In 1273, the year before he died, St. Thomas Aquinas was in Naples working on the third part of his Summa Theologica. Having just completed the section on the Eucharist, he was praying in front of the crucifix on the altar, before Matins, and caught up in mystical ecstasy in the presence of Christ. Three of his brethren were there, and they heard a voice come from the image of Christ on the cross, saying, “Thou hast written well of me, Thomas; what reward wilt thou have?” St. Thomas replied, “None other than Thyself, Lord.”

“Triumph of St. Thomas Aquinas”

Benozzo di Lese di Sandro Gozzoli (1453-1478)

After that event St. Thomas continued his work in the Summa, now writing on the sacrament of Penance. He completed seven questions (thirty-six pages in my edition) on this sacrament. Then on December 6, 1273, while he was celebrating Mass on the Feast of Saint Nicholas, he experienced “an unusually long ecstasy.” From that moment on he did not write. Father Reginald urged him to finish the Summa, but St. Thomas replied, “Reginald, I can do no more; such things [secrets] have been revealed to me that all that I have written seems to me as so much straw. Now, I await the end of my life after that of my works.”

In this post I will examine one of the articles within one of the seven questions that St. Thomas wrote between the time that the voice spoke to him from the crucifix, and the day he laid down his pen for good. The article is Summa Theologica III Question 86 article 4, which concerns the effect of the sacrament of Penance, as regards the pardon of mortal sin. First I will summarize what he says in articles 1-3 of that question.

In the first article of Question 86, St. Thomas asks whether all sins [omnia peccata] are taken away by the sacrament of Penance. His answer is ‘yes, for two reasons’. The first reason is that although at death the will is confirmed [i.e. permanently fixed, established] in its orientation toward or against God such that after death no one whose will is opposed to God can repent, yet during this present life the human will remains flexible to good and to evil, such that repentance (and apostasy) is always possible while we remain in this present life. Second, the power of Christ’s Passion, “through which Penance produces its effect” is such that no sin is incapable of being pardoned through the sacrament of Penance. These two reasons together imply that in this life, true repentance always remains possible. And when repentance takes place, the power of Christ’s Passion, made available to us through the sacrament of Penance, is always sufficient to pardon the sin.

In order to understand the argument in the second article, we need to understand what St. Thomas means by “penance as a virtue,” because the sacrament of penance is not the same thing as the virtue of penance. St. Thomas discusses the virtue of penance in Summa Theologica III Q. 85. There he says that penance as a virtue (which we could also refer to as repentance) belongs to the Divine law, because God commands that we repent of our sins. What kind of virtue is penance? Penance, he says, is a species of justice. Recall that justice is the virtue of giving to each his due. Penance (or repentance) is a kind of giving to God what is His rightful due. Penance is the disposition of the will or an act of the will that aims at the destruction of one’s past sins which one recognizes to be offenses against God. Penance thus is aimed at giving God what is His rightful due, by grieving (with the will, not necessarily the emotions) for those acts that have offended God, and by seeking to make amends for them, through some kind of compensation.

Destruction of our offenses against God is not effected merely by ceasing to sin; some kind of compensation is necessary, to make amends for one’s sins against God. That is because sin leaves wounds, marks and debts in our relation to God. For example, if a man has been abusing his wife, the emotional wounds are not removed simply by his ceasing to abuse her, even if she forgives him. He must not only be truly sorry for what he has done, he must do whatever is in his power to make amends, something that may take years. Sin, as St. Augustine defined it, is a “word, deed, or desire, contrary to the eternal law.” But the eternal law is not a creature; it is God Himself. For this reason sin always involves a component that is against God Himself. And thus sin always involves our taking some pleasure in a word, deed or desire that deprives God of the charity, honor and obedience that He is justly due. So sin always contracts a debt of justice. By sinning we have taken something from God, by not giving to Him what is rightly due to Him. For this reason, penance involves two things: contrition, that is, grieving for one’s sins, and satisfaction, i.e. depriving oneself of temporal pleasures, or subjecting oneself to hardship in some way, to make amends to God for the pleasure that one took at God’s expense. Of course no one who has turned away from God can make sufficient satisfaction for that offense. St. Thomas says, “wherefore in such cases, he that falls short of the other must do whatever he can. Yet this will not be sufficient simply, but only according to the acceptance of the higher one”. In other words, just because we cannot fully make amends for our offenses against God, nevertheless, we must still do what we can to make amends, not because we think our penance is objectively sufficient to rectify our offenses, but in the hope that in His mercy God will find acceptable what penance we offer to Him out of sorrow for having offended Him whom we should love above all things.

