VIDE Eneada-I, 8, 9
9. But what approach have we to the knowing of Good and Evil?
And first of the Evil of soul: Virtue, we may know by the Intellectual-Principle and by means of the philosophic habit; but Vice?
A a ruler marks off straight from crooked, so Vice is known by its divergence from the line of Virtue.
But are we able to affirm Vice by any vision we can have of it, or is there some other way of knowing it?
Utter viciousness, certainly not by any vision, for it is utterly outside of bound and measure; this thing which is nowhere can be seized only by abstraction; but any degree of evil falling short of The Absolute is knowable by the extent of that falling short.
We see partial wrong; from what is before us we divine that which is lacking to the entire form (or Kind) thus indicated; we see that the completed Kind would be the Indeterminate; by this process we are able to identify and affirm Evil. In the same way when we observe what we feel to be an ugly appearance in Matter – left there because the Reason-Principle has not become so completely the master as to cover over the unseemliness – we recognise Ugliness by the falling-short from Ideal-Form.
But how can we identify what has never had any touch of Form?
We utterly eliminate every kind of Form; and the object in which there is none whatever we call Matter: if we are to see Matter we must so completely abolish Form that we take shapelessness into our very selves.
In fact it is another Intellectual-Principle, not the true, this which ventures a vision so uncongenial.
To see darkness the eye withdraws from the light; it is striving to cease from seeing, therefore it abandons the light which would make the darkness invisible; away from the light its power is rather that of not-seeing than of seeing and this not-seeing is its nearest approach to seeing Darkness. So the Intellectual-Principle, in order to see its contrary (Matter), must leave its own light locked up within itself, and as it were go forth from itself into an outside realm, it must ignore its native brightness and submit itself to the very contradition of its being.