On the Allegories of the Sacred Laws (1.66-1.70)

The name of one river is Pheison. This is that

And when he uses the expression, that is the country where there is gold, he is not speaking geographically, that is, where gold exists, but that is the country in which that valuable possession exists, brilliant as gold, tried in the fire, and valuable, namely, prudence. And this is confessed to be the most valuable possession of God. But with reference to the geographical position of virtue, there are two personages, each invested with distinctive qualities. One, the being who has prudence, the other, the being who exerts it; and these he likens to the carbuncle and the emerald.

And the name of the second river is Gihon. This is that which encircles all the land of Ethiopia. Under the symbol of this river courage is intended. For the name of Gihon being interpreted means chest, or an animal which attacks with its horns; each of which interpretations is emblematical of courage. For courage has its abode about the chest, where also is the seat of the heart, and where man is prepared to defend himself. For courage is the knowledge of what is to be withstood, and of what is not to be withstood, and of what is indifferent. And it encircles and surrounds Ethiopia, making demonstrations of war against it; and the name of Ethiopia, being interpreted, means humiliation. And cowardice is a humiliating thing; but courage is adverse to humiliation and to cowardice.

And the third river is the Tigris; this is that which flows in front of Assyria. The third virtue is temperance, which resolutely opposes that kind of pleasure which appears to be the directress of human infirmity. For the translation of the name Assyrians in the Greek tongue is εὑθύνοντες, (directors).

It is worth while therefore to raise the question why courage has been spoken of as the second virtue, and temperance as the third, and prudence as the first; and why Moses has not also explained the course of action of the other virtues. Now we must understand that our soul is divided into three parts, and that it has one portion which is conversant about reason; another which is subject to passion; and another which is that in which the desires are conceived. And we find that the proper place and abode of the reasoning part of the soul, is the head; of the passionate part, the chest; and of the part in which the desires are conceived, the stomach. And we find that appropriate virtues are adapted to each of these parts. To the rational part, prudence; in it is the office of reason, to have a knowledge of what one might, and of what one ought not to do. And the virtue of the passionate part of the soul is courage: and of the appetitive part, temperance. For it is through temperance that we remedy and cure the appetites.