In the second article, St. Thomas asks whether sin can be pardoned without Penance, that is, without repentance. His answer is ‘no.’ He writes:

It is impossible for a mortal actual sin to be pardoned without penance, if we speak of penance as a virtue. For, as sin is an offense against God, He pardons sin in the same way as he pardons an offense committed against Him. Now an offense is directly opposed to grace, since one man is said to be offended with another, because he excludes him from his grace. Now, as stated in Summa Theologica I-II, 110, 1, the difference between the grace of God and the grace of man, is that the latter does not cause, but presupposes true or apparent goodness in him who is graced, whereas the grace of God causes goodness in the man who is graced, because the good-will of God, which is denoted by the word “grace,” is the cause of all created good. Hence it is possible for a man to pardon an offense, for which he is offended with someone, without any change in the latter’s will; but it is impossible that God pardon a man for an offense, without his will being changed. Now the offense of mortal sin is due to man’s will being turned away from God, through being turned to some mutable good. Consequently, for the pardon of this offense against God, it is necessary for man’s will to be so changed as to turn to God and to renounce having turned to something else in the aforesaid manner, together with a purpose of amendment; all of which belongs to the nature of penance as a virtue. Therefore it is impossible for a sin to be pardoned anyone without penance as a virtue.

Here St. Thomas says that an offense is directly opposed to grace, since that is just what it means to be offended with another person, to exclude him from one’s grace. But there is a very important difference between the grace of God and the grace of man. The grace of man does not cause, but rather presupposes either true or apparent good in him who is graced by man. The grace of God, however, causes the goodness in the man who is graced by God. Thus for any man who is graced by God, that man has goodness, and that goodness was caused by God’s grace. Therefore, while a man may pardon another man’s offense without a change in the offender’s will, it is impossible for God to pardon a man for an offense, without that man’s will being changed. Since the offense of mortal sin is due to man’s will being turned away from God and inordinately turned to some mutable good, therefore for the pardon of mortal sin, it is necessary that man’s will be turned toward God and away from the inordinate love of the mutable good, with the intention of making amends for the wrongs he did to God. Since this turning toward God and away from the inordinate love of created goods, belongs to the nature of penance as a virtue, it follows that it is impossible for a sin to be pardoned anyone without his having penance as a virtue.

In the third article, St. Thomas asks whether by penance one [mortal] sin can be pardoned while another [mortal] sin remains unpardoned. He answers that this is impossible, because, as he has shown already, without grace no sin can be forgiven. But since every mortal sin is opposed to grace and excludes grace, therefore it is impossible for one mortal sin to be pardoned while another remains unpardoned, for then grace and mortal sin would be co-present, which is impossible. The reason that grace and mortal sin cannot be co-present within the soul is that to be in mortal sin is to be at enmity with God, not in friendship with God. But to have sanctifying grace is to be in friendship with God. And since person cannot both be in friendship with God and be at enmity with God, therefore grace and mortal sin cannot be co-present in the soul.

These first three articles help us understand what St. Thomas says in the fourth article. Before I turn to the fourth article, I want first to explain what St. Thomas argues in Summa Theologica I-II Q.87 a.4, because his analysis of sin is essential for understanding what he says in article four of Summa Theologica III Q.86 a.4. Speaking of mortal sin, he writes:

Punishment is proportionate to sin. Now sin comprises two things. First, there is the turning away from the immutable good, which is infinite, wherefore, in this respect, sin is infinite. Secondly, there is the inordinate turning to mutable good. In this respect sin is finite, both because the mutable good itself is finite, and because the movement of turning towards it is finite, since the acts of a creature cannot be infinite. Accordingly, in so far as sin consists in turning away from something, its corresponding punishment is the “pain of loss,” which also is infinite, because it is the loss of the infinite good, i.e. God. But in so far as sin turns inordinately to something, its corresponding punishment is the “pain of sense,” which is also finite.

Notice that mortal sin always has a two-fold component. It necessary involves a turning away from God in some respect, and an inordinate (i.e. disordered) turning to some finite created good. This two-fold aspect of sin means that justice is violated in two ways, in each mortal sin. In turning away from God, the sinner has not given to the eternal God His due, for which action the just punishment is the eternal loss of God, because the nature of the sin determines the punishment of the sin. But the sinner has also turned inordinately to some finite mutable good, for which action the just punishment is the “pain of sense,” which is a finite punishment.

