REMARKS ON NATURAL SELECTION. 359 



taneous variability, which is itself only an expression 

 for unknown causes) " the innumerable structures which 

 are so well adapted to the habits of life of each species. 

 I can no more believe in this " (i. e. that the innumer- 

 able structures, &c., can be due to unknown causes) 

 " than that the well adapted form of a racehorse or 

 greyhound, which, before the principle of selection by 

 man was well understood, excited so much surprise in 

 the minds of the older naturalists, can thus " (i. e. by 

 attributing them to unknown causes) " be explained." * 



This amounts to saying that unknown causes can do 

 so much, but cannot do so much more. On this pas- 

 sage I wrote, in * Life and Habit ' : — 



" It is impossible to believe that, after years of re- 

 flection upon his subject, Mr. Darwin should have writ- 

 ten as above, especially in such a place, if his mind was 

 clear about his own position. Immediately after the 

 admission of a certain amount of miscalculation there 

 comes a more or less exculpatory sentence, which 

 sounds so right that ninety-nine people out of a hun- 

 dred would walk through it, unless led by some exi- 

 gency of their own position to examine it closely, but 

 which yet, upon examination, proves to be as nearly 

 meaningless as a sentence can be." t 



No one, to my knowledge, has impugned the justice 

 of this criticism, and I may say that further study 

 of Mr. Darwin's works has only strengthened my con- 

 viction of the confusion and inaccuracy of thought, 

 which detracts so greatly from t^ieir value. 



* ' Origin of Species,' p. 171, ed. 1876. 

 t ' Life and Habit,' p. 260. 



