15. Now the objects attracting the sun-rays to themselves- illuminated by a fire of the sense-order- are necessarily of the sense-order; there is perceptibility because there has been a union of things at once external to each other and continuous, contiguous, in direct contact, two extremes in one line. But the Reason-Principle operating upon Matter is external to it only in a very different mode and sense: exteriority in this case is amply supplied by contrariety of essence and can dispense with any opposite ends [any question of lineal position]; or, rather, the difference is one that actually debars any local extremity; sheer incongruity of essence, the utter failure in relationship, inhibits admixture [between Matter and any form of Being].
The reason, then, of the immutability of Matter is that the entrant principle neither possesses it nor is possessed by it. Consider, as an example, the mode in which an opinion or representation is present in the mind; there is no admixture; the notion that came goes in its time, still integrally itself alone, taking nothing with it, leaving nothing after it, because it has not been blended with the mind; there is no "outside" in the sense of contact broken, and the distinction between base and entrant is patent not to the senses but to the reason.
In that example, no doubt, the mental representation- though it seems to have a wide and unchecked control- is an image, while the Soul [Mind] is in its nature not an image [but a Reality]: none the less the Soul or Mind certainly stands to the concept as Matter, or in some analogous relation. The representation, however, does not cover the Mind over; on the contrary it is often expelled by some activity there; however urgently it presses in, it never effects such an obliteration as to be taken for the Soul; it is confronted there by indwelling powers, by Reason-Principles, which repel all such attack.
Matter- feebler far than the Soul for any exercise of power, and possessing no phase of the Authentic Existents, not even in possession of its own falsity- lacks the very means of manifesting itself, utter void as it is; it becomes the means by which other things appear, but it cannot announce its own presence. Penetrating thought may arrive at it, discriminating it from Authentic Existence; then, it is discerned as something abandoned by all that really is, by even the dimmest semblants of being, as a thing dragged towards every shape and property and appearing to follow- yet in fact not even following.