26 Darwin, and after Darwin, 



that through all these changes of theory or principle, 

 and through all the ever-advancing construction of 

 their taxonomic science, naturalists themselves were 

 unable to give any intelligible reason for the faith that 

 was in them — or the faith that over and above the 

 artificial classifications which were made for the mere 

 purpose of cataloguing the living library of organic 

 nature, there was deeply hidden in nature itself a truly 

 natural classification, for the eventual discovery of 

 which artificial systems might prove to be of more or 

 less assistance. 



Linnaeus, for example, expressly says — "You ask 

 me for the characters of the natural orders ; I confess 

 that I cannot give them." Yet he maintains that, 

 although he cannot define the characters, he knows, 

 by a sort of naturalist's instinct, what in a general way 

 will subsequently be found to be the organs of most 

 importance in the eventual grouping of plants under 

 a natural system. " I will not give my reasons for the 

 distribution of the natural orders which I have pub- 

 lished," he said : " you, or some other person, after 

 twenty or after fifty years, will discover them, and see 

 that I was right." 



Thus we perceive that in forming their provisional 

 or artificial classifications, naturalists have been guided 

 by an instinctive belief in some general principle of 

 natural affinity, the character of which they have not 

 been able to define ; and that the structures which 

 they selected as the bases of their classifications when 

 these were consciously artificial, were selected because 

 it seemed that they were the structures most likely to 

 prove of use in subsequent attempts at working out the 

 natural system. 



