Thomas Aquinas Commentary 1 Corinthians 5

After discussing matters pertaining to the sacrament of baptism, the Apostle begins to consider matters pertaining to marriage. First, he attacks a sin contrary to marriage, namely, sexual immorality; second, he discusses marriage itself (in chapter 7). Regarding the first point, he does two things: first, he mentions the crime, and second, he censures it (in verse 6). Concerning the first of these, he does two things: first, he mentions the crime of a specific sexually immoral person, and second, the crime of those who condoned this sin (in verse 2).

Regarding the first point, he mentions three things that pertain to the seriousness of the crime. First, he shows that the sin is notorious, saying it was not without reason that I asked whether you wish me to come to you with a rod. For there is one among you deserving the rod of discipline, because it is actually reported—that is, publicly known—that there is sexual immorality among you. Against this, it is said, Fornication must not even be named among you (Ephesians 5:3), and, They proclaim their sin like Sodom, they do not hide it (Isaiah 3:9).

Second, he amplifies the sin by comparison when he says it is of a kind that is not found or regarded as lawful, even among pagans. For example, general sexual immorality was not considered a sin among the pagans; therefore, to rid them of this error, the apostles imposed on pagans converted to the faith the obligation to abstain from it (Acts 15:29). Yet this was a form of sexual immorality regarded as unlawful even among pagans. Hence he says, for a man is living with his father’s wife. As it is written, Unstable as water, you shall not have pre-eminence because you went up to your father’s bed and defiled his couch (Genesis 49:4). This was monstrous even among the pagans, being contrary to natural reason. For the laws of every civilization dictated that the natural reverence owed to parents prevents sons and daughters from marrying their father or mother. This is even implied in Genesis 2:24: Wherefore a man shall leave father and mother (in contracting marriage) and shall cleave to his wife. Furthermore, since it goes on to say that the man and woman will be two in one flesh, the wife of the father is excluded from marriage, just as the person of the father or mother is. For it says in Leviticus 18:8: You shall not uncover the nakedness of your father’s wife; for it is the nakedness of the father.

Then, when he says, you are arrogant, he mentions the guilt of those who condoned this sin. First, he condemns them for condoning it; second, he supplies what they failed to do (in verse 3).

Regarding the first point, he detects three vices. First is pride, when he says, You are arrogant [puffed up]—that is, with the wind of pride, for considering yourselves innocent in comparison with the sinner, just as the Pharisee who said, I am not as the rest of men… or even as this tax collector (Luke 18:11). As it is written, He will dash them puffed up and speechless to the ground . Second, he touches on their injustice when he says, Ought you not rather to mourn? This means mourning for the benefit of the sinner: O that my head were waters, and my eyes a fountain of tears, that I might weep day and night for the slain of the daughters of my people! (Jeremiah 9:1). For true justice, as Gregory says in homily 34, On The Gospel, shows compassion, not disdain. Third, he touches on their failure to judge: let him who has done this be removed from among you. For such compassion from a just person bruises the sinner in order to deliver him: If you beat him with the rod, you will save his life from Sheol (Proverbs 23:14). It also helps to correct others, for it says in Proverbs 19:25: The wicked man being scourged, the fool shall be wiser. Hence Ecclesiastes 8:11 says, Because sentence against an evil deed is not executed speedily, the heart of the sons of men is fully set to do evil. Indeed, if others are to be corrected, the sinner must sometimes be cast out when there is fear of his conduct spreading: Drive out the scoffer, and strife will go out, and quarreling and abuse will cease (Proverbs 22:10).

Then, when he says, For though absent in body, he makes up for their failure by pronouncing sentence against the sinner. In this regard, he does three things: first, he shows the authority of the judge; second, the method of judging; and third, the sentence of the judge (in verse 5).

