At the same time there have been developing under the same three sanctions, restraints and incentives of another order, similarly characterized by subordination of the proximate to the remote. Joint aggressions upon men outside the society cannot prosper if there are many aggressions of man on man within the society. War implies co-operation; and co-operation is prevented by antagonisms among those who are to co-operate. We saw that in the primitive ungoverned group, the main check on immediate satisfaction of his desires by each man, is the fear of other men's vengeance if they are injured by taking the satisfaction; and through early stages of social development this dread of retaliation continues to be the chief motive to such forbearance as exists. But though long after political authority has become established the taking of personal satisfaction for injuries persists, the growth of political authority gradually checks it. The fact that success in war is endangered if his followers fight among themselves, forces itself on the attention of the ruler. He has a strong motive for restraining quarrels, and therefore for preventing the aggressions which cause quarrels; and as his power becomes greater he forbids the aggressions and inflicts punishments for disobedience. Presently, political restraints of this class, like those of the preceding class, are enforced by religious restraints. The sagacious chief, succeeding in war partly because he thus enforces order among his followers, leaves behind him a tradition of the commands he habitually gave. Dread of his ghost tends to produce regard for these commands; and they eventually acquire sacredness. With further social evolution come, in like manner, further interdicts, checking aggressions of less serious kinds; until eventually there grows up a body of civil laws. And then, in the way shown, arise beliefs concerning the divine disapproval of these minor, as well as of the major, civil offences: ending, occasionally, in a set of religious injunctions harmonizing with, and enforcing, the political injunctions; while simultaneously there develops, as before, a social sanction for these rules of internal conduct, strengthening the political and religious sanctions.