Objection 3: Further, all things knowable scientifically [*Science is certain knowledge of a demonstrated conclusion through its demonstration] would seem to come under one head: so that if some of them are proposed to man as objects of faith, in like manner the others should also be believed. But this is not true. Therefore it is not necessary to believe those things which can be proved by natural reason.
On the contrary, It is necessary to believe that God is one and incorporeal: which things philosophers prove by natural reason.
I answer that, It is necessary for man to accept by faith not only things which are above reason, but also those which can be known by reason: and this for three motives. First, in order that man may arrive more quickly at the knowledge of Divine truth. Because the science to whose province it belongs to prove the existence of God, is the last of all to offer itself to human research, since it presupposes many other sciences: so that it would not by until late in life that man would arrive at the knowledge of God. The second reason is, in order that the knowledge of God may be more general. For many are unable to make progress in the study of science, either through dullness of mind, or through having a number of occupations, and temporal needs, or even through laziness in learning, all of whom would be altogether deprived of
the knowledge of God, unless Divine things were brought to their knowledge under the guise of faith. The third reason is for the sake of certitude. For human reason is very deficient in things concerning God. A sign of this is that philosophers in their researches, by natural investigation, into human affairs, have fallen into many errors, and have disagreed among themselves. And consequently, in order that men might have knowledge of God, free of doubt and uncertainty, it was necessary for Divine matters to be delivered to them by way of faith, being told to them, as it were, by God Himself Who cannot lie.
Reply to Objection 1: The researches of natural reason do not suffice mankind for the knowledge of Divine matters, even of those that can be proved by reason: and so it is not superfluous if these others be believed.
Reply to Objection 2: Science and faith cannot be in the same subject and about the same object: but what is an object of science for one, can be an object of faith for another, as stated above (Q[1], A[5]).
Reply to Objection 3: Although all things that can be known by science are of one common scientific aspect, they do not all alike lead man to beatitude: hence they are not all equally proposed to our belief.
Whether man is bound to believe anything explicitly?
Objection 1: It would seem that man is not bound to believe anything explicitly. For no man is bound to do what is not in his power. Now it is not in man's power to believe a thing explicitly, for it is written ( Rom. 10:14 , 15 ): "How shall they believe Him, of whom they have not heard? And how shall they hear without a preacher? And how shall they preach unless they be sent?" Therefore man is not bound to believe anything explicitly.
Objection 2: Further, just as we are directed to God by faith, so are we by charity. Now man is not bound to keep the precepts of charity, and it is enough if he be ready to fulfil them: as is evidenced by the precept of Our Lord ( Mat. 5:39 ): "If one strike thee on one [Vulg.: 'thy right'] cheek, turn to him also the other"; and by others of the same kind, according to Augustine's exposition (De Serm. Dom. in Monte xix). Therefore neither is man bound to believe anything explicitly, and it is enough if he be ready to believe whatever God proposes to be believed.
Objection 3: Further, the good of faith consists in obedience, according to Rom. 1:5 : "For obedience to the faith in all nations." Now the virtue of obedience does not require man to keep certain fixed precepts, but it is enough that his mind be ready to obey, according to Ps. 118:60 : "I am ready and am not troubled; that I may keep Thy commandments." Therefore it seems enough for faith, too, that man should be ready to believe whatever God may propose, without his believing anything explicitly.
On the contrary, It is written ( Heb. 11:6 ): "He that cometh to God, must believe that He is, and is a rewarder to them that seek Him."
I answer that, The precepts of the Law, which man is bound to fulfil, concern acts of virtue which are the means of attaining salvation. Now an act of virtue, as stated above (FS, Q[60], A[5]) depends on the relation of the habit to its object. Again two things may be considered in the object of any virtue; namely, that which is the proper and direct object of that virtue, and that which is accidental and consequent to the object properly so called. Thus it belongs properly and directly to the object of fortitude, to face the dangers of death, and to charge at the foe with danger to oneself, for the sake of the common good: yet that, in a just war, a man be armed, or strike another with his sword, and so forth, is reduced to the object of fortitude, but indirectly.