Concerning the first point, he does two things. First, he shows the authority of the minister—that is, himself. Here he seems to act contrary to proper judicial procedure by condemning an absent person, for it was not the custom of the Romans to give up anyone, before the accused met the accusers face to face (Acts 25:16). But the Apostle justifies this, saying, For though absent in body I am present in spirit—that is, with love and concern. As he says elsewhere, For though I am absent in body, yet I am with you in spirit, rejoicing to see your good order and the firmness of your faith in Christ (Colossians 2:5). Or, he is present in spirit because by the Spirit he knew what was taking place among them as if he were there, just as Elisha also says, Did I not go with you in spirit when the man turned from his chariot to meet you? (2 Kings 5:26). Because I am present in spirit, I have already pronounced judgment—that is, I have passed a sentence of condemnation on the one who has acted in this way. Second, he mentions the authority of the principal Lord, saying, in the name of the Lord Jesus Christ—that is, in His place and by His authority, or with the invocation of His name: Whatever you do in word or in deed, do all in the name of our Lord Jesus Christ (Colossians 3:17).

Then, with the words When you are assembled, he shows the manner of judging, touching on three things. First is the assembling of the congregation. For serious offenses should be punished according to the considered agreement of many people; hence in ancient times judges sat at the gates where the people were gathered: You shall appoint judges in all your gates (Deuteronomy 16:18); In the company of the upright, in the congregation (Psalms 111:1); Where two or three are gathered in my name, there am I in the midst of them (Matthew 18:20). Second, he indicates his assent when he says, and my spirit is present—that is, with my will and authority. Third, he presents the authority of the principal Lord, namely, Jesus Christ, saying, with the power of the Lord Jesus—the power that gives strength and validity to the judgment of the Church: Whatever you bind on earth shall be bound also in heaven (Matthew 18:18).

Then, with the words you are to deliver, he delivers the sentence of condemnation, regarding which he does three things. First, he assigns the punishment when he says, you are to deliver this man to Satan. This can be understood in two ways. First, that just as the Lord gave the apostles power over unclean spirits to cast them out (Matthew 10:8), so by the same power they could command the unclean spirits to torment in the body those whom they judged deserved it. Accordingly, the Apostle commanded the Corinthians on his own authority to deliver this sexually immoral person to Satan to be tortured. Second, he discloses the effect of this sentence when he says, for the destruction of the flesh—that is, for the torment and affliction of the flesh in which he sinned: One is punished by the very things by which he sins . Third, he mentions its fruit when he says, that his spirit may be saved in the day of the Lord Jesus—that is, that he may be saved on the day of death or on the day of judgment, as was explained above : but he himself shall be saved, yet so as by fire, meaning, through temporal punishment. For the Apostle did not deliver the sinner over to Satan’s power forever, but only until the time when he would be converted to repentance by bodily torment: Vexation alone shall make you understand what you hear (Isaiah 28:19). This sentence of the Apostle corresponds to what the Lord observed when he said to Satan, Behold he is in your hand (namely, his flesh), but yet keep his life unharmed (Job 2:6).

Alternatively, to deliver this man to Satan can be understood as referring to the sentence of excommunication, by which a person is cut off from the community of believers, from partaking of the sacraments, and is deprived of the blessings of the Church. Hence it says in Song of Solomon 6:10, Terrible as an army set in array—that is, to the devils. In this case, for the destruction of the flesh would mean that, being cut off from the Church and exposed to the temptations of the devil, he might more easily fall into sin: Let the filthy still be filthy (Revelation 22:11). Therefore, he calls mortal sins the destruction of the flesh, because He who sows to his own flesh will from the flesh reap corruption (Galatians 6:8). But he adds, that his spirit may be saved—that is, that the sinner, recognizing his own vileness, may repent and thus be healed: I was ashamed, and I was confounded, because I bore the disgrace of my youth (Jeremiah 31:19). This can also mean that his spirit—namely, the Church’s Holy Spirit—may be saved for the faithful on the day of judgment. This means that they should not destroy it by contact with the sinner, because it says in Wisdom 1:5: For a holy and disciplined spirit will flee from deceit and will rise and depart from foolish thoughts.

