This participation in the circumstances and feelings of others is a reciprocal phenomenon. The spectator takes pains to share the sentiments of the person observed; and the latter, on his part, endeavors to reduce the emotions which move him to a degree which will render participation in them possible for the former. In these reciprocal efforts we have the beginnings of the two classes of virtues--the gentle, amiable virtues of sympathy and sensibility, and the exalted, estimable virtues of self-denial and self-command. Both of these conditions of mind, however, are considered virtues only when they are manifested in unusual intensity: humanity is a remarkably delicate fellow-feeling, greatness of soul a rare degree of self-command. (The consideration for those about one which is ethically demanded is given, moreover, to a certain extent involuntarily. The man in trouble and the merry man alike restrain themselves in the company of persons who are indifferent, or in an opposite mood, while they give rein to their emotions when with those similarly affected. Joy is enhanced by sympathy, and grief mitigated.) Thus the perfection of human nature and the divinely willed harmony among the feelings of men are dependent on every man feeling little for himself and much for others; on his holding his selfish inclinations in check and giving free course to his benevolent ones. This is the injunction of Christianity as well as of nature. And as, on the one hand, the content of the moral law is thus deduced from sympathy, so, on the other, this yields the formal criterion of good: Look upon thy sentiments and actions in the light in which the impartial spectator would see them. Conscience is the spectator taken up into our own breast. It remains to consider the origin of this third, imperative stage.