A priest is bound by the natural law, the divine law and the law of the Church to keep absolutely secret whatever he hears in Confession. Canon 983 §states, “The sacramental seal in inviolable; therefore, it is a crime for a confessor in any way to betray a penitent by word or in any other manner or for any reason.” As early as 554 the Second Ecumenical Council of Dvin in Sasanian Armenia decreed: “A priest who reveals the confession of the penitents shall be deposed with anathema.” The Fourth Lateran Ecumenical Council (1215) commanded confessors “not to betray the sinner in any manner, whether by word or sign or in any other way,” and decreed that priests guilty of this crime “be deposed from their office, and imprisoned in a monastery for life.” The New Code of Canon Law (Canon 1388 says: “A confessor who directly violates the seal of confession incurs an automatic (latae sententiae) excommunication reserved to the Apostolic See; if he does so only indirectly, he is to be punished in accord with the seriousness of the offense.” There are no exceptions to this law. A priest may not break the seal of Confession, either to save his own life or his own good name, to save the life of another, or to further the aims of justice. This is eminently reasonable, for no criminal would dream of going to Confession, if he knew the confessor were bound to reveal his crime to the State authorities. The civil courts recognize the confessor’s privilege of silence both here and abroad.
St. Anthony of Padua (Fernando Martins de Bulhões; 15 August 1195 – 13 June 1231) offers an interesting commentary on the law laid down by the IV Lateran Council.
“The confession,” he says, “is made in secret; remote from any human knowledge, it is confided to the memory of the priest and protected against all human knowledge by an inviolable seal, in such a manner that if all men on earth knew the sins of him who confessed to you, you must nevertheless cover them by an inviolable silence. They are truly children of the devil, rejected by the living and true God, debarred from the Church Triumphant, cast out of the Church Militant, removed from their ecclesiastical office and handed over to public infamy, who not merely by words—which would be worse than any kind of murder—but also by signs, or in some other manner, secretly or openly, by derision or applause, reveal and expose what has been confessed to them. Nay, I maintain that whosoever reveals the confession made to him, sins more grievously than the traitor Judas, who sold the Son of God, Jesus Christ, to the Jews. I confess to a man not as a man, but as one who holds God’s place. The Lord says in Isaias (24:16): ‘My secret to myself, to me alone.’ And man, made of clay, should he not preserve the secret of confession in the innermost recesses of his heart? Very pertinently, therefore, has it been said that confession must be an uninhabited and inaccessible land, so that no man has access to the secret of confession.’’ The Saint applies Exodus 19:12-13 to the confessors, whom he addresses in these words: “Take heed, therefore, ye confessors, ye priests, that you go not up into the mountain. To go up into the mountain means to reveal the secret of confession. You shall not climb it, neither shall you touch the borders thereof. The borders of the mountain are the circumstances connected with confession, which you may not touch either by word, or sign, or in any other manner whatever. But alas, there are some who indeed fear to go up into the mountain, but do not dread to touch its borders by revealing the circumstances of sins by certain expressions and signs. Let these unfortunate persons hear their condemnation: ‘Every one, saith the Lord, that toucheth the mount, dying he shall die.’ But, O Lord, what a death? The arm of the civil power shall not seize him and hang him like a robber or a murderer; that would be too lenient; but he shall be stoned, i.e., he shall incur the most severe excommunication and eternal damnation. Beast or man shall perish, i.e., the uneducated as well as learned priests, or be it a layman or simple cleric to whom a confession may be made in case of necessity when a priest cannot be had, or be it a priest of the Church, he shall not live because he has gone up into the mountain and touched its borders.”