If we examine, in fact, our pleasures and pains, our moments of elation and depression, we find that they go back for the most part to instincts developed in the struggle for food and rivalry for mates. We can perhaps best get at the meaning of the conflict interest to the organism in terms of the significance to itself or the organism's own movements. Locomotion, of whatever type, is primarily to enable the animal to reach and grasp food, and also to escape other animals bent on finding food. The structure of the organism has been built up gradually through the survival of the most efficient structures. Corresponding with a structure mechanically adapted to successful movements, there is developed on the psychic side an interest in the conflict situation as complete and perfect as is the structure itself. The emotional states are, indeed, organic preparations for action, corresponding broadly with a tendency to advance or retreat, and a connection has even been made out between pleasurable states and the extensor muscles, and painful states and the flexor muscles. We can have no adequate idea of the time consumed and the experiments made in nature before the development of these types of structure and interest of the conflict pattern, but we know from the geological records that the time and experiments were long and many, and the competition so sharp, that finally, not in man alone, but in all the higher classes of animals, body and mind, structure and interest, were working perfectly in motor actions of the violent type involved in a life of conflict, competition, and rivalry. There could not have been developed an organism depending on offensive and defensive movements for food and life without an interest in what we call a dangerous or precarious situation. A type without this interest would have been defective, and would have dropped out in the course of development. There has been comparatively little change in human structure or human interest in historical times. It is a popular view that moral and cultural views and interests have superseded our animal instincts; but the cultural period is only a span in comparison with prehistoric times and the prehuman period of life, and it seems probable that types of psychic reaction were once for all developed and fixed; and while objects of attention and interest in different historical periods are different, we shall never get far away from the original types of stimulus and reaction. It is, indeed, a condition of normal life that we should not get too far away from them.