8. (According to Aristotle[59]), it is absolutely necessary that what can be affected must have powers and qualities opposed to the things that approach it, and affect it. Thus, it is the cold that alters the heat of an object, and humidity that alters its dryness, and we say that the substrate is altered, when it ceases being hot, and grows cold; and ceasing to be dry, becomes humid. Another proof of this truth is the destruction of the fire that, by changing, becomes another element. Then we say that it is the fire, but not the matter that has been destroyed. What is affected is therefore that which is destroyed; for it is always a passive modification that occasions destruction. Consequently being destroyed and being affected are inseparable notions. Now it is impossible for matter to be destroyed; for how could it be destroyed, and in what would it change?
OBJECTION THAT MATTER MUST BE PASSIBLE IF ITS QUALITIES CHANGE AS THEY DO.
It may be objected that matter receives heat, cold, and numerous, or even innumerable qualities; it is characterized by them, it possesses them as somehow inherent in its nature, and mingled with each other, as they do not exist in isolated condition. How could nature avoid being affected along with them,[60] serving as it does as a medium for the mutual action of these qualities by their mixture?[61] If matter is to be considered impassible, we shall have to consider it as somehow outside of these qualities. But every quality which is present in a subject cannot be present in it without communicating to it something of itself.
DIFFERENT SENSES OF "PARTICIPATION" WILL ALLOW FOR MATTER TO REMAIN IMPASSIBLE.
9. It must be noticed that the expressions: "such a thing is present to such a thing" and "such a thing is in such other thing" have several meanings. Sometimes one thing improves or deteriorates some other thing by its presence, making it undergo a change; as may be seen in bodies, especially those of living beings. Again, one thing improves or deteriorates another without affecting it; this occurs with the soul, as we have already seen.[62] Again, it is as when one impresses a figure on a piece of wax; the presence of the figure adds nothing to the (nature) of the wax, and its destruction makes it lose nothing. Likewise, light does not change the figure of the object which it enlightens with its rays. A cooled stone participates a little in the nature characteristic of the thing that cools it; but none the less remains stone. What suffering can light inflict on a line or a surface?[63] One might perhaps say that in this case corporeal substance is affected; but how can it suffer (or be affected) by the action of light? Suffering, in fact, is not to enjoy the presence of something, nor to receive something. Mirrors, and, in general, transparent things, do not suffer (or are not affected) by the effect of images that form in them, and they offer a striking example of the truth we are here presenting. Indeed, qualities inhere in matter like simple images, and matter itself is more impassible than a mirror. Heat and cold occur in it without warming or cooling it; for heating and cooling consist in that one quality of the substrate gives place to another. In passing, we might notice that it would not be without interest to examine whether cold is not merely absence of heat. On entering into matter, qualities mostly react on each other only when they are opposite. What action, indeed, could be exercised by a smell on a sweet taste? By a color on a figure? How, in general, could things that belong to one genus act on another? This shows how one quality can give place to another in a same subject, or how one thing can be in another, without its presence causing any modification in the subject for which or in which it is present. Just as a thing is not altered by the first comer, likewise that which is affected and which changes does not receive a passive modification, or change, from any kind of an object. Qualities are affected only by the action of contraries. Things which are simply different cause no change in each other. Those which have no contraries could evidently not be modified by the action of any contrary. That which is affected, therefore, can not be matter; it must be a composite (of form and matter), or something multiple. But that which is isolated or separated from the rest, what is quite simple must remain impassible in respect of all things, and remain as a kind of medium in which other things may act on each other. Likewise, within a house, several objects can shock each other without the house itself or the air within it being affected. It is therefore qualities gathered in matter that act on each other, so far as it belongs to their nature. Matter itself, however, is still far more impassible than the qualities are among each other, when they do not find themselves opposite.
IF FORM BE UNCHANGEABLE, SO IS MATTER.
