Inconsistencies of Utilitarianism. 127 



forms, ill whatever way it is secured, is the one necessary 

 and always eftective caiiseot' divergence, so, in nature, wherever 

 there arises the isolated breeding of other than average 

 forms, there divergence will be produced ; or that, as exposure 

 to different environments is only one of the causes that lead 

 isolated bands of men to desire and select different types of 

 variation in the same species of animal, so exposure of wild 

 species to different environments is only one of several classes 

 of causes that may subject isolated portions of one of these 

 species to different forms of selection, producing divergence ; 

 or, again, that as differences in the uses to which men put an 

 animal are not necessarily useful differences, so the differences 

 in the uses which isolated portions of a species make of the 

 environment, though they produce diversity of natural selec- 

 tion, leading to permanent divergence, are not necessarily 

 useful diff'erences. These, with other allied doctrines, which 

 were presented in my paper on "Divergent Evolution through 

 Cumulative Segregation," have received adverse criticism 

 from Mr. Wallace in the work mentioned above. He says : — 

 " In Mr. Gulick's last paper (Journ. of Linn. Soc, Zoology, 

 vol. XX. ])p. 189-274) he discusses the various forms of 

 isolation above referred to under no less than thirty-eight 

 different divisions, with an elaborate terminology, and he 

 argues that these will frequently bring about divergent evolu- 

 tion without any change in the environment or any action 

 of natural selection. The discussion of the problem iiere 

 given will, I believe, sufficiently expose the fallacy of his 

 contention ; but his illustrations of the varied and often recon- 

 dite modes by which practical isolation may be brought 

 about may help to remove one of the popular difficulties in 

 the way of the action of natural selection in the origination 

 of species " (note on p. 150). 



In this passage Mr. Wallace seems to take issue with each 

 and all of my propositions ; but after a careful study of his 

 whole discussion one cannot but be in doubt whether he fully 

 dissents from any of them. This uncertainty arises either 

 from his failing to recognize distinctions which I have made, 

 or from ambiguities and inconsistencies in his own statements. 



Extending the meaning of Natural Selection does 

 not save the Theory. 



He represents me as contending that divergent groups are 

 frequently found in which the action of natural selection is 

 wanting. He here fails to distinguish between the absence of 

 diversity in the action of natural selection and the absence of 



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