After reminding the Corinthians of two crimes—namely, the fornicator's and that of those who condoned his sin—the Apostle now censures both. He first addresses the crime of condoning the sin, and second, the sin of the fornication itself (in chapter 6). Concerning the first crime, he does two things: first, he rebukes the Corinthians for failing to pass judgment; second, he addresses other vices related to judgment (in chapter 6). Regarding their failure to pass judgment, he again does two things: first, he blames them for not casting out the fornicator; second, he corrects the false understanding they took from his words (in verse 9).

Regarding the first point, he does two things: first, he rebukes what they had done, and second, he shows what should be done (in verse 7). He begins by rebuking their past crime at its root, for he had said above that because they were "puffed up," they lacked compassion, which led to their failure to correct others and set them straight. Therefore, he first censures them for being puffed up, saying, Your boasting is not good, because you boast in the defects of others as though you were without faults yourselves.

Everyone should boast in the blessings given to them by God and not in others: Let each one test his own work, and then his reason to boast will be in himself alone and not in his neighbor (Galatians 6:4). And it is especially evil to boast in the failures of others: Why do you boast of mischief? (Psalms 51:3).

Second, he gives the reason for his rebuke, asking, Do you not know that a little leaven leavens the whole lump? As if to say, "Surely you cannot be unaware of this." It should be noted that there are two aspects to consider in leaven. The first is the flavor it gives to bread. In this sense, leaven signifies the wisdom of God, through which everything human is made savory. Accordingly, it says in Matthew 13:33, The kingdom of heaven is like leaven which a woman took and hid in three measures of meal, till it was all leavened.

The second aspect of leaven is corruption. In this sense, leaven can signify sin, because by one sin all of a person's works are corrupted. For example, the sin of hypocrisy is compared to leaven in Luke 12:1: Beware of the leaven of the Pharisees, which is hypocrisy. In another way, a sinful man himself can be signified by leaven.

This is precisely the point of his metaphor. Just as the entire lump of dough is corrupted by a little leaven, so a whole group can be defiled by one sinner: From one spark comes a great fire and from one deceitful man much blood . This happens when the sin of one person leads others to sin, or even when they consent to his sin by failing to correct him when they are able: They are worthy of death, not only who do these things but also who consent to those who do them (Romans 1:32).

Consequently, the Corinthians should not have boasted of another’s sin but should have taken steps to prevent others from being defiled by associating with him. This is in accord with what is said in the Song of Solomon 2:2, As a lily among brambles, so is my love among maidens, on which a gloss comments, "He was not a good man who could not endure evil men."

When he says, Cleanse out the old leaven, he shows what should be done in the future. First, he presents the teaching; second, he gives the reason for it (in verse 7).

He says, therefore, because a little leaven corrupts the whole lump, cleanse out the old leaven. This means you should cleanse yourselves by casting out the "old leaven" from your midst—that is, the fornicator who returned to the old state of corruption by sinning: You are growing old in a foreign country, you are defiled with the dead . By cutting off one sinner, the whole group is cleansed; thus, when Judas left, the Lord said, Now is the Son of Man glorified (John 13:31). The "old leaven" can also be understood as the old error, as in Isaiah 26:3, The old error is passed away, or even the corruption of original sin: Seeing that you have put off the old nature with its practices (Colossians 3:9), for a person is cleansed by removing these things.

Second, he mentions the effect of this cleansing, saying, that you may be a new lump. Here, "lump" means a mixture of water and new flour before leaven is added. Therefore, once the leaven—that is, the sinner or the sin—is removed from the faithful, they become like a new lump, renewed in purity: Your youth is renewed like the eagle’s (Psalms 103:5); Be renewed in the spirit of your minds (Ephesians 4:23). Third, he mentions the basis for this cleansing when he says, as you really are unleavened—that is, without the leaven of sin. In this sense, the Lord says, Beware of the leaven of the Pharisees and Sadducees (Matthew 16:6).

