Summa - Supplement 402

Whether a priest can always absolve his subject?


Objection 1: It would seem that a priest cannot always absolve his subject. For, as Augustine says (De vera et false Poenitentia [*Work of an unknown author]), "no man should exercise the priestly office, unless he be free from those things which he condemns in others." But a priest might happen to share in a sin committed by his subject, e.g. by knowledge of a woman who is his subject. Therefore it seems that he cannot always use the power of the keys on his subjects.

Objection 2: Further, by the power of the keys a man is healed of all his shortcomings. Now it happens sometimes that a sin has attached to it a defect of irregularity or a sentence of excommunication, from which a simple priest cannot absolve. Therefore it seems that he cannot use the power of the keys on such as are shackled by these things in the above manner.

Objection 3: Further, the judgment and power of our priesthood was foreshadowed by the judgment of the ancient priesthood. Now according to the Law, the lesser judges were not competent to decide all cases, and had recourse to the higher judges, according to
Ex 24,14: "If any question shall arise" among you, "you shall refer it to them." It seems, therefore, that a priest cannot absolve his subject from graver sins, but should refer him to his superior.

On the contrary, Whoever has charge of the principal has charge of the accessory. Now priests are charged with the dispensation of the Eucharist to their subjects, to which sacrament the absolution of sins is subordinate [*Cf. Question [17], Article [2], ad 1]. Therefore, as far as the power of the keys is concerned, a priest can absolve his subject from any sins whatever.

Further, grace, however small, removes all sin. But a priest dispenses sacraments whereby grace is given. Therefore, as far as the power of the keys is concerned, he can absolve from all sins.

I answer that, The power of order, considered in itself, extends to the remission of all sins. But since, as stated above, the use of this power requires jurisdiction which inferiors derive from their superiors, it follows that the superior can reserve certain matters to himself, the judgment of which he does not commit to his inferior; otherwise any simple priest who has jurisdiction can absolve from any sin. Now there are five cases in which a simple priest must refer his penitent to his superior. The first is when a public penance has to be imposed, because in that case the bishop is the proper minister of the sacrament. The second is the case of those who are excommunicated when the inferior priest cannot absolve a penitent through the latter being excommunicated by his superior. The third case is when he finds that an irregularity has been contracted, for the dispensation of which he has to have recourse to his superior. The fourth is the case of arson. The fifth is when it is the custom in a diocese for the more heinous crimes to be reserved to the bishop, in order to inspire fear, because custom in these cases either gives the power or takes it away.

Reply to Objection 1: In this case the priest should not hear the confession of his accomplice, with regard to that particular sin, but must refer her to another: nor should she confess to him but should ask permission to go to another, or should have recourse to his superior if he refused, both on account of the danger, and for the sake of less shame. If, however, he were to absolve her it would be valid*: because when Augustine says that they should not be guilty of the same sin, he is speaking of what is congruous, not of what is essential to the sacrament. [*Benedict XIV declared the absolution of an accomplice "in materia turpi" to be invalid.]

Reply to Objection 2: Penance delivers man from all defects of guilt, but not from all defects of punishment, since even after doing penance for murder, a man remains irregular. Hence a priest can absolve from a crime, but for the remission of the punishment he must refer the penitent to the superior, except in the case of excommunication, absolution from which should precede absolution from sin, for as long as a man is excommunicated, he cannot receive any sacrament of the Church.

Reply to Objection 3: This objection considers those cases in which superiors reserve the power of jurisdiction to themselves.

Whether a man can use the keys with regard to his superior?


Objection 1: It would seem that a man cannot use the keys in respect of a superior. For every sacramental act requires its proper matter. Now the proper matter for the use of the keys, is a person who is subject, as stated above (Question [19], Article [6]). Therefore a priest cannot use the keys in respect of one who is not his subject.

Objection 2: Further, the Church Militant is an image of the Church Triumphant. Now in the heavenly Church an inferior angel never cleanses, enlightens or perfects a higher angel. Therefore neither can an inferior priest exercise on a superior a hierarchical action such as absolution.

Objection 3: Further, the judgment of Penance should be better regulated than the judgment of an external court. Now in the external court an inferior cannot excommunicate or absolve his superior. Therefore, seemingly, neither can he do so in the penitential court.

On the contrary, The higher prelate is also "compassed with infirmity," and may happen to sin. Now the power of the keys is the remedy for sin. Therefore, since he cannot use the key on himself, for he cannot be both judge and accused at the same time, it seems that an inferior can use the power of the keys on him.

