48 Here, too, in like manner, when we deny that souls are the offspring of God Supreme, it does not necessarily follow that we are bound to declare from what parent they have sprung, and by what causes they have been produced. For who prevents us from being either ignorant of the source from which they issued and came, or aware that they are not God's descendants? By what method, you say, in what way? Because it is most true and certain that, as has been pretty frequently said, nothing is effected, made, determined by the Supreme, except that which it is right and fitting should be done; except that which is complete and entire, and wholly perfect in its integrity.
But further, we see that men, that is, these very souls— for what are men but souls bound to bodies?— themselves show by perversely falling into vice, times without number, that they belong to no patrician race, but have sprung from insignificant families. For we see some harsh, vicious, presumptuous, rash, reckless, blinded, false, dissemblers, liars, proud, overbearing, covetous, greedy, lustful, fickle, weak, and unable to observe their own precepts; but they would assuredly not be so, if their original goodness defended them, and they traced their honourable descent from the head of the universe.
Source: Against the Heathen (New Advent)