192 COMTE TO BENJAMIN KIDD PART in 



selection B). In one sense therefore, even if hardly 

 more than a truism, we make bold (as our first step) 

 to affirm that natural selection exists. 



Natural Selection, C or A, is also to be regarded 

 as a reality. Perhaps the following consideration may 

 enable us to take another step forward. Science now 

 seems to teach that organic evolution is a fact, that, 

 in spite of their apparent fixity and distinctness, species 

 have somehow grown out of each other, and, presumably, 

 are growing still. Then, if that be so, and if a selective 

 process among organisms is simultaneously taking place, 

 the two processes must have affected each other (C) if 

 they were not really one process (A). In other words ; 

 if from any cause whatever, variations capable of build- 

 ing up a new species are coming into existence, and if 

 it is impossible that all organisms should live out their 

 full span, then the new varieties will be weeded, and 

 weeded selectively, like the rest, and this process must 

 at least contribute something towards maturing the 

 slowly evolving types (C; but A is possible), as well 

 as towards maintaining in efficiency organisms of the 

 types already constituted (B). Now, if this considera- 

 tion be admitted, we may narrow the problem. We 

 need no longer ask, Does natural selection exist ? Or 

 even, does it exist as a cause of progress ? We ask, Is 

 it the only cause ? In an evolving world B implies C 

 as a minimum, and suggests A as a possibility. Does A 

 anywhere actually exist ? Does natural selection any- 

 where operate by itself alone ? That is our narrowed 

 problem. That is our burning question. One school 

 will say, Natural selection is so strong a force that we 

 need postulate no other besides it. Another school 

 will reply, Natural selection is perfectly credible as an 

 auxiliary or accelerating force, but perfectly incredible 



