Dr. Feser has been writing on the doctrine of hell and punishment these days. I wanted to highlight some very useful arguments he makes connecting punishment to natural law. He says in his recent post, “Does God damn you?“:
Now, given what has been said, happiness – which is, again, the realization of the ends set for us by nature – without pleasure or delight in this realization entails a kind of defect or dysfunction. For pleasure or delight, as a proper accident of happiness, would naturally follow from it if everything were functioning as it should. Aquinas, following Aristotle, thus holds that pleasure “perfects” the operation of our faculties as those faculties realize their natural ends. Hence even though happiness is not the same thing as pleasure, perfect happiness necessarily requires pleasure or delight as a concomitant. The reward of those who do what is right will, accordingly, involve pleasure or delight. God will ensure that nothing prevents this in the afterlife, as it is sometimes prevented in this life.
By the same token, however, disordered desire and behavior – that which is contrary to the realization of our natural ends, and thus entails unhappiness – without pain or unpleasantness also involves a kind of defect. A life of evil behavior that is nevertheless more or less pleasant is just as dysfunctional as a life of good behavior that is nevertheless miserable, and both dysfunctions need to be remedied. Just as good behavior naturally ought to be associated with pleasure, a feeling of well-being, etc., so too bad behavior naturally ought tobe associated with pain and an absence of a feeling of well-being. When the former correlation does not hold, things need to be made right by rewarding those who do what is good. When the latter correlation does not hold, things need to be made right by punishing those who do what is bad.
And that is the essence of punishment: restoring the teleological relationship, ordained by nature, between evil behavior on the one hand and the unpleasantness or pain that is its proper accident on the other. Punishing evil is thus like healing a wound, restoring a damaged painting, or fixing a leak. It is a matter of repairing things, putting things back in order, making them how they are supposed to be. And given the essentialist and teleological metaphysics that underlies the Thomistic natural law conception of morality, that cannot fail to be a good thing.
Aquinas describes it as a matter of “restor[ing]… the equality of justice,” by which “he who has been too indulgent to his will, by transgressing God’s commandments, suffers, either willingly or unwillingly, something contrary to what he would wish” (Summa Theologiae I-II.87.6). Willing what is evil naturally tends to misery, but this natural tendency, like other natural tendencies, is sometimes unfulfilled. When it is, the result is an inequality or imbalance, viz. between the evil act on the one hand and the pain or lack thereof actually suffered by the evildoer on the other. Punishment is a matter of restoring this balance.