Question — Merkelbach, Summa Theologiae Moralis
Question One: On the Existence of the Sacrament of Penance
419.
419. Order of discussion. - Christ the Lord properly instituted this sacrament when He conferred upon the apostles the power of remitting sins, which is called the power of the keys. Whence we must treat:
419.
1° of the existence of this power of the keys, according to the documents of Scripture and Tradition;
419.
2° of the existence of the sacrament itself, which is the effect of this power.