76 Scientific Explanation. 



causce, to agencies actually known to be in opera 

 tion. The excessive fecundity of all organic be 

 ings, the limited means of subsistence, the inev 

 itable struggle for life, the advantage accruing, 

 in this struggle, to some individuals in conse 

 quence of slight modifications in organ or func 

 tion, structure or habit, such as nature in liberal 

 variety is perennially turning up, the preserva 

 tion of these favored forms, and the consolidation 

 and accumulation, through transmission to suc 

 cessive generations, of their beneficial peculiar 

 ities until first varieties and then species are pro 

 duced these are facts which every observer 

 may verify for himself, and which, it is almost 

 universally conceded, account for the origin of 

 many, if not of all, organic species. And for the 

 scientist who finds no species too marked for gen 

 esis through this common process the problem 

 has been completely solved. 



But where science ends philosophy begins. 

 The one is concerned with the discovery of pro 

 cesses, the other lias to analyze the ultimates 

 realities or conceptions, being or thought- which 

 the processes everywhere involve. While science, 

 accordingly, sees no difference between the vari 

 ous links of the causal chain with which Darwin 

 draws out the development of life, philosophy 