Further, absolution which is given through the power of the keys, is ordained to the reception of the Eucharist. But an inferior can give Communion to his superior, if the latter asks him to. Therefore he can use the power of the keys on him if he submit to him.

I answer that, The power of the keys, considered in itself, is applicable to all, as stated above (Article [2]): and that a priest is unable to use the keys on some particular person is due to his power being limited to certain individuals. Therefore he who limited his power can extend it to whom he wills, so that he can give him power over himself, although he cannot use the power of the keys on himself, because this power requires to be exercised on a subject, and therefore on someone else, for no man can be subject to himself.

Reply to Objection 1: Although the bishop whom a simple priest absolves is his superior absolutely speaking, yet he is beneath him in so far as he submits himself as a sinner to him.

Reply to Objection 2: In the angels there can be no defect by reason of which the higher angel can submit to the lower, such as there can happen to be among men; and so there is no comparison.

Reply to Objection 3: External judgment is according to men, whereas the judgment of confession is according to God, in Whose sight a man is lessened by sinning, which is not the case in human prelacy. Therefore just as in external judgment no man can pass sentence of excommunication on himself, so neither can he empower another to excommunicate him. On the other hand, in the tribunal of conscience he can give another the power to absolve him, though he cannot use that power himself.

It may also be replied that absolution in the tribunal of the confessional belongs principally to the power of the keys and consequently to the power of jurisdiction, whereas excommunication regards jurisdiction exclusively. And, as to the power of orders, all are equal, but not as to jurisdiction. Wherefore there is no comparison.



We must now treat of excommunication: we shall consider: (1) the definition, congruity and cause of excommunication; (2) who has the power to excommunicate; (3) communication with excommunicated persons; (4) absolution from excommunication.

Under the first head there are four points of inquiry:

(1) Whether excommunication is suitably defined?

(2) Whether the Church should excommunicate anyone?

(3) Whether anyone should be excommunicated for inflicting temporal harm?

(4) Whether an excommunication unjustly pronounced has any effect?

Whether excommunication is suitably defined as separation from the communion of the Church, etc?


Objection 1: It would seem that excommunication is unsuitably defined by some thus: "Excommunication is separation from the communion of the Church, as to fruit and general suffrages." For the suffrages of the Church avail for those for whom they are offered. But the Church prays for those who are outside the Church, as, for instance, for heretics and pagans. Therefore she prays also for the excommunicated, since they are outside the Church, and so the suffrages of the Church avail for them.

Objection 2: Further, no one loses the suffrages of the Church except by his own fault. Now excommunication is not a fault, but a punishment. Therefore excommunication does not deprive a man of the general suffrages of the Church.

Objection 3: Further, the fruit of the Church seems to be the same as the Church's suffrages, for it cannot mean the fruit of temporal goods, since excommunication does not deprive a man of these. Therefore there is no reason for mentioning both.

Objection 4: Further, there is a kind of excommunication called minor*, by which man is not deprived of the suffrages of the Church. [*Minor excommunication is no longer recognized by Canon Law.] Therefore this definition is unsuitable.

I answer that, When a man enters the Church by Baptism, he is admitted to two things, viz. the body of the faithful and the participation of the sacraments: and this latter presupposes the former, since the faithful are united together in the participation of the sacraments. Consequently a person may be expelled from the Church in two ways. First, by being deprived merely of the participation of the sacraments, and this is the minor excommunication. Secondly, by being deprived of both, and this is the major excommunication, of which the above is the definition. Nor can there be a third, consisting in the privation of communion with the faithful, but not of the participation of the sacraments, for the reason already given, because, to wit, the faithful communicate together in the sacraments. Now communion with the faithful is twofold. One consists in spiritual things, such as their praying for one another, and meeting together for the reception of sacred things; while another consists in certain legitimate bodily actions. These different manners of communion are signified in the verse which declares that those who are excommunicate are deprived of---

"os, orare, vale, communio, mensa." "Os," i.e. we must not give them tokens of goodwill; "orare," i.e. we must not pray with them; "vale," we must not give them marks of respect; "communio," i.e. we must not communicate with them in the sacraments; "mensa," i.e. we must not take meals with them. Accordingly the above definition includes privation of the sacraments in the words "as to the fruit," and from partaking together with the faithful in spiritual things, in the words, "and the general prayers of the Church."

