Less well known, however, is an exposition of the Mass that Thomas as a young friar and prospective university teacher gave his Parisian audience at the end of Distinction 8 of Book IV of his Commentary on the Sentences of Peter Lombard. Here follows this fine text of the Angelic Doctor, in its first complete translation in English, thanks to Dr. Beth Mortensen of The Aquinas Institute for the Study of Sacred Doctrine. As part of its long-term Opera Omnia project, of which 17 volumes are currently in print and 9 more are in the works (see here for an update), the Aquinas Institute is in the midst of a three-year NEH project to publish a bilingual annotated translation of Book IV of Aquinas's Commentary on the Sentences. Paragraph numbers have been added for the reader’s convenience.
St. Thomas Aquinas, In IV Sent., Distinction 8, expositio textus
[2] Nevertheless when he is praying in the person of the people he also prefaces all his words with, The Lord be with you, so that the minds of the people may be united with him by a right intention. And since the people have the priest as their leader in that which is directed to God, for this reason at the end of every prayer the people consent by answering Amen; and this is also why every prayer of the priest ends aloud, even if it is done privately.
[3] Now for those things that are divinely handed down through the minister to others, the people are directed by the ministers of the altar. But those things that pertain to disposing the people, the choir accomplishes: of these, the ones that pertain to those things that surpass human reason, are started by the priest, as though divinely received; the ones that are consonant with reason are declared by the choir by itself. Likewise some pertain to the people as preparatory to receiving divine things; and these are said by the choir before those that are said by the ministers and priest. But some things are caused by the reception of divine things in the people, and these follow what the priest says.
[4] Therefore, having seen these things, it should be known that since all our activity is begun by God, it should likewise end in him, coming full circle. And this is why the office of the Mass begins from a prayer and ends in thanksgiving. Hence it has three principal parts: namely, the beginning of the prayer that lasts until the epistle [Part I]; the middle celebration itself that lasts until the postcommunion [Part II]; and the end of thanksgiving from there until the end [Part III].
[5] The first part contains two things, namely, the preparation of the people for prayer, and the prayer itself.
[6] Now the people are prepared for prayer in three ways. The first is by devotion, which is aroused in the Introit; hence it is also received by something pertaining to the solemnity, in the devotion of which the people are brought together, and the psalm is also added. Second, humility, which is done by the Kyrie eleison, for the one seeking mercy declares his wretchedness; and it is said nine times because of the nine choirs of angels, or because of faith in the Trinity, according as any Person is considered in himself and in relation to the other two. Third, by right intention, which is directed to the heavenly fatherland and glory, which exceeds all human reason; and this is done by the Glory to God in the highest, which the choir completes once the priest has started it. And so it is only said on solemnities which represent to us heavenly solemnity; but in the offices of grief it is completely omitted.
[7] Next comes the prayer poured out to God for the people, which the priest publically pronounces after The Lord be with you; it is taken from Ruth 2:4. However, the high priest says: Peace be with you, bearing the type of Christ who addressed his disciples with these words after the resurrection, in John 20:19 and 21.
[8] But the second main part contains three parts. The first is the instruction of the people until the offertory; the second, the offering of the matter until the Preface; the third, the consummation of the sacrament until the postcommunion.
Part II-1
[9] The instruction of the people is done through the word of God, which indeed reaches the people from God through his ministers; and so those things that pertain to the instruction of the people are not said by the priest, but by the ministers.
[10] There are three kinds of ministry of the word of God. The first is from authority, which belongs to Christ who is called ‘minister’ in Romans 15:8, of whom it is said, but he was teaching as one having power (Matt 7:29). The second is from the truth made plain which applies to the preachers of the New Testament, of whom it says, he has made us also worthy ministers, etc. (2 Cor 3:6). The third is from prefiguration, which applies to the preachers of the Old Testament, and this is why the deacon sets down Christ’s teaching. And since Christ is not only man, but God, for this reason the deacon says first, The Lord be with you, so that he might make men attentive to Christ as God. Now the teaching of the preachers of the New Testament is set down by subdeacons. Nor is it inconsistent that sometimes in place of an epistle something is read by them from the Old Testament, since the preachers of the New Testament also preached the Old. But the teaching of the preachers of the Old Testament is not always read by lower ministers, but for those days in which the configuration of the New and Old Testaments is especially indicated, like in the four fasting times of the year, and when certain things are celebrated that were prefigured in the Old Law, like the Passion, Christmas, the Baptism, and things like that. And since either teaching is directed to Christ, both of those who went before, and of those who came after, this is why the teaching of Christ is reserved for the end.
