Summa summae S. Thomae, Tomus III

The very controversies that arise daily concerning the things of faith prove the need of some supreme and infallible judge in matters of faith, to whom all are bound to defer. For the things of faith are abstract, sublime, hidden; not all are capable of examining and discussing matters so sublime and not self-evident. Hence, if there were not some supreme judge by whose infallible authority men might be held in check, nothing would be fixed in religion; we should be forever wavering, carried away by every wind of doctrine; disputes would be endless; and while each man abounded in his own opinion, there would be as many dogmas as heads.

Among heretics, some assign Scripture itself as supreme judge, which they wish to be clear and open; others assign the inspiration of the Holy Spirit to each private individual, or Scripture itself as understood according to this private spirit; others, like Brentius, the secular princes.

I say : The supreme and infallible judge of controversies of faith is not sacred Scripture, nor the private spirit, nor the secular prince, but the Church.

This conclusion already follows from dissertation I of the tractate On Faith, art. 2, where we showed that the rule for discerning revealed things is not Scripture itself, nor the private spirit, but the Church; and from dissertation I of this tractate, art. 3, where we proved that the meaning of Scripture is obscure, and that neither Scripture itself nor the private spirit, but the Church, is its judge. But because this question is of the highest importance, the arguments already given are renewed.

Proof of the first part. 1° In Scripture there are two things, the letter and the meaning. About the letter there are very many controversies : is what we have truly the word of God? Is it conformed to its autograph? Are these or those books canonical, or not? Luther rejects the Epistle to the Hebrews, the Epistle of St. James, and the Apocalypse; Calvin admits them. Who will decide the controversy? Not Scripture itself; for nowhere does it say that these books are or are not canonical, and even if it did say so, we should not be bound to believe it unless it were first established from another source that it is canonical. About the meaning, Scripture is drawn into various and contrary meanings, and about these there are the chief controversies. Among others, famous is that about the meaning of these words : This is my body. Calvinists understand it in a figurative sense, Lutherans and Catholics in the literal sense. Who will be judge between them? Not Scripture itself, which is the object and matter of the controversy. Therefore another judge must be sought, otherwise it will be disputed until the end of the world. Let the Calvinist say the Lutheran understands badly; the Lutheran will retort the same to the Calvinist.

It is confirmed. The judge of some controversy ought to hear the litigating parties, pronounce sentence, and be able to compel the parties to acquiesce in the sentence; otherwise the judgment would be futile. But Scripture cannot perform these things. Ergo.

Proof of the second part. 1° A judge in any cause must be public, known to the litigating parties, hear them, be heard by them, and have the authority to compel them to stand by his judgment; otherwise nothing will avail. But these things do not belong to the private spirit of each one, as is evident. Ergo.

2° A judge in some controversy must be one, not variable, not uncertain, not self-contradictory. But the private spirit is variable in different persons, uncertain, and often self-contradictory, dictating one thing to one man and the contrary to another. Thus it dictates to a Lutheran that these books are canonical, to a Calvinist that they are not canonical; it dictates to a Lutheran that these words, This is my body, are to be understood of the real presence, and to a Calvinist that they are to be understood of a spiritual and figurative presence. The Calvinist will tell the Lutheran that he is not led by a good spirit; the Lutheran will return the same answer to the Calvinist. Who will be judge? They will dispute forever, as they have now been disputing for two hundred years.

3° In every well-ordered commonwealth there is a public judge who interprets the law and decides by it all controversies, nor is any private person permitted to interpret the law according to his own spirit and pleasure; otherwise everything would be turned topsy-turvy and subverted. The heretics themselves know this. How much more, then, must this be admitted in the Church, which Christ instituted and ordered ! Unless you wish there to be as many dogmas of faith as heads, and those for the most part contrary to one another, and that all heresies must be tolerated; than which nothing is more absurd. Ergo.

4° Not all are capable of examining and discussing the things of faith, which are obscure, abstract, and sublime. Therefore neither can they define them by their own private spirit. If you say that each private man holds this from the Holy Spirit inspiring and revealing to him what is of faith or not : on the contrary, all claim to have this inspiration and revelation, and yet not all think the same thing. Therefore the Holy Spirit reveals contraries.

Proof of the third part. Nowhere in Scripture do we read that Christ constituted secular princes judges of controversies of faith; for it was not to them, but to the Apostles and their successors that he said : Going forth, teach, etc., or anything similar. Indeed the prince, according to the Apostle, Rom., XIII, 4, is the minister of God, not that he may judge the Church, but that he may defend her. Hence the celebrated Hosius wrote to the emperor Constantius : « Do not mingle yourself in ecclesiastical affairs, nor impose commands on us about these matters; rather learn these things from us. God has handed over the empire to you, the affairs of the Church he has entrusted to us. »

The fourth part follows from what has been said. It is necessary to acknowledge a living rule and supreme judge of controversies of faith, as we showed at the beginning of the article. But this is not sacred Scripture, not the private spirit, not the secular prince. Therefore the Church; for nothing else is assignable.

It is confirmed. 1°. He is rightly assigned supreme judge of controversies who is infallible in defining them. But such is the Church, as was proved in the preceding article. Ergo.

It is confirmed. 2° from the practice of the Church in the time of the Apostles. When a controversy arose about the legal observances to be kept by converted Gentiles, it was not settled by Scripture alone, nor by the private spirit, nor by the secular prince, but by the Church gathered at Jerusalem. Ergo.

What concerns the obscurity of Scripture, which the heretics deny, see diss. I of this tractate, art. 3, petitio 4. What they object about the sufficiency of Scripture you have answered in the preceding dissertation, art. 2. As to what they object against us, namely that we commit a vicious circle in proving the infallible veracity of the Church through Scripture, and the truth of Scripture through the Church, you have it fully discussed in the tractate On Faith, dissertation I, art. 2.