Concerning the First Principle of Cold (9)

But it is much the better way for us in the first place to move forward upon those things which are perceptible to sense, wherein Empedocles, Strato, and the Stoics placed the substances of active qualities; the Stoics ascribing primitive cold to the air, Empedocles and Strato

to the water; and perhaps there might be somebody else who might affirm the earth to be the substance of cold. But first let us consider the opinions of those already named.

Seeing then that fire is both hot and bright, therefore there must be something opposite to fire which is cold and dark. For as dark is opposite to light, so is cold to hot. Besides, as dark confounds the sight, so cold confounds the feeling. But heat diffuses the sense of feeling, as light diffuses the sense of seeing. Therefore that which is first dark in nature is first cold. Now that the air is first dark, was not unknown to the poets; for that they call the air darkness:

The thickened air the fleet with darkness covered,

Nor could the moonlight be from heaven discovered.

[*]

And again:

Then darkness scattered and the fog dispelled,

The sun brake forth, and all the fight beheld.

[*]

They also call the air, when it is without light κνεφας, as being as it were κενὸν φάους (void of light.) The air collected and condensed into a cloud is called νέφος, from its negation of light (νή-φάος). The words also ἀχλύς and ὁμίκλη (mist), and whatever else restrains the perception of light from the sense, are but distinctions of the air; insomuch that the same part of it which is invisible and without color (ἀειδές and ἀρχωστον) is called Hades and Acheron. So that, as the air grows dark when the splendor of it fails, in like manner when heat fails, that which is left is no more than cold air, which by reason of its coldness is called Tartarus. And this Hesiod makes manifest, when he calls it Τάρταρον ἠερόεντα (or cloudy Tartarus); and when a man quakes and shivers for cold, he is said to tartarize. And so much for this.