All these are legitimate questions for the psychologist. He will approach the study of man's mind by finding how his body acts--that is, by watching the phenomena of mental life--under various conditions; then he will seek for the "why" of the action. For we can only conclude what is in the mind of another by interpreting his expression of his thinking and feeling. We cannot see within his mind. But experience with ourselves and others has taught us that certain attitudes of body, certain shades of countenance, certain gestures, tones of voice, spontaneous or willed actions, represent anger or joy, impatience or irritability, stern control or poise of mind. We realize that the average man has learned to conceal his mental reactions from the casual observer at will. But if we see him at an unguarded moment, we can very often get a fair idea of his mental attitude. Through these outward expressions we are able to judge to some extent of the phenomena of his mental life. But let us list them from our own minds as they occur to us this work-a-day moment, then, later on, find what elements go to make up the present consciousness. As I turn my thoughts inward at this instant I am aware of these mental impressions passing in review: You nurses for whom I am writing. The hospitals you represent. What you already know or do not know along these lines. A child calling on the street some distance away. A brilliant sunshine bringing out the sheen of the green grass. The unmelodious call of a flicker in the pine-tree, and a towhee singing in the distance. A whistling wind bending the pines. A desire to throw work aside and go for a long tramp. A patient moving about overhead (she is supposed to be out for her walk, and I'm wondering why she is not). The face and voice of an old friend whom I was just now called from my work to see. The plan and details of my writing. The face and gestures of my old psychology professor and the assembled class engaged in a tangling metaphysic discussion. A cramped position. Some loose hair about my face distracting me. An engagement at 7.30. A sharp resolve to stop wool-gathering and finish this chapter. And yet, until I stopped to examine my consciousness, I was keenly aware _only_ of the thoughts on psychology I was trying to put on paper. But how shall we classify these various contents? Some are _emotion_, _i. e._, feelings; others are _intellect_, _i. e._, thoughts; still others represent _determination_, _i. e._, volition or will. There is nothing in this varied consciousness that will not be included in one or another of these headings. Let us group the contents for ourselves. The nurses for whom I am writing: A result of memory and of imagination (both intellect). A sense of kinship and interest in them (emotion). A determination that they must have my best (will, volition). And so of the hospitals: