Chapter 53 [XXXI.]—Volition and Ability.
Some one will ask whether the faith itself, in which seems to be the beginning either of salvation, or of that series leading to salvation which I have just mentioned, is placed in our power. We shall see more easily, if we first examine with some care what “our power” means. Since, then, there are two things,—will and ability; it follows that not every one that has the will has therefore the ability also, nor has every one that possesses the ability the will also; for as we sometimes will what we cannot do, so also we sometimes can do what we do not will. From the words themselves when sufficiently considered, we shall detect, in the very ring of the terms, the derivation of volition from willingness, and of ability from ableness. 1005 Therefore, even as the man who wishes has volition, so also the man who can has ability. But in order that a thing may be done by ability, the volition must be present. For no man is usually said to do a thing with ability if he did it unwillingly. Although, at the same time, if we observe more precisely, even what a man is compelled to do unwillingly, he does, if he does it, by his volition; only he is said to be an unwilling agent, or to act against his will, because he would prefer some other thing. He is compelled, indeed, by some unfortunate influence, to do what he does under compulsion, wishing to escape it or to remove it out of his way. For if his volition be so strong that he prefers not doing this to not suffering that, then beyond doubt he resists the compelling influence, and does it not. And accordingly, if he does it, it is not with a full and free will, but yet it is not without will that he does it; and inasmuch as the volition is followed by its effect, we cannot say that he lacked the ability to do it. If, indeed, he willed to do it, yielding to compulsion, but could not, although we should allow that a coerced will was present, we should yet say that ability was absent. But when he did not do the thing because he was unwilling, then of course the ability was present, but the volition was absent, since he did it not, by his resistance to the compelling influence. Hence it is that even they who compel, or who persuade, are accustomed to say, Why don’t you do what you have in your ability, in order to avoid this evil? While they who are utterly unable to do what they are compelled to do, because they are supposed to be able usually answer by excusing themselves, and say, I would do it if it were in my ability. What then do we ask more, since we call that ability when to the volition is added the faculty of doing? Accordingly, every one is said to have that in his ability which he does if he likes, and does not if he dislikes.
[That is, in the Latin, “voluntas” (choice, will, volition) comes from velle (to wish, desire, determine), and “potestas” (power, ability) from “posse” (to be able).—W.]