Another definition is given which expresses the privation of both kinds of acts, and is as follows: "Excommunication is the privation of all lawful communion with the faithful."

Reply to Objection 1: Prayers are said for unbelievers, but they do not receive the fruit of those prayers unless they be converted to the faith. In like manner prayers may be offered up for those who are excommunicated, but not among the prayers that are said for the members of the Church. Yet they do not receive the fruit so long as they remain under the excommunication, but prayers are said for them that they may receive the spirit of repentance, so that they may be loosed from excommunication.

Reply to Objection 2: One man's prayers profit another in so far as they can reach to him. Now the action of one man may reach to another in two ways. First, by virtue of charity which unites all the faithful, making them one in God, according to
Ps 118,63: "I am a partaker with all them that fear Thee." Now excommunication does not interrupt this union, since no man can be justly excommunicated except for a mortal sin, whereby a man is already separated from charity, even without being excommunicated. An unjust excommunication cannot deprive a man of charity, since this is one of the greatest of all goods, of which a man cannot be deprived against his will. Secondly, through the intention of the one who prays, which intention is directed to the person he prays for, and this union is interrupted by excommunication, because by passing sentence of excommunication, the Church severs a man from the whole body of the faithful, for whom she prays. Hence those prayers of the Church which are offered up for the whole Church, do not profit those who are excommunicated. Nor can prayers be said for them among the members of the Church as speaking in the Church's name, although a private individual may say a prayer with the intention of offering it for their conversion.

Reply to Objection 3: The spiritual fruit of the Church is derived not only from her prayers, but also from the sacraments received and from the faithful dwelling together.

Reply to Objection 4: The minor excommunication does not fulfill all the conditions of excommunication but only a part of them, hence the definition of excommunication need not apply to it in every respect, but only in some.

Whether the Church should excommunicate anyone?


Objection 1: It would seem that the Church ought not to excommunicate anyone, because excommunication is a kind of curse, and we are forbidden to curse (
Rm 12,14). Therefore the Church should not excommunicate.

Objection 2: Further, the Church Militant should imitate the Church Triumphant. Now we read in the epistle of Jude (verse 9) that "when Michael the Archangel disputing with the devil contended about the body of Moses, he durst not bring against him the judgment of railing speech, but said: The Lord command thee." Therefore the Church Militant ought not to judge any man by cursing or excommunicating him.

Objection 3: Further, no man should be given into the hands of his enemies, unless there be no hope for him. Now by excommunication a man is given into the hands of Satan, as is clear from 1Co 5,5. Since then we should never give up hope about anyone in this life, the Church should not excommunicate anyone.

On the contrary, The Apostle (1Co 5,5) ordered a man to be excommunicated.

Further, it is written (Mt 18,17) about the man who refuses to hear the Church: "Let him be to thee as the heathen or publican." But heathens are outside the Church. Therefore they also who refuse to hear the Church, should be banished from the Church by excommunication.

I answer that, The judgment of the Church should be conformed to the judgment of God. Now God punishes the sinner in many ways, in order to draw him to good, either by chastising him with stripes, or by leaving him to himself so that being deprived of those helps whereby he was kept out of evil, he may acknowledge his weakness, and humbly return to God Whom he had abandoned in his pride. In both these respects the Church by passing sentence of excommunication imitates the judgment of God. For by severing a man from the communion of the faithful that he may blush with shame, she imitates the judgment whereby God chastises man with stripes; and by depriving him of prayers and other spiritual things, she imitates the judgment of God in leaving man to himself, in order that by humility he may learn to know himself and return to God.

Reply to Objection 1: A curse may be pronounced in two ways: first, so that the intention of the one who curses is fixed on the evil which he invokes or pronounces, and cursing in this sense is altogether forbidden. Secondly, so that the evil which a man invokes in cursing is intended for the good of the one who is cursed, and thus cursing is sometimes lawful and salutary: thus a physician makes a sick man undergo pain, by cutting him, for instance, in order to deliver him from his sickness.

Reply to Objection 2: The devil cannot be brought to repentance, wherefore the pain of excommunication cannot do him any good.

