LATERAN COUNCIL IV 1215
Ecumenical XII (against the Albigensians, Joachim, Waldensians etc.)
The Trinity, Sacraments, Canonical Mission, etc.*
Chap. 21. The Obligation of Making Confession and of its not being Revealed by the Priest, and the Obligation of Receiving the Sacrament at least in Paschal Time.*
437 Let everyone of the faithful of both sexes, after he has arrived at the years of discretion, alone faithfully confess all his sins at least once a year to his own priest, and let him strive to fulfill with all his power the penance enjoined upon him, receiving reverently the sacrament of the Eucharist at least in Paschal time, unless by chance on the advice of his own priest for some reasonable cause it shall be decided that he must abstain from the precept temporarily; otherwise both while living let him be barred from entrance to the church, and when dying let him be deprived of Christian burial. Therefore, let this salutary law be published frequently in the churches, lest anyone assume a pretext of excuse in the blindness of ignorance. Moreover if anyone from a just cause shall wish to confess his sins to another priest, let him first ask and obtain permission from his own priest, since otherwise that one (the other priest) cannot absolve or bind him. Let the priest, however, be discreet and cautious, so that skilled by practice “he may pour wine and oil” [ Luke 10:34] on the wounds of the wounded, diligently inquiring into both the circumstances of the sinner and the sin, by which prudently he may understand what kind of advice he ought to give to him, and, using various experiments to save the sick, what kind of a remedy he ought to apply.
438 Moreover, let him constantly take care, lest by word or sign or any other way whatsoever he may at any time betray the sinner; but if he should need more prudent counsel, he should seek it cautiously without any mention of the person, since he who shall presume to reveal a sin entrusted to him in confession, we decree not only must be deposed from priestly office but must also be thrust into a strict monastery to do perpetual penance.