Summa summae S. Thomae, Tomus III

You will ask 1° whether faith is rightly defined by the Apostle, Hebr. XI, 1: the substance of things to be hoped for, the proof of things that appear not.

I answer. ¹ this definition, although the words are not arranged under the form of a definition, is legitimate, because it contains all that pertains to the definition of faith, as will appear from the following explanation.

It is called substance, in Greek hypostasis or subsistence: partly because faith is the beginning, basis and foundation of our hope; for substance is the substratum of all qualities: partly because it makes the things to be hoped for subsist in our intellect, and makes us assent to them as certainly as if they were present.

It is called the proof of things that appear not, taking proof for its effect, or, as another reading has it, conviction; for just as an argument leads the intellect to adhere to some truth, so through faith the intellect firmly adheres to truths that appear not, on account of the authority of God revealing.

It is called, of things that appear not: both because the object of faith is unseen; and to signify that more things pertain to faith than are hoped for, such as past goods and evils to come upon sinners, e. g., hell.

By this definition faith is distinguished from all other intellectual habits. By the phrase, substance of things to be hoped for, it is distinguished from human faith, by which one is not ordered to the happiness hoped for. By τῷ proof, it is distinguished from opinion, suspicion and doubt. By τῷ of things that appear not, it is distinguished from science and the understanding of first principles.

If therefore anyone wishes to reduce these words into the form of a definition, he may say ² that faith is « a habit of the mind whereby eternal life begins in us, making the intellect assent firmly to things that appear not, on account of the authority of God revealing. » And this definition coincides with that other one commonly current: « A virtue infused by God, whereby the intellect firmly assents to those things that have been revealed by God, on account of the authority of him who reveals them. »

[You will ask 2° whether unformed faith is a virtue,

It must be noted that the ultimate form of faith, as of the other virtues, is charity. But charity is not the intrinsic and essential form of faith ³, but is its extrinsic and accidental form, insofar as through charity faith, like all the other virtues, is ordered to the supernatural last end, and thus from charity it has it that its act is perfect and meritorious. This granted,

I answer. Faith is of itself a true virtue, but imperfect.

Proof. of the first part. 1° Because it is the principle of a good act determining the intellect to assent to revealed truths. Hence, although it does not make its possessor good simply, in the moral order, which belongs to a perfect virtue, it nevertheless makes him good in its own order, namely the intellective. 2° Because the definition of virtue applies to it. For it is a good quality of the mind whereby one lives well, namely the principle of a good act, and which no one uses as a bad principle. 3° It is the same habit as formed faith; for charity does not create this habit, but perfects it only extrinsically and accidentally. 4° Precepts are given only concerning acts of virtues. But a precept is given concerning the act of unformed faith, as appears in Hebr., XI, 6: He that cometh to God must believe that he is, and is a rewarder to them that seek him. Moreover, he who comes to God is not yet perfectly united to him; which union takes place only through charity. Therefore.

Proof. of the second part ⁴; because unformed faith does not make a man good simply. For although it is the principle of a good act, yet this act is not meritorious in order to the last end, namely eternal life, and thus faith does not have the state and mode of a perfect virtue.]

You will ask 3° whether faith is more certain than all natural cognitions.

I answer. Faith is more certain, in itself, than all natural cognitions, but not as regards us.

Proof. of the first part ⁵, Faith has its certitude from the divine truth, which cannot be deceived, and which is applied with certainty to the revealed truths through the infallible Church. Natural cognitions, however, have their certitude from the natural light of reason, which, although the object about which it deals is sometimes certain, is nevertheless enveloped in darkness through sin and liable to error, nor is it certain that it is applied rightly to the things apprehended. Therefore.

Proof. of the second part ⁶, That is said to be more certain as regards us which the intellect attains more fully, which is more connatural and proportionate to it, and which satisfies and quiets it more, although it assents to it less certainly from elsewhere. Now natural cognitions are more connatural and proportionate to the human intellect, are penetrated more deeply by it, satisfy and quiet it more on account of the evidence of things, in which the human intellect ultimately rests, than does faith, which is concerned with obscure and unevident things: hence it happens that, although it is most certain on the side of the motive, it nevertheless suffers, on the side of the subject, certain undeliberated movements of doubt, on account of the weakness of a mind not yet seeing the truth. Therefore.

You will ask 4° whether faith is discursive.

I answer. negatively; because, as by the same vision we see color and light, so by the same act we assent to the thing revealed and to the revelation; for the object of faith is the thing revealed, not materially, but formally as revealed. In a discursive process, however, the assent to the principles is really distinguished from the assent to the conclusion.

[You will ask 5° whether faith is free.

I answer. affirmatively, from the Vatican Council defining thus: « If anyone shall say that the assent of Christian faith is not free, but is necessarily produced by arguments of human reason; or that the grace of God is necessary for faith alone living, which works through charity; let him be anathema. »]