91. The celebration of the Eucharist is the action of Christ and of the Church, namely, of the holy people united and ordered under the Bishop. It therefore pertains to the whole Body of the Church, manifests it, and has its effect upon it. Indeed, it also affects the individual members of the Church in a different way, according to their different orders, functions, and actual participation. In this way, the Christian people, “a chosen race, a royal Priesthood, a holy nation, a people for his own possession,” expresses its cohesion and its hierarchical ordering. All, therefore, whether ordained ministers or lay Christian faithful, in fulfilling their function or their duty, should carry out solely but totally that which pertains to them.
I. The Duties of Those in Holy Orders
92. Every legitimate celebration of the Eucharist is directed by the Bishop, either in person or through Priests who are his helpers.
When the Bishop is present at a Mass where the people are gathered, it is most fitting that he himself celebrate the Eucharist and associate Priests with himself in the sacred action as concelebrants. This is done not for the sake of adding outward solemnity to the rite, but to signify more vividly the mystery of the Church, “the sacrament of unity.”
If, on the other hand, the Bishop does not celebrate the Eucharist but has assigned it to someone else to do this, then it is appropriate that he should preside over the Liturgy of the Word, wearing the pectoral cross, stole, and cope over an alb, and that he should give the blessing at the end of Mass.
93. A Priest, also, who possesses within the Church the sacred power of Orders to offer sacrifice in the person of Christ, presides by this fact over the faithful people gathered here and now, presides over their prayer, proclaims to them the message of salvation, associates the people with himself in the offering of sacrifice through Christ in the Holy Spirit to God the Father, and gives his brothers and sisters the Bread of eternal life and partakes of it with them. Therefore, when he celebrates the Eucharist, he must serve God and the people with dignity and humility, and by his bearing and by the way he pronounces the divine words he must convey to the faithful the living presence of Christ.
94. After the Priest, the Deacon, in virtue of the sacred Ordination he has received, holds first place among those who minister in the celebration of the Eucharist. For the sacred Order of the Diaconate has been held in high honor in the Church even from the early time of the Apostles. At Mass the Deacon has his own part in proclaiming the Gospel, from time to time in preaching God’s Word, in announcing the intentions of the Universal Prayer, in ministering to the Priest, in preparing the altar and in serving the celebration of the Sacrifice, in distributing the Eucharist to the faithful, especially under the species of wine, and from time to time in giving instructions regarding the people’s gestures and posture.
II. The Functions of the People of God
95. In the celebration of Mass the faithful form a holy people, a people of God’s own possession and a royal Priesthood, so that they may give thanks to God and offer the unblemished sacrificial Victim not only by means of the hands of the Priest but also together with him and so that they may learn to offer their very selves. They should, moreover, take care to show this by their deep religious sense and their charity toward brothers and sisters who participate with them in the same celebration.
They are consequently to avoid any appearance of singularity or division, keeping in mind that they have only one Father in heaven and that hence are all brothers or sisters one to the other.
96. Moreover, they are to form one body, whether in hearing the Word of God, or in taking part in the prayers and in the singing, or above all by the common offering of the Sacrifice and by participating together at the Lord’s table. This unity is beautifully apparent from the gestures and bodily postures observed together by the faithful.
97. The faithful, moreover, should not refuse to serve the People of God in gladness whenever they are asked to perform some particular service or function in the celebration.
III. Particular Ministries
The Ministry of the Instituted Acolyte and Lector
98. The acolyte is instituted for service at the altar and to assist the Priest and Deacon. It is his place principally to prepare the altar and the sacred vessels and, if necessary, to distribute the Eucharist to the faithful as an extraordinary minister.
In the ministry of the altar, the acolyte has his own proper functions (cf. nos. 187-193), which he must carry out in person.
99. The lector is instituted to proclaim the readings from Sacred Scripture, with the exception of the Gospel. He may also announce the intentions for the Universal Prayer and, in the absence of a psalmist, recite the Psalm between the readings.
In the celebration of the Eucharist, the lector has his own proper function (cf. nos. 194-198), which he himself must carry out.
100. In the absence of an instituted acolyte, there may be deputed lay ministers to serve at the altar and assist the Priest and the Deacon; these carry the cross, the candles, the thurible, the bread, the wine, and the water, or who are even deputed to distribute Holy Communion as extraordinary ministers.
101. In the absence of an instituted lector, other lay people may be deputed to proclaim the readings from Sacred Scripture, people who are truly suited to carrying out this function and carefully prepared, so that by their hearing the readings from the sacred texts the faithful may conceive in their hearts a sweet and living affection for Sacred Scripture.
102. It is the psalmist’s place to sing the Psalm or other biblical canticle to be found between the readings. To carry out this function correctly, it is necessary for the psalmist to be accomplished in the art of singing Psalms and have a facility in public speaking and elocution.
103. Among the faithful, the schola cantorum or choir exercises its own liturgical function, its place being to take care that the parts proper to it, in keeping with the different genres of chant, are properly carried out and to foster the active participation of the faithful by means of the singing. What is said about the schola cantorum also applies, with due regard for the relevant norms, to other musicians, and especially the organist.
104. It is fitting that there be a cantor or a choir director to direct and support the people’s singing. Indeed, when there is no choir, it is up to the cantor to direct the different chants, with the people taking the part proper to them.
105. A liturgical function is also exercised by:
a) The sacristan, who diligently arranges the liturgical books, the vestments, and other things that are necessary for the celebration of Mass.
b) The commentator, who, if appropriate, provides the faithful briefly with explanations and exhortations so as to direct their attention to the celebration and ensure that they are better disposed for understanding it. The commentator’s remarks should be thoroughly prepared and notable for their restraint. In performing this function the commentator stands in a suitable place within sight of the faithful, but not at the ambo.
c) Those who take up the collections in the church.
d) Those who, in some regions, welcome the faithful at the church doors, seat them appropriately, and marshal them in processions.
106. It is desirable, at least in cathedrals and in larger churches, to have some competent minister or master of ceremonies, to see to the appropriate arrangement of sacred actions and to their being carried out by the sacred ministers and lay faithful with decorum, order, and devotion.
107. Liturgical functions that are not proper to the Priest or the Deacon and are mentioned above (nos. 100-106) may even be entrusted by means of a liturgical blessing or a temporary deputation to suitable lay persons chosen by the pastor or the rector of the church. As to the function of serving the Priest at the altar, the norms established by the Bishop for his diocese should be observed.
IV. The Distribution of Functions and the Preparation of the Celebration
108. One and the same Priest must always exercise the presidential function in all of its parts, except for those parts which are proper to a Mass at which the Bishop is present (cf. above no. 92).
109. If there are several present who are able to exercise the same ministry, nothing forbids their distributing among themselves and performing different parts of the same ministry or duty. For example, one Deacon may be assigned to execute the sung parts, another to serve at the altar; if there are several readings, it is well to distribute them among a number of readers, and the same applies for other matters. However, it is not at all appropriate that several persons divide a single element of the celebration among themselves, e.g., that the same reading be proclaimed by two readers, one after the other, with the exception of the Passion of the Lord.
110. If at a Mass with the people only one minister is present, that minister may exercise several different functions.
111. There should be harmony and diligence among all those involved in the effective preparation of each liturgical celebration in accordance with the Missal and other liturgical books, both as regards the rites and as regards the pastoral and musical aspects. This should take place under the direction of the rector of the church and after consultation with the faithful in things that directly pertain to them. However, the Priest who presides at the celebration always retains the right of arranging those things that pertain to him.