THE THEORY OF SENSATION. 185 



that of Dr. Reid. " Let the connection between the organ and the 

 brain be cut ofl' by the compression or severance of the nerve, and 

 no sensation will be felt." From this necessary connection, it is 

 inferred that the impression is transmitted along the nerve. 



Dr. Thomas Brown, in opposing the idea of the brain being the 

 ultimate material seat of the sensation, has contended that the seve- 

 rance of the nerve may destroy sensation by preventing its healthy 

 action, not by impeding the transference to the brain. 



To this Dr. Payne has replied, satisfactorily as many consider, 

 that were Dr. Brown's theory true, the nerve above the point of 

 severance would be as incapable of receiving the impression of the 

 object as the part beyond ; and, also, that injury done to the nerves 

 of one sense would prevent the action of the rest, the connection of 

 the entire sensorial mass, destroying, in both cases, the healthy state 

 necessary for action. But this is found not to be the case. The 

 nerve above the point of severence is as sensitive as before, and injury 

 done to one set of nerves does not destroy the activity of the rest. 

 Dr. Payne concludes, therefore, that Dr. Brown's ai'gunient is falla- 

 cious, and, that in all cases, the impression is conveyed to the brain. 

 For my own part, I cannot regard this rejoinder as at all conclu- 

 sive. The healthy state of the nerve below the point of separation 

 may be destroyed without necessarily interfering with that of the 

 part above. The state of disease may be induced, not by the mere 

 application of the knife or the ligature, in which case it would, it is 

 true, affect the entire nerve, but by the fact of a separation having 

 taken place between that part of the nerve and the brain. This con- 

 nexion may, in all cases, be necessary for that healthy state of the 

 nerves, without which there can be no sensation ; yet it surely does 

 not follow, that the impression needs to be conveyed to the brain. 

 It seems to me, therefore, that Dr. Brown's reply to the argument 

 generally drawn from the facts proving the dependence of the 

 sensitive nerves on the brain for the exercise of their functions, is 

 perfectly satisfactory. Those facts prove the necessity of the con- 

 nection being kept up between the two, but they do not prove the 

 transmission of impressions. 



Why, then, may not the process in sensation be even simpler than 

 the generally received theory ? Why may not the mind become con- 

 scious of the change produced on the orgin, immediately on that 

 change taking place, then and there becoming cognisant of it, and not 

 after the conveyance of the impression to the brain ? " The mind is 

 not," supposes Isaac Taylor, "the prisoner of the attic story, but is 

 the occupant at large of the entire animal organization, acting in each 

 part of the structure according to the purpose of each — in the skin, the 

 eye, the ear, the tongue, the nasal membrane, receiving immediately 

 the impressions of external objects by its inherent susceptibility of 

 the properties of matter, and, let it be granted, within the cranium, 

 carrying on the higher processes of thought." To prove that this is 

 probably the tme state of the case, I shall offer very briefly the 

 following arguments. 



First. — It is recommended by its simplicity* It is unphilosophical 



