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.