Holy Church here makes use of the formula of confession, which she has drawn up; it probably dates from the 8th century. We are not allowed to make the slightest change in the words. It has this prerogative, in common with all the other Sacramentals, that its recitation produces the forgiveness of venial sins, provided we be contrite for them. Thus it is, that God, in His Infinite Goodness, has provided us with other means, over and above the Sacrament of Penance, whereby we may be cleansed from our venial sins: He, for this end, inspired His Church to give us her Sacramentals.
The Priest, as we were saying, begins the Confession; and, first of all, he accuses himself to God. But, he is not satisfied with that; he as good as says: "I not only desire to confess my sins to God, but to all the Saints; in order that they may join their prayers with mine, and obtain pardon for me." Therefore, he immediately adds: "I confess to the Blessed Mary ever Virgin." Not that he has ever committed any offence against this holy Mother; but he has sinned in her sight; and the very thought of it urges him to make his sins known to Her also. He does the same to the glorious St. Michael, the great Archangel, who is appointed to watch over our souls, especially at the hour of death. In like manner, he confesses to St. John the Baptist, who was so dear to our Lord, and was His precursor. Lastly, he desires to own his sins to Saints Peter and Paul, the two Princes of the Apostles. Certain Religious Orders have permission to add the name of their Patriarch or Founder. Thus, the Benedictines insert the name of St. Benedict; the Dominicans, St Dominic; the Franciscans, St. Francis.
After mentioning these and all the Saints, he would have even the Faithful, who are present, know that he is a sinner; and he therefore says to them: And to you, Brethren! because, as he is now humbling himself on account of his sins, he not only accuses himself before those who are glorified in God, but moreover, before those his fellow-mortals who are there visibly present, near the sanctuary. And not satisfied with declaring himself to be a sinner, he adds in what way he has sinned; and confesses, that it is by all the three ways wherein men commit sin, namely, by thought, word, and deed: cogitatione, verba, et opere. Then wishing to express that he has thus sinned and through his own free will, he utters these words: Mea culpa, mea culpa, mea maxima culpa: through my fault, through my fault, through my most grievous fault. And, that he may, like the publican of the Gospel, outwardly testify his inward repentance, he thrice strikes his breast, whilst saying those words.
Conscious of the need he has of pardon, he once more turns towards Mary and all the Saints, as likewise to the Faithful who are present, begging that they will all pray for him. In reference to this formula of Confession, which has been established by our holy Mother the Church, it may be well to remind our readers that it would, of itself, suffice for one who was in danger of death, and unable to make a more explicit Confession.
The Ministers answer the Priest by wishing him the grace of God's mercy; they express their wish under the form of prayer, during which he, the Priest, remains bowed down, and answers: Amen. But, the Ministers themselves stand in need of God's pardon; and, therefore, they repeat the same formula as the Priest, for the confession of their sins; only, instead of saying: Et vobis, fratres, and to you, Brethren, they address the Priest, and call him Father: Et tibi, Pater.
It is never allowable to change anything which Holy Church has prescribed for the celebration of the Mass. Hence, in the Confiteor, the Ministers must always use the simple words: Et tibi, Pater, Et te, Pater, they must add no further title, not even were they serving the Pope's Mass.
As soon as the Ministers have finished the Confession formula, the Priest says the same prayer for them, as they had previously made for him; and they, also, respond to it by an Amen. A sort of blessing then follows: Indulgentiam ... whereby the Priest asks, both for himself and his brethren, pardon and forgiveness of their sins; he makes the sign of the Cross, and uses the word nobis and not vobis, for he puts himself on an equality with his Ministers, and takes his share in the prayer that is said for all.
The above excerpt, on the Confiteor, is taken from Explanation of the Prayers and Ceremonies of Holy Mass by Dom Prosper Gueranger, Abbot of Solesmes, France, from 1837 until his death in 1875. He wrote extensively on spiritual matters, especially the Mass, and is credited with the revival of the Benedictine Order and the restoration of the Mass in France following the upheaval wrought by the French Revolution.
