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 Does it amount to an utter absence of Knowledge, as if the Soul or Mind had withdrawn?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.
11."But, given Magnitude and the properties we know, what else can be necessary to the existence of body?"Some base to be the container of all the rest.
"A certain mass then; and if mass, then Magnitude? Obviously if your Base has no Magnitude it offers no footing to any entrant.And suppose it sizeless; then, what end does it serve? It never helped Idea or quality; now it ceases to account for differentiation or for magnitude, though the last, wheresoever it resides, seems to find its way into embodied entities by way of Matter.""Or, taking a larger view, observe that actions, productive operations, periods of time, movements, none of these have any such substratum and yet are real things; in the same way the most elementary body has no need of Matter; things may be, all, what they are, each after its own kind, in their great variety, deriving the coherence of their being from the blending of the various Ideal-Forms.
This Matter with its sizelessness seems, then, to be a name without a content."Now, to begin with: extension is not an imperative condition of being a recipient; it is necessary only where it happens to be a property inherent to the recipient's peculiar mode of being.The Soul, for example, contains all things but holds them all in an unextended unity; if magnitude were one of its attributes it would contain things in extension.Matter does actually contain in spatial extension what it takes in; but this is because itself is a potential recipient of spatial extension: animals and plants, in the same way, as they increase in size, take quality in parallel development with quantity, and they lose in the one as the other lessens.
No doubt in the case of things as we know them there is a certain mass lying ready beforehand to the shaping power: but that is no reason for expecting bulk in Matter strictly so called; for in such cases Matter is not the absolute; it is that of some definite object; the Absolute Matter must take its magnitude, as every other property, from outside itself.
A thing then need not have magnitude in order to receive form:
it may receive mass with everything else that comes to it at the moment of becoming what it is to be: a phantasm of mass is enough, a primary aptness for extension, a magnitude of no content- whence the identification that has been made of Matter with The Void.
But I prefer to use the word phantasm as hinting the indefiniteness into which the Soul spills itself when it seeks to communicate with Matter, finding no possibility of delimiting it, neither encompassing it nor able to penetrate to any fixed point of it, either of which achievements would be an act of delimitation.
In other words, we have something which is to be described not as small or great but as the great-and-small: for it is at once a mass and a thing without magnitude, in the sense that it is the Matter on which Mass is based and that, as it changes from great to small and small to great, it traverses magnitude.Its very undeterminateness is a mass in the same sense that of being a recipient of Magnitude-though of course only in the visible object.
In the order of things without Mass, all that is Ideal-Principle possesses delimitation, each entity for itself, so that the conception of Mass has no place in them: Matter, not delimited, having in its own nature no stability, swept into any or every form by turns, ready to go here, there and everywhere, becomes a thing of multiplicity: driven into all shapes, becoming all things, it has that much of the character of mass.
12.It is the corporeal, then, that demands magnitude: the Ideal-Forms of body are Ideas installed in Mass.