The idea of justice is different from the mere sentiment of justice; the former gradually arising from the latter, in the course of generations, by experience of the limits to which action can be carried without causing resentment from others. But since the kinds of activity are many and become increasingly various with the development of social life, it is a long time before the general nature of the limit common to all cases can be conceived. A further reason for the slowness of development is, that the arising ideas of justice have been perpetually confused by the conflicting requirements of internal amity and external enmity.
Two elements, a positive and a negative, constitute the idea of justice—that of man's recognition of his claims to unimpeded activities and the results they bring, and that of the limits which the presence of other men necessitate. The primordial ideal suggested is inequality, for since the principal is that each should receive the results due to his own nature, then, since men differ in their powers, unequal benefits are implied. But mutual limitations suggest a contrary idea, experience showing that the bounds to which one may pursue his own ends are, on the average, the same for all, so that the idea of equality arises. Unbalanced appreciations of these two factors in human justice lead to divergent moral and social theories.
Among the rudest men the appreciations are no higher than among inferior gregarious animals. Where war has developed political organization the idea of inequality predominates, but the idea is one, not of natural, but of artificial apportionment. And in general, we find that the primary or brute factor in justice is but little qualified by the human factor.
All movements are rhythmical, social movements included, and after the idea of justice in which inequality predominates comes a conception in which the idea of equality unduly predominates—as in Bentham's ethical theory, where "one person's happiness, supposed equal in degree (with proper allowance made for kind), is accounted for exactly as much as another's"; and this is the theory which Communism would reduce to practice. It is an absolute denial of the principle of inequality, and must apply alike to the worthy and unworthy, as well as to the superior and inferior in physical and intellectual capacities, since moral inequalities are as much inherited as others. Here we have a deliberate abolition of that cardinal distinction between the ethics of the family and the ethics of the state emphasized at the outset—"an abolition which, as we saw, must eventuate in decay and disappearance of the species or variety in which it takes place."
The true principle shows an amalgamation of these two. "The equality concerns the mutually limited spheres of action which must be maintained if associated men are to coöperate harmoniously. The inequality concerns the results which each may achieve by carrying on his actions within the implied limits. No incongruity exists when the ideas of equality and inequality are applied, the one to the bounds and the other to the benefits. Contrariwise, the two may be, and must be, simultaneously asserted."
"Any considerable acceptance of so definite an idea of justice is not to be expected. It is an idea appropriate to an ultimate state, and can be but partially entertained during transitional states; for the prevailing ideas must, on the average, be congruous with existing institutions and activities." During the thirty, or rather forty years' peace, and weakening of militant organization, the idea of justice became clearer; but since then the idea of regimentation has spread. It is predominant in the conception of socialism with its army of workers with appointed tasks and apportioned shares of products, and every act of Parliament which takes money from the individual for public purposes shows a tendency in the same direction. In the countries where militancy is most pronounced, socialism is most highly developed. "Sympathy, which, a generation ago, was taking the shape of justice, is relapsing into generosity; and the generosity is exercised by inflicting injustice. Daily legislation betrays little anxiety that each shall have that which belongs to him, but great anxiety that he shall have that which belongs to somebody else."
The formula of justice may be expressed thus: "Every man is free to do that which he wills, provided he infringes not the equal freedom of any other man."
This is not to be interpreted as meaning that aggression is permissible as long as retaliation is permitted; for the formula means that interference with another's life is limited, that life shall not be impeded in one case further than is necessary to the maintenance of other lives; it does not countenance a superfluous interference on the ground that an equal interference may balance it. In earlier stages, the conception of justice was this erroneous one of a balancing of injuries—an eye for an eye and a tooth for a tooth. By oscillations which become gradually less, social equilibrium is approached; and with this approach to equilibrium comes approach to a definite theory of equilibrium.