GENESIS OF MAN, MORALLY 



the parts affected. And the feelings of pain or 

 discomfort, both local and systemic, attendant 

 upon overexercise, overeating, or excessive use 

 of a narcotic, are to be similarly explained. 



Thus we may say that pleasure, generally 

 speaking, is " the concomitant of an activity 

 which is neither too small nor too great," and 

 we get at the significance of the Epicurean 

 maxim, firjSei/ ayav. But this doctrine, as al- 

 ready hinted, is by no means complete. For, 

 as Mr. Mill and Mr. Spencer ask, " What con- 

 stitutes a medium activity ? What determines 

 that lower limit of pleasurable action below 

 which there is craving, and that higher limit of 

 pleasurable action above which there is pain ? " 

 And furthermore, how happen there to be cer- 

 tain feelings (as among tastes and odours) which 

 are disagreeable in all degrees of intensity, and 

 others that are agreeable in all degrees of in- 

 tensity ? The answer, as Mr. Spencer shows, 

 is to be sought in the study of the past con- 

 ditions under which feelings have been evolved. 



If the tentacles of a polyp are rudely struck 

 by some passing or approaching body, the whole 

 polyp contracts violently in such a manner as 

 to throw itself slightly out of the way ; but if a 

 fragment of assimilable food, floating by, hap- 

 pens to touch one of the tentacles gently, the 

 tentacle grasps it and draws it slowly down to 

 the polyp's digestive sac. Now between these 

 III 