In the fourth article of Summa Theologica III Q.86, St. Thomas asks whether after the remission of guilt [remissa culpa] through the sacrament of penance, there remains any debt of punishment. His answer is “yes, there remains a debt of punishment.” But first he raises three objections to his answer. I will present and explain his three objections, and then at the end present and explain his replies to these objections.

The first objection is this:

It would seem that no debt of punishment remains after the guilt [culpa] has been forgiven through Penance. For when the cause is removed, the effect is removed. But the guilt is the cause of the debt of punishment: since a man deserves to be punished because he has been guilty of committing a sin. Therefore when the sin has been forgiven, no debt of punishment can remain.

This is a good objection, and one that many Protestants might be inclined to raise. Here’s the objection. The cause of the debt of punishment is the [objective] guilt [culpa] of sin. This is because of the requirement of justice, that each person be given his due, as discussed above. The person who is guilty of an offense against God, by justice has a debt of punishment on account of that guilt. Hence, it would seem that when the sin is forgiven (i.e. the guilt is remitted), there should no longer be any debt of punishment.

The second objection is as follows:

Further, according to the Apostle (Romans 5) the gift of Christ is more effective than the sin [of Adam]. Now, by sinning, man incurs at the same time guilt [culpam] and the debt of punishment. Much more therefore, by the gift of grace, is the guilt forgiven and at the same time the debt of punishment remitted.

In this objection St. Thomas is saying that since the gift of Christ is more effective than the sin of Adam, and since when man sins, man incurs at the same time both guilt and the debt of punishment, therefore, it would seem to follow a fortiori that by the gift of grace not only is the guilt forgiven but also the debt of punishment remitted.

The third objection is as follows:

Further, the forgiveness of sins is effected in Penance through the power of Christ’s Passion, according to Romans 3:25: “Whom God hath proposed to be a propitiation, through faith in His Blood . . . for the remission of former sins.” Now Christ’s Passion made satisfaction sufficient for all sins, as stated above (Q.48, Q.49, Q.79, a.5). Therefore after the guilt has been pardoned, no debt of punishment remains.

In this third objection St. Thomas explains that the forgiveness of sins in the sacrament of Penance is effected through the power of Christ’s Passion. But Christ’s Passion made satisfaction sufficient for all sins. Therefore, it would seem that after the guilt of sin has been pardoned through the sacrament of Penance, no debt of punishment would remain. To claim that some debt of punishment remains after the forgiveness of sin would seemingly imply that Christ’s Passion was insufficient. This too is an objection a Protestant might raise.

St. Thomas then offers the Sed contra (But on the contrary), which appeals to an authority to support his position. He writes:

On the contrary, It is related (2 Samuel 12:13) that when David penitent had said to Nathan: “I have sinned against the Lord,” Nathan said to him: “The Lord also hath taken away thy sin, thou shalt not die. Nevertheless . . . the child that is born to thee shall surely die,” which was to punish him for the sin he had committed, as stated in the same place. Therefore a debt of some punishment remains after the guilt has been forgiven.

St. Thomas understands this incident recorded in the Old Testament to reveal that the forgiveness of sin does not necessarily take away the debt of all punishment. He explains why in his Respondeo where he writes:

I answer that, As stated in I-II, 87, 4, in mortal sin there are two things, namely, a turning from the immutable Good, and an inordinate turning to mutable good. Accordingly, in so far as mortal sin turns away from the immutable Good, it induces a debt of eternal punishment, so that whosoever sins against the eternal Good should be punished eternally. Again, in so far as mortal sin turns inordinately to a mutable good, it gives rise to a debt of some punishment, because the disorder of guilt is not brought back to the order of justice, except by punishment: since it is just that he who has been too indulgent to his will, should suffer something against his will, for thus will equality be restored. Hence it is written (Apocalypse 18:7): “As much as she hath glorified herself, and lived in delicacies, so much torment and sorrow give ye to her.” Since, however, the turning to mutable good is finite, sin does not, in this respect, induce a debt of eternal punishment. Wherefore, if man turns inordinately to a mutable good, without turning from God, as happens in venial sins, he incurs a debt, not of eternal but of temporal punishment. Consequently when guilt is pardoned through grace, the soul ceases to be turned away from God, through being united to God by grace: so that at the same time, the debt of punishment is taken away, albeit a debt of some temporal punishment may yet remain.

