Select Works, Section 132

Section 10 10. But how can I form the conception of the sizelessness of Matter? How do you form the concept of any absence of quality? What is the Act of the Intellect, what is the mental approach, in such a case? The secret is Indetermination. Likeness knows its like: the indeterminate knows the indeterminate. Around this indefinite a definite conception will be realized, but the way lies through indefiniteness. All knowledge comes by Reason and the Intellectual Act; in this case Reason conveys information in any account it gives, but the act which aims at being intellectual is, here, not intellection but rather its failure: therefore the representation of Matter must be spurious, unreal, something sprung of the Alien, of the unreal, and bound up with the alien reason. This is Plato's meaning where he says that Matter is apprehended by a sort of spurious reasoning. What, then, is this indetermination in the Soul? Does it amount to an utter absence of Knowledge, as if the Soul or Mind had withdrawn? No: the indeterminate has some footing in the sphere of affirmation. The eye is aware of darkness as a base capable of receiving any colour not yet seen against it: so the Mind, putting aside all attributes perceptible to sense- all that corresponds to light- comes upon a residuum which it cannot bring under determination: it is thus in the state of the eye which, when directed towards darkness, has become in some way identical with the object of its spurious vision. There is vision, then, in this approach of the Mind towards Matter? Some vision, yes; of shapelessness, of colourlessness, of the unlit, and therefore of the sizeless. More than this would mean that the Soul is already bestowing Form. But is not such a void precisely what the Soul experiences when it has no intellection whatever? No: in that case it affirms nothing, or rather has no experience: but in knowing Matter, it has an experience, what may be described as the impact of the shapeless; for in its very consciousness of objects that have taken shape and size it knows them as compounds [i.e., as possessing with these forms a formless base] for they appear as things that have accepted colour and other quality. It knows, therefore, a whole which includes two components; it has a clear Knowledge or perception of the overlie [the Ideas] but only a dim awareness of the underlie, the shapeless which is not an Ideal-Principle. With what is perceptible to it there is presented something else: what it can directly apprehend it sets on one side as its own; but the something else which Reason rejects, this, the dim, it knows dimly, this, the dark, it knows darkly, this it knows in a sort of non-knowing. And just as even Matter itself is not stably shapeless but, in things, is always shaped, the Soul also is eager to throw over it the thing-form; for the Soul recoils from the indefinite, dreads, almost, to be outside of reality, does not endure to linger about Non-Being.