Critics of the doctrine of hell often argue that it’s unjust, because eternal punishment exceeds the temporal nature of a mortal sin. Why should any sin we commit on earth, in time, require everlasting punishment in hell? It’s not proportional.
St. Thomas Aquinas responded to this objection by saying that the measure of a punishment is not determined by the duration of the fault, but rather by its gravity. And since for Aquinas a mortal sin “in a certain respect is infinite,” being committed against God, he concludes that “a punishment that is infinite in duration is rightly inflicted for mortal sin.”
There is another conundrum, though: the infinite duration of punishment can be just only if the sinner no longer has the ability to repent and will the good. Aquinas writes:
There would be no everlasting punishment of the souls of the damned if they were able to change their will for a better will; it would be unjust, indeed, if from the moment of their having a good will their punishment would be everlasting (Summa Contra Gentiles 4.93).
In other words, the infinite duration of punishment due a mortal sin is just only if a person is no longer able to change his will for the better.
So, the question before us is: Is a soul able to redirect its will and choose God as its ultimate end after death?
The Catholic Church says no. For example, the Catechism teaches, “there is no repentance for men after death,” and bases this teaching on the irrevocable character that man’s choice takes on after the soul separates from the body—similar to that of the angels (CCC 393). This is why the Catechism defines hell as the “definitive self-exclusion from communion with God and the blessed” (1033; emphasis added).
But why does our choice become irrevocable after death? To answer this question, we must first consider why our choices are mutable in this life.
As human beings, we’re hardwired to choose things insofar as we perceive some good in them that will make us happy. We can’t help it. Even to ask the question, “Why should I choose what’s good?” presupposes a desire for the good; otherwise, why would we ask whether we should choose what’s good or not?
However, we’re all too familiar with the change in our desires for what we think will make us happy. As Aquinas goes on to add in the Summa Contra Gentiles (4.95), sometimes this is due to a fleeting passion in the body.
For example, a young engaged couple may set out to find happiness by living consistent with God’s plan for human sexuality and abstain from intercourse before marriage. Yet in the heat of the moment they can be distracted by their desire for sexual pleasure and begin to pursue it as a source for their happiness instead. Through the exercise of reason and virtue, they may overcome that distraction, and the passion for sexual pleasure wanes. The passion was fleeting.
Aquinas also explains that sometimes, though, rather than a fleeting passion “we are disposed to the desire of a good end or a bad one by a habit, and that disposition is not easily taken away.”
Take the couple from above, for example. Rather than having a fleeting passion in the heat of the moment, they may be habitually committing fornication. In this case, the appetite for sexual pleasure dominates, thus disposing the couple habitually to pursue their happiness in sexual pleasure outside marriage.
But, suppose they discover the truth of their human sexuality, and become convicted of the immoral nature of fornication, and choose to pursue the virtue of chastity instead. They may seek to counteract the overindulgence of the appetite for sexual pleasure by abstaining, and may even employ fasting and physical mortification. Such efforts eventually free them from the domination of the sensitive appetite for sexual pleasure. They’re able to change even their habits, and thus where they habitually seek happiness.
There is another reason why we’re able to change our choices in this life: intellectual error. As human beings, we know things in a discursive manner: we gather evidence, we consider and weigh it, and we reason from premises to conclusions. Then we direct our actions based on that knowledge. This is why the will is called the “rational appetite” (Summa Theologiae I-II:8:1).
But we know that we often make mistakes in this process and are led into error. And when we become aware of this, we change the course of our actions.
Now, all of these causes for change in our choices (fleeting passions, a change of habit, and correction of intellectual error) involve the body.
It’s obvious that fleeting passions and dominating sensitive appetites do. Yet even our cognitive processes involve the body. We use our sensory experience to gather information about something, we use mental images as aids when we’re trying to reason with certain concepts, and so forth. This is our mode of knowledge as a rational animal. This being the case, certain passions and the habitual indulgence of sensitive appetites can lead us into intellectual error. Aquinas’s teaching on “blindness of mind” as a daughter of lust is an example of this (ST II-II:15:3).
We’re now in a position to see why our choice becomes irrevocable after death.
If those things that motivate us to change our course of action are rooted in the body, then it follows that when the body is gone the disembodied soul will no longer be able to change its choice. The soul will be forever fixed on whatever it chose as its ultimate end.
There is no longer any fleeting passion that can distract the soul. There is no dominating sensitive appetite to pull the will away from what it sets its sight on. The will, therefore, becomes habitually aimed at that which it chose as its ultimate end upon death.
Also, there is no intellectual error to be made, since the preconditions for erroneous judgments (discursive reasoning with the use of sensation and imagination) are no longer present. The soul’s mode of knowledge upon death is very much like that of the angels: what is known is known all-at-once (ST I:68:3).
Rather than hell undermining God’s justice, it’s actually a manifestation of it. God allows the soul to function in accord with its nature, which includes the irrevocability of choices without the body. So, if a person dies choosing something other than God as his final end, that choice is irrevocable. It’s “locked on,” so to speak, to something other than God. And it’s locked on forever.