Book 2: Moral Virtue.
Chapter 5: Virtue not an emotion, nor a faculty, but a trained faculty or habit.
We have next to inquire what excellence or virtue is.
A quality of the soul is either (1) a passion or emotion, or (2) a power or faculty, or (3) a habit or trained faculty; and so virtue must be one of these three. By (1) a passion or emotion we mean appetite, anger, fear, confidence, envy, joy, love, hate, longing, emulation, pity, or generally that which is accompanied by pleasure or pain; (2) a power or faculty is that in respect of which we are said to be capable of being affected in any of these ways, as, for instance, that in respect of which we are able to be angered or pained or to pity; and (3) a habit or trained faculty is that in respect of which we are well or ill regulated or disposed in the matter of our affections; as, for instance, in the matter of being angered, we are ill regulated if we are too violent or too slack, but if we are moderate in our anger we are well regulated. And so with the rest.
Now, the virtues are not emotions, nor are the vices—(1) because we are not called good or bad in respect of our emotions, but are called so in respect of our virtues or vices; (2) because we are neither praised nor blamed in respect of our emotions (a man is not praised for being afraid or angry, nor blamed for being angry simply, but for being angry in a particular way), but we are praised or blamed in respect of our virtues or vices; (3) because we may be angered or frightened without deliberate choice, but the virtues are a kind of deliberate choice, or at least are impossible without it; and (4) because in respect of our emotions we are said to be moved, but in respect of our virtues and vices we are not said to be moved, but to be regulated or disposed in this way or in that.
For these same reasons also they are not powers or faculties; for we are not called either good or bad for being merely capable of emotion, nor are we either praised or blamed for this. And further, while nature gives us our powers or faculties, she does not make us either good or bad. (This point, however, we have already treated.)
If, then, the virtues be neither emotions nor faculties, it only remains for them to be habits or trained faculties.