DARWIN'S PLACE IN FUTURE BIOLOGY 37 



form of snpernaturalism. It is failure to recognize that by its essential 

 nature physical science can deal with causation only piecemeal; that it 

 can only grasp causes one by one and can never get them all. Abso- 

 lutism is supernaturalism, and under whatever disguise is the seemingly 

 everlasting and implacable foe, not merely of inductive science, but of 

 rational conduct. Would that somebody might set forth this truth in 

 words so hot that they should burn themselves ineffacably into the phi- 

 losophy, the science and the daily round of common life of our and of 

 all future generations of men ! With what serenity some of our best 

 accredited men of science are themselves striving, and advising the 

 neoph}i;es in science to strive, for the solution of ultimate problems ! 

 So long as this is so there is necessity for, and will surely always be, 

 theosophy, christian science and the whole retinue of psychic absolut- 

 isms. The one brand of finality is but the counterpoise of the other. 



Though still in the second stage of idea-development as regards 

 natural selection, a few important truths about the process are being 

 revealed to us that Darwin overlooked, or did not sufficiently emphasize. 

 In the first place, while he soon saw that natural selection could not be 

 the sole cause of evolution, and while he recognized it to be a cause of a 

 general nature, he never grasped in its full meaning the truth that there 

 are not one, nor a few, nor even many, but literally an infinite number 

 of causes at work in the production of species. 



It is curious, once one comes to think of it, that Darwin and the 

 rest of us should have talked so long and so absorbedly about one or a 

 few " factors " of evolution when the demands of rigorous science are 

 that there shall be at least as many causes as there are species. Were this 

 not so the same cause would produce different effects, and that would 

 make biology a hocus-pocus indeed. Supernatural causes would be 

 quite as amenable to science as such natural ones. Trouble has befallen 

 us here from not having listened with due attention to what David 

 Hume has told us about causes. His definition of a cause as " an 

 object folloived by another, where, if the first had not been, the second 

 never had existed," has not sunk deeply enough into our minds. 



The course by which we have seemed to keep out of this limbo has 

 been exactly one element in our discomfiture. We have said " Why, 

 to be sure natural selection always takes variation and heredity for 

 granted. Darwin made that clear enough."- But when we make the 

 causes of evolution our problem, why not face the music squarely? 

 Why not make sure of the causes first and classify and name them after- 

 wards ? That is the way we proceed in systematic botany and zoology. 



The truth is, natural selection itself is a great bundle of causes some 

 of which are different in each particular case to which the bundle 

 applies, so must be separately investigated for each particular species. 



Does any AUmacht natural selectionist believe in his heart of hearts 



