CONSCIOUSNESS AND SENSATION. 



109 



manner, is perfectly aware of the site of irritation 

 when a nerve-trunk in the stump is touched, and it 

 seems reasonable to suppose therefore that the 

 sense of the presence of the removed part is some- 

 how to be explained by habit, the reversion of 

 consciousness to previous conditions, and is com- 

 parable with other waking illusions of the phantom 

 sort. The production of pain in the temple from 

 toothache may be explained on the supposition 

 that intensity of the impressed condition sufficient 

 to produce pain is conducted to a nerve-centre and 

 spread centrifugally, just as I have suggested that 

 the alteration in an ulnar nerve struck at the elbow 

 spreads down to the fingers. 



If I have put forward these views of sensation 

 simply as a suggestion I should be still more 

 unwilling to be dogmatic in applying them to the 

 motor nerves. Yet it may be mentioned that one 

 of the most inscrutable of all phenomena, looked at 

 from the received point of view, is the circumstance 

 that the will is able to regulate delicately the 

 movements of the limbs by adjusting the contrac- 

 tions of complicated muscles of which the mind is 

 wholly unconscious; and the difficulty in this 

 matter will be greatly simplified if we can see 

 our way to believe that, when a motor nerve is set 

 in action from the brain, the mind is brought into 



