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,