The question just asked by our venerable friend reinforces a consideration that I have many times presented in our Sodality. Psychology cannot be satisfied to work within the very broad categories of biology; she must find her categories within the specific material with which she deals, and she must pursue her analyses to the end--that is, until the simple elements are laid bare. Pursuing this truly scientific procedure, she finds that mind is a general term for aggregates of sense-elements on the one hand and elementary drives on the other. These drives, inherited, of course, and having biological significance, are more numerous than we once supposed. Each of the so-called trunk-roots is in reality a cluster of roots, and there are others not contained in either cluster. The sex-instinct knows nothing of offspring; does not look forward to progeny nor provide care for the young--often quite the opposite. These things are managed by another set of instincts. Moreover, food-getting is not the only sort of instinctive getting. Curiosity, the prime root of science, is obviously instinctive. Therefore we may affirm that the trouble with The Sphinx’s head is the unrest of an unsatisfied instinct. A Single-Track Behaviorist: This makes me as tired as it must make The Sphinx. Instincts, forsooth! An instinct is nothing but a name for a class of responses; it does not do anything nor explain anything. You can have as many or as few instincts as you like by choosing your method of classifying behavior. In fact, the whole notion that desires, instinctive or other, explain the occurrence of anything is simply a leftover from the belief in flitting ghosts who did things in the dark but never where you could see just what was happening. Bring the facts into the light, and what do you see (for I know nothing but what I see and touch)? You behold in our behavior nothing whatever but a few reflex movements modified in numerous ways by the conditions, purely physical, under which they occur. Behavior, which is change of place, has to be explained from within its own genus, which is, change of place. This is the last mountain height of psychology; climb up here, and you shall see that there are no desires, no wants. Men don’t want anything; a want is nothing but a bit of vocal or sub-vocal behavior. The Sphinx: