After the inquiry concerning the nature of virtue, the next question of importance in Moral Philosophy, is concerning the principle of approbation, concerning the power or faculty of the mind which renders certain characters agreeable or disagreeable to us, makes us prefer one tenour of conduct to another, denominate the one right and the other wrong, and consider the one as the object of approbation, honour, and reward; the other as that of blame, censure, and punishment.

Three different accounts have been given of this principle of approbation. According to some, we approve and disapprove both of our own actions and of those of others, from self-love only, or from some view of their tendency to our own happiness or disadvantage: according to others, reason, the same faculty by which we distinguish between truth and falsehood, enables us to distinguish between what is fit and unfit both in actions and affections: accorDing to others this distinction is altogether the effect of immediate sentiment and feeling, and arises from the satisfaction or disgust with which the view of certain actions or affections inspires us. Self-love, reason, and sentiment, therefore, are the three different sources which have been assigned for the principle of approbation.

Before I proceed to give an account of those different systems, I must observe, that the determination of this second question, though of the greatest importance in speculation, is of none in practice. The question concerning the nature of virtue necessarily has some influence upon our notions of right and wrong in many particular cases. That concerning the principle of approbation can possibly have no such effect. To examine from what contrivance or mechanism within, those different notions or sentiments arise, is a mere matter of philosophical curiosity.