And here is a fundamental law of interest: it must lead to a profitable, pleasurable result or else it tends to disappear. If this is too bold a statement, let me qualify it by stating that a profitable, pleasurable result must be foreseen or foreseeable. Either in some affective state, or in some tangible good, interest seeks fulfillment. Disappointment is the foe of interest, and too prolonged a "vestibule of satisfaction" (to use Hocking's phrase) destroys or impairs interest. CHAPTER VIII. THE SENTIMENTS OF LOVE, FRIENDSHIP, HATE, PITY AND DUTY. COMPENSATION AND ESCAPE I shall ignore the complexities that arise when we seek to organize our reactions into various groups by making a simple classification of feeling, for the purposes of this book. There is a primary result of any stimulation, whether from within ourselves or without, which we have called excitement. This excitement may have a pleasurable or an unpleasurable quality, and we cannot understand just what is back of pleasure and pain in this sense. Such an explanation, that pleasure is a sign of good for the organism and pain a sign of bad, is an error in that often an experience that produces pleasure is a detriment and an injury. If pleasure were an infallible sign of good, no books on character, morals or hygiene would need to be written. This primary excitement, when associated with outer events or things, becomes differentiated into many forms. Curiosity (or interest) is the focusing of that excitement on particular objects or ends, in order that the essential value or meaning of that object or individual become known. Curiosity and interest develop into the seeking of experience and the general intellectual pursuits. We have already discussed this phase of excitement.