§ 3. Success and Defeat as Determining Pleasure and Pain. — Under the second head is included a very extensive class of cases so familiar and obvious that it scarcely seems necessary to mention them. Everybody knows that it is unpleasant to be defeated in an endeavour by adverse external circumstances, and that circumstances which facilitate the attainment of the end of an activity are for that reason pleasing. The cat is displeased when the mouse escapes it; the golfplayer is displeased when he digs up the turf instead of hitting his ball; the sportsman is displeased when he misses his bird. An analysis of such cases is unnecessary. We need only insist on their importance for the general theory of pleasure-pain. The very fact that they are obvious and familiar makes them important. If we can reduce other instances in which the conditions of the feeling-tone are less obvious to the same general principle, we may fairly claim to have given an explanation. It should be noted that the physiological theory which refers all pleasure-pain to relations of wear and repair in nervous tissue can scarcely be made to apply here. We are pleased when we hit a nail on the head and displeased when we miss it; there seems to be no reason whatever for supposing that in the one case surplusstored energy is being used up, and in the other not. One would suppose that whatever surplus existed would be common to both. These remarks apply to those conditions of success or failure which arise from external circumstances.

There is another group of cases in which the conditions of efficiency or inefficiency are found, not in external circumstances, but in the activity itself as a subjective process. The simultaneous and successive coordination of movements directed towards one end involves delicate adjustment of innumerable motor impulses. Each of these must have a certain intensity, duration, and rapidity, and they must accompany and succeed each other in a certain order. In general, failure in adjustment, disturbing the activity as a whole and rendering it inefficient, is unpleasant. The peculiar experience of losing one's balance is a good illustration. Part of the unpleasantness of extreme fatigue lies in the muscular tremblings and convulsive jerks to which it gives rise. On the other hand, ease and certainty of adjustment in performing complex movements is a source of pleasure when the movements have not become so habitual as to lose feeling-tone. A free and easy flow of delicately adjusted movements is pleasurable, as such. The pleasures of play in children and young animals are largely of this kind. Compare the mental state of a dog in its struggle to keep standing on its hind legs with that of the same dog in its natural gambols, its mockfights with its companions, and the like.

There are certain general conditions which contribute to easy and effective motor adjustment. Among these perhaps the most important is rhythm. In rhythmic movements the same adjustment is repeated at regular intervals, so that it is possible to prepare for it beforehand. In this way waste of energy is avoided, and the maximum of efficiency is attained. All workmen who have to repeat a movement again and again, as in striking with a hammer, or hauling on a rope, fall into a regular rhythm. Concurrence in rhythm between two distinct and simultaneous processes, greatly facilitates both. Each process is not only facilitated by its own rhythm, but also by that of the other, and the result is often intensely agreeable. The best instances are dancing and marching to music.*

* Rhythmic activity also produces a diffused excitement of an agreeable kind which intensifies the effect of other pleasuregiving conditions. Thus the rhythm of verse intensifies the effect of poetic ideas and sentiments.