We have found that the essential, and we might say, primary psychological datum of war is a war-mood, that the central motive of this war-mood is a general impulse which we called the intoxication motive, and that this intoxication motive, considered generically, and in regard to its specific meaning is a craving for power and for the experience of exerting and feeling power. The war-mood is not a mere collection of instincts; it is a new product, in which instincts and emotions have a place. There are several reasons, practical and theoretical, for regarding it as a highly important problem to discover what the actual content of this war-mood is. This mood, being one of the greatest of all powers of good and evil, and one most in need to-day of education and re-direction, it may be, it will probably be controlled, if ever, upon the basis of a knowledge of what it means as a whole, and of what its elements are which appear in the form of fused, transformed, truncated, generalized and aborted instincts and feelings. _Primitive Tendencies_ First of all, the highly complex emotions, moods and impulses we find in the social consciousness as expressed in the moods of war, do contain and revert to instincts and feelings that are part of the primitive equipment of organic life, and are usually identified as nutritional and reproductive tendencies. The part played in war by the migratory impulse, the predatory impulse and the like indicates the connection of the war-moods with the nutritional tendencies; and the display elements found already in primitive warfare and, as we have already inferred, in all forms of ecstasy contain factors that are at bottom sexual. We no longer eat our enemies, and we do not bring home their heads to our women or practice wife stealing, but it is easy to observe the remnants of these old feelings and instincts in war. Trophy hunting continues, and we may suppose that even the moods of primitive cannibalism have not entirely been lost. The ready habituation of soldiers to some of the scenes of the recent war seems to suggest a lingering trace of this motive, while the looting impulse which plays such a part in war, and some aspects of the destructive impulses and the like that are displayed, are, with a high degree of probability, closely related to instincts that were once specifically practical and belong to the fundamental nutritional motives. Nor is it a mere euphemism, perhaps, when we speak of the greed of nations, nor solely analogical when we compare the ambitions of peoples with certain adolescent phenomena in the life of the individual. Plainly the social consciousness, as a collective mood, does not command the specific reactions connected with sexuality and nutrition, but we may observe the presence of these instinctive reactions in two phases of war. We see them in the tendencies of various individuals, who under the excitements of the war moods are controlled more or less