[11] However, from the teaching that is directed to Christ, two effects come forth for the people, by which also man is prepared for Christ’s teaching: namely, the progress of the virtues, which is suggested by the Gradual, for it is named from the step by which one ascends from one virtue to another, or from the steps of the altar before which it is said; and the exultation possessed from the hope of eternal things, which the Alleluia suggests; hence it is also repeated because of the stole of the soul and body. But on days and in offices of grieving it is omitted, and a Tract is put in its place, which by the harshness of voices and verbiosity of words suggests our residence in this present misery. However, during Eastertide, two alleluias are said because of the joy of the resurrection of head and of the members. But the effect of Gospel teaching is the confession of faith, which, since it is above reason, the Creed is begun by the priest and completed by the choir, nor is it said except for on those solemnities about which mention is made in the Creed, like the Nativity, the Resurrection, the apostles, who stood out as founders of the faith, as it says: like a skilled architect I have laid the foundation (1 Cor 3:10).
Part II-2
[12] Next comes the second part of the second main part, which pertains to the offering of the matter to be consecrated; and this contains three things. For the exultation of the ones offering it is stated first as preparatory to the offering, for God loves a cheerful giver (2 Cor 9:7). The offering itself is expressed when it is said, Receive, O Holy Trinity; the acceptance of the offering is said by prayers silently spoken, for it belongs to the priest alone to appease God by these offerings, for which prayer the priest prepares himself through humiliation, saying: humbled in spirit and contrite of heart may we find favor with you, O Lord. And since these three things named require that the mind be raised to God, this is why before all three is said, The Lord be with you (but in place of which is said Pray brethren when the prayer is to be said silently).
Part II-3
[13] The third part of the second main part, which pertains to the sacrament’s reception, contains three things. First, preparation; second, the sacrament’s completion, at: Therefore we humbly pray and beseech you, most merciful Father, etc.; third, the consuming of the sacrament, at: Let us pray. At the Savior’s command and formed by divine institution, we dare to say.
[14] However, the preparation of the people, ministers, and priest for such a great sacrament is done by devout praise of God; therefore in the Preface, in which the preparation mentioned happens, three things are contained. First, the people’s arousal to praise, where the priest, having said The Lord be with you, which is to be referred to this entire third part, invites them to raise their minds, saying: Lift up your hearts, and to thanksgiving, saying: Let us give thanks to the Lord our God. Second, he implores God to receive our praise, showing that praise is due, saying: Truly it is worthy, by reason of his dominion (hence he adds, Holy Lord), and just, because of his fatherhood (hence he adds: all-powerful Father); right, because of his deity (hence he adds, eternal God); and for our salvation, because of our redemption (hence he adds: through Christ our Lord). But sometimes some other matter of praise is added suited to the solemnity, e.g., and to praise you in the assumption of Blessed Mary, ever Virgin; also setting forth an example of praise, through whom the angels praise your majesty. Third, the people offer up praises of the divinity, taking up the words of the angels: Holy, holy, holy, Lord God of hosts (Isa 6:3); and of Christ’s humanity, taking up the words of the children: Blessed is he who comes in the name of the Lord (Matt 21:9).
[15] However, the part that contains the sacrament’s completion is divided in three, according to the three things that are integral to this sacrament: namely, what is the sacrament alone; what is the reality-and-sacrament; and what is the reality alone. In the first part, therefore, is contained the blessing of the matter offered, which is the sacrament alone; in the second part, the consecration of the body and blood of Christ, which is the reality-and-sacrament, at: bless and approve this our offering; in the third, the request of the sacrament’s effect, which is the reality alone, at: vouchsafe to look upon them with a gracious and tranquil countenance.
[16] Concerning the first, the priest does two things: first, he asks a blessing on the offering, which is called a gift from God having given it to us, a present as something offered to God by us, a sacrifice as something sanctified by God for our salvation. Second, he asks salvation for the ones offering it, or for whom it is offered, at: which we offer up to you in the first place, etc.
