republic (books 6 - 10)
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 addi-
tional 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?
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 invisi-
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 visi-
bility, 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.
And which, I said, of the gods in heaven would you say was
the lord of this element? Whose is that light which makes
the eye to see perfectly and the visible to appear?
You mean the sun, as you and all mankind say.
May not the relation of sight to this deity be described as
Neither sight nor the eye in which sight resides is the sun?
Yet of all the organs of sense the eye is the most like the
By far the most like.
And the power which the eye possesses is a sort of effluence
which is dispensed from the sun?