SOME RELATIONS OF MIND AND BODY. ' 163 



uot deceived, and do not deceive others, into believing them 

 to be natural. 



Thus, when our teeth are on edge from sounds, we do not 

 go to a dentist : if we are sick from ideas, we do not think 

 we are dyspeptic ; if we hear noises in the ear, we do not 

 look for them extei'nally ; if Ave shiver from thinking of cold, 

 we do not put on more clothing. But now let us go one 

 step further, into the region of the sub-conscious mind, and 

 of memories and habits ; and the theory I Avish to present 

 as to the mental causation of these nerA^e troubles we group 

 under the Avord " hysteria " Avill be made plain. 



Our brain not only acts by the Avill and the ideas of the con- 

 scious mind, as Ave haA^e seen, but is continuously vibrating 

 with ideas, memories, and trains of thought of the sub- 

 conscious. It is so even Avith regard to common sensation. 

 If you concentrate your attention on any part of your body, 

 you become aAvaro of sensations in it that escaped your 

 attention before, but Avere equally there then. If Avitli a 

 feather I lightly tickle the back of your neck, and at the 

 time you are engaged in very earnest conA^ersation, the 

 vibration aroused in the brain sensory centre is unnoticed by 

 you ; and yet if I call your attention to the part it is noticed 

 at once. By increasing the stimulus I can make the waA'^es 

 of vibration set in action other centres ; involuntary ones, 

 8uch as cause a shaking or shuddering of the neck ; or 

 voluntary, such as turning the head round or moving aAvay. 

 If you are asleep I may tickle your foot so that you draw 

 the leg away and you Avake up. In this case you are pro- 

 bably conscious of moving your leg ; but the stimulus that 

 made you do it Avas