For the social system as a whole, the great thing is to achieve effectual team-work. It must inculcate discipline, loyalty, and industrial and social intelligence in the members, must embrace an adequate system of communication for organizing and developing the social mind, and also a body of special traditions and customs to meet the exigencies to which the tribe is liable. Stability is a prime necessity, and needs to be fortified by a conviction of the sanctity of what comes down from the past; and yet the system must not be so rigid as to be incapable of meeting new situations. The “folkways” must become such as assist, or at least do not greatly hinder, in the struggles of life. And of course the whole thing hangs together, individuals, family and social system being inseparable aspects of an integral whole. The ideas which make up the social order are impressed upon the member mainly by sheer suggestion; they form the environment in which he lives. In case of opposition, however, they must be reinforced by the pressure of public opinion, by emulation, praise and blame. _Mores_ are set up and the individual is made to feel that the great thing in life is to conform to them. Disloyalty to them is universally abhorred. Thus virtue is determined by what the mind of the group approves, which rests, in great part, upon what has been found to work in the struggles of the group, and especially in war. In these respects the requirements of primitive conflict were not essentially different from those of to-day. Life was simpler, cruder, and on a smaller scale, but the main elements were much the same—biological and social continuity, adaptive growth, individual exertion, and institutional discipline. There was no riot of irresponsible brute force, but then as now the man fit to survive was a moral man, a “good” man in his relation to the life of the group—devoted, law-abiding, and kindly, as well as strong and bold. The influence of group conflict, actual or anticipated, upon social development has continued in full vigor throughout history and down to the present time. The growth of states in size and internal structure, as civilization progresses, is natural on other grounds, but has been immensely stimulated and directed by military requirements. France, England, Germany—all the great modern nations, including the United States—were consolidated largely in this way. It is a commonplace of history. And the case is much the same with internal structure. On the continent of Europe, where war has always been imminent if not present, there are few institutions which do not bear its stamp. Even general education arose for its military value as much as for any other reason.