Summa summae S. Thomae, Tomus III

The question is commonly proposed thus, but it comes to the same as if you asked what the motive of faith is. This can be understood in two ways: either of the motive for assenting to revealed truths, or of the motive or rule for discerning which things are revealed. The first is disputed among Catholics, the second between Catholics and heretics.

[Protestants commonly hold that the motive and rule for discerning revealed truths is sacred Scripture, or the private spirit of each one, that is, the understanding breathed by the Holy Spirit into each one of the Scriptures he inspires.]

I say 1°: The motive for believing and assenting to revealed truths is the authority and veracity of God revealing, not the testimony or proposition of the Church.

It is proved — the first part, from the second conclusion of the preceding article. The motive for believing revealed truths is the formal object quo of faith; for that is called the formal object quo of a habit which is the medium and motive for attaining the formal object quod, as is clear from what has been said. Now the veracity of God revealing is the formal object quo of faith, as was said. Hence, to one asking why I believe God to be triune, I rightly answer: « Because God, who revealed it, is true. »

It is proved — the second part. The proposition or testimony of the Church in no way pertains to the formal object quo of faith. Therefore. — Proof of the antecedent. 1° Because it is something created; but nothing created can enter into the formal object of faith, any more than of hope and charity, otherwise they would not be purely divine and theological virtues. 2° The proposition of revealed truths through the Church is related to faith just as the proposition of goodness is related to love; for just as the will cannot love an object unless it is proposed and known, so the intellect cannot believe unless revealed truths are proposed to it. Now the proposition of goodness, in relation to the will and love, is not its formal object, but only the application of the object and a condition sine qua non. Therefore, similarly, the proposition of revealed truths through the Church, in relation to the intellect and faith.

I say 2°: The rule for discerning revealed truths is not Scripture, nor the private spirit, but the Church alone.

It is proved — the first part. The rule for discerning revealed truths from non-revealed ones must be incorruptible; otherwise it would expose one to error. Now Scripture is not incorruptible; for it can be corrupted and is corrupted daily, whether through the carelessness of typesetters or the malice of men; hence nothing certain can be drawn from it so long as it is not proposed by the Church as authentic and as containing the revealed truths. Therefore. The same must be said of the Creed, which, being scripture, is also liable to corruption, and besides does not contain all the revealed truths, any more than sacred Scripture does.

It is confirmed. Scripture is obscure in many places. Therefore another rule must be assigned for drawing out its true and legitimate meaning.

It is proved — the second part. 1° The rule for discerning revealed truths from non-revealed ones must be certain, and not doubtful. Now the Spirit breathed by God into each one is not certain, but doubtful; for Calvinists deny that it is in Lutherans, Lutherans in Calvinists, and both in Catholics. 2° A sufficient rule for discerning revealed truths from non-revealed ones must be able to settle controversies in this matter. Now the private spirit of each one not only cannot settle controversies about revealed and non-revealed matters, but rather from it there have continually sprung schisms and dissensions, just as if in civil affairs everyone were constituted judge in his own cause. For if a Calvinist says, from his private spirit, that this article is revealed, a Lutheran will deny it, and a Catholic too will deny it, equally from his private spirit. Who will settle the controversy? Who will be able to instruct and convince the other? And hence so many sects mutually opposed among the heretics themselves. 3° Here we are not dealing with private revelation which God can extraordinarily make to some private person, as he once made to the first parents, the patriarchs, the prophets, and the Apostles — in which case the interior light given, or the immediate revelation itself, would be the rule for discerning what must be believed; but we are dealing with revelation common to the whole society of the faithful, and therefore the proposition must be common, not private. On both parts of this see more in the following treatise, dissertation III, article 6.

The third part follows from what has been said, and it is proved both from the notes of the Church and the motives of credibility, of which below, and from the Scriptures, from which we have that the Church is directed by the Holy Spirit and infallible: Matt., XVI, 18: The gates of hell shall not prevail against her. 1 Tim., III, 15, she is called the pillar and firmament of truth.¹ Matt., XXVIII, 20: Behold I am with you all days, even to the consummation of the world.

