Article — Merkelbach, Summa Theologiae Moralis
Article III: On Faith Considered Relatively to the Intellectual Habits
St. Thomas, II-II, q. 4, a. 8; De Verit., q. 10, a. 12, ad 6; q. 14, a. 1, ad 7.
720. Notions concerning certitude. - Faith is compared with the intellectual habits under the respect of certitude. To understand this, it is fitting to recall that certitude properly so called or speculative is the determination of the intellect to one thing, or firm adherence of the mind to the object without fear of erring. Hence it includes a twofold element: one negative, namely, exclusion of actual doubt; the other positive, namely, firm adherence of the mind; and therefore certitude can be considered under a twofold respect: 1. negatively, insofar as it excludes all doubt or fear, and thus it does not admit degrees but consists in an indivisible; 2. positively, insofar as it adheres firmly to something, and thus it admits degrees and is greater or lesser. This happens in a twofold mode:
a) Simply and as to itself, on the part of the cause and motive, that is more certain which has a more certain cause or motive, to which error is more repugnant; whence the intellect adheres to it more firmly estimatively.
According to the diverse motive, natural certitude is metaphysical, physical, or moral. The first rests upon the essential or metaphysical necessity of things known from their very essences. The second rests upon their natural necessity known from induction, by which, when the same cause (antecedent) is posited even in various circumstances, always or almost always and for the most part the same effect (consequent) recurs, which could not be unless there were a natural property and law according to which that cause constantly tends to this effect and also, unless impeded from elsewhere, will certainly produce it, for example, the sun rises in the morning, from hydrogen and oxygen water is made, mothers love sons. The third rests upon the testimony of other men, which from a quasi-moral induction is demonstrated true, because so many and such great concordant testimonies, diverse from one another and independent, have been given in such various circumstances, that the concord could not be explained except by the truth of the thing asserted, for example, the existence of Julius Caesar, Napoleon, William II, of Rome.
Moreover metaphysical certitude is greater than physical, and this greater than moral, because error is more repugnant to the essence of things than to their natural inclination, and to this than to human testimony.
b) Also according to a certain respect and as to us, that is, on the part of the subject, that is more certain which the intellect attains more fully because it is manifested more clearly to it, and consequently that which more satisfies and quiets the intellect and to which it adheres more firmly intensively without any possibility of doubting. In this mode evident or intrinsic certitude, which necessitates the intellect, is greater than non-evident and extrinsic certitude, which does not necessitate but is sought from the authority of others.
Besides, there is had certitude improperly so called, prudential or practical, which excludes not every speculative doubt, but every reasonable and prudent fear of erring. This is not strict certitude because it does not exclude every fear, but is the greatest probability which is equivalent to certitude, because it suffices for acting rightly and prudently; whence it renders us rather morally, that is, almost and equivalently certain, than being true moral certitude. Such among many is the knowledge of metaphysical and essential moral truths which they admit without full evidence of them; likewise often experimental certitude; especially human faith, which does not seem easily able to rise to strict certitude.
a) But it is more certain simply and as to itself, that is, on the part of the cause and motive: for in this mode faith is even more certain than metaphysical certitude, because it is more repugnant to admit the false on account of the truth of God by the light of divine grace than on account of any other motive whatever, even on account of the evidence in every way of the natural light of our reason. Wherefore we adhere more and more firmly to the truths of faith than to others, because the will in faith moves the intellect to an adherence estimatively firmer, before every other natural knowledge; whence man is prepared to deny, so far as is possible for him, all those things which would contradict revealed truths (I John V, 9; Pius IX, encyclical, November 9, 1846: nothing more certain).
b) Nevertheless it is not more certain according to a certain respect, namely, as to us, that is, on the part of the subject, of the man believing: for in this mode faith, because it does not exclude involuntary doubt, is less certain than fully evident assent, which excludes every possible doubt. Yet this is per accidens as to the motive of faith, which in itself has sufficient power of altogether confirming the intellect, and it comes from our imperfect mode of conceiving it, and therefore faith is more certain simply.
Certitude on the part of the motive is called by theologians certitude of infallibility; certitude on our part, certitude of indubitability.
The certitude of faith is proclaimed in the Scriptures:
a) firm adherence is required (Acts II, 36; VIII, 37; Rom. IV, 3-10, 21-25; Heb. X, 22; Gal. I, 8);
b) all doubt is reproved (Mk. XVI, 14; Luke XXIV, 25);
c) the reason is indicated why adherence must be firm (Acts I, 16 sq.; Heb. X, 19 to the end of the epistle; Gal. I, 8, 11; I John V, 9);
d) whence those things to which human reason seems repugnant are said to be humbly admitted (Heb. XI, 1; II Tim. I, 12), and in the Athanasian symbol it is read: This is the Catholic faith, which unless each one shall have believed firmly...
722. Observations. - 1. The certitude of faith is greater on the part of the motive than the certitude of the judgment and motives of credibility; in this sense proposition 19 was condemned by Innocent XI: "The will cannot effect that the assent of faith in itself be firmer than the weight of reasons impelling to the assent of faith deserves," that is, of the preambles on account of which we judge that one must believe, or of the motives thus remotely disposing to faith.
- Since the conclusion is not more certain than the premises, it follows in the opinion of Lugo, who says that the act of faith is a ratiocination, that it cannot be explained that faith is more certain than rational knowledge; indeed, since he says (in the minor of the syllogism) that revelation is only practically certain, it would follow that faith has only practical and improperly so called certitude.
- Certain theologians falsely contend that divine grace partially supplies the defect of certitude on the part of the motive, and causes an adherence firmer than the proximate motive of adherence on account of which we adhere and believe demands: for the will cannot reasonably command an adherence firmer than the motive of adherence deserves. Yet grace can illuminate the intellect so that it may more clearly and better perceive the motives of faith and credibility, even those which otherwise it would not perceive; indeed exceptionally it can internally manifest to someone a new and special motive of credibility.1
1 Concerning this De Poulpiquet, Le Miracle et ses suppleances, deserves to be inspected.