HUMAN PSYCHOLOGY. 



21 



this will not bring us one whit nearer the explanation of the 

 ultimate nature of that which constitutes the sensation. The 

 one is objective, and the other subjective ; and neither can be 

 explained in terms of the other. We cannot say that they are 

 identical, or even that one passes into the other, but only, as 

 Laycock expresses it, that the two are correlated." {Functions 

 of the Brain, pp. 255, 256.) 



Experiment IV. — If you like to try it — Press the 'point of a 

 fin into your finger. You feel a pain. 



What causes that pain ? The point stimulates the little bulbous 

 bodies in which the sensory nerve fibres end and sets up changes, 

 movements, waves, vibrations, what you like, in the nerve 

 substance. This molecular movement runs up at the rate of 

 100 feet per second the sensory nerve ; the posterior part of the 

 spinal cord ; and so on until it reaches the Rolandic area of the 

 brain. It ends there — in cells. 



Now we can prevent that pain by (1) poisoning the sensory 

 nerve endings by certain drugs known as local anaesthetics ; 

 (2) by dividing the sensory nerve or injuring the spine ; (3) 

 by poisoning the brain-cells by drugs known as general anaes- 

 thetics. But we can go further, for (4) by hypnotism we can 

 prevent the pain being felt without interfering with the brain- 

 cells ; that is to say, without interfering with the sufferer's con- 

 sciousness. Permit me to suppose that this interference takes 

 place just where mind and matter meet. 



And may I not do so since McDougall in his explanation of 

 Hypnotism in the Encyclopcedia Britamiica, 11th Ed., writes thus 

 of the theory of mental dissociation which he thinks is the best 

 explanation of hypnotism : " Suppose now that all the nervous con- 

 nexions between the multitudinous dispositions of the cerebrum 

 are by some means rendered less effective, that the association- 

 paths are partially blocked or functionally depressed ; the result 

 will be that, while the most intimate connexions, those between 

 dispositions of any one system remain functional or permeable, 

 the weaker less intimate connexions, those between dispositions 

 belonging to different systems, will be practically abolished for 

 the time being ; each system of dispositions will then function 

 more or less as an isolated system, and its activity will no longer 

 be subject to the depressing or inhibiting influence of other 

 systems ; therefore each system, on being excited in any way, 

 will tend to its end with more than normal force, being freed 

 from all interferences ; that is to say, each idea or system of 



