54 Unconscious Memory- 



repeat them. Not only is the main idea the same, but I 

 was surprised to find how often Professor Hering and I had 

 taken the same illustrations with which to point our 

 meaning. 



Nevertheless, we have each of us left undealt with some 

 points which the other has treated of. Professor Hering, 

 for example, goes into the question of what memory is, 

 and this I did not venture to do, I confined myself to 

 saying that whatever memory was, heredity was also. 

 Professor Hering adds that memory is due to vibrations 

 of the molecules of the nerve fibres, which under certain 

 circumstances recur, and bring about a corresponding 

 recurrence of visible action. 



This approaches closely to the theory concerning the 

 physics of memory which has been most generally adopted 

 since the time of Bonnet, who wrote as follows : — 



" The soul never has a new sensation but by the inter- 

 position of the senses. This sensation has been originally 

 attached to the motion of certain fibres. Its reproduction or 

 recollection by the senses will then be likewise connected 

 with these same fibres."^ . . . 



And again : — 



" It appeared to me that since this memory is connected 

 with the bod3^ it must depend upon some change which 

 must happen to the primitive state of the sensible fibres by the 

 action of objects. I have, therefore, admitted as probable 

 that the state of the fibres on which an object has acted is 

 not precisely the same after this action as it was before, I 

 have conjectured that the sensible fibres experience more or 

 less durable modifications, which constitute the physics of 

 memory and recollection,"^ , . . 



Professor Hering comes near to endorsing this view, 

 and uses it for the purpose of explaining personal identity. 

 This, at least, is what he does in fact, though perhaps 

 hardly in words. I did not say more upon the essence of 



^ "Contemplation of Nature," Engl, trans., Lend. 1776. Preface, 

 p. xxxvi. 



2 Ibid., p. xxxviii. 