Reply to Objection 3: From the very fact that a man is deprived of the prayers of the Church, he incurs a triple loss, corresponding to the three things which a man acquires through the Church's prayers. For they bring an increase of grace to those who have it, or merit grace for those who have it not; and in this respect the Master of the Sentences says (Sent. iv, D, 18): "The grace of God is taken away by excommunication." They also prove a safeguard of virtue; and in this respect he says that "protection is taken away," not that the excommunicated person is withdrawn altogether from God's providence, but that he is excluded from that protection with which He watches over the children of the Church in a more special way. Moreover, they are useful as a defense against the enemy, and in this respect he says that "the devil receives greater power of assaulting the excommunicated person, both spiritually and corporally." Hence in the early Church, when men had to be enticed to the faith by means of outward signs (thus the gift of the Holy Ghost was shown openly by a visible sign), so too excommunication was evidenced by a person being troubled in his body by the devil. Nor is it unreasonable that one, for whom there is still hope, be given over to the enemy, for he is surrendered, not unto damnation, but unto correction, since the Church has the power to rescue him from the hands of the enemy, whenever he is willing.

Whether anyone should be excommunicated for inflicting temporal harm?


Objection 1: It would seem that no man should be excommunicated for inflicting a temporal harm. For the punishment should not exceed the fault. But the punishment of excommunication is the privation of a spiritual good, which surpasses all temporal goods. Therefore no man should be excommunicated for temporal injuries.

Objection 2: Further, we should render to no man evil for evil, according to the precept of the Apostle (
Rm 12,17). But this would be rendering evil for evil, if a man were to be excommunicated for doing such an injury. Therefore this ought by no means to be done.

On the contrary, Peter sentenced Ananias and Saphira to death for keeping back the price of their piece of land (Ac 5,1-10). Therefore it is lawful for the Church to excommunicate for temporal injuries.

I answer that, By excommunication the ecclesiastical judge excludes a man, in a sense, from the kingdom. Wherefore, since he ought not to exclude from the kingdom others than the unworthy, as was made clear from the definition of the keys (Question [17], Article [2]), and since no one becomes unworthy, unless, through committing a mortal sin, he lose charity which is the way leading to the kingdom, it follows that no man should be excommunicated except for a mortal sin. And since by injuring a man in his body or in his temporalities, one may sin mortally and act against charity, the Church can excommunicate a man for having inflicted temporal injury on anyone. Yet, as excommunication is the most severe punishment, and since punishments are intended as remedies, according to the Philosopher (Ethic. ii), and again since a prudent physician begins with lighter and less risky remedies, therefore excommunication should not be inflicted, even for a mortal sin, unless the sinner be obstinate, either by not coming up for judgment, or by going away before judgment is pronounced, or by failing to obey the decision of the court. For then, if, after due warning, he refuse to obey, he is reckoned to be obstinate, and the judge, not being able to proceed otherwise against him, must excommunicate him.

Reply to Objection 1: A fault is not measured by the extent of the damage a man does, but by the will with which he does it, acting against charity. Wherefore, though the punishment of excommunication exceeds the harm done, it does not exceed the measure of the sin.

Reply to Objection 2: When a man is corrected by being punished, evil is not rendered to him, but good: since punishments are remedies, as stated above.

Whether an excommunication unjustly pronounced has any effect?


Objection 1: It would seem that an excommunication which is pronounced unjustly has no effect at all. Because excommunication deprives a man of the protection and grace of God, which cannot be forfeited unjustly. Therefore excommunication has no effect if it be unjustly pronounced.

Objection 2: Further, Jerome says (on
Mt 16,19, "I will give to thee the keys"): "It is a pharisaical severity to reckon as really bound or loosed, that which is bound or loosed unjustly." But that severity was proud and erroneous. Therefore an unjust excommunication has no effect.

On the contrary, According to Gregory (Hom. xxvi in Evang.), "the sentence of the pastor is to be feared whether it be just or unjust." Now there would be no reason to fear an unjust excommunication if it did not hurt. Therefore, etc.

I answer that, An excommunication may be unjust for two reasons. First, on the part of its author, as when anyone excommunicates through hatred or anger, and then, nevertheless, the excommunication takes effect, though its author sins, because the one who is excommunicated suffers justly, even if the author act wrongly in excommunicating him. Secondly, on the part of the excommunication, through there being no proper cause, or through the sentence being passed without the forms of law being observed. In this case, if the error, on the part of the sentence, be such as to render the sentence void, this has no effect, for there is no excommunication; but if the error does not annul the sentence, this takes effect, and the person excommunicated should humbly submit (which will be credited to him as a merit), and either seek absolution from the person who has excommunicated him, or appeal to a higher judge. If, however, he were to contemn the sentence, he would "ipso facto" sin mortally.

