Exposition of the Faith

Air is the most subtle element, and is moist and warm: heavier, indeed, than fire: but lighter than earth and water: it is the cause of respiration and voice: it is colourless, that is, it has no colour by nature: it is clear and transparent, for it is capable of receiving light: it ministers to three of our senses, for it is by its aid that we see, hear and smell: it has the power likewise of receiving heat and cold, dryness and moisture, and its movements in space are up, down, within, without, to the right and to the left, and the cyclical movement.

It does not derive its light from itself, but is illuminated by sun, and moon, and stars, and fire. And this is just what the Scripture means when it says, And darkness was upon the deep; for its object is to show that the air has not derived its light from itself, but that it is quite a different essence from light.

And wind is a movement of air: or wind is a rush of air which changes its name as it changes the place whence it rushes.

Its place is in the air. For place is the circumference of a body. But what is it that surrounds bodies but air? There are, moreover, different places in which the movement of air originates, and from these the winds get their names. There are in all twelve winds. It is said that air is just fire after it has been extinguished, or the vapour of heated water. At all events, in its own special nature the air is warm, but it becomes cold owing to the proximity of water and earth, so that the lower parts of it are cold, and the higher warm.

These then are the winds: Cæcias, or Meses, arises in the region where the sun rises in summer. Subsolanus, where the sun rises at the equinoxes. Eurus, where it rises in winter. Africus, where it sets in winter. Favonius, where it sets at the equinoxes, and Corus, or Olympias, or Iapyx, where it sets in summer. Then come Auster and Aquilo, whose blasts oppose one another. Between Aquilo and Cæcias comes Boreas: and between Eurus and Auster, Phœnix or Euronotus; between Auster and Africus, Libonotus or Leuconotus: and lastly, between Aquilo and Corus, Thrascias, or Cercius, as it is called by the inhabitants of that region.

[These, then, are the races which dwell at the ends of the world: beside Subsolanus are the Bactriani: beside Eurus, the Indians: beside Phœnix, the Red Sea and Ethiopia: beside Libonotus, the Garamantes, who are beyond Systis: beside Africus, the Ethiopians and the Western Mauri: beside Favonius, the columns of Hercules and the beginnings of Libya and Europe: beside Corus, Iberia, which is now called Spain: beside Thrascia, the Gauls and the neighbouring nations: beside Aquilo, the Scythians who are beyond Thrace: beside Boreas, Pontus, Mæotis and the Sarmatæ: beside Cæcias, the Caspian Sea and the Sacai.]