Accordingly, just as a virtuous act is required for the fulfilment of a precept, so is it necessary that the virtuous act should terminate in its proper and direct object: but, on the other hand, the fulfilment of the precept does not require that a virtuous act should terminate in those things which have an accidental or secondary relation to the proper and direct object of that virtue, except in certain places and at certain times. We must, therefore, say that the direct object of faith is that whereby man is made one of the Blessed, as stated above (Q[1], A[8]): while the indirect and secondary object comprises all things delivered by God to us in Holy Writ, for instance that Abraham had two sons, that David was the son of Jesse, and so forth.
Therefore, as regards the primary points or articles of faith, man is bound to believe them, just as he is bound to have faith; but as to other points of faith, man is not bound to believe them explicitly, but only implicitly, or to be ready to believe them, in so far as he is prepared to believe whatever is contained in the Divine Scriptures. Then alone is he bound to believe such things explicitly, when it is clear to him that they are contained in the doctrine of faith.
Reply to Objection 1: If we understand those things alone to be in a man's power, which we can do without the help of grace, then we are bound to do many things which we cannot do without the aid of healing grace, such as to love God and our neighbor, and likewise to believe the articles of faith. But with the help of grace we can do this, for this help "to whomsoever it is given from above it is mercifully given; and from whom it is withheld it is justly withheld, as a punishment of a previous, or at least of original, sin," as Augustine states (De Corr. et Grat. v, vi [*Cf. Ep. cxc; De Praed. Sanct. viii.]).
Reply to Objection 2: Man is bound to love definitely those lovable things which are properly and directly the objects of charity, namely, God and our neighbor. The objection refers to those precepts of charity which belong, as a consequence, to the objects of charity.
Reply to Objection 3: The virtue of obedience is seated, properly speaking, in the will; hence promptness of the will subject to authority, suffices for the act of obedience, because it is the proper and direct object of obedience. But this or that precept is accidental or consequent to that proper and direct object.
Whether all are equally bound to have explicit faith?
Objection 1: It would seem that all are equally bound to have explicit faith. For all are bound to those things which are necessary for salvation, as is evidenced by the precepts of charity. Now it is necessary for salvation that certain things should be believed explicitly. Therefore all are equally bound to have explicit faith.
Objection 2: Further, no one should be put to test in matters that he is not bound to believe. But simple reasons are sometimes tested in reference to the slightest articles of faith. Therefore all are bound to believe everything explicitly.
Objection 3: Further, if the simple are bound to have, not explicit but only implicit faith, their faith must needs be implied in the faith of the learned. But this seems unsafe, since it is possible for the learned to err. Therefore it seems that the simple should also have explicit faith; so that all are, therefore, equally bound to have explicit faith.
On the contrary, It is written ( Job 1:14 ): "The oxen were ploughing, and the asses feeding beside them," because, as Gregory expounds this passage (Moral. ii, 17), the simple, who are signified by the asses, ought, in matters of faith, to stay by the learned, who are denoted by the oxen.
I answer that, The unfolding of matters of faith is the result of Divine revelation: for matters of faith surpass natural reason. Now Divine revelation reaches those of lower degree through those who are over them, in a certain order; to men, for instance, through the angels, and to the lower angels through the higher, as Dionysius explains (Coel. Hier. iv, vii). In like manner therefore the unfolding of faith must needs reach men of lower degree through those of higher degree. Consequently, just as the higher angels, who enlighten those who are below them, have a fuller knowledge of Divine things than the lower angels, as Dionysius states (Coel. Hier. xii), so too, men of higher degree, whose business it is to teach others, are under obligation to have fuller knowledge of matters of faith, and to believe them more explicitly.
Reply to Objection 1: The unfolding of the articles of faith is not equally necessary for the salvation of all, since those of higher degree, whose duty it is to teach others, are bound to believe explicitly more things than others are.