But sometimes it happens that there is sufficient cause on the part of the excommunicator, but not on the part of the excommunicated, as when a man is excommunicated for a crime which he has not committed, but which has been proved against him: in this case, if he submit humbly, the merit of his humility will compensate him for the harm of excommunication.

Reply to Objection 1: Although a man cannot lose God's grace unjustly, yet he can unjustly lose those things which on our part dispose us to receive grace. for instance, a man may be deprived of the instruction which he ought to have. It is in this sense that excommunication is said to deprive a man of God's grace, as was explained above (Article [2], ad 3).

Reply to Objection 2: Jerome is speaking of sin not of its punishments, which can be inflicted unjustly by ecclesiastical superiors.



We must now consider those who can excommunicate or be excommunicated. Under this head there are six points of inquiry:

(1) Whether every priest can excommunicate?

(2) Whether one who is not a priest can excommunicate?

(3) Whether one who is excommunicated or suspended, can excommunicate?

(4) Whether anyone can excommunicate himself, or an equal, or a superior?

(5) Whether a multitude can be excommunicated?

(6) Whether one who is already excommunicated can be excommunicated again?

Whether every priest can excommunicate?


Objection 1: It would seem that every priest can excommunicate. For excommunication is an act of the keys. But every priest has the keys. Therefore every priest can excommunicate.

Objection 2: Further, it is a greater thing to loose and bind in the tribunal of penance than in the tribunal of judgment. But every priest can loose and bind his subjects in the tribunal of Penance. Therefore every priest can excommunicate his subjects.

On the contrary, Matters fraught with danger should be left to the decision of superiors. Now the punishment of excommunication is fraught with many dangers, unless it be inflicted with moderation. Therefore it should not be entrusted to every priest.

I answer that, In the tribunal of conscience the plea is between man and God, whereas in the outward tribunal it is between man and man. Wherefore the loosing or binding of one man in relation to God alone, belongs to the tribunal of Penance, whereas the binding or loosing of a man in relation to other men, belongs to the public tribunal of external judgment. And since excommunication severs a man from the communion of the faithful, it belongs to the external tribunal. Consequently those alone can excommunicate who have jurisdiction in the judicial tribunal. Hence, of their own authority, only bishops and higher prelates, according to the more common opinion can excommunicate, whereas parish priests can do so only by commission or in certain cases, as those of theft, rapine and the like, in which the law allows them to excommunicate. Others, however, have maintained that even parish priests can excommunicate: but the former opinion is more reasonable.

Reply to Objection 1: Excommunication is an act of the keys not directly, but with respect to the external judgment. The sentence of excommunication, however, though it is promulgated by an external verdict, still, as it belongs somewhat to the entrance to the kingdom, in so far as the Church Militant is the way to the Church Triumphant, this jurisdiction whereby a man is competent to excommunicate, can be called a key. It is in this sense that some distinguish between the key of orders, which all priests have, and the key of jurisdiction in the tribunal of judgment, which none have but the judges of the external tribunal. Nevertheless God bestowed both on Peter (
Mt 16,19), from whom they are derived by others, whichever of them they have.

Reply to Objection 2: Parish priests have jurisdiction indeed over their subjects, in the tribunal of conscience, but not in the judicial tribunal, for they cannot summons them in contentious cases. Hence they cannot excommunicate, but they can absolve them in the tribunal of Penance. And though the tribunal of Penance is higher, yet more solemnity is requisite in the judicial tribunal, because therein it is necessary to make satisfaction not only to God but also to man.

Whether those who are not priests can excommunicate?


Objection 1: It would seem that those who are not priests cannot excommunicate. Because excommunication is an act of the keys, as stated in Sent. iv, D, 18. But those who are not priests have not the keys. Therefore they cannot excommunicate.

Objection 2: Further, more is required for excommunication than for absolution in the tribunal of Penance. But one who is not a priest cannot absolve in the tribunal of Penance. Neither therefore can he excommunicate.

On the contrary, Archdeacons, legates and bishops-elect excommunicate, and yet sometimes they are not priests. Therefore not only priests can excommunicate.

