6 J. T. Gulick — Inconsistencies of Utilitarianism. 



they are the same, the geographical features, size, contour, and 

 relation to winds, seas and rivers would certainly differ. Bio- 

 logically, the differences are sure to be considerable. The 

 isolated portion of a species will almost always be in a much 

 smaller area than that occupied by the species as a whole, hence 

 it is at once in a different position as regards its own hind" 

 He then enumerates several differences in the biological en- 

 vironment that are liable to occur ; but the point I wish now 

 to note is, that he mentions as one of the differences in the 

 environment the " different position as regards its own 

 kind." This is exactly the difference which, in so far as it is 

 the prevention of intercrossing and the consequent unification 

 of endowments and habits, constitutes isolation ; and unless he 

 is able to show that this difference is incapable of producing 

 any divergence, his contention is unsustained. But he here 

 yields the point at issue, by mentioning this amongst the 

 effective differences. The only way to escape the force of his 

 concession is to claim, as he virtually does here, that isolation, 

 being the separation of the isolated fragment from the influ- 

 ence of the original stock, is in itself a difference in the en- 

 vironment. By taking this position, however, he involves 

 himself in another contradiction ; for, if isolation is a differ- 

 ence in the environment, why does he deny that it has a direct 

 influence in producing change in the oi'ganism ? 



Diversity of Natural Selection during exposure to the same 



Environment. 



Another discrepancy in Mr. Wallace's theory is that, while 

 he rightly assigns great importance to diversity of natural se- 

 lection arising from divergent habits in appropriating the 

 resources of the same environment, exhibited by different 

 sections of the same species occupying the same area, he, 

 nevertheless, insists that the representatives of a species, iso- 

 lated in different areas of the same environment, will be 

 neccessarily subjected to the same influences from natural 

 selection, and will inevitably maintain the same characters 

 and of course, the same habits. That he believes divergent 

 habits may arise, when the divergent groups are occupying the 

 same area, and are prevented from crossing simply by the 

 divergence of habits, will be seen by the case of the varieties 

 of wolves mentioned on p. 105, and by some of the cases 

 mentioned on pp. 108 and 117; also by the statement, on p. 

 119, that — " When one portion of a terrestrial species takes to 

 a more arboreal or a more aquatic mode of life, the change of 

 habits itself leads to the isolation of each portion," and by a 

 similar statement at the bottom of p. 145. That he believes 



