9 2 Evolution and its Consequences 



supply the conditions for the existence of thought.' He 



' If I recall the impression made by a colour or an odour, and dis- 

 tinctly remember blueness and muskiness, I may say with perfect 

 propriety that I ' think of ' blue or musk ; and so long as the thought 

 lasts, it is simply a faint reproduction of the state of consciousness to 

 which I gave the name in question, when it first became known to me 

 as a sensation. 



' Now, if that faint reproduction of a sensation, which we call the 

 memory of it, is properly termed a thought, it seems to me to be a 

 somewhat forced proceeding to draw a hard-and-fast line of demarca- 

 tion between thoughts and sensations. If sensations are not rudimen- 

 tary thoughts, it may be said that some thoughts are rudimentary 

 sensations. No amount of sound constitutes an echo, but for all that 

 no one would pretend that an echo is something of totally different 

 nature from sound.' 



To this I can now only reply by observing that according 

 to my view a recalled thought is not a ' rudimentary sensa- 

 tion,' though the sensible memory is made use of with regard 

 to it. I also deny utterly that the faint recurrence of a 

 sensation can ever be properly termed a thought, and the act 

 of 'recalling' such sensation is only to be so named on 

 account not of the sensation recalled, but of the intellectual, 

 voluntary act of recalling. 



The analogy of an echo is false and misleading. An echo 

 is merely a particular kind of sound, but a thought is not 

 merely a particular kind of sensation. 



Again, Professor Huxley objects to the assertion that 

 sensations supply the conditions for the existence of thought 

 or knowledge — saying : — 



*If this implies that sensations supply the conditions for the 

 existence of our memory of sensations, or of our thoughts about 

 sensations, it is a truism which it is hardly worth while to state so 

 solemnly. If it implies that sensations supply anything else it is 

 obviously erroneous. And if it means, as the context would seem to 

 show it does, that sensations are the subject-matter of all thought 



