Next there is the power to balance pleasure and pain, and estimate the compound result, both in reference to self and to the commonwealth. With this is combined the feeling that whatever secures _the most_ good with _the least_ evil is right and fit, and that the opposite is wrong and unfitted to the nature of things. Next comes the _sense of justice_, which results in an impulse _to discover the cause_ of good and evil, and when this cause is found to be a voluntary agent, a consequent impulse to make returns of good for good, and of evil for evil, and also to _proportion_ retributive rewards or penalties to the amount of good or evil done. With this, also, is combined the feeling that those retributions should be applied only where there was _voluntary_ power to have done otherwise. When it is seen that there was no such power, the impulse to reward or punish is repressed. Such is the deep conviction that such retributions are indispensable, that where natural pains and penalties do not avail, others are demanded, both in the family and in the commonwealth. Lastly, we find the susceptibility of _conscience_, which, by the very framework of the mind itself, apportions the retributive pangs of remorse for wrong doing, and the pleasure of self-approval for well doing. These, too, are retributions never to be escaped, and the most exquisite, both in elevated happiness and exquisite pain. The mind carries about in itself its own certain and gracious remunerator--its own inexorable prosecutor, judge, and executioner. This same design of the Creator may be most delightfully traced in what may be called the _economy_ of happiness and pain. One particular of this is set forth at large in the chapter on the _emotions of taste_. Here we find the mind formed not only to secure multitudinous enjoyments through the nerves of sensation, but that, by the principle of association, there is a perpetual _reproduction_ of these emotions in connection with the colors, forms, sounds, and motions with which they were originally associated. Thus there are perpetually returning emotions of pleasure so recondite, so refined, so almost infinite in variety and extent, and yet how little noticed or understood! Another indication of the same kind is the peculiarity pointed out on former pages, where it is shown that securing certain enjoyments which tend to promote the _general_ happiness increases both desire and capacity for enjoyment, while those that terminate in the individual diminish by possession. Thus the enjoyment of power, which must, from its nature, be confined to a few, diminishes by possession. Thus, too, the pleasures of sense pall by indulgence. But the enjoyment resulting from the exercise and reciprocation of love, and that resulting from benevolent actions, and that which is included in a course of perfect obedience to all the rules of rectitude, increases the capacity for enjoyment.