We proceed to the second article thus:

1. It seems that faith is not in the intellect as its subject. For Augustine says (implicitly in De Praed. Sanct.5): "faith depends on the will of those who believe." But the will is a power distinct from the intellect. It follows that faith is not in the intellect as its subject.

2. Again, assent to matters of faith is the outcome of a will obedient to God. Hence the praiseworthiness of faith seems to lie entirely in obedience. Now obedience is in the will. It follows that faith also is in the will, not in the intellect.

3. Again, the intellect is either speculative or practical. Now faith is not in the speculative intellect. For faith "worketh by love" (Gal.5:6), whereas the speculative intellect is not a principle of action, since it has nothing to say about what we ought to shun or avoid, as is said in 3 De Anima, texts 34, 35. Yet neither is it in the practical intellect, the object of which is some contingent truth about something which can be made or done, whereas the object of faith is eternal truth, as was explained in Q.1, Art.1. It follows that faith is not in the intellect as its subject.

On the other hand: faith is succeeded in heaven by vision, according to I Cor.13:12: "Now we see through a glass, darkly; but then face to face." Now vision is in the intellect. So also, therefore, is faith.

I answer: since faith is a virtue, the act of faith must be perfect. Now the perfection of an act which springs from two active principles requires the perfection of both these principles. For one cannot saw well unless one knows the art of sawing, and unless the saw is also well adapted for sawing. Further, when a disposition to act well exists in powers of the soul which tend to do the opposite, such a disposition is a habit, as we explained in 12ae, Q.49, Art.4, ad, 1, 2, and 3. An act which springs from two such powers can be perfect, therefore, only if such a habit already exists in both of them. Now to believe is an act of the intellect as moved to assent by the will, as we said in Q.2, Arts.1 and 2. Thus the act of belief springs both from the intellect and from the will, and each of these two powers is such that it is perfected by means of some habit, as we have explained. [57] Hence if the act of faith is to be perfect, there must be a habit in the will as well as in the intellect; just as there must be a habit of prudence in the reason, and also a habit of temperance in the faculty of desire, if an act of desire is to be perfect. Nevertheless, the act of belief is immediately an act of the intellect, since the object of belief is "the true," which properly pertains to the intellect. Faith must therefore be in the intellect as its subject, since it is the proper principle of the act of belief.

On the first point: by faith Augustine means the act of faith, which is said to depend on the will of believers in as much as the intellect assents to matters of faith by command of the will.

On the second point: not only must the will be ready to obey, but the intellect must also be disposed to follow the command of the will, just as desire must be well disposed to follow the direction of reason. There must therefore be a habit in the intellect which assents, as well as in the will which commands the intellect.

On the third point: it is quite clear from the object of faith that faith is in the intellect as its subject. Yet since the first truth, which is the object of faith, is the end of all our desires and actions (as Augustine explains in 1 De Trin.8), faith works by love, just as "the speculative intellect becomes practical by extension," as it is said in 3 De Anima, text 49.

[57] 12ae, Q. 49. A habit is necessary whenever a power, in spite of possessing its form to the full, may tend to diverse objects, such as good and evil.