The Eucharist as a sacrifice is called the Mass, most probably from the dismissal (missa) of the catechumens before the celebration. The Mass is a true proper sacrifice, namely, “the external offering up of a sensible gift, which is destroyed or transformed by an authorized minister in recognition of God’s supreme dominion.” This is Catholic doctrine, proved from prophecies, from the sacrificial character of the Last Supper, and from the unvarying belief of the faithful. The Mass is identical with the Sacrifice of the Cross in the Victim and the Priest, which is Christ. On the Cross He offered Himself in person and in a bloody manner; in the Mass, through His ministers, in an unbloody manner. As He offered up His death while consecrating the bread and wine, the priest also, acting in remembrance of Him, offers up His death at the consecration of the Mass. He is mystically slain in the separate consecration of bread and wine; the offering is perfected in the Communion of the priest. The value of this offering is infinite from the application of the merits of Christ’s Passion and Death, giving adequate praise and thanksgiving to God. Inexhaustible also are its fruits as satisfaction for sins and punishment due them, and for obtaining all benefits. These fruits are applied partly by the will of the Church, partly by the intention of the priest offering, and partly by those devoutly assisting, for both the living and the dead. Whether the satisfactory fruits of each Mass are infinite in application or limited by the will of Christ is not certainly known.
The Mass is the center of Catholic liturgy or worship; as Cabrol says, the mustard seed whence all liturgy has sprung. To appreciate the ritual of the Mass, one must keep in mind that it is a sacrifice by which a sacrament, the Holy Eucharist, is provided for priest and faithful. The nature of the sacrifice is explained under that title. The ritual is a fixed order or framework of prayers and ceremonies into which certain variable prayers and ceremonies are fitted. The fixed order or Ordinary of the Mass, as it is called, precisely because it is part of every Mass, is known as the Common; the variable parts, or special for certain days, as the Proper. The fixed or Ordinary part of the Mass consists of
- Confession at the foot of the altar which is always the same, except at Passiontide and at Requiems, when Psalm 42 is omitted
- the Introit, entrance or opening prayer, at the priest’s right hand corner of the altar, to the Offertory, all of which part is variable except the Gloria and Credo, which are not always said
- the Offertory, which is fixed or Common, except for the Secret prayer and the Preface which is adapted for certain feasts
- the Canon, which varies slightly on Easter and Pentecost Sundays
- the Communion, always Proper, and the rest to the end Common as a rule, except the Postcommunion, the Ite Missa Est when the vestments are purple or black, and the Last Gospel in Lent, on vigils, and Sundays when a special Feast is celebrated.
As High Mass is the norm for all Masses, incense ceremony is part of the Common before the Introit, before and after the Gospel, at the Offertory and Consecration. The only part of the Mass therefore which is invariable strictly speaking is the Kyrie Eleison. All the others are variable to some extent, and though the Gloria or Credo never change, they are frequently omitted. The parts of the Mass are listed as jollows, the Proper being indented. These are treated in separate, linked entries.