XXVI. (145) This then is the meaning of the words, "out of her." We must now consider the third point, namely, what that is which is called her son. In the first place, then, there is this worthy of our admiration, that God does not say that he will give her many children, but that he will give her one only. And why is this? Because it is the nature of what is good to be investigated, not so much with respect to its number or magnitude, as with respect to its power; (146) for musical precepts, to take them for an instance, or rules of grammar, or of geometry, or of justice, or of wisdom, or of manly courage, or of temperance, are very numerous indeed; but the science itself of music, or grammar, or geometry, and still more the virtue of justice, or temperance, or wisdom, or manly courage, is only one thing, the loftiest perfection, in no respect differing from the archetypal model, after which all those numerous and countless precepts were formed. (147) And this is why he only says that he will give her one son. And now he called it a son, not speaking carelessly or inconsiderately, but for the sake of showing that it is not a foreign, or a supposititious, nor an adopted, nor an illegitimate child, but a legitimate child, a proper citizen, inasmuch as a foreign child cannot be the offspring of a truly citizen soul, for the Greek word teknon (son), is derived from tokos (bringing forth), by way of showing the kindred by which children are, by nature, united to their parents.