The heretics have one thing to object, namely that we commit a circle in the resolution of our faith. For, they say, we believe revelation on account of the authority of the Church, and we believe the authority of the Church on account of revelation.

I answer. 1° We believe the authority of the Church not only on account of revelation, but also and primarily on account of the notes of the Church herself and the motives of credibility. Hence in this respect there is no circle. 2° Even if we believe the authority of the Church on account of revelation, it is not under the same aspect under which we believe revelation on account of the authority of the Church, but under a different one. We believe revelation on account of the authority of the Church as applying that revelation; but we believe the authority of the Church on account of revelation or divine veracity, as on account of the formal motive of assent; and thus in a different genus of cause. Now it is the ordinary case that causes are causes of one another in different genera. Thus fire depends upon application, as upon a condition, in order to burn, and the application depends upon the combustive power of fire, as upon an efficient cause. From this it is clear that our circle, in this respect, is only material, and not formal, nor vicious; a circle is vicious whose nature is to run from one thing to another and back again under the same aspect.

This twofold answer is usually explained by the familiar and common example of a messenger carrying the letters of a king. When the trustworthiness of the messenger is not certain, his signs are looked into; once it is established, the letters of the king are accepted on account of the trustworthiness of the messenger: but what is contained in the king's letters is believed, not on account of the trustworthiness of the messenger, but on account of the trustworthiness of the king; and if in the king's letters the trustworthiness of the messenger is asserted, it is thereby confirmed and more firmly believed on account of the trustworthiness of the king. Apply this to the case.

The Church proposes that this and that is revealed by God. Concerning the veracity and infallibility of the Church we have certainty from her notes and motives of credibility, on account of which these things are accepted and believed to be revealed in Scripture or tradition; but the revealed truths themselves contained in Scripture or tradition we believe on account of the authority and veracity of God revealing. Hence you see that the knowledge of the veracity of the Church, though it is strengthened by Scripture, nevertheless does not depend upon it necessarily; for when the Church was being born, there was no Scripture, and yet the veracity of the Church was noted and certain; but it is had primarily from her notes and motives of credibility, though we do not deny that it is confirmed by Scripture: and thus, on the one hand, there is no circle at all, and, on the other, there is no formal and vicious circle, in which one returns to the same thing under the same aspect — just as, conversely, happens in the private spirit of the heretics themselves; for they say they know that this Scripture is true, because their private spirit dictates it to them, and they say they know that they have a private spirit, because Scripture says so.

I insist. According to this solution, it follows that the certainty of our faith is not supreme and divine. — It is proved — the inference.

It hangs, as from an antecedent, upon the veracity of the Church, which is had at first only from the notes and motives of credibility. Now the certainty of the consequent is measured and taken from the certainty of the antecedent. Therefore.

I answer. I deny the inference. To the proof of the antecedent, I distinguish the minor. The certainty of the consequent is measured and taken from the certainty of the antecedent in discursive knowledge — I concede: thus the certainty of the conclusion is derived and measured from the certainty of the antecedent from which it is drawn. In simple knowledge, such as the knowledge of faith is, I deny it. This is clear in the very knowledge of principles, which is simple; for principles are not proved. Although a teacher may set before his disciples many preliminaries, examples, comparisons, suppositions, and other things, to explain them, once these have been explained and made known, the intellect gives its assent with certainty, even though the preliminaries were not certain, but at one time only probable, at another false; for the intellect does not assent to the principles on account of those things, but on account of their clearly seen truth.

Similarly in the case at hand. The proposition of the Church precedes as a preamble explaining what is revealed; once this has been explained and taken as supposed, the intellect assents to the revealed truth, not on account of the Church proposing it — for that is something extrinsic to the assent of faith — but on account of the veracity of God revealing, just as we said above that assent is given to what is contained in the letters of the king on account of the veracity, not of the messenger, but of the king.

[It is objected also: If the judgment of the Church is required in order that what must be believed with divine faith may become known, her sentence will have to be awaited, so that it may become certain that some doctrine pertains to the faith. Hence the faithful could not even have believed the divinity of Christ with divine faith before the Council of Nicaea. But this is repugnant. Therefore.]

