From the Supplement, compiled after Aquinas’s death from his Commentary on the Sentences and transcribed here from the 1917 to 1922 printings. About the Supplement.
Text: Summa Theologiae, Supplement to the Third Part (Supplementum Tertiae Partis), transcribed from Internet Archive scans, translated by the Fathers of the English Dominican Province. The Supplement, compiled after Aquinas’s death from his earlier Commentary on the Sentences, in the same English Dominican translation as the Gutenberg Parts. Transcribed by Bibliotheca Catholica from the OCR of four Internet Archive scans of the pre-1931 printings (Questions 1 to 33 from the 1917 Washbourne and Benziger volume, 34 to 68 from the 1922 volume, 69 to 86 from the 1921 volume, and 87 to 99 from the 1922 Benziger volume), with OCR errors corrected and doubtful passages marked, not rewritten. 99 questions and 446 articles. The two appendices printed after Question 99 are not included. Sources, SHA-256 of each OCR file, and the method are in the source record. Rights: Public domain (US)
The Supplement is not a Project Gutenberg text. It is Bibliotheca Catholica’s transcription of public-domain scans at the Internet Archive; obvious OCR errors were corrected, and passages marked “OCR uncertain” could not be confidently corrected, so check them against the linked scan page.
Objection 1: It seems that not only the priest is bound by the seal of confession. For sometimes a priest hears a confession through an interpreter, if there be an urgent reason for so doing. But it seems that the interpreter is bound to keep the confession secret. Therefore one who is not a priest knows something under the seal of confession.
Obj. 2: Further, it is possible sometimes in cases of urgency for a layman to hear a confession. But he is bound to secrecy with regard to those sins, since they are told to him as to God. Therefore not only the priest is bound by the seal of confession.
Obj. 3: Further, it may happen that a man pretends to be a priest, so that by this deceit he may know what is on another's conscience: and it would seem that he also sins if he divulges the confession. Therefore not only the priest is bound by the seal of confession.
On the contrary, A priest alone is the minister of this sacrament. But the seal of confession is connected with this sacrament. Therefore the priest alone is bound by the seal of confession.
Further, the reason why a man is bound to keep secret what he hears in confession, is because he knows them, not as man but as God knows them. But the priest alone is God's minister. Therefore he alone is bound to secrecy.
I answer that, The seal of confession affects the priest as minister of this sacrament: which seal is nothing else than the obligation of keeping the confession secret, even as the key is the power of absolving. Yet, as one who is not a priest, in a particular case has a kind of share in the act of the keys, when he hears a confession in a case of urgency, so also does he have a certain share in the act of the seal of confession, and is bound to secrecy, though, properly speaking, he is not bound by the seal of confession.
This suffices for the Replies to the Objections.
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Also online, linked only: the same translation at New Advent and the Latin text at Corpus Thomisticum. Neither is copied here.