Select Works, Section 125

Section 3 3. Now it may be observed, first of all, that we cannot hold utterly cheap either the indeterminate, or even a Kind whose very idea implies absence of form, provided only that it offer itself to its Priors and [through them] to the Highest Beings. We have the parallel of the Soul itself in its relation to the Intellectual-Principle and the Divine Reason, taking shape by these and led so to a nobler principle of form. Further, a compound in the Intellectual order is not to be confounded with a compound in the realm of Matter; the Divine Reasons are compounds and their Act is to produce a compound, namely that [lower] Nature which works towards Idea. And there is not only a difference of function; there is a still more notable difference of source. Then, too, the Matter of the realm of process ceaselessly changes its form: in the eternal, Matter is immutably one and the same, so that the two are diametrically opposites. The Matter of this realm is all things in turn, a new entity in every separate case, so that nothing is permanent and one thing ceaselessly pushes another out of being: Matter has no identity here. In the Intellectual it is all things at once: and therefore has nothing to change into: it already and ever contains all. This means that not even in its own Sphere is the Matter there at any moment shapeless: no doubt that is true of the Matter here as well; but shape is held by a very different right in the two orders of Matter. As to whether Matter is eternal or a thing of process, this will be clear when we are sure of its precise nature.