36 THE POPULAR SCIENCE MONTHLY 



It will require some generations yet to find out even approximately 

 what role the wonderful process of struggle and selection plays in 

 species-making. But it is becoming clear in part wherein and why 

 Darwin and, following him, all the rest of us, have gone so wide of the 

 mark concerning it. The subject is too vast to touch more than sum- 

 marily here. 



It is the very essence of the human mind to inquire after the causes 

 of whatever happens in this world of ours. It is the essence of science 

 to hold that these causes are natural, not supernatural. Darwin be- 

 came convinced that species arise naturally while yet the philosophy of 

 living things in which he had been nurtured contained practically 

 nothing concerning any natural cause that could be assigned to species 

 production. Special or supernatural causation was held as a dogma 

 rather in default of evidence of natural causes than from proof of 

 supernatural ones. So religious superstition and dogmatism had a free 

 field here. Darwin's naturalist instincts said : " Since species arise 

 naturally, natural causes sufficient therefor must exist. If they are 

 natural they are ascertainable. I will search for them." So he set 

 about the task with the result that all the world knows. He discovered 

 the process called by him natural selection, and saw it to be a real cause 

 in the generation of species. 



Now comes the greatly important point. I have said Darwin car- 

 ried the evolution idea into the second of three stages through which 

 interpretations of the world usually run; the stage, namely, of quali- 

 tative, discursive demonstration. Not having yet reached the third 

 stage, that of quantitative demonstration, he had no way of measuring 

 in a mathematical sense the efficiency of natural selection. He could 

 establish no quantitative relation between cause and effect. In fact he 

 did not look at the problem from the quantitative standpoint in the 

 proper sense at all. So it was almost inevitable that he should exag- 

 gerate the power of the cause he had discovered. And see the essential 

 nature of this exaggeration : Before Darwin supernatural causes were 

 held to account for the origin of species. But supernatural causes are 

 always adequate, final. Supernaturalist doctrines are always absolutist 

 doctrines. Therefore effort to make natural selection supplant super- 

 natural causation is effort to make it, too, adequate, final. Attempt to 

 make natural selection the sole, the complete cause of evolution, and 

 you become a finalist, an absolutist. In a word you retain the essence of 

 supernaturalism. Absolutist natural selectionism is only a disguised 



the misshapen legs, cloven feet, pendulous lips, and curiously mounded back of 

 the sleepy beast, the old man turned away with the remark " there ain't no 

 such animal! " 



I may be wrong as my sources of knowledge are limited, but I believe a 

 considerable number of British naturalists will refuse to let Sir E. Ray take 

 them with him into the class with the Jersey farmer. 