I’ll go through his argument step by step. First he reminds us, as we saw above, that in every mortal sin there are two turnings: a turning away from God who is the immutable Good, and an inordinate turning to some mutable good. This two-fold turning of mortal sin induces two debts of punishment, because these two turnings intrinsic to every mortal sin are not equal in their degree of injustice. The just punishment for turning away from the eternal God is eternal separation from God; this separation is called ‘hell.’

But the sin of turning inordinately to some mutable, finite good also incurs a debt of punishment, “because the disorder of guilt is not brought back to the order of justice, except by punishment.” Hence there must be temporal punishment, “since it is just that he who has been too indulgent to his will, should suffer something against his will, for thus will equality be restored.” Justice can be violated in the short-term, as when someone commits an unjust act. But ultimately justice cannot be violated, because all violations of justice must eventually be brought back to the order of justice, and this can only be done by just punishment.

The debt of punishment for turning inordinately to some mutable, finite good is not eternal punishment, but temporal punishment, because a finite sin does not justly deserve an eternal punishment. So when a man turns inordinately to a finite good without turning away from God, as happens in venial sin, he does not incur a debt of eternal punishment but he does incur a debt of temporal punishment. Thus, when the guilt of sin is pardoned through the grace that comes to us through the sacrament of penance, “the soul ceases to be turned away from God, through being united to God by grace.” But, the debt of temporal punishment may yet remain.

Let’s consider now St. Thomas’s replies to the three objections raised earlier. The first objection was that the removal of the guilt of sin should also remove the debt of punishment. In reply to this first objection he writes:

Mortal sin both turns away from God and turns to a created good. But, as stated in I-II, 71, 6, the turning away from God is as its form while the turning to created good is as its matter. Now if the formal element of anything be removed, the species is taken away: thus, if you take away rational, you take away the human species. Consequently mortal sin is said to be pardoned from the very fact that, by means of grace, the aversion of the mind from God is taken away together with the debt of eternal punishment: and yet the material element remains, viz. the inordinate turning to a created good, for which a debt of temporal punishment is due.

As St. Thomas has already explained, every mortal sin involves both turning away from God and inordinately turning to a finite good. But the essence of mortal sin is turning away from God. Therefore, since by the sacrament of penance the essence of mortal sin is removed, in the pardon of mortal sin, by means of grace the aversion of the mind from God as well as the debt of eternal punishment are removed. But, says St. Thomas, in the sacrament of penance, the inordinate turning to a created good remains, and therefore a debt of temporal punishment remains. What does St. Thomas mean in saying that in the sacrament of penance the pardon of the guilt of mortal sin does not in itself remove the inordinate turning to a created good? St. Thomas explains this in the very next article. There St. Thomas writes:

Mortal sin, in so far as it turns inordinately to a mutable good, produces in the soul a certain disposition, or even a habit, if the acts be repeated frequently. Now it has been said above (Article 4) that the guilt of mortal sin is pardoned through grace removing the aversion of the mind from God. Nevertheless when that which is on the part of the aversion has been taken away by grace, that which is on the part of the inordinate turning to a mutable good can remain, since this may happen to be without the other, as stated above (Article 4). Consequently, there is no reason why, after the guilt has been forgiven, the dispositions caused by preceding acts should not remain, which are called the remnants of sin. Yet they remain weakened and diminished, so as not to domineer over man, and they are after the manner of dispositions rather than of habits, like the “fomes” which remains after Baptism.

Here St. Thomas explains that mortal sin produces in the soul a disposition or even a habit, of inordinate love for a mutable good. When the guilt of mortal sin and the eternal debt that it incurs, are removed from the soul by the grace that comes through the sacrament of penance, these inordinate dispositions remain in the soul. These remaining inordinate dispositions are called “remnants of sin.” In a sense, we bear in our bodies the debt of temporal punishment, the sign within us that justice has not been restored. But since our eternal debt has already been paid through the grace Christ merited by His Passion and death, which we receive through the sacrament of penance, therefore the remaining debt is the debt of temporal punishment. This is why, in response to the objection, the pardon of the guilt of mortal sin through the sacrament of penance does not in itself remove the debt of temporal punishment.

