I did not say that the practicing psychologist knows the whole anatomy of man’s desires. For the most part he takes the word of his clients as to what they want, and then goes ahead. I simply do not ask what other demands of human nature may possibly exist. At the same time I must admit that, in order to find the economical way to handle the human factor in any situation, I must always take account of a complex of instincts. The farther I go in my work, too, the more complicated the instincts appear to be. For example, we are discovering that the workman wants out of his work a great many things besides wages, even things that wages won’t buy. As yet, however, we are not sure that the capitalist (except a queer one now and then) desires anything but profits. The acquisitive instinct seems completely to explain the conduct of business. A Biological Psychologist: What has just been said illustrates the need of an inclusive point of view from which to approach the problem of the instincts. Biology, in its concept of adjustment, presents us with such a point of view. All living beings exhibit a push towards the maintenance and the reproduction of themselves. Thus, there are two great trunk-roots of behavior, the demand for self-maintenance (at base the requirement of food), and the demand for reproduction. Where reproduction is sexual, we may say that food and sex, broadly considered, contain the clue to all behavior. It is necessary, of course, to perceive that each of these trunk-roots divides into branches and subdivides into rootlets. Thus, food-getting includes accumulation for future use, and so it founds what is sometimes called the acquisitive instinct. Rivalry, jealousy, and pugnacity belong to the same trunk-root. On the other hand, the reproductive drive differentiates into complex activities of courtship, the care of offspring, the family organization, and all the social institutions that have sprung from it. The Sphinx: You puzzle me. I haven’t been hungry or amorous since the pyramids were built, and I know I never wanted offspring. The only thing I’ve really wanted for these thousands of years is to know what man is--that is, what he really wants. At this minute I’m all excited about a particular aspect of this general question of mine: Does man himself, or only this queer head of mine, want to know what he wants? And if so, of which of the two trunk-roots of instinct is this a rootlet? An Analytical Psychologist: