554 PHILOSOPHICAL THOUGHT. 



Development 1 And he was further probably quite as 

 deficient as Schelling and his followers in recognising 

 the rdle which the exact or mathematical methods were 

 destined one day to play also in the historical sciences 

 of nature. 



If, in the light of our present knowledge, we read 

 afresh the writings of such thinkers as Kielmeyer, 

 Schelling, Steffens, Oken, and others, to which we may 

 add the names of Lamarck and Geoffrey, of Treviranus 

 and Yon Baer, we meet with almost all the leading ideas 

 which governed natural science at the end of the century 

 except one, and that is, if I may say so, a mathematical 

 or arithmetical conception. 2 This idea, nevertheless, was 

 put forward about the same time in this country by 

 Malthus in his ' Essay on Population.' It refers to the 

 disproportionate increase of all organisms if compared 

 with their means of subsistence: it is the phenomenon 

 of overcrowding which, combined with that of " varia- 

 tion," necessitates an automatic " selection " leading to 

 the " struggle for existence " and the " survival of the 



fittest." But it was not till fortv years after this period 

 la. , 



Afterwards that the reflections contained in Malthus's ' Essay ' met 



taken up 



Darwin, jjj fo e mind o f Darwin with the necessary conditions by 



1 This, however, with the quail- ematical or arithmetical methods 



fications contained in Lotze's and into the study of the living creation. 



Wundt's criticisms of this school : This is the conception anticipated 



see rupra. pp. 549, 550. already by Francis Gallon and ren- 



3 Since I wrote this passage, in dered more precise by the accept- 



the first years of the present cen- ance of Mendel's theories, which 



tury. a second important concep- had been neglected and forgotten. 



tion has been added, of which we Though published far back in the 



find no trace among the naturalists nineteenth century (1865), they do 



and philosophers I am here dealing not belong to the history of Thought 



with, but which has likewise tended during that period. 

 in the direction of introducing math- 



