20 Unconscious Memory 



are done involuntarily, as our [growth of] limbs, eyes, &c., 

 and our power of digesting food, &c. . . . 



" We say of the chicken that it knows how to run about 

 as soon as it is hatched, . . . but had it no knowledge before 

 it was hatched ? 



" It knew how to make a great many things before it was 

 hatched. 



" It grew eyes and feathers and bones. 



" Yet we say it knew nothing about all this. 



" After it is born it grows more feathers, and makes its 

 bones larger, and develops a reproductive system. 



" Again we say it knows nothing about all this. 



" What then does it know ? 



" Whatever it does not know so well as to be unconscious 

 of knowing it. 



" Knowledge dwells upon the confines of uncertainty. 



" When we are very certain, we do not know that we 

 know. Wlien we will very strongly, we do not know that 

 we will." 



I then began my book, but considering myself still a 

 painter by profession, I gave comparatively little time to 

 writing, and got on but slowly. I left England for North 

 Italy in the middle of May 1876 and returned early in 

 August. It was perhaps thus that I failed to hear of the 

 account of Professor Hering's lecture given by Professor 

 Ray Lankester in Nature, July 13, 1876 ; though, never 

 at that time seeing Nature, I should probably have missed 

 it under any circumstances. On my return I continued 

 slowly writing. By August 1877 I considered that I had 

 to all intents and purposes completed my book. My first 

 proof bears date October 13, 1877. 



At this time I had not been able to find that anything 

 like what I was advancing had been said already. I asked 

 many friends, but not one of them knew of anything more 

 than I did ; to them, as to me, it seemed an idea so new as 

 to be almost preposterous ; but knowing how things turn 

 up after one has written, of the existence of which one had 

 not known before, I was particularly careful to guard 

 against being supposed to claim originality. I neither 

 claimed it nor wished for it ; for if a theory has any truth 



