The Catechism of the Catholic Church teaches that at the Last Judgment “the truth of each man’s relationship with God will be laid bare” (CCC 1039). This means the blessed in heaven will know which of their loved ones are in hell.
But this seems to cause a problem. If heaven is a “state of supreme, definitive happiness” (CCC 1024), how can the souls in heaven be happy knowing their loved ones are in hell? It would seem that they couldn’t be happy since, being animated by charity, they would pity the damned, and to pity the damned is to partake of their unhappiness in some way.
Is there a way to reconcile the happiness of the blessed in heaven and their knowledge of the sufferings of the damned? Yes, there is.
Blessed happiness in knowledge of the damned
One way is to see that knowledge of the sufferings of the damned actually contributes to the happiness of the blessed. In response to the question of whether the saints see the suffering of the damned, Aquinas writes:
Nothing should be denied the blessed that belongs to the perfection of their beatitude. Now everything is known the more for being compared with its contrary, because when contraries are placed beside one another they become more conspicuous. Wherefore in order that the happiness of the saints may be more delightful to them and that they may render more copious thanks to God for it, they are allowed to see perfectly the sufferings of the damned (Summa Theoloogiae suppl. III:94:1).
Knowing the sufferings of those in hell doesn’t take away from the happiness of the blessed, but contributes to it.
Is there hatred in the blessed?
This raises yet another problem. If the blessed experience happiness due to their knowledge of the sufferings of the damned, then that implies they in some way rejoice in the punishment of the wicked. But if that were true, then the blessed would have hatred, since it belongs to hate to rejoice in another’s evil, which is impossible for the blessed.
So, how do we reconcile this?
Once again, Aquinas gives us a solution (ST suppl. III:94:2). He points out that hatred would belong to the blessed only if the punishment of the wicked was directly a matter of their rejoicing—that is to say, if the blessed rejoiced in the punishment of the wicked in and of itself.
But, as Aquinas explains, the blessed don’t do this, because they are perfected in charity. The sufferings of the damned are only indirectly a matter of rejoicing for the blessed “by reason . . . of something annexed to it” (ST suppl. III:94:2).
What is annexed to the suffering of the wicked? The order of divine justice and the deliverance from such punishment, which the blessed have received.
Imagine a sexual predator stalks a woman for months, causing the woman much distress, and eventually rapes her, but is caught and is sentenced to life in prison. Would the woman rejoice?
If she were a virtuous woman, she wouldn’t rejoice in the punishment itself but in that which is “annexed” to the punishment—namely, the justice served and knowing she doesn’t have to worry about him stalking her anymore.
Similarly, being perfected in virtue, the blessed don’t rejoice in the punishment of the damned as such, but only in that which is “annexed” to the torments of the damned—namely, the order of divine justice and their deliverance from experiencing such torment. It is these two things that directly fill the blessed with joy while the punishment of the wicked cause their joy indirectly.
So, seeing how knowledge of the suffering of the damned contributes to the happiness of the blessed is one way to reconcile their happiness with them having knowledge of their loved ones in hell.
I don’t pity the fool
Another approach is to deny the fundamental assumption that the blessed pity the damned. Notice the dilemma only arises because one thinks the blessed would be unhappy due to their pity. But if the blessed didn’t pity the damned, then there is no problem.
Do the blessed pity the damned? Aquinas addresses this issue specifically in article two of the same question (Question 94) of the supplement to the third part of the Summa that concerns the relation of the saints to the damned.
Aquinas starts by distinguishing the two ways a person can have compassion or mercy. The first is by way of passion, and the second is by way of choice. Aquinas denies that the blessed will have mercy by way of passion since “in the blessed there will be no passion in the lower powers except as a result of the reason’s choice.” Since the blessed will not be able to have mercy by way of passion, Aquinas concludes they will have it by way of choice.
Aquinas then explains that when someone has compassion by choice he wills that another’s evil cease:
Now mercy or compassion comes of the reason’s choice when a person wishes another’s evil to be dispelled: wherefore in those things which, in accordance with reason, we do not wish to be dispelled, we have no such compassion (ST Suppl. III:94:2).
Notice compassion by choice presupposes the possibility of the pitied to move from a state of unhappiness to a state of happiness. As such, when such movement is not possible, there can be no compassion.
It is this principle that grounds Aquinas’s belief that the blessed do not pity the damned. The damned are incapable of moving from a state of unhappiness to happiness because their choice is irrevocable after death (see Edward Feser’s article “How to Go to Hell”). Their wills are fixed on evil, leaving nothing good within them. The possibility of a sinner reforming his evil ways and turning toward the good, moving from a state of unhappiness to a state of happiness, belongs to this world only.
So, if pity presupposes the possibility of the pitied to move from unhappiness to happiness, and such movement is impossible for the damned, then it follows the blessed can’t pity the damned.
Aquinas puts the argument this way:
[S]o long as sinners are in this world they are in such a state that without prejudice to the divine justice they can be taken away from a state of unhappiness and sin to a state of happiness. Consequently it is possible to have compassion on them. . . . But in the future state it will be impossible for them to be taken away from their unhappiness: and consequently it will not be possible to pity their sufferings according to right reason. Therefore the blessed in glory will have no pity on the damned.
Since the blessed can’t pity the damned, then it follows they do not share in their unhappiness. Therefore, the happiness the blessed experience in heaven can be reconciled with their knowledge of their loved ones in hell.
Conclusion
I’ll admit that when we limit ourselves only to our experience of life on this side of the veil, it is hard to reconcile the happiness of heaven with the knowledge of the suffering of the damned, especially our loved ones. But when we take a step back and look at how divine justice is annexed to the suffering of the damned, and how the blessed can’t pity the damned, it becomes clear how the blessed can have knowledge of the suffering of those in hell and still be happy.