510 SOCIAL DIFFERENTIATION past have quite generally been romanticized. Nationalistic history—the sort that is everywhere taught to school children—glorifies the nation's warriors and the wars that they have won. In this and in a variety of other ways, military values and an acceptance of war are perpetuated in latent form, to be aroused and focalized upon an enemy when war does occur. If the military tradition were not maintained as an integral part of modern societies, such normally peaceful nations as Britain, Russia, and the United States could not possibly have been able to defeat such clearly militant nations as Germany and Japan. As long as any one of the major nations of the world remains militant —and this probably means as long as there are nations—all the others must preserve their military traditions if they are to survive as politically inde- pendent units. Likewise, those peoples, such as the Chinese, who are by tradition nonmilitary must cultivate the military values and techniques if they are to become nations and remain independent. In the very long run, the pen—knowledge—may be mightier than the sword. But nations, like the individuals who compose them, live in and by the short run. The Predatory Ideal.—Neither nationalism nor the military tradition is of itself sufficient to account for the prevalence of war in the mod- ern world. Both are, in a sense, passive conditions that permit but do not of themselves promote the occurrence of war. The precipitation of war is traceable to another and equally complex cultural factor—the predatory ideal. As was mentioned earlier, under premodern conditions of life some societies were able to live by theft rather than by productive labor. To the members of these societies to rob, to plunder, and to con- quer were all in the day's work. In the Western world military predatism seems to have reached its highest development under the Romans. The heroes of Rome during the empire period were the military leaders who conquered and subjugated non-Roman peoples, from whom tribute could thereafter be extracted. Roman society was imbued with the idea that the way to wealth is via arms and that the greatest of men is he who leads his people to the conquering of other peoples. The predatory ideal was perpetuated in miniature through the feudal system; a superior lord was one who won wars with other lords, sacked their castles, and robbed them of their stores. The ideal was revived on a grand scale by Charlemagne, who apparently saw himself as a new- day version of the Roman Caesar. Since the time of Charlemagne there has been a succession of aspirants for the title of Caesar in western Eu- rope, and first this and then that people has become enamored of the idea of becoming the heart of a new and equally predatory empire. The Germans and Italians were only the latest of these. And in recent years the predatory ideal spread to, or was developed by, the Japanese in the Asiatic area.