On the Life of the Wise Man made perfect by Instruction or, on the Unwritten Law, that is to say, on Abraham (156-160)

But we must now proceed to speak of that which is the most necessary part of all, the advantage which we derive from the eyes. For it is to sight alone of the external senses that God has caused light to arise, which is both the most beautiful of all existing things, and is, moreover, the first thing which is pronounced in the sacred scriptures to be good.

Now the nature of light is twofold: for there is one light which proceeds from the fire which we use, a perishable light proceeding from a perishable material, and one which admits of being extinguished. But the other kind is inextinguishable and imperishable, descending to us from above from heaven, as if every one of the stars was pouring down its beams upon us from an everlasting spring. And the sense of sight associates with each of these kinds of light, and through the medium of both of them does it approach the objects of sight so as to arrive at a most accurate comprehension of them.

Why now need we attempt to panegyrize the eyes further by a speech,

On which account men, using the most excellent of all gifts, contemplate the things which exist in the world, the earth, the plants, the animals, the fruits of the earth, the seas, the effusion of waters springing from the earth and gushing forth in torrents and floods, and the varieties of fountains, some of which give forth cold and others hot water, and the natures of all things that exist in the air; and all the different species, of which we thus arrive at the knowledge, are innumerable and indescribable, and cannot be comprised in speech. And above all these things, the eyes can behold the heaven, which is truly a world created in another world, and it can also survey the beauties and divine images existing in heaven. Which now of the other external senses can boast that it has arrived at such a pitch of power as this?

But now, dismissing the consideration of those of the outward senses which are in the stables, as it were, fattening up an animal which is born with us, namely, appetite, let us investigate the nature of that sense which receives speech, namely, hearing; the continued and vigorous, and most perfect course of which exists in the atmosphere which surrounds the earth, when the violence of the winds and the noise of thunder sound with a great dragging noise and terrible crash.