SELECTION AS AN EXPLANATION. 31 



differing more and more widely from each other? To explain such a 

 result we must find some oilier law. I am prepared to show that there is 

 such a law rising out of the very nature of organic activities — a law of 

 segregation— bringing together those similarly endowed and separating 

 them from those differently endowed. 



(3) Selection does not explain the establishing of unnecessary char- 

 acters. 



Again, selection can not explain the divergent transformation of 

 forms distinguished from each other in qualities that are not related 

 to their success in gaining a living and propagating their kind. As 

 illustrations of such transformation may be mentioned beautiful 

 arrangements of color that can not be attributed either to natural 

 selection or to sexual selection ; for example, the patterns with which 

 many Hawaiian snails are ornamented, which can not be of use either 

 in attracting mates or in gaining a living. 



2. Selection — How fur Determined by External Nature. 



Passing to the next point, we inquire whether change in the char- 

 acter of the selection affecting any organism is wholly determined by 

 change in external nature? Or can change in the character of the 

 selection be initiated and maintained through change in the organism, 

 without any change in the environment? 



( 1 ) Herbert S power's view. — Spencer distinctly affirms that the latter 

 method of change is impossible. The following are his words : "That 

 there maybe continuous changes in organism, there must be continu- 

 ous changes in incident forces." And, again, "At first, changes in the 

 amounts and combinations of external inorganic forces, astronomic, 

 geologic, and meteorologic, were the only causes of the successive 

 changes undergone by organisms. [In time, however,] the actions 

 of organisms on one another became new sources of organic modifica- 

 tions." (Principles of Biology, sees. 169, 170.) 



Spencer rests his denial of the freedom of the human will on the 

 assumption that all vital activities are predetermined by activities in 

 the environment.* It is evident that if our natural powers and our 

 present conditions are so determined by the environment that we 

 can produce but one set of actions, then no effort on our part, either 

 individual or collective, can in the least affect the result ; for we can 

 not change our circumstances without acting, and our actions are 

 already determined by our circumstances. 



* See Principles of Psychology, sec. 220. 



