"The good of the grace of one soul is greater than the good of the nature of the whole universe"
- St Thomas Aquinas Ia IIa, q.24, a. 3, ad 2

— A Commentary on the First Part of St Thomas' Theological Summa

by Reginald Garrigou-Lagrange, O. P.


Eighth article: whether sacred doctrine is a matter of argument

State of the question. The meaning of the title is: Have those things which sacred doctrine teaches the force of conviction? The difficulty is that what is transmitted to us in theology is believed rather than proved. In fact, it seems that proof would lessen the merit of faith. The reply, however, is that sacred theology is a matter of argument, and this for three reasons:

1) That it may prove, not its principles, but the conclusions to be deduced from them.

2) That it may defend its principles from the revealed truths admitted by the opponent.

3) That it may defend its principles by solving the objections of opponents, if they concede nothing at all of divine revelation.

As regards the proof of conclusions, sacred theology is in this repect like all the sciences. As for the defense of its principles, in this it does not differ from metaphysics which, since it is wisdom, defends its own principles against those denying them, solving their objections at any rate, and proving them to be false or at least not convincing.

Thus Aristotle (102) defends the real validity of the first principle of reason, that is, of the principle of contradiction, and also the validity of reason itself. In this process metaphysics, to be sure, makes use of logic, but it does not leave the defence of its principles to logic, for these are concerned not only with logical being but also with real being. It is the privilege of wisdom as such to defend its principles by the analysis of their concepts and the solution of objections, before it proceeds to the deduction of conclusions. So also sacred theology, inasmuch as it is wisdom, before deducing conclusions analyzes the principles of faith, and defends these principles against those who deny them and, by positive and speculative arguments drawn from revelation, solves the objections. In doing so, sacred theology makes use of history and philosophy.

As St. Thomas says: "It refutes those things that are said against the faith by showing that they are false or of no consequence," that is, not convincing. Cajetan admirably says: "There is a difference between the solution of an objection and the proof of thesis. For a proof is drawn from the evidence of argument . . . ; a solution, however, does not require evidence, but simply that the intellect be not compelled. A solution is also obtained from what does not seem to be false, though it may not be known to true." (104)

We have an example of this in the case of the Trinity. If it objected that one and the same nature does not belong numerical to several persons, the theologian replies: that this can be said a finite nature, I concede; of an infinite nature, that I deny. It is not that the theologian positively knows that the infinite nature pertains to several persons; this he believes and consequently maintains that there is no means of proving the impossibility of this an infinite nature. Thus the possibility of essentially supernatural mysteries is neither proved nor disproved. But we are reasonably persuaded of the same; it is defended against those denying and firmly believed. St Thomas says: "Therefore what is of faith can be proved by .authority alone to those who accept the authority while as regards others it suffices to prove that what faith teaches is not impossible." (105) John of St. Thomas says: "It is not evident to reason that a proposition contradictory to the faith is in itself false, but simply that the arguments by which it is proved are not cogent." (106)

Essentially supernatural mysteries are, of course, likewise supernatural as to their knowableness, for being and truth are one and the same. Therefore not only the existence of mysteries but even their intrinsic possibility is neither proved nor disproved, but are reasonably persuaded of the same (by an argument of congruence), and it is firmly believed. If, indeed, it were positively proved, for instance, that the Trinity is really possible, then the fact of existence would be proved because, in necessary things, what is really possible demands of necessity the existence of the same. And if it were positively proved that the beatific vision or eternal life is really possible, this mystery would transcend our naturally acquired knowledge, not because of its essentially supernatural nature but because of its contingency, in that it is a contingent future of the natural order which depends upon God's most free good pleasure, just as the last day of this material world does.

From the privilege sacred theology enjoys as wisdom, it follows, as we already remarked, that apologetics is not a specifically distinct science from sacred theology, but is the same science functioning rationally for the defense of the credibility of the mysteries of faith. Just as the critical part of metaphysics defends the real validity of the first principles of reason and of intellectual evidence, and in this it makes use of logic, so sacred theology defends the credibility of the mysteries of faith, and in this it makes use of history and philosophy, presenting from its lofty standpoint, under
the direction of faith, arguments drawn from reason as to the demonstrative force, for instance, of miracles and other signs, so that unbelievers may know from these signs that revelation is a fact and may so present unto God "a reasonable service." (107)

What is the mode of argumentation that is pre-eminently proper to sacred theology?

In the reply to the second objection it is stated that the argumentation is from divine authority, for sacred theology proceeds under the guidance of the light of revelation or of the authority of God revealing.

In this reply to the second objection we have the germ, as it were, of the treatise on the theological sources. Melchior Cano, O.P., was the first in this field. The theological sources are divided as follows:

Cajetan points out (108) that sacred theology makes use of natural or metaphysical reasons, as extrinsic or probable arguments, if these reasons are absolutely considered; it makes use of them as proper and sometimes necessary arguments, if these are considered as ministering to theology, that is, as helping in the deduction of the theological conclusion. But if we use these reasons as persuasive arguments in favor of the possibility of mysteries, then they furnish us with only a probable argument or with one of fitness that may be, however, most profound and always to be examined, but that is not apodictic.

Melchior Cano (109) in treating of history as an extrinsic theological source, holds that, if all the approved and weighty historians concur in admitting the same historical fact, then we have an argument of certainty on their authority.
Hence sacred theology first of all appeals to the argument from authority, and then has recourse to reason for the explanation, defense, right ordering of the authorities, and for the deduction of the conclusions from them.

The method of procedure in sacred theology is explained in the treatise on the theological sources, especially as regards the positive part. It lays down rules for discerning the literal sense of Sacred Scripture, for the discernment of divine tradition, as also for the correct interpretation of the definitions of the solemn utterance of the Church and for the validity of the other decisions. It also decides the doctrinal authority of the Fathers and theologians. It likewise concerned with the appeal to reason and history.

But as to the speculative part of theology, the fundamentals of the analogical method are explained by St. Thomas when he discusses the divine names; (110) for our knowledge of God and of the supernatural gifts is but analogical, derived by means of a comparison with things in nature.

Index Top


103. Com. in Boetium de Trinitate, q.2, a.3.

104. Com. in a.8, nos. 4 f.

105. Summa theol., Ia, q. 32, a.1; also Contra Gentes, Bk. I, chap. 8. Such is common teaching of the theologians. Thus Billuart (De Deo trino, dins. prooem, a.4) says: 'The possibility of the Trinity is not proved by a positive and evident argument, but by a negative and probable proof."

106. Com. in Iam, q.1, a. 12, nos. 5 f.

107. Rom. 12:1.

108. Com. in Iam, q. i, a.8, no. 8.

109. De locis theologicis, XI, 4.

110. Summa theol., Ia, q. 13.


"For what would it profit us to know the whole Bible by heart and the principles of all the philosophers if we live without grace and the love of God?"

Thomas Kempis

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"Lord, here burn, here cut, and dry up in me all that hinders me from going to You, that You may spare me in eternity."

St Louis Bertrand

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"The more you know and the better you understand, the more severely will you be judged, unless your life is also the more holy. Do not be proud, therefore, because of your learning or skill. Rather, fear because of the talent given you."

Thomas Kempis

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