The fundamental laws of sympathy are as follows: We are roused to imitate the feeling of another by the perception either of its signs (its natural consequences or its natural expression in visible and audible motions), or of its causes (the circumstances and experiences which occasion it), the latter exercising a more potent influence than the former. The wooden leg of the beggar is more effective in exciting our pity than his anxious air; the sight of dental instruments is more eloquent than the plaints of the sufferer from toothache. In order to be able to imitate vividly the feelings of a person, we must know the causes of them.--The feeling of the spectator is, on the average, less intense than that of the person observed, so long as the latter does not control and repress his emotions in view of the calmness of the former. The difference of intensity between the original and the sympathetic feelings differs widely with the various classes of emotions. It is difficult to take part in feelings which arise from bodily conditions, but easy to share those in the production of which the imagination is concerned--hence easier to share in hope and fear than in pleasure and pain.--We sympathize more readily with feelings which are agreeable to the observer, the observed, and other participants than with such as are not so; more willingly, therefore, with cheerfulness, love, benevolence than with grief, hatred, malevolence. This is not only true of temporary affections, but especially of those general dispositions which depend on a more or less happy situation in life; we sympathize more vividly with the fortunes of the rich and noble, because we consider them happier than the poor and lowly. Wealth and high rank are objects of general desire chiefly because their possessor enjoys the advantage of knowing that whatever gives him joy or sorrow always arouses similar feelings in countless other men. The 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.