10. If matter could be affected, it would have to preserve some of the affection, retaining either the affection itself, or remain in a state different from the one in which it was before it was affected. But when one quality appears after another quality, it is no longer matter that receives it, but matter as determined by a quality. If even this quality should evanesce, though leaving some trace of itself by the action it has exercised, the substrate will still more be altered; proceeding thus it will come to be something entirely different from pure matter, it will be something multiple by its forms and by its manners of existence. It will no longer be the common receptacle of all things, since it will contain an obstacle to many things that could happen to it; matter would no longer subsist within it, and would no longer be incorruptible. Now if, by definition, matter always remains what it was since its origin, namely "matter," then, if we insist that it be altered, it is evident that matter no longer remains such. Moreover, if everything that is altered must remain unchanged in kind, so as not to be changed in itself, though changed in accidents; in one word, if that which is changed must be permanent, and if that which is permanent be not that which is affected, we come to a dilemma; either matter is altered, and abandons its nature; or it does not abandon its nature, and is not changed. If we say that matter is changed, but not in so far as it is matter, it will, to begin with, be impossible to state in what it is changed; and further, we would thereby be forced to insist it was not changed. Indeed, just as other things, which are forms, cannot be changed in their "being" (or, nature), because it is this very unalterability which constitutes their "being" (or, nature), likewise, as the "being" (or, nature) of matter is to exist in so far as it is matter, it cannot be altered in so far as it is matter, and it must necessarily be permanent in this respect. Therefore if form be unalterable, matter must be equally unalterable.
MATTER PARTICIPATES IN THE INTELLIGIBLE ONLY BY APPEARANCE.
11. This was no doubt the thought present to Plato when[64] he rightly said, "These imitations of the eternal beings which enter into matter, and which issue therefrom." Not without good reason did he employ the terms "enter" and "issue"; he wanted us carefully to scrutinize the manner in which matter participates in ideas. When Plato thus tries to clear up how matter participates in ideas, his object is to show, not how ideas enter into matter, as before so many have believed, but their condition within it. Doubtless, it does seem astonishing that matter remains impassible in respect to the ideas that are present therein, while the things that enter in it are affected by each other. We nevertheless have to acknowledge that the things which enter into matter expel their predecessors, and that it is only the composite that is affected. Nevertheless it is not every kind of composite that is affected, but only that composite that happens to need the thing that was introduced or expelled, so that its constitution becomes defective by the absence of that (quality), or more complete by its presence. Nothing is added to the nature of matter, however, by the introduction of anything; the presence of that thing does not make matter what it is, and matter loses nothing by its absence; matter remains what it was since its origin. To be ornamented is to the interest of something that admits of order or ornament; it can receive that ornament without being changed, when it only puts it on, so to speak. But if this ornament penetrate into it as something that forms part of its nature, it then cannot receive it without being altered, without ceasing to be what it was before, as for instance, ceasing to be ugly; without, by that very fact, changing; without, for instance, becoming beautiful, though ugly before. Therefore if matter become beautiful, though before ugly, it ceases to be what it was before; namely, ugly; so that on being adorned it loses its nature, so much the more as it was ugly only accidentally. Being ugly enough to be ugliness itself, it could not participate in beauty; being bad enough to be badness itself, it could not participate in goodness. Therefore matter participates in the ideas without being affected; and consequently, this participation must operate in another manner; and, for instance, consist in appearance.[65] This kind of participation solves the problem we had set ourselves; it enables us to understand how, while being evil, matter can aspire to the Good without ceasing to be what it was, in spite of its participation in the Good. Indeed if this participation operate in a manner such that matter remains without alteration, as we say, and if it always continue to be what it was, there is no reason to be surprised if, though being evil, it can participate in the Good; it does not swerve from its manner of existence. On one hand, as for her, this participation is unavoidable, it participates as long as it endures; on the other hand, as matter continues to be what it is, by virtue of the kind of participation which does not interfere with its nature, it undergoes no alteration on the part of the principle which gives it something; it always remains as bad as it was, because its nature persists. If matter really participated in the Good, if matter were really modified thereby, its nature would no longer be evil. Therefore, the statement that matter is evil is true enough if it be considered to imply that it is impassible in respect to Good; and this really amounts to saying that it is entirely impassible.