384 THE WORLD OF LIFE CHAP. z 



such health for every individual is the one and only test of 

 a true civilisation. 



A few words in conclusion on the main question of pain 

 in the animal world. In my treatment of the subject I 

 believe I have given unnecessary weight to those appear- 

 ances by which alone we judge of pain in the lower animals. 

 I feel sure that those appearances are often deceptive, and 

 that the only true guide to the evolutionist is a full and careful 

 consideration of the amount of necessity there exists in each 

 group for pain-sensation to have been developed in order to 

 preserve the young from common dangers to life and limb 

 before they have reached full maturity. It is exactly the 

 same argument as I have made use of in discussing the 

 question of how much colour-sense can have been developed 

 in mammals or in butterflies. In both cases it depends 

 fundamentally on utilities of life -saving value as required 

 for the continuance of the race. Hitherto the problem has 

 never been considered from this point of view, the only 

 one for the evolutionist to adopt. Hence the ludicrously 

 exaggerated view adopted by men of such eminence and 

 usually of such calm judgment as Huxley a view almost as 

 far removed from fact or science as the purely imaginary 

 and humanitarian dogma of the poet : 



" The poor beetle, that we tread upon, 

 In corporal sufferance finds a pang as great 

 As when a giant dies." 



Whatever the giant may feel, if the theory of evolution 

 is true, the " poor beetle " certainly feels an almost irreducible 

 minimum of pain, probably none at all. 



