the craving for visible empire, and also a longing that is deep and intense because tradition and romance are deeply embedded in it. Probably no one now believes that war among modern nations is due to a pure predatory instinct or to a migratory instinct which is supposed to have led primitive hordes to seek new habitats and to prey upon other peoples. Hunger does not now drive people in companies from their homes and pour them into other lands, although it is true that any threat which excites the old hunger-fear tends to arouse the war spirit and to stir the migratory impulse; and a deep sensitiveness to climatic conditions and a claustrophobia of peoples have remained long after the need of land urged as the main cause of war, and we hear war justified on the ground that crowded peoples require more land. This _land hunger_ is an old motive and it still remains deep in the consciousness of peoples long after its economic significance has ceased. Just as we say the threat of hunger is often imagined, and the fear of hunger and a deep and persistent fear of peoples and the sense of danger of being engulfed and destroyed by other peoples linger in consciousness, so the consciousness of the old struggle for land remains as one of the most powerful of traditions, and any threat, near or remote, to a nation's land arouses all the forces of the war spirit, and the thought of aggression as a means of conquest of land is always alluring. Land was once the main possession and the main need. To-day it is the chief symbol of the power of a nation. The possession of it is desired when it gives nothing in return, certainly when there are no valid economic reasons for taking it. This land hunger becomes the excuse of nations for their sins of aggression. A differentiated society, so organized that only the few, if any at all, can by any possibility profit by the taking of lands still hungers for this primitive possession. To a great extent land as a national possession has an ideal rather than a practical value. It was one of the original sources of prestige and distinction, having become the main material interest of man as soon as he came to have fixed abode. The whole historic period of the world has been a story of a struggle for land. It is the memory of this land struggle, which is one of the deep motives of war, which often determines the strategy of war, and the policies of nations.