Chapter VII-B. Choice of Individual Texts
317. In the choice of texts for the for the several parts of the Mass, the following rules are to be observed. They apply to Masses of the season and of the saints.
318. Sundays and holydays have three readings, that is, from the Old Testament, from the writings of an apostle, and from a Gospel. Thus God's own teaching brings the Christian people to a knowledge of the continuity of the work of salvation.
Accordingly, it is expected that there will be three readings, but for pastoral reasons and by decree of the conference of bishops the use of only two readings is allowed in some places. In such a case, the choice between the first two readings should be based on the norms in the Lectionary and on the intention to lead the people to a deeper knowledge of Scripture; there should never be any though of choosing a text because it is shorter or easier.
319. In the weekday lectionary, readings are provided for each day of every week throughout the year; therefore, unless a solemnity or a feast occurs, these readings are for the most part to be used on the days to which they are assigned.
The continuous reading during the week, however, is sometimes interrupted by the occurrence of a feast or particular celebration. In this case the priest, taking into consideration the entire week's plan of readings, is allowed either to combine omitted parts of other readings or to give preference to certain readings.
In Masses with special groups, the priest may choose texts more suited to the particular celebration, provided they are taken from the texts of an approved lectionary.
320. The Lectionary has a special selection of texts from Scripture for Masses that incorporate certain sacraments or sacramentals or that are celebrated by reason of special circumstances.
These selections of readings have been assigned so that by hearing a more pertinent passage from God's word the faithful may be led to a better understanding of the mystery they are taking part in and may be led to a more ardent love for God's word.
Therefore the texts for proclamation in the liturgical assembly are to be chosen on the basis of their pastoral relevance and the options allowed in this matter.
321. The many prefaces enriching the Roman Missal are intended to develop in different ways the theme of thanksgiving in the eucharistic prayer and bring out more clearly the different facets of the mystery of salvation.
322. The choice of the eucharistic prayer may be guided by the following norms.
a) Eucharistic Prayer I, the Roman Canon, which may be used on any day, is particularly apt on days when there is a special text for the prayer, In union with the whole Church, or in Masses that have a special form of the prayer, Father, accept this offering; also on the feasts of the apostles and saints mentioned in it and on Sundays, unless for pastoral considerations another eucharistic prayer is preferred.
Eucharistic Prayer II has features that make it particularly suitable for weekdays and special circumstances.
Although it has its own preface, it may also be used with other prefaces, especially those that summarize the mystery of salvation, such as the Sunday prefaces or the common prefaces.
When Mass is celebrated for a dead person, the special formulary may be inserted in the place indicated, namely, before the intercession, Remember our brothers and sisters.
c) Eucharistic Prayer III may be said with any preface. Its use is particularly suited to Sundays and holydays.
The special formulary for a dead person may be used with this prayer in the place indicated, namely, at the prayer, In mercy and love unite all Your children.
d) Eucharistic Prayer IV has a fixed preface and provides a fuller summary of the history of salvation. It may be used when a Mass has no preface of its own.
Because of the structure of this prayer no special formulary for the dead may be inserted.
323. In any Mass the prayers belonging to that Mass are used, unless otherwise noted.
In Masses on a memorial, however, the opening prayer or collect may be from the Mass itself or from the common; the prayer over the gifts and prayer after communion, unless they are proper, may be taken either from the common or from the weekdays of the current season.
On the weekdays in Ordinary Time, the prayer may be taken from the preceding Sunday, from another Sunday in Ordinary Time, or from the prayers for various needs and occasions listed in the Missal. It is always permissible even to use the opening prayer from these Masses.
This provides a rich collection of texts that create an opportunity continually to rephrase the themes of prayer for the liturgical assembly and also to adapt the prayer to the needs of the people, the Church, and the world. During the more important seasons of the year, however, the proper seasonal prayer appointed for each day in the Missal already makes this adaptation.
324. The norms laid down in their proper places are to be observed for the choice of chants between the readings and the songs for the processions at the entrance, presentation of the gifts, and communion.
325. In addition to the permissions just given to choose more suitable texts, the conference of bishops have the right in some circumstances to make further adaptations of readings, but on condition that the texts are taken from an approved lectionary.