24 INTRODUCTION TO SCIENCE 



longed battles with Herbert Spencer on the 

 subject. "But even my friend's rare dialectic 

 skill and copiousness of apt illustration could 

 not drive me from my agnostic position. I took 

 my stand upon two grounds: Firstly, that up 

 to that time, the evidence in favour of transmuta- 

 tion was wholly insufficient; and secondly, that 

 no suggestion respecting the causes of transmuta- 

 tion assumed, which had been made, was in any 

 way adequate to explain the phenomena. Look- 

 ing back at, the state of knowledge at that time, 

 I really do not see that any other conclusion was 

 justifiable/' . . . "That which we were looking 

 lor, and could not find, was a hypothesis respect- 

 ing the orij^in of known organic forms which as- 

 sumed the operation of no causes but such as 

 could be proved to be actually at work. We 

 wanted, not to pin our faith to that or any other 

 speculation, but to get hold of clear and definite 

 conceptions which could be brought face to face 

 with facts and have their validity tested. The 

 Origin provided us with the working hypothesis 

 we sought." . . . "The only rational course for 

 those who had no other object than the attain- 

 ment of truth was to accept * Darwinism' as a 

 working hypothesis and see what could be made 

 of it. Either it would prove its capacity to eluci- 

 date the facts of organic life, or it would break 

 down under the strain." (See Huxley's Life and 



