ARTICLE I: ON THE OBLIGATION OF CELEBRATING BY REASON OF THE PRIESTHOOD

1320. - I say: All priests, by reason of the Priesthood, are bound by divine law, under grave obligation, to celebrate at some time. This is proved from the words of Christ:¹ Do this in commemoration of me. By these words, according to the testimony of the Council of Trent, Christ commanded the Apostles and their successors to offer Sacrifice. Moreover, all priests in their ordination receive not only the power, but also the charge and office annexed to it, of sacrificing. Hence the Apostle:² For every Pontiff taken from among men is appointed for men in those things which are toward God, that he may offer gifts and Sacrifices. But in a grave matter anyone is gravely bound to execute an office undertaken. Therefore ... Thus St. Thomas.³ See St. Alphonsus.⁴

1321. Questions. - Query 1° How often in life or in the year is a priest bound to celebrate?

Resp. It is not clearly established. It seems more probable that he is not bound to celebrate except three or four times in the year, or on the more solemn feasts. Indeed it appears not improbable that a priest has satisfied his office if, on whatever days at last, he offers Sacrifice three or four times in the year.

Query 2° Is he excused from every sin who celebrates only four times in the year?

Resp. No. For he does not seem to be excused from some venial sin. Thus commonly according to the mind of Trent,² where it is said: "Let the Bishop take care that they" (Presbyters) "celebrate Masses at least on Lord's days and solemn feasts." Indeed Holy Mother Church desires that a priest offer Sacrifice on individual days, and pious priests are accustomed very rarely to omit it.