[17] There he does three things. First he commemorates those for whose benefit the victim is offered: for the general state of the Church, as well as for particular persons, at: Remember your servants. Second, he commemorates those in whose reverence it is offered, at: in union with the whole church, and the Virgin who offered Christ in the temple is included, the apostles who handed down this rite of offering to us, and the martyrs who offered themselves to God, but not confessors, because in ancient times the Church did not invoke them in solemnizing, or because they did not suffer like Christ, of whose Passion this sacrament is the memorial. Third, what is sought to be obtained by the offering of this victim is expressly concluded, at: accept this offering, etc.
[18] Deign to make this our offering blessed, approved, etc. This part belongs to the consecration, which contains three things: first, the power of consecrating is implored; second, the consecration is completed, at: who the day before he suffered, took the bread; third, the commemoration of the thing consecrated is explained, at: wherefore, calling to mind the blessed Passion, etc.
[19] However, the words that are said here: make this our offering blessed, approved, ratified, reasonable, acceptable, can be referred in one way to what is the reality contained in this sacrament, namely, Christ, who is the blessed victim free from any stain of sin; approved, i.e. prefigured by the figures of the Old Testament, and by divine predestination foreordained; ratified, because not transitory; reasonable, because of its suitability for appeasing; acceptable, because of its efficacy. In another way, it can be referred to the host itself, which is the sacrament only; which he asks it to be blessed, that God consecrate it; but that he confirm it as regards memory, approved, [and] as regards a fixed purpose, ratified, that he may accept it; reasonable, as regards the judgment of reason; acceptable, as regards something pleasing to the will. In a third way, it can be referred to the effect, hence he says, blessed, by which we are blessed; approved, by which we may be enrolled in heaven; ratified, by which we may be counted among Christ’s members; reasonable, by which we may be torn from all beastly sensuality; acceptable, by which we may be accepted by God.
[20] Vouchsafe to look upon them with a gracious and tranquil countenance. Here the priest asks for the effect of the sacrament; and first the effect of grace; second, the effect of glory, at: remember also your servants, Lord. Concerning the first he does two things: first he asks that the sacrament be received, which is the cause of grace; second, he asks that the gift of grace be given, at: we humbly pray and beseech you, the exposition of which will be given further on, at Distinction 13. However he first asks the effect of glory for those already dead, at: remember; second, for those still living, at: for us, though sinners.
[21] However, the Canon of the Mass is customarily completed by other prayers in Christ, at: through Christ our Lord, by whom this sacrament has its origin and as to its substance; hence he says, you create, because of the natural being; you sanctify, because of the sacrament’s being, and as to its power; hence he says, you give life, because of the effect of grace, which is the life of the soul; you bless, because of the increase of grace, and as to its operation, or use, hence he says: and bestow on us.
[22] Let us pray. At the Savior’s command and formed by divine institution, we dare to say. Here the reception of the sacrament is set down, before which is the general and specific preparation. The general preparation has three parts: for, first, the sacrament’s petition is set down in the Lord’s Prayer, in which is said, give us this day our daily bread; second, the expiation of those receiving through the prayer of the priest: deliver us, Lord, from all evil; third, the fulfillment of peace, at, The peace of the Lord be with you. For this is the sacrament of holiness and peace; and since the peace of Christ exceeds all the senses, for this reason the petition of peace is begun by the priest, when he says, The peace of the Lord be with you, and it is completed by the choir, when it says, Lamb of God. And in this way it finishes three things begun by the priest, namely, Glory to God in the highest, which pertains to hope; I believe in one God, which pertains to faith; and The peace of the Lord be with you, which pertains to charity.
[23] Now the people asks mercy in the removal of evil against the wretchedness of fault and punishment, and peace, in the accomplishment of all good; and for this the Lamb of God is said three times. However, the special preparation of the priest consuming happens throught he prayers he says privately: Lord, Jesus Christ, and whatever others there are.
[24] The third main part is the thanksgiving; and it contains two things: the calling to mind of the benefit received, in singing the antiphon after communion, and thanksgiving in prayer, which the priest carries out, so that the end of the Mass might correspond in likeness to the beginning.
[25] However, it should be known that in the office of the Mass where the Passion is represented, certain Greek words are contained, like kyrie eleison, i.e., Lord have mercy; and certain Hebrew words, like alleluia, i.e., praise God; Sabaoth, i.e. of hosts; hosanna, save I beg; amen, i.e. truly, or so be it: and certain Latin ones, which are evident. For the placard over the Cross of Christ was written in these three languages (Jn 19:20).
