What we have just discussed makes it necessary for us to enter further into the origin and significance of that mental activity that is called imagination. As you well know, it enjoys universal esteem, although we have never clearly understood its place in the psychic life. I have this much to say about it. As you know, the ego of man is slowly educated by the influence of external necessity to an appreciation of reality and a pursuit of the principle of reality, and must therefore renounce temporarily or permanently various objects and goals of its strivings for satisfaction, sexual and otherwise. But renunciation of gratification has always been difficult for man. He cannot accomplish it without something in the nature of compensation. Accordingly he has reserved for himself a psychological activity wherein all these abandoned sources of pleasures and means of pleasurable gratification are granted a further existence, a form of existence in which they are freed from the requirements of reality and what we like to call the test of reality. Every impulse is soon transformed into the form of its own fulfillment. There is no doubt that dwelling on the imagined fulfillment of a given wish affords some satisfaction, although the realization that it is unreal is unobscured. In the activity of the imagination, man enjoys that freedom from external compulsion that he has long since renounced. He has made it possible to be alternately a pleasure-seeking animal and a reasoning human being. He finds that the scant satisfaction that he can force out of reality is not enough. "There is no getting along without auxiliary-constructions," Th. Fontaine once said. The creation of the psychic realm of fancy has its complete counterpart in the establishment of "preserves" and "conservation projects" in those places where the demands of husbandry, traffic and industry threaten quickly to change the original face of the earth into something unrecognizable. The national reserves maintain this old condition of things, which otherwise has everywhere been regretfully sacrificed to necessity. Everything may grow and spread there as it will, even that which is useless and harmful. The psychic realm of phantasy is such a reservation withdrawn from the principles of reality.