Four things must be considered here concerning faith...
First, what faith is. For it involves willed assent, with certitude, to that which is not seen: because, as Augustine says, no one believes unless he is willing. According to this definition a believer differs from a doubter, who assents to neither side; he also differs from one holding an opinion, who assents to one side not with certitude but with fear concerning the other side; he differs also from one who knows scientifically, who through certitude assents by the necessity of reason. Accordingly, faith is midway between scientific knowledge and opinion.
The second consideration is whether faith is a virtue. Clearly it is not, if faith is taken for that which is believed, as in the statement: “This is the Catholic faith, that we venerate one God in Trinity.” But if it is taken for the habit by which we believe, then sometimes it is a virtue and sometimes not.
For a virtue is a principle of a perfect act. But an act depending on two principles cannot be perfect, if either of the principles lacks its perfection, just as riding cannot be perfect, if the horse does not run well or the rider does not know how to guide the horse. Now the act of faith, which is to believe, depends on the intellect and on the will moving the intellect to assent. Hence, the act of faith will be perfect, if the will is perfected by the habit of charity and the intellect by the habit of faith, but not if the habit of charity is lacking. Consequently, faith formed by charity is a virtue; but not unformed faith.
The third point to be considered is that the same numerical habit of faith which was not formed by charity becomes a virtue with the advent of charity, because, since charity is outside the essence of faith, the substance of faith is not changed by the coming or going of charity.
Fourthly, we must consider that just as the body lives its natural life through the soul, so the soul lives the life of grace through God. First of all, God dwells in the soul through faith: “That Christ may dwell in your hearts through faith” (Eph 3:17); but this indwelling is not perfect, unless faith is formed by charity, which by the bond of perfection unites us to God, as Col 3(:14) says. Consequently, the phrase, lives by faith, must be understood of formed faith.
Sunday, March 7, 2010
St. Thomas Aquinas' Lectures on the Book of Romans
Translated by Fabian Larcher, you can get it online here. Here is an excerpt;