When he says, For Christ our paschal lamb has been sacrificed, he gives the reason for what he had said. The reason why the faithful should be unleavened is taken from the mystery of Christ’s passion. First, he mentions the mystery; second, he draws his conclusion from it (in verse 8).

Regarding the mystery, it should be noted that the foremost sacrament of the Old Law was the Paschal lamb. As commanded in Exodus chapter 11, it was sacrificed by the whole multitude of the children of Israel to commemorate the event in which the angel, striking the firstborn in Egypt, passed over the homes of the Jews, whose doorposts were smeared with the blood of a lamb. The word "Pasch" (Passover) is derived from this event: It is the Lord’s Passover (Exodus 12:11). By virtue of this blessing, the people passed through the Red Sea (Exodus 14:15 and following). This lamb was a figure of the innocent Christ, of whom it is said, Behold the Lamb of God (John 1:36).

Therefore, just as that lamb was slain by the children of Israel so that God’s people could be delivered from the destroying angel and, after being freed from slavery in Egypt, pass through the Red Sea, so Christ was slain by the children of Israel so that God’s people might be delivered from the devil's attacks by His blood and from the slavery of sin by baptism, as if passing through the Red Sea. That lamb was called the Pasch of the Jews because it was sacrificed as a sign of the passing over; thus the disciples ask, Where do you wish us to prepare for you to eat the Passover? (Matthew 26:17), that is, the Paschal lamb.

Therefore, the Apostle says that you ought to be unleavened because, just as the Passover of the old people was the sacrificed lamb, so our Passover—that of the new people—is the sacrificed Christ. His sacrifice deserves the name "Pasch" both because of what the word means in Hebrew (namely, "passage") and what it means in Greek (namely, "passion"), for Christ passed from this world to the Father by means of His passion, in which He was sacrificed (John 13:1).

When he says, Let us, therefore, celebrate the festival, he draws his conclusion. To understand this, it should be noted that the Paschal lamb, after being sacrificed, was eaten with unleavened bread. Therefore, just as the Paschal lamb was a figure of our sacrificed Passover, so the observance of the new Passover should conform to the old. Accordingly, because the sacrificed Christ is our Passover, let us celebrate the festival by eating Christ not only sacramentally—Unless you eat the flesh of the Son of Man and drink his blood, you have no life in you (John 6:54)—but also spiritually by savoring His wisdom: Those who eat me will hunger for more, and those who drink me will thirst for more . And we should do so with spiritual joy: with glad shouts and songs of thanksgiving, a multitude keeping festival (Psalms 42:4).

He then describes how to celebrate by conforming the reality to the symbol, saying, not with the old leaven, the leaven of malice and evil. For it was commanded in Exodus chapter 12 that no leaven be found in the homes of those eating the Paschal lamb. Leaven involves both oldness and corruption. Thus, the removal of leaven could first mean the removal of the obligation to observe the precepts of the Old Law, which was rendered obsolete by the passion of Christ: The new coming on, you shall cast away the old (Leviticus 26:10).

Second, the removal of leaven could mean the removal of the corruption of sin, as we said above. In this sense, he says, nor with the leaven of malice and evil. Here, "malice" would refer to perverse actions—Casting away all uncleanness and abundance of malice (James 1:21)—and "wickedness" to crafty mischief: When he speaks graciously, believe him not, for there are seven mischiefs in his heart (Proverbs 26:25). Alternatively, according to a gloss, when he says, not with the old leaven, he refers to sin in general; but in adding, nor with the leaven of malice and evil, he becomes more specific, because malice refers to sin committed against oneself, and wickedness refers to sin against someone else.

Therefore, having set aside the improper way to celebrate, he describes the proper way when he continues, but with the unleavened bread of sincerity and truth. This means celebrating in sincerity and truth, which are symbolized by unleavened bread. Here, sincerity is contrasted with the corruption of sin, which he referred to as the leaven of malice and evil. "Sincere" means without corruption; thus in 2 Corinthians 2:17 he says, We do not adulterate the word of God but with sincerity in Christ we speak.

