THE LOGIC OF DARWINISM 537 



proof. For my part then I cannot see that we have not here a 

 proof of the theory just as complete as if it had been devised by 

 scientists with all possible precautions and " controls " for the 

 express purpose of scientific demonstration. Indeed the process 

 must be much more conclusive than most experimental proofs, 

 on account of the enormous number and variety of instances in 

 which it has been tried and not found wanting. Those who 

 differ from this opinion may fairly be challenged to devise and 

 describe fully a crucial experiment or series of experiments 

 which shall finally prove or disprove the theory ; there will 

 then possibly be found those who can spare the time and 

 the means to put it into practice. 



Suppose however it should be held that the interpretation I 

 have here given of the word experiment is too wide and that 

 to constitute an experiment properly so called definite and 

 conscious purpose is a requisite, what then ? In that case 

 all breeding and nursery gardening carried on since 1858 by 

 intelligent breeders and nurserymen who had read their Darwin, 

 with the deliberate purpose of improving their stock, must 

 still be regarded as experimental proof of the theory ; for it 

 cannot surely be vitiated as such by the fact that their chief 

 purpose has been to profit by the sale of improved stocks and 

 strains. The experimental production of artificial diamonds 

 in proof of a theory as to the manner of their formation 

 would not be held any less conclusive on account of the hope 

 of the experimenters that a valuable product would be obtained. 



Such considerations incidentally go to show the profound 

 unreason of much of the early criticism of Darwinism. Darwin 

 argued mainly from the phenomena of domestication in plants 

 and animals (although indeed he also availed himself of all that 

 was known of them under natural conditions) that species were 

 proved to be artificially modifiable by means of selection for the 

 purpose of reproduction of slightly superior plants and animals 

 and must therefore also be modifiable and have been accordingly 

 modified in a state of nature, unless we were to suppose that 

 all the individuals of each species were of exactly equal fitness 

 to cope with their environments. Oh but, it was replied, you 

 cannot argue from the artificial conditions of domesticated 

 animals to their conditions in a state of nature. That, said the 

 then Duke of Argyll, is a " loose analogy." Man, was his 

 unexpressed assumption, is so much more powerful than Nature 