I answer that, Priests alone are competent to dispense the sacraments wherein grace is given: wherefore they alone can loose and bind in the tribunal of Penance. On the other hand excommunication regards grace, not directly but consequently, in so far as it deprives a man of the Church's prayers, by which he is disposed for grace or preserved therein. Consequently even those who are not priests, provided they have jurisdiction in a contentious court, can excommunicate.

Reply to Objection 1: Though they have not the key of orders, they have the key of jurisdiction.

Reply to Objection 2: These two are related to one another as something exceeding and something exceeded [*Cf. Article [1], a[2]; Question [24], Article [1], ad 1], and consequently one of them may be within the competency of someone while the other is not.

Whether a man who is excommunicated or suspended can excommunicate another?


Objection 1: It would seem that one who is excommunicated or suspended can excommunicate another. For such a one has lost neither orders nor jurisdiction, since neither is he ordained anew when he is absolved, nor is his jurisdiction renewed. But excommunication requires nothing more than orders or jurisdiction. Therefore even one who is excommunicated or suspended can excommunicate.

Objection 2: Further. it is a greater thing to consecrate the body of Christ than to excommunicate. But such persons can consecrate. Therefore they can excommunicate.

On the contrary, one whose body is bound cannot bind another. But spiritual gyves are stronger than bodily fetters. Therefore one who is excommunicated cannot excommunicate another, since excommunication is a spiritual chain.

I answer that, Jurisdiction can only be used in relation to another man. Consequently, since every excommunicated person is severed from the communion of the faithful, he is deprived of the use of jurisdiction. And as excommunication requires jurisdiction, an excommunicated person cannot excommunicate, and the same reason applies to one who is suspended from jurisdiction. For if he be suspended from orders only, then he cannot exercise his order, but he can use his jurisdiction, while, on the other hand, if he be suspended from jurisdiction and not from orders. he cannot use his jurisdiction, though he can exercise his order: and if he be suspended from both, he can exercise neither.

Reply to Objection 1: Although an excommunicated or suspended person does not lose his jurisdiction, yet he does lose its use.

Reply to Objection 2: The power of consecration results from the power of the character which is indelible, wherefore, from the very fact that a man has the character of order, he can always consecrate, though not always lawfully. It is different with the power of excommunication which results from jurisdiction, for this can be taken away and bound.

Whether a man can excommunicate himself, his equal, or his superior?


Objection 1: It would seem that a man can excommunicate himself, his equal, or his superior. For an angel of God was greater than Paul, according to
Mt 11,11: "He that is lesser in the kingdom of heaven is greater then he, a greater" than whom "hath not risen among men that are born of women." Now Paul excommunicated an angel from heaven (Ga 1,8). Therefore a man can excommunicate his superior.

Objection 2: Further, sometimes a priest pronounces a general excommunication for theft or the like. But it might happen that he, or his equal, or a superior has done such things. Therefore a man can excommunicate himself, his equal, or a superior.

Objection 3: Further, a man can absolve his superior or his equal in the tribunal of Penance, as when a bishop confesses to his subject, or one priest confesses venial sins to another. Therefore it seems that a man may also excommunicate his superior, or his equal.

On the contrary, Excommunication is an act of jurisdiction. But no man has jurisdiction over himself (since one cannot be both judge and defendant in the same trial), or over his superior, or over an equal. Therefore a man cannot excommunicate his superior, or his equal, or himself.

I answer that, Since, by jurisdiction, a man is placed above those over whom he has jurisdiction, through being their judge, it follows that no man has jurisdiction over himself, his superior, or his equal, and that, consequently, no one can excommunicate either himself, or his superior, or his equal.

Reply to Objection 1: The Apostle is speaking hypothetically, i.e. supposing an angel were to sin, for in that case he would not be higher than the Apostle, but lower. Nor is it absurd that, if the antecedent of a conditional sentence be impossible, the consequence be impossible also.

Reply to Objection 2: In that case no one would be excommunicated, since no man has power over his peer.

Reply to Objection 3: Loosing and binding in the tribunal of confession affects our relation to God only, in Whose sight a man from being above another sinks below him through sin; while on the other hand excommunication is the affair of an external tribunal in which a man does not forfeit his superiority on account of sin. Hence there is no comparison between the two tribunals. Nevertheless, even in the tribunal of confession, a man cannot absolve himself, or his superior, or his equal, unless the power to do so be committed to him. This does not apply to venial sins, because they can be remitted through any sacraments which confer grace, hence remission of venial sins follows the power of orders.

Summa - Supplement 402