root of all ambition is the wish to rule over the hearts of our fellows by compelling them to make our feelings their own; the central nerve of all happiness consists in seeing our own sensations shared by those about us and reflected back, as it were, from manifold mirrors.  Small annoyances often have a diverting effect on the spectator; great success easily excites his envy; great sorrows and minor joys, on the contrary, are always sure of our sympathy.  Hence the morose man, to whom everything is an occasion of ill-humor, is nowhere welcome, and the man of cheerful disposition, who rejoices in each little event and whose good spirits are contagious, everywhere.

Not less admirable than the fine gift of observation which guides Smith in his discovery of the primary manifestations and the laws of sympathy is the skill with which he deduces moral phenomena, from the simplest to the most complex—­moral judgment, the moral law, its application to one’s own conduct, the conscience—­from the interchange of sympathetic feelings.  From involuntary comparison of the representative feeling of the spectator with its original in the person observed arises an agreeable or disagreeable feeling of judgment, a judgment of value, approbating or rejecting the latter.  This is approving when the intensity of the original harmonizes with that of the copy, disapproving when the former exceeds or fails to attain the latter.  In the one case the emotion is judged suitable to the object which causes it; in the other, too violent or too weak.  It is always a certain mean of passion which, as “proper,” receives approval (esteem, love, or admiration).  In the case of the social passions excess is more readily condoned, in the case of the unsocial and selfish ones, defect; hence we judge the over-sensitive more leniently than the over-vengeful.  Anger must be well-grounded and must express itself with great moderation to arouse in the spectator a like degree of sympathetic resentment.  For here the sympathy of the spectator is divided between two parties, and fellow-feeling with the angry one is weakened by fear for the person menaced by him, whereas, in the case of kind affections, sympathy is increased by doubling.  While our judgment of propriety or decorum rests on simple participation in the sentiments of the agent, our judgment of merit and demerit is based, in addition, on sympathy with the feelings of gratitude or resentment experienced by the person on whom the action terminates.  An act is meritorious if it appears to us to deserve thanks and reward, ill-deserving if it seems to merit resentment and punishment.  Nature has inscribed on the heart, apart from all reflection on the utility of punishment, an independent, immediate, and instinctive approbation of the sacred law of retribution.  This is the point at which a hitherto purely contemplative sympathy passes over into an active impulse, which prepares us to support the victim of attack and insult in his defense and revenge.