12. The idea of justice demands that the pupil abstain from contention. It demands, furthermore, reflection on strife, so that respect for justice may strike deep root. No idea appeals more strongly to the unperverted youthful mind than that of justice or fair play; even the gentlest natures become indignant at manifestations of injustice. The basis of the idea is, in the thought of our author, our natural displeasure in contention over that which, in the nature of the case, only one person can have. Primarily, it concerns property rights, but secondarily it may extend to other relations in which two or more wills are at issue. Justice in the acquisition, possession, and disposition of wealth is the theme of the greater part of every judicial system. The idea of justice is the second of the three concrete moral virtues necessary for civilized society. 13. The idea of equity is especially involved in cases where the pupil has merited punishment as requital for the intentional infliction of pain. Here the degree of punishment must be carefully ascertained and acknowledged as just. =Note.=--This kind of punishment should not be confounded with educative punishment--so called, _i.e._, punishment through natural consequences. The third concrete moral idea is that of _equity_, or _requital_. It arises when existing will-relations are altered either for good or bad. The natural demand is that the requital shall be adequate to the deed. Lack of requital for good deeds we call ingratitude, one of the most hateful of human failings. In savagery and barbarism private vengeance is the normal method of requiting injuries. Remnants of this system still exist in the duel, and in the fierce vendettas of some sparsely settled regions. Civilization demands that requital for evil deeds shall be remanded to the executors of established law. Only in this way is society saved from destructive broils. In this respect, as in so many others, the school is the miniature of the institutional world. The teacher is, to a considerable extent, lawgiver, judge, and executive. Not a small part of his moral influence upon his pupils depends upon the justice of his requitals for violated law. Good-will, justice or rights, and requital are the three fundamental concrete moral ideas upon which sound character, both individual and national, is based. The remaining two are that of inner freedom and that of efficiency. Though formal in character, _i.e._, devoid of positive content, they are equally important with the more concrete conceptions. 14. Where a number of pupils are assembled there arises, naturally, on a small scale, a system of laws and rewards. This system, and the demands which in the world at large spring from the same ideas, must be brought into accord.