158 MR. DARWIN'S CRITICS v 



which goes on in the nervous system of the man. 

 Unless the nerve-elements of the retina, of the 

 optic nerve, of the brain, of the spinal cord, and 

 of the nerves of the arms, went through certain 

 physical changes in due order and correlation, the 

 various states of consciousness which have been 

 enumerated would not make their appearance. So 

 that in this, as in all other intellectual operations, 

 we have to distinguish two sets of successive 

 changes one in the physical basis of conscious- 

 ness, and the other in consciousness itself ; one set 

 which may, and doubtless will, in course of time, 

 be followed through all their complexities by the 

 anatomist and the physicist, and one of which only 

 the man himself can have immediate knowledge. 



As it is very necessary to keep up a clear 

 distinction between these two processes, let the one 

 be called neurosis, and the other psychosis. When 

 the gamekeeper was first trained to his work 

 every step in the process of neurosis was accom- 

 panied by a corresponding step in that of psychosis, 

 or nearly so. He was conscious of seeing some- 

 thing, conscious of making sure it was a hare, 

 conscious of desiring to catch it, and therefore to 

 loose the greyhound at the right time, conscious of 

 the acts by which he let the dog out of the leash. 

 But with practice, though the various steps of the 

 neurosis remain for otherwise the impression on 

 the retina would not result in the loosing of the 

 dog the great majority of the steps of the 



