But, in the experience of infancy and childhood, the _law of sacrifice_ is speedily developed. It is perceived that much of the good to be gained, if sought to excess, occasions pain, so that there must be a certain amount of self-denial practiced, which, to the young novice, sometimes involves disappointment and discomfort. It is also seen that frequently two or more enjoyments are offered which are incompatible, so that one must be relinquished to gain the other. It is perceived, also, that there is a constant calculation going on as to which will be the _best_--that is, which will secure _the most good with the least evil_. And the child is constantly instructed that it must avoid excess, and must give up what is of less value to secure the greater good. All this training involves _sacrifices_ which are more or less painful, so that a young child will sometimes cry as it voluntarily gives up one kind of pleasure as the only mode of securing what is preferred. It is perceived, also, that there is a constant _balancing_ of good and evil, so that a given amount of enjoyment cancels or repays for a certain amount of evil. When a great amount of enjoyment is purchased by a small degree of labor or trouble, the _compound result_ is deemed a good, and called right; on the contrary, when the evil involved exceeds a given amount in comparison to the good, the compound result is called evil and wrong. Thus is generated the impression that there is a law of sacrifice instituted requiring the greatest possible good with the least possible evil, and that this is the great design of all things. The impression is, not merely that we are to seek enjoyment and avoid pain, but that we are to seek the _greatest possible_ good with the _least possible_ evil, and that in doing this we are to obey the law of sacrifice and suffering, by which the greatest possible good _is to be bought_ by a certain amount of evil _voluntarily_ assumed. In regard to this great law of sacrifice, the highest part of it is discerned in the earliest experiences of life. The young child very soon perceives that its mother and its other friends are constantly making sacrifices for its own good, and bearing inconveniences and trouble for the good of those around. And those who perform such acts of benevolent self-sacrifice are praised, and their conduct is called good and right. _Voluntary suffering to promote the welfare of others_ is discerned to be the highest kind of good and right conduct in the estimation of all. The first feature, then, in our moral nature is that _impression of the great design of our Creator_ which furnishes us the means of deciding on the rectitude of all voluntary action. The second feature of our moral constitution is what is ordinarily called the _sense of justice_. It is that susceptibility which is excited at the view of the conduct of others as _voluntary_ causes of good or evil.