XIL] THE ORIGIN OF SPECIES. 255 



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 

 acquaintance with the process of scientific investigation is denied 

 them, they may learn, by the perusal of Mr. Mill s admirable 

 chapter &quot; On the Deductive Method,&quot; that there are multitudes 

 of scientific inquiries, in which the method of pure induction 

 helps the investigator but a very little way. 



&quot; The mode of investigation,&quot; says Mr. Mill, &quot; which, from the proved 

 inapplicability of direct methods of observation and experiment, 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, the deductive method, 

 and consists of three operations : the first, one of direct induction ; the 

 second, of ratiocination ; and the third, of verification.&quot; 



Now, the conditions which have determined the existence of 

 species are not only exceedingly complex, but, so far as the great 

 majority of them are concerned, are necessarily beyond our 

 cognizance. But what Mr. Darwin has attempted to do is in 

 exact accordance with the rule laid down by Mr. Mill ; he has 

 endeavoured to determine certain great facts inductively, by 

 observation and experiment ; he has then reasoned from the data 

 thus furnished ; and lastly, he has tested the validity of his 

 ratiocination by comparing his deductions with the observed facts 

 of Nature. Inductively, Mr. Darwin endeavours to prove that 

 species arise in a given way. Deductively, he desires to show 

 that, if they arise in that way, the facts of distribution, develop 

 ment, classification, &c., may be accounted for, i.e. may be deduced 

 from their mode of origin, combined with admitted changes in 

 physical geography and climate, during an indefinite period. 

 And this explanation, or coincidence of observed with deduced 

 facts, is, so far as it extends, a verification of the Darwinian view. 



