ON ACQUIRED PSYCHICAL HABITS. 305 



not how we can refuse to regard Thought as the product of Chemical 

 change in the other; nor (in the view that all the Forces of Nature 

 are simply expressions of Mind) do I see that we need entertain any 

 repugnance to such a view. I do not say that it explains any Mental 

 phenomenon. No sound Physicist would say that he can " explain " 

 how it is that Electricity is generated by Chemical change ; but he 

 knows that such a relation of cause and effect exists between the two 

 orders of phenomena, that every Chemical change is accompanied by 

 an Electric disturbance ; so that, whenever he witnesses Electric dis- 

 turbance, he looks with assurance for some Chemical change as its 

 Physical Cause. And in precisely the same sense, and in no other, I 

 affirm that the Physiologist must regard some change in the Nervous 

 substance of the Brain as the immediate Physical cause of all auto- 

 matic Mental action. If this be admitted of Sensational conscious- 

 ness (and how can it be denied ?), we can scarcely help admitting it 

 of Emotional ; and, if of Emotional, why not of Ideational ? 



There is no part of our purely Physical activity, the relation of 

 which to Physical conditions is more obvious and more intimate, than 

 that Reproduction of past states of Consciousness; which when sup- 

 plemented by the recognition of them as having been formerly ex- 

 perienced we call Memory. It is now very generally accepted by 

 Physiologists as (to say the least) a probable doctrine, that any Idea 

 which has once passed through the Mind, may be thus reproduced, at 

 however long an interval, through the instrumentality of Suggestive 

 action ; the recurrence of any other state of Consciousness with which 

 that Idea was originally linked by Association, being adequate to 

 awaken it also from its dormant or latent condition, and to bring it 

 within the " sphere of consciousness." And as our Ideas are thus 

 linked in " trains " or " series," which further inosculate with each 

 other like the branch-lines of a railway or the ramifications of an 

 artery, so, it is considered, an Idea which has been " hidden in the 

 obscure recesses of the mind" for years perhaps for a lifetime and 

 which seems to have completely faded out of the conscious Memory 

 (having never either recurred Automatically, or been found capable of 

 recall by Volitional Recollection, or been recognized as a past expe- 

 rience when again brought before the mind), may be reproduced, as 

 by the touching of a spring, through a nexus of Suggestions, which 

 we can sometimes trace out continuously, but of which it does not 

 seem necessary that all the intermediate steps should fall within our 

 cognizance. Such a "reproduction" not unfrequently occurs when 

 persons, revisiting certain scenes of their childhood, have found the 

 renewal of the Sensorial impressions of places bring vividly back to 

 their minds the remembrance of events which had occurred in connec- 

 tion with them ; and which had not only been long forgotten by them- 

 selves, but, if narrated to them by others, would not have been recog- 

 nized by them as having ever formed part of their own experience. 

 vol. in. 20 



