x.j J/72. DARWIN S OTWS. 243 



He begins by laying down the following proposition : 

 &quot; Sensation is not thought/ and no amount of 

 the former would constitute the most rudimentary 

 condition of the latter, though sensations supply the 

 conditions for the existence of thought or ( know 

 ledge (p. 67). 



This proposition is true, or not, according to the sense 

 in which the word &quot; thought&quot; is employed. Thought is 

 not uncommonly used in a sense co-extensive with 

 consciousness, and, especially, with those states of 

 consciousness we call memory. If I recall the impres 

 sion made by a colour or an odour, and distinctly 

 remember blueness or muskiness, I may say with perfect 

 propriety that I &quot;think of&quot; blue or musk; and, so 

 long as the thought lasts, it is simply a faint repro 

 duction 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 demarcation between 

 thoughts and sensations. If sensations are not rudi 

 mentary thoughts, it may be said that some thoughts 

 are rudimentary sensations. No amount of sound con 

 stitutes an echo, but for all that no one would pretend 

 that an echo is something of totally different nature 

 from a sound. Again, nothing can be looser, or more 

 inaccurate, than the assertion that &quot;sensations supply 

 the conditions for the existence of thought or know 

 ledge.&quot; If this implies that sensations supply the 

 conditions for the existence of our memory of sensa 

 tions 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 



