Chapter VII. The Rubrics of the Missal

In the rubrics of the Missal the Church has laid down a series of minute rules for the celebration of Mass. Their number and minuteness show her solicitude concerning the proper performance of this divine sacrifice. Those which have reference to the Mass itself are in general preceptive and bind under pain of sin. Grave sin, then, is committed by violating the rubrics of the Mass in serious matters; venial sin is committed by their violation in smaller matters. If a notable or important portion of the rite is omitted, or if notable additions are made to it by private authority, or any considerable change be made in it, there is a serious violation of the law. The rubrics which ordain that certain portions of the Mass be said in a loud or low or middle tone of voice only bind under venial sin, and so, if their observance would cause annoyance to other priests who are saying Mass, they cease to bind. Similarly, if through infirmity a priest is unable to observe some smaller rubrics, it is not the mind of the Church that he should be obliged to abstain from celebrating the holy mysteries.

It is a probable opinion that those rubrics in the Missal which have reference to what should be done out of Mass are only directive, not strictly preceptive so as to bind under pain of sin.

The general rule is that the Mass must agree with the office which the calendar prescribes to be said. However, by the decree S.R.C., December 7, 1895, when Mass is said in a church or public oratory which is not one’s own, which uses a different calendar, and celebrates a feast of double or higher rite, the Mass must always agree with the calendar of the church or public oratory, and not with the office of the celebrant.

When Mass has been once begun it may not be broken off without grave reason, even before the consecration. After the consecration a still graver cause is required, as, for example, the sudden breaking out of fire in the church, when the sacred species might be at once consumed and the Mass brought to an end. Moreover, even temporary interruptions of Mass are forbidden except after the Gospel, according to custom. The prohibition is stricter according to the greater solemnity of the part of the Mass where there is question of interruption. However, for good cause, an interruption may be permitted before the offertory; to justify an interruption between the offertory and the consecration a graver cause is required, and a very grave cause after the consecration.