The second objection was that since Christ’s gift is more effective than Adam’s gift, therefore, since by sin we incur both guilt and the debt of punishment, so a fortiori they should both be removed by the grace of Christ. In reply to this second objection, St. Thomas writes:

As stated in I-II, Q.109, a.7, a.8, I-II, Q.111, a.2, it belongs to grace to operate in man by justifying him from sin, and to co-operate with man that his work may be rightly done. Consequently the forgiveness of guilt and of the debt of eternal punishment belongs to operating grace, while the remission of the debt of temporal punishment belongs to co-operating grace, in so far as man, by bearing punishment patiently with the help of Divine grace, is released also from the debt of temporal punishment. Consequently just as the effect of operating grace precedes the effect of co-operating grace, so too, the remission of guilt and of eternal punishment precedes the complete release from temporal punishment, since both are from grace, but the former, from grace alone, the latter, from grace and free-will.

Here St. Thomas draws upon a previous distinction between operating grace and and co-operating grace, which is a distinction St. Augustine makes in his work titled On Grace and Free Will. Operating grace is the actual grace whereby God works in us without us. Co-operating grace is the actual grace whereby God works in us with us, by strengthening our will and granting us the capability of performing some act. According to St. Thomas, the forgiveness of guilt and of the debt of eternal punishment belongs to operating grace. We cannot merit either the forgiveness of sin or the removal of the debt of eternal punishment. But, says, St. Thomas, the remission of the debt of temporal punishment belongs to co-operating grace. Then, just as the effect of operating grace precedes the effect of co-operating grace, so the remission of guilt and of eternal punishment in the sacrament of penance precedes the completion of our payment of the debt of temporal punishment. This is why when we walk out of the confessional after receiving absolution from our sins, all our sins are forgiven and our debt of eternal punishment is paid, but we must do some penance, as assigned to us by the priest. In doing so we are making satisfaction for the purpose of paying our debt of temporal punishment, which payment is, at the same time, a growth in sanctification, by removing from us the dispositions of inordinate love for created goods.

The third objection was this: The forgiveness of sins in the sacrament of Penance is effected through the power of Christ’s Passion. But Christ’s Passion made satisfaction sufficient for all sins. Therefore, it would seem that after the guilt of sin has been pardoned through the sacrament of Penance, no debt of punishment whatsoever would remain. In reply to this objection St. Thomas writes:

Christ’s Passion is of itself sufficient to remove all debt of punishment, not only eternal, but also temporal; and man is released from the debt of punishment according to the measure to which he participates [participat] in the power [virtutem] of Christ’s Passion. Now in Baptism man participates totally [totaliter] in the power of Christ’s Passion, since by water and the Spirit of Christ, he dies with Him to sin, and is born again in Him to a new life, so that, in Baptism, man receives the total [totius] remission of debt of punishment. In Penance, on the other hand, man shares in the power of Christ’s Passion according to the measure of his own acts, which are the matter of Penance, as water is of Baptism, as stated above (84, 1,3). Wherefore the entire [totius] debt of punishment is not remitted at once after the first act of Penance, by which act the guilt is remitted, but only when all the acts of Penance have been completed.

St. Thomas teaches here that Christ’s Passion is sufficient in itself to remove all debt of punishment, not only eternal but also temporal. But we are released from the debt of punishment according to the measure of our participation in the power of Christ’s Passion. But we participate in Christ’s Passion differently in the sacrament of Baptism and in the sacrament of Penance; otherwise they would be one sacrament, not two. Every sacrament has both a form and matter. The matter of the sacrament of Baptism is water; the form is the baptismal formulate “I baptize you in the name of the Father, and of the Son, and of the Holy Spirit.” In the sacrament of Penance the acts of the penitent are the matter. Because the matter in the sacrament of Baptism is water, our participation in the power of Christ’s Passion is immediate and total. Hence in baptism all debt, both eternal and temporal, is remitted. By contrast, because in the sacrament of Penance the acts of the penitent are the matter, therefore, explains St. Thomas, in the sacrament of Penance we share in Christ’s Passion in one respect according to the measure of our own acts. That is, in the sacrament of Penance, while the entire debt of eternal punishment is remitted at once, the entire debt of temporal punishment is not remitted at once, but only when all the acts of penance have been completed.

Why is this significant?