Truth, however, is contrasted with the symbols of the Old Law, as it says in John 1:17: Truth and grace came by Jesus Christ. This is because we should celebrate the true Passover in reality and not in symbols. Thus, according to a gloss, sincerity is understood as innocence from vice or newness of life, while truth is understood as the righteousness of good works or the directness that excludes deception.

Previously, the Apostle had advised the Corinthians to remove a sinner from their midst. But they postponed doing this because they misinterpreted something he had written in a previous letter. Consequently, in correcting this misunderstanding, he does three things:

1. He repeats what he had said in the previous letter.
2. He corrects their false interpretation (verse 10).
3. He gives the true interpretation (verse 11).

First, therefore, he says, I wrote to you in my letter (which is not in the canon) not to associate with fornicators—that is, not to have any fellowship or communion with them. As it is written, My son, walk not with them, restrain your feet from their paths (Proverbs 1:15); and, Give not your soul to harlots in any point .

Then, when he says, not at all meaning, he corrects the false interpretation of the above words. First, he states what he does mean, and second, he draws a conclusion (verse 10b).

Regarding the first point, it should be noted that the Corinthians had misinterpreted his statement in two ways. First, they supposed he was referring to fornicators who are unbelievers. He corrects this when he says, not at all meaning to say that you shall avoid communicating with the fornicators of this world. He refers to unbelievers by the name “world,” in keeping with John 1:21: The world has not know him, and 1 Corinthians 1:21: the world did not know God through wisdom.

Second, they falsely supposed that the Apostle’s prohibition referred only to fornicators and not to other sinners. To correct this, he now adds, or the greedy, who unjustly keep what belongs to others—as it is written, No one who is covetous (which is serving of idols) has any inheritance in the kingdom of Christ and of God (Ephesians 5:5)—or robbers, who violently plunder the property of others, or idolaters, against whom it says in Wisdom 14:27, The worship of abominable idols is the cause, and the beginning and the end of all evil. Consequently, the Apostle is prohibiting fellowship not only with fornicators but with all other sinners. It should be noted that by fornication a person sins against himself; by greed and robbery against his neighbor; and by the worship of idols he sins against God. In mentioning these, therefore, he includes every type of sin.

Then, when he says, since then you would need to go out of the world, he gives the reason for this clarification. He is saying that if he had meant the fornicators of this world, you would need to leave the world entirely, for the whole world is filled with them. Therefore, you could not avoid them except by leaving this world, for The whole world is in the power of the evil one (1 John 5:19). Alternatively, you would need to go out of the world could mean that since you should have been separated from the sinners of this world from the time of your conversion, there is no need to advise you further on this matter, for it says in John 15:19, I chose you out of the world. Or again, it could mean you would need to go out of the world by dying, for it is better for a person to die than to consent to sin with sinners. As he says later, For I would rather die than have any one deprive me of my ground for boasting (1 Corinthians 9:15).

Next, with the words But now I am writing to you, he presents the true interpretation. First, he states his intention; second, he gives a reason (verse 12); and third, he draws the intended conclusion (verse 13b).

First, therefore, he says: I will now explain what I wrote to you earlier: do not associate with fornicators and other sinners who bear the name of “brother,” in the sense that the Lord speaks of in Matthew 23:8: You are all brothers. The Apostle does not say “if any man is a brother,” but if anyone who is called a brother, because through mortal sin a person departs from the charity that is the cause of spiritual brotherhood. As it says in Hebrews 13:1, Let brotherly love continue. Therefore, a person is called a brother on account of true faith, even though he is not truly a brother if he lacks charity as a result of sin.

He then adds that if such a person is guilty of fornication or greed, or is an idolater, reviler, drunkard or robber—not even to eat with such a one. This is supported by 2 John 1:10: If any one comes to you and does not bring this doctrine, do not receive him into the house or give him any greeting. In other words, when I said that you should not keep company with sinners, I meant with believers who are called brothers and live among you.

