[127] This is the reason for what is said in Genesis, “A spring went up out of the earth and watered all the face of the earth” (Gen. 2:6). For since Nature allotted the face to the senses as the choicest portion of the whole body, the spring that rises from the dominant faculty, dividing itself in many directions, sends up conduits, so to speak, as far as the face, and by them conveys the powers they need to each of the organs of sense. It is in this way that the word of God waters the virtues; for the word of God is the source and spring of noble conduct.
[128] The lawgiver intimates as much by the words: “A river goeth out of Eden to water the garden. From thence it is parted into four heads” (Gen. 2:10). For there are four main virtues, wisdom, courage, temperance, justice. Each one of these is a sovereign wielding authority, and the man that has acquired them is by the mere fact of doing so a ruling monarch, even if he be destitute of material resources.
[129] For the phrase “is parted into four heads” is not meant to indicate a dividing asunder, but a sway and sovereignty belonging to virtues. These have sprung from the Divine word as from a single root; and that word is likened to a river by reason of the unbroken flow of the constant stream of words and doctrines ever sweet and fresh, by which it brings nourishment and growth to souls that love God.