Summa summae S. Thomae, Tomus III

[Since we are weighing the dogmatic authority of the sacred liturgy, inasmuch as it is an authentic monument of ecclesiastical tradition, attention must be given only to legitimate liturgies, that is, those approved by the Church. For there arose, especially in the last century and at the beginning of the present one, particularly in Gaul, new liturgies substituted either for the Roman liturgy itself, or for the other ancient liturgies which had been declared legitimate by St. Pius V, in the constitution Quod a nobis — either because they were approved by the Apostolic See from their first institution, or because they had been in use for two hundred years. These more recent liturgies, introduced contrary to the law, are stripped by that very fact of all authority. Moreover, since they were, for the most part, drawn up by men more or less hostile to the Roman See, not only must the genuine doctrine of the Church be sought out in them with care; certainly many things were deliberately inserted into them which appear singular or paradoxical, sometimes even false. Hence they are to be regarded as of no account by a theologian who wishes to establish the ancient faith from the formulas of sacred worship. Happily, therefore, those new and illegitimate liturgies, with the approval and encouragement of the Apostolic See, were everywhere abolished by the bishops, and the Roman liturgy restored in the churches of Gaul, so that all, being of one mind toward one another according to Jesus Christ, with one accord glorify God with one mouth. Rom., XV, 5 and 6. Among the liturgies taken separately, those are to be preferred for asserting true doctrine which have been received into the nobler use in the Church. Among the Western churches the Roman liturgy holds first place, then the ancient Gallican and Hispanic liturgy, commonly called Mozarabic, to which must be joined the Ambrosian, which is still retained in the metropolitan church of Milan. Among the Eastern churches the liturgy of James claims the principal place, the most ancient of all, which flourished among most of the Eastern churches and is still observed today in many places. After it come the Greek liturgies which take their names from SS. Cyril, Basil, and Chrysostom, and the Armenian liturgy.

Dico: The authority of the liturgy must be held in the highest esteem, and it must be regarded as an irrefragable witness of tradition and of the faith of the Church.

Proof. 1° from authorities. Pope St. Celestine, writing to the bishops of Gaul against the error of the Pelagians, says in epistle xxi: « Besides these inviolable sanctions of the most blessed and Apostolic See, by which our most pious fathers, casting down the pride of pestilential novelty, taught us to refer to the grace of Christ the beginnings and growths of good will and of approved studies, and perseverance in them unto the end, let us also consider the sacraments of the priestly prayers, which, handed down from the Apostles, are celebrated uniformly throughout the whole world and in every catholic Church, so that the law of praying may establish the law of believing. » What could be more explicit? Augustine, epist. 217¹, to Vitalis, a favorer of Pelagianism, c. 1, n. 2: « Bring forth your disputations against the prayers of the Church; and when you hear the priest of God exhorting the people of God at the altar to pray for unbelievers, that God may convert them to the faith, and for catechumens, that he may inspire in them the desire of regeneration, and for the faithful, that by his gift they may persevere in what they have begun to be: receive those pious voices, and say that you do not do what he exhorts, that is, that God does not pray for unbelievers to make them faithful, on the ground that these benefits are not gifts of divine mercy but offices of human will. » The holy Doctor intends to prove from the liturgical prayers of the Church that the beginning of faith is a gift of God. The same, de Dono perseverantiae, c. 23, n. 63: « Would that those slow of heart and weak, who cannot or who cannot yet understand the Scriptures or their expositions, would so hear, or not hear, our disputations on this question, as to look rather upon their own prayers, which the Church has always had from her beginnings, and will have until this age is brought to its end! » Here he demonstrates equally from the public prayers of the Church that final perseverance is a gratuitous gift of God.

Proof. 2° from the nature and end of the liturgy. For the liturgy is ordered to the public worship to be rendered to God, and to procuring the sanctification of souls through supplications, sacrifice, and the administration of the sacraments. Further, included in divine worship is the honor to be paid to the saints, whom God, sanctified by his grace, has set before us for our example and succor, as is said in the prayer of the feast of St. William. Yet scarcely any dogma of the faith exists among those which the Catholic Church professes to which the liturgical formulas do not bear witness.

1° As to the truths to be believed: in her liturgy the Church openly professes the dogmas of the Trinity, of the divinity of the Word and of the Holy Spirit, of the divinity of Christ, of the truth of the incarnation and of the redemption that followed from it, of the Mother of God, of virginity not only but of integrity in childbirth, of the primacy of St. Peter and of the Roman Pontiff, of the infallibility of the Church, of the preeminence of bishops over priests, of the necessity of grace, of the propagation of original sin, of the unbloody sacrifice, of the real presence of Christ in the Eucharist, of transubstantiation, finally of purgatory and of the cult and invocation of the saints.

2° The administration of the sacraments is daily. From it, therefore, public, constant, and universal testimony is derived concerning the number of these same sacraments, their efficacy, their special effects, and the dispositions required for receiving them rightly. But since from the euchologies of the Greek and Eastern churches, and from the rituals and sacramentaries of the Western or Latin churches, we discover that seven sacraments were everywhere conferred at every time, are not Protestants convicted of audacity, indeed of madness, who reduced them to four or three, and finally to two? The same must be said of the grace which all those documents likewise testify is conferred through them, of the effects which are attributed to three of them with respect to character, of the baptism of infants, of the use of exorcisms, with which Augustine was already pressing the Pelagians of his own age, of the purity of conscience required for approaching the sacred communion, of the practice of auricular confession, and other similar matters,

3° As to what concerns religious worship, what the doctrine of the primitive Church was is thence discovered concerning the veneration of the saints, since we see feast days instituted and fasts celebrated for recalling the memories of the saints, some from the very infancy of the Church herself; concerning the veneration of relics and images; concerning lustral water, which Protestants reject and despise; and very many other things which, if they do not touch dogmas, yet avail greatly to deliver the Roman Church from the calumny so often hurled against her of base superstition.

Now when religious worship is under discussion, what is dealt with is that which is received in the universal Church, not, however, the particular rites which have been handed down for use in individual churches, although these can have a partial value, whether for proving their agreement with the universal Church, or for demonstrating the antiquity and nobility of the churches in which they were customarily observed ²

There are also reckoned among the means, whether general or particular, by which the ancient Catholic tradition can be determined: ecclesiastical history, the remains of ancient Christian monuments, epigraphy, and the writings of the earlier and more recent heretics, insofar as they are opposed to Catholic dogma. These things are indeed treated opportunely in the fuller theological works; but they must be passed over by us, as being confined within stricter limits.]