We don’t even get past the first page of St. Augustine’s On Free Choice of the Will without a clear statement of the relationship of justice to free will. By way of entering into the dialogue, Evodius asks him “whether God is not the cause of evil.” Augustine explains that “evil” might be understood in more than one sense: “God does not do evil,” but because He is just, “He assigns rewards to the righteous and punishments to the wicked—punishments that are indeed evil for those who suffer them.”
Keeping in mind that (as we saw in a previous post) at least part of the book’s purpose is to counter the opinions of the Manichaeans, and that among other things the Manichaeans believed in two deities—one good, the source of all created good, and one evil, the source of all evil—Evodius pursues with a followup question: well, if God isn’t the cause of evil, is there some other cause? St. Augustine replies:
Certainly, for evil could not have come into being without a cause. However, if you ask what the cause may be, I cannot say, since there is no one cause; rather, each evil man is the cause of his own evildoing. If you doubt this, then listen to what we said above: evil deeds are punished by the justice of God. It would not be just to punish evil deeds if they were not done willfully. [p. 3; emphasis added]
On this score we see that the Reformed—at any rate, those who hold to the Heidelberg Catechism—are flatly out of accord with Augustine, and simply may not claim him as their own, for this catechism says:
Question 8. Are we then so corrupt that we are wholly incapable of doing any good, and inclined to all wickedness?
Answer: Indeed we are; except we are regenerated by the Spirit of God.
Similarly the Westminster Confession:
III. Man, by his fall into a state of sin, has wholly lost all ability of will to any spiritual good accompanying salvation: so as, a natural man, being altogether averse from that good, and dead in sin, is not able, by his own strength, to convert himself, or to prepare himself thereunto.
If we are “wholly incapable of doing any good,” then everything that we do must be evil. If we are not capable of doing good, then it is impossible for us not to sin. But as St. Augustine says, it would be unjust to punish us for evil done that we could not help doing. On St. Augustine’s account, then, such views clearly undermine God’s justice. So we see on this point that he was not some sort of proto-Calvinist, and that Calvinists are not some sort of latter-day Augustinians when they deny that we have free will. If we do not, we cannot be justly held culpable for what we do.