I answer. This argument confuses the definition given by the Church concerning the articles to which the heterodox object, with the general and public consent of the Church. Whatever is known with certain and infallible reason to be contained in the word of God pertains to divine faith. That becomes known both from the constant sense and doctrine of the Church, and, where this doctrine seems darkened by new errors, through the decretorial judgment of the Church, which then does not create and introduce a new truth, but authentically and solemnly affirms her constant and universal faith, so that the Christian people, fortified against error, may be confirmed and strengthened in their former and ancient faith.

It is objected besides: The Catholic way, as proposed, abounds in so many and so great difficulties that the multitude cannot follow it. Therefore the opposite way is to be preferred. — Proof of the antecedent. For a Catholic to be secure in his faith, he must know: 1° whether the Church is infallible; 2° whether the Roman Church is the true Church of Christ; 3° what the subject of infallibility is; 4° what this infallible Church teaches; 5° whether her decisions are clothed with all the conditions required for a legitimate judgment; 6° what the meaning of each judgment is; and many other things of this kind. Now it is far more difficult to discuss all these than to investigate the truth of the dogmas by way of examination. Therefore.

I answer. I deny the antecedent. To the proof, answering the first part: I deny the minor. For even if all these things had to be examined by a Catholic, there would be the greatest difference between a discussion of this kind and the examination of each individual dogma, as is clear. — Answer to the second part: I deny the major. If once a Catholic is persuaded that he is in the true Church of Christ, he will at once understand that, by following her, he cannot stray from the truth. Moreover, the arguments that demonstrate the divine origin and infallibility of the Church are obvious and suited to convince even unlearned minds. Protestants alleged that among Catholics there is dispute about the subject of infallibility. But it has always been believed among us that the supreme power of judging in matters of faith was conferred by Christ upon the teaching Church, that is, the body of pastors. This rule, certain and safe from every danger of error, surely sufficed for the faithful. The greater and sounder part of theologians ascribed this magisterium personally to the Roman Pontiff, and at the same time to ecumenical councils, that is, assemblies of bishops judging together with the same Pontiff. After the Vatican Council, of which below, all Catholics firmly hold that the Roman Pontiff, fulfilling the office of teacher of all Christians and defining doctrine concerning faith or morals, is infallible — which takes nothing away from the collective infallibility of the Church together with the supreme Pastor teaching. Now this rule of faith is simple, obvious to all, and easiest in use. Therefore.

You will ask whether private revelations pertain to faith.

I answer. Private revelations concerning things that are ordered to God as their supernatural author pertain to faith as it is a theological virtue, not as it is catholic.

The reason of the former part is that for the notion of faith as a theological virtue only this is required: that it have God for its formal object quod, and the veracity of God revealing for its formal object under which; and this is found here. But the proposition of the Church is something extrinsic and accidental to faith as a theological virtue, as is clear in the angels in the wayfaring state, the first parents, the patriarchs, the prophets, and the Apostles, who had theological faith without the proposition of the Church.

Confirmation. 1° The Council of Trent, session VI, chapter 12, decrees: « apart from special revelation, it cannot be known whom God has chosen for himself. » And canon 16 defines: « If anyone shall say that he will certainly have that great gift of perseverance unto the end, with absolute and infallible certainty, unless he shall have learned this by special revelation; let him be anathema. » Therefore the sacred synod presupposes that private revelation can confer certainty of faith, and by that very fact that it is possible; otherwise the exception supposed in these places would become absurd.

Confirmation. 2° Sacred Scripture, especially in Heb., XI, recounts very many revelations made to the Fathers of the Old Testament, and elsewhere narrates similar ones which the Blessed Virgin, St. Joseph, Zacharias, and others received from God, and no one doubts that these pertained to their theological faith. In ecclesiastical history not a few examples of revelations of this kind are found concerning predestination and the death of certain saints, and other events, which it would be rash to refuse belief.

The reason of the latter part is that catholic faith, that is, universal, is concerned only with truths universal and common to the whole Church and to be proposed through the Church. Hence, if God were to reveal to some private person something pertaining to religion, that private person would be bound to believe it, but not others, even if he swore that it had been revealed to him; because it would not be proposed by the Church, which is the catholic rule for discerning revealed truths, as was said.]