xii.] THE ORIGIN OF SPECIES. 293 



that selective action which lie performs in artificial 

 selection. 



The evidence brought forward by Mr. Darwin in 

 support of his hypothesis is of three kinds. First, he 

 endeavours to prove that species may be originated by 

 selection ; secondly, he attempts to show that natural 

 causes arc competent to exert selection ; and thirdly, he 

 tries to prove that the most remarkable and apparently 

 anomalous phrenomena exhibited by the distribution, de- 

 velopment, and mutual relations of species, can be shown 

 to be dcducible from the general doctrine of their origin, 

 which he propounds, combined with the known facts of 

 geological change ; and that, even if all these phenomena 

 are not at present explicable by it, none are necessarily 

 inconsistent with it. 



There cannot be a doubt that the method of inquiry 

 which Mr. Darwin has adopted is not only rigorously in 

 accordance with the canons of scientific logic, but that it 

 is the only adequate method. Critics exclusively trained 

 in classics or in mathematics, who have never determined a 

 scientific fact in their lives by induction from experiment 

 or observation, prate learnedly about Mr. Darwin's 

 method, which is not inductive enough, not Baconian 

 enough, forsooth, for them. But even if practical ac- 

 quaintance with the process of scientific investigation is 

 denied them, they may learn, by the perusal of Mr. 

 Mill's admirable chapter " On the Deductive Method," 

 that there are multitudes of scientific inquiries, in which 

 the method of pure induction helps the investigator but 

 a very little way. 



"The mode of investigation," says Mr. Mill, "which, from the 

 proved inapplicability of direct methods of observation and experi- 

 ment, remains to us as the main source of the knowledge we possess, 

 or can acquire, respecting the conditions and laws of recurrence of the 

 more complex phenomena, is called, in its most general expression. 