One reason it is helpful to consider what St. Thomas says here is that his teaching on this subject quite perfectly matches the doctrine of the Catholic Church. The Catechism of the Catholic Church clearly teaches that sin incurs this twofold debt:

[I]t is necessary to understand that sin has a double consequence. Grave sin deprives us of communion with God and therefore makes us incapable of eternal life, the privation of which is called the “eternal punishment” of sin. On the other hand every sin, even venial, entails an unhealthy attachment to creatures, which must be purified either here on earth, or after death in the state called Purgatory. This purification frees one from what is called the “temporal punishment” of sin. These two punishments must not be conceived of as a kind of vengeance inflicted by God from without, but as following from the very nature of sin.

And the Catechism likewise teaches that the absolution we receive in the sacrament of Penance removes sin, but not the temporal punishment of sin:

Many sins wrong our neighbor. One must do what is possible in order to repair the harm (e.g., return stolen goods, restore the reputation of someone slandered, pay compensation for injuries). Simple justice requires as much. But sin also injures and weakens the sinner himself, as well as his relationships with God and neighbor. Absolution takes away sin, but it does not remedy all the disorders sin has caused. Raised up from sin, the sinner must still recover his full spiritual health by doing something more to make amends for the sin: he must “make satisfaction for” or “expiate” his sins. This satisfaction is also called “penance.” The penance the confessor imposes must take into account the penitent’s personal situation and must seek his spiritual good. It must correspond as far as possible with the gravity and nature of the sins committed. It can consist of prayer, an offering, works of mercy, service of neighbor, voluntary self-denial, sacrifices, and above all the patient acceptance of the cross we must bear. Such penances help configure us to Christ, who alone expiated our sins once for all. They allow us to become co-heirs with the risen Christ, “provided we suffer with him.”

Once we understand the distinction between the debt of eternal punishment and the debt of temporal punishment, and the basis for that distinction, then we can begin to understand certain other Catholic doctrines such as purgatory and indulgences. Purgatory is that place in which those who died in a state of grace pay any remaining debt of temporal punishment, in order that with a pure heart they may enter into the joy of seeing God in the Beatific Vision, for only those with a pure heart will see God. An indulgence is a remission of the temporal punishment for sins whose guilt has already been forgiven, and thus whose debt of eternal punishment has already been paid. These doctrines only make sense if we first apprehend the two-fold turning intrinsic to every mortal sin, by its very nature.

The primary Protestant objection to the notion of penance is that it is incompatible with the finished work of Christ. According to this objection, since on the cross Christ already paid for all our sins, therefore the notion that we must still make satisfaction for our sins is a denial or belittlement of the sufficiency and completion of Christ’s sacrifice. This objection typically presupposes that there is no distinction between eternal and temporal punishment, and in addition presupposes that our satisfactions would in some way diminish the satisfaction made by Christ, rather than be a participation in and acceptable through His satisfaction. Another objection is that the distinction between eternal and temporal punishment is not found in Scripture. But the Council of Trent gives a number of examples from Scripture that presuppose or imply the distinction. Another objection is that doing penance would give us ground for boasting. The Council of Trent also addresses that objection, teaching:

The satisfaction that we make for our sins, however, is not so much ours as though it were not done through Jesus Christ. We who can do nothing ourselves, as if just by ourselves, can do all things with the cooperation of “him who strengthens” us. Thus man has nothing of which to boast, but all our boasting is in Christ . . . in whom we make satisfaction by bringing forth “fruits that befit repentance.” These fruits have their efficacy from him, by him they are offered to the Father, and through him they are accepted by the Father. … But let [priests] bear in mind that the satisfaction they impose [in the sacrament of Penance] be not only for the protection of a new life and a remedy against infirmity, but also for the atonement and punishment of past sins; for the early Fathers also believed and taught that the keys of the priests were bestowed not to loose only but also to bind. It was not their understanding, moreover, that the sacrament of penance is a tribunal of wrath or of punishments, as no Catholic ever understood that through our satisfactions the efficacy of the merit and satisfaction of our Lord Jesus Christ is either obscured or in any way diminished.

In this way temporal punishment, penance, and purgatory are all compatible with an affirmation of the forgiveness of all our past sins, and with the perfection and completion of Christ’s Passion. Temporal punishment is compatible with the forgiveness of all our past sins, because of the two-fold injustice in every mortal sin. Temporal punishment is compatible with the perfection and completion of Christ’s Passion because of the distinction between operating grace and co-operating grace. By way of these distinctions, the saint to whom Christ had just spoken days earlier, saying, “Thou hast written well of me, Thomas,” teaches us here why it is wrong to think either that we can make full satisfaction for our sins or that we do not need to make any satisfaction for our sins.

Domine, miserere nobis. Amen.