On the World and the Movements of Rational Creatures, Whether Good or Bad; And on the Causes of Them
5 Now, when we say that this world was established in the variety in which we have above explained that it was created by God, and when we say that this God is good, and righteous, and most just, there are numerous individuals, especially those who, coming from the school of Marcion, and Valentinus, and Basilides, have heard that there are souls of different natures, who object to us, that it cannot consist with the justice of God in creating the world to assign to some of His creatures an abode in the heavens, and not only to give such a better habitation, but also to grant them a higher and more honourable position; to favour others with the grant of principalities; to bestow powers upon some, dominions on others; to confer upon some the most honourable seats in the celestial tribunals; to enable some to shine with more resplendent glory, and to glitter with a starry splendour; to give to some the glory of the sun, to others the glory of the moon, to others the glory of the stars; to cause one star to differ from another star in glory. And, to speak once for all, and briefly, if the Creator God wants neither the will to undertake nor the power to complete a good and perfect work, what reason can there be that, in the creation of rational natures, i.e., of beings of whose existence He Himself is the cause, He should make some of higher rank, and others of second, or third, or of many lower and inferior degrees? In the next place, they object to us, with regard to terrestrial beings, that a happier lot by birth is the case with some rather than with others; as one man, e.g., is begotten of Abraham, and born of the promise; another, too, of Isaac and Rebekah, and who, while still in the womb, supplants his brother, and is said to be loved by God before he is born. Nay, this very circumstance—especially that one man is born among the Hebrews, with whom he finds instruction in the divine law; another among the Greeks, themselves also wise, and men of no small learning; and then another among the Ethiopians, who are accustomed to feed on human flesh; or among the Scythians, with whom parricide is an act sanctioned by law; or among the people of Taurus, where strangers are offered in sacrifice—is a ground of strong objection. Their argument accordingly is this: If there be this great diversity of circumstances, and this diverse and varying condition by birth, in which the faculty of free-will has no scope (for no one chooses for himself either where, or with whom, or in what condition he is born); if, then, this is not caused by the difference in the nature of souls, i.e., that a soul of an evil nature is destined for a wicked nation, and a good soul for a righteous nation, what other conclusion remains than that these things must be supposed to be regulated by accident and chance? And if that be admitted, then it will be no longer believed that the world was made by God, or administered by His providence; and as a consequence, a judgment of God upon the deeds of each individual will appear a thing not to be looked for. In which matter, indeed, what is clearly the truth of things is the privilege of Him alone to know who searches all things, even the deep things of God.
6. We, however, although but men, not to nourish the insolence of the heretics by our silence, will return to their objections such answers as occur to us, so far as our abilities enable us. We have frequently shown, by those declarations which we were able to produce from the holy Scriptures, that God, the Creator of all things, is good, and just, and all-powerful. When He in the beginning created those beings which He desired to create, i.e., rational natures, He had no other reason for creating them than on account of Himself, i.e., His own goodness. As He Himself, then, was the cause of the existence of those things which were to be created, in whom there was neither any variation nor change, nor want of power, He created all whom He made equal and alike, because there was in Himself no reason for producing variety and diversity. But since those rational creatures themselves, as we have frequently shown, and will yet show in the proper place, were endowed with the power of free-will, this freedom of will incited each one either to progress by imitation of God, or reduced him to failure through negligence. And this, as we have already stated, is the cause of the diversity among rational creatures, deriving its origin not from the will or judgment of the Creator, but from the freedom of the individual will. Now God, who deemed it just to arrange His creatures according to their merit, brought down these different understandings into the harmony of one world, that He might adorn, as it were, one dwelling, in which there ought to be not only vessels of gold and silver, but also of wood and clay (and some indeed to honour, and others to dishonour), with those different vessels, or souls, or understandings. And these are the causes, in my opinion, why that world presents the aspect of diversity, while Divine Providence continues to regulate each individual according to the variety of his movements, or of his feelings and purpose. On which account the Creator will neither appear to be unjust in distributing (for the causes already mentioned) to every one according to his merits; nor will the happiness or unhappiness of each one's birth, or whatever be the condition that falls to his lot, be deemed accidental; nor will different creators, or souls of different natures, be believed to exist.
Source: De Principiis (New Advent)