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 the seal of confession extends to other matters besides those which have reference to confession. For sins alone have reference to confession. Now sometimes, besides sins other matters are told which have no reference to confession. Therefore, since such things are told to the priest, as to God, it seems that the seal of confession extends to them also.
Obj. 2: Further, sometimes one person tells another a secret, which the latter receives under the seal of confession. Therefore the seal of confession extends to matters having no relation to confession.
On the contrary, The seal of confession is connected with sacramental confession. But those things which are connected with a sacrament, do not extend outside the bounds of the sacrament. Therefore the seal of confession does not extend to matters other than those which have reference to sacramental confession.
I answer that, The seal of confession does not extend directly to other matters than those which have reference to sacramental confession, yet indirectly matters also which are not connected with sacramental confession are affected by the seal of confession, those, for instance, which might lead to the discovery of a sinner or of his sin. Nevertheless these matters also must be most carefully hidden, both on account of scandal, and to avoid leading others into sin through their becoming familiar with it.
This suffices for the Reply to the First Objection.
Reply Obj. 2: A confidence ought not easily to be accepted in this way: but if it be done, the secret must be kept in the way promised, as though one had the secret through confession, though not through the seal of confession.
_______________________
Also online, linked only: the same translation at New Advent and the Latin text at Corpus Thomisticum. Neither is copied here.