Chapter III: Whence Morality Is Estimated, or On the Sources of Morality

Principle. Since by willing good or evil, and not otherwise, the will itself becomes good or evil, this also holds in the moral order: Acts are specified by the object. Therefore one source of morality can be spoken of, or that whence the moral quality of an act is discerned. But then object is taken in its full signification: it is whatever is proposed by the intellect to the will, or is set before it to be embraced or fled. In this signification it includes the end, the object taken more strictly, and the circumstances with which the object or act is clothed. And three sources of morality are customarily distinguished, about which we must now speak individually.

Nothing terminates the will more than the end, or the good on account of which the will acts. Wherefore the end is the principal source of morality. Yet because the object, even if it is chosen as a means, confers an immediate morality from which one cannot prescind - so that, if it is evil, it impedes the very morality which the action would borrow from a good end - and because in the object there is per se the notion of an intrinsic end, therefore, with St. Thomas, we shall speak first of the object, then of the end, then of the circumstances.