And there is an absolute beauty and an absolute good, and of other things to which the term “many” is applied there is an absolute; for they may be brought under a single idea, which is called the essence of each.
Very true.
The many, as we say, are seen but not known, and the ideas are known but not seen.
Exactly.
And what is the organ with which we see the visible things?
The sight, he said.
And with the hearing, I said, we hear, and with the other senses perceive the other objects of sense?
True.
But have you remarked that sight is by far the most costly and complex piece of workmanship which the artificer of the senses ever contrived?
No, I never have, he said.
Then reflect: has the ear or voice need of any third or additional nature in order that the one may be able to hear and the other to be heard?
Nothing of the sort.
No, indeed, I replied; and the same is true of most, if not all, the other senses—you would not say that any of them requires such an addition?
Certainly not.
But you see that without the addition of some other nature there is no seeing or being seen?
How do you mean?
Sight being, as I conceive, in the eyes, and he who has eyes wanting to see; color being also present in them, still unless there be a third nature specially adapted to the purpose, the owner of the eyes will see nothing and the colors will be invisible.
Of what nature are you speaking?
Of that which you term light, I replied.
True, he said.
Noble, then, is the bond which links together sight and visibility, and great beyond other bonds by no small difference of nature; for light is their bond, and light is no ignoble thing?
Nay, he said, the reverse of ignoble.
