Empirical principles are wholly incapable of serving as a foundation for moral laws. For the universality with which these should hold for all rational beings without distinction… is lost when their foundation is taken from the particular constitution of human nature, or accidental circumstances in which it is placed. The principle of private happiness, however, is the most objectionable, not merely because it is false, and experience contradicts the supposition that prosperity is always proportioned to good conduct… – [besides] it is quite a different thing to make a prosperous man and a good man, or to make one prudent and sharp-sighted for his own interests, and to make him virtuous – but because… they put the motives to virtue and to vice in the same class, and only teach us to become better calculators, the specific difference between virtue and vice being entirely extinguished. On the other hand, as to moral feeling, this supposed special sense, the appeal to it is superficial when those who cannot think believe that feeling will help them out, even in what concerns general laws: and besides, feelings which naturally differ infinitely in degree cannot furnish a uniform standard of good and evil, nor has anyone a right to form judgments for others by his own feelings; nevertheless this moral feeling is nearer to morality and its dignity in this respect, that it pays virtue the honor of ascribing to her immediately the satisfaction and esteem we have for her, and does not, as it were, tell her to her face that we are not attached to her by beauty but by profit.
-Second Section: Transition from Popular Moral Philosophy to the Metaphysic of Morals