact. For action and passion (in the proper sense of the terms) can [25] only occur between things which are such as to touch one another; nor can things enter into combination at all unless they have come into
a certain kind of contact. Hence we must give a definite account of these three things—of contact, combination, and acting.
Let us start as follows. All things which admit of combination must be capable of reciprocal contact; and the same is true of any two things, of which one acts and the other suffers action in the proper sense of the terms. For this reason we must treat of contact first.
[30] Now no doubt, just as every other name is used in many senses (in some cases homonymously, in others one use being derived from other and prior uses), so too is it with contact. Nevertheless contact in the proper sense applies only to things which have position. And position belongs only to those things which also have a [323a1] place; for in so far as we attribute contact to the mathematical things, we must also attribute place to them, whether they exist in separation or in some other fashion. Assuming, therefore, that to touch is—as we have defined it in a previous work 8—to have the extremes together, only those things will touch one another which, being [5] separate magnitudes and possessing position, have their extremes together. And since position belongs only to those things which also have a place, while the primary differentiation of place is the above and the below (and the similar pairs of opposites), all things which touch one another will have weight or lightness—either both these qualities or one or the other of them. But bodies which are heavy or light [10] are such as to act and suffer action. Hence it is clear that those things are by nature such as to touch one another, which (being separate magnitudes) have their extremes together and are able to move, and be moved by, one another.