Pleasure and Pain. 715 



being outside the limits, destroys the tissues, or stuns the sense organ 

 or nerves so that no sensation is conveyed. 



If the sensation of satisfaction arises from the impact upon an organ 

 of the kind of stimuli by which it has been built up, we ma}' suppose 

 that this sense of satisfaction is the most intense when the organ is in 

 the best state for reflecting such stimulus. There are two conditions 

 requisite for pleasurable sensations ; one is that the organ be fresh and 

 not fatigued, the other is that the attention be concentrated upon it, and 

 not distracted by other actions. The sense of fatigue arises when the 

 organ has become so far depleted and worn in its tissues through the 

 waste of action that it can no longer be stimulated by its accustomed 

 stimulus, or is moved by it in a sluggish and inadequate manner. After 

 the action is over, the restoration of the depleted tissues proceeds by 

 the assimilation of fresh matter supplied by the blood. This process of 

 rebuilding is negatively agreeable ; that is, it gradually relieves the dis- 

 agreeable sense of fatigue. When the organ is fully restored and 

 rested, its stimulation by the appropriate object will give the greatest 

 pleasure it is competent to give, provided the attention, that is, the blood 

 supply, is directed to it chiefly or exclusively. If the' blood flow is di- 

 vided between this and too many other organs, it soon becomes ex- 

 hausted and fatigued again. We are glad to entertain a friend whom 

 we have not seen for some time, unless we should happen to have the 

 presence of some other friend we like better, or some pressing business 

 or occupation demands our attention. In such case, the visit will soon 

 become irksome, which otherwise would be enjoyable. The first action 

 of the organ under the stimulation compels a flow of blood to it, which 

 tends to supply the new tissue as it is required by the waste of the old. 

 If it could be forever supplied as fast as wasted, there would be no end 

 to our enjoyment of the action. But the supply is limited, and one or- 

 gan cannot monopolize it, so exhaustion and fatigue finally obscures 

 pleasure, and puts an end to action. 



It is common to distinguish between bodily pains and pleasures, and 

 mental pains and pleasures. From what has gone before, it is obvious 

 that such distinction is unscientific. All pains and pleasures result 

 from agitations of the brain by stimuli from its environment, which in- 

 cludes not only every object accessible to us outside of the body, but 

 the body itself, too, with all its parts. The principle upon which our 

 sensations are painful or pleasurable, is just the same for all, whether 

 they are derived from conditions in the body, or from conditions in the 

 part of the environment beyond the body. If by bodily pains is meant 

 those consequent upon a vicious condition of the body, then it would 

 follow that the mental pains are those consequent upon an undesirable 

 condition of our outside relations, our political standing, our business 