However, as Augustine says in Contra Parmenianum, and as the Gloss here notes, this should not be understood to mean that someone should be separated from communion with others by an extraordinary private judgment, because one can often be mistaken. Rather, this ought to be done according to the order of the Church, when someone is expelled from communion after being convicted or having freely confessed. The Apostle says this clearly—if any are called—so that we understand this designation is made through the sentence of the Church, by a judicial order against someone brought forward. Those who are expelled from communion are to be shunned with respect to the Table, as it says here; with respect to greetings, as is preached by the authority of John; and further, with respect to sacred communion. Hence it is said in verse: “the mouth, to pray, farewell communion, the table is denied”—that is, he is excommunicated.

It should be noted that the Apostle mentions only mortal sins to show that a person should not be excommunicated except for a mortal sin. However, a question arises about one of these sins—namely, drunkenness—which does not always seem to be a mortal sin. For Augustine says in a sermon on purgatory that drunkenness, unless it is frequent, is not a mortal sin. I believe the reason for this is that drunkenness is, in general, a mortal sin. It seems contrary to charity that for the pleasure of wine, a person would be willing to lose the use of reason and expose himself to the danger of committing many other sins. Yet it might happen that a particular instance of drunkenness is not a mortal sin, perhaps because the strength of the wine or one’s own physical weakness was not known. This excuse, however, loses its validity when drunkenness is frequent. Hence, it is significant that the Apostle does not say “a drinker” but “a drunkard.”

It is noteworthy that to the list given earlier, he added two sins: the reviler and the drunkard. Drunkenness is in the class of sins committed against oneself, which includes not only lust but gluttony as well. Reviling is among the sins committed against one’s neighbor, whom a person can harm not only by deed but also by word. This can be done by calling down evil upon him, by defaming him (which is detraction), or by speaking evil to his face (which is contumely). All of this is included under the term “reviler,” as has been stated.

Then, when he says, For what have I to do with judging outsiders?, he gives the reason for what he has said. In this regard, he does three things. First, he gives the reason, saying: I have said that this is to be understood of brothers and not unbelievers, for what have I to do—that is, what business is it of mine—to judge—that is, to pass a sentence of condemnation on—outsiders—that is, on unbelievers who are completely outside the Church? For the Church's hierarchy has spiritual power only over those who have submitted to the faith, as it says in 2 Corinthians 10:6: Being ready to punish every disobedience, when your obedience is complete. Indirectly, however, the hierarchy has power over those outside, inasmuch as it forbids believers to associate with them on account of their guilt.

Second, he uses a comparison, saying, Is it not those inside the church whom you are to judge? It is as if he is saying: You judge with the same authority as I do. Therefore, just as you do not judge anyone but your own, neither do I. As it is written, A wise judge shall judge his people .

Third, he resolves a potential doubt. Someone might conclude that unbelievers are better off for not being condemned for the sins mentioned above. But he rejects this when he says that it is not his business to judge those who are outside, for God judges those outside—namely, unbelievers. As Gregory says in his Morals, unbelievers will be condemned without discussion and investigation. This is in line with John 3:18: He that does not believe has already been judged, meaning he has within himself an obvious cause for condemnation.

Then, when he says, Drive out the wicked one from among you, he draws the main conclusion. He is saying: Since my command that you not keep company with fornicators must be understood as referring to believers and not to those who are outside, then drive out the wicked one—that is, this man—from among you—that is, expel him from your company. This echoes the command in Deuteronomy 13:5: You shall purge the evil from the midst of you.

These words of the Apostle do not mean that we are forbidden to associate with unbelievers who have never received the faith, simply for their punishment. Yet the weak are cautioned to avoid them, so that they are not drawn away. But those strong in the faith can lawfully associate with them and try to convert them, as it says later in 1 Corinthians 10:27: If an unbeliever invites you to dinner and you are disposed to go, eat whatever is set before you. However, unbelievers who once were believers or who received the sacrament of faith—such as heretics or apostates—are to be excluded from all contact with believers. This is a punishment for them, just as it is for other sinners who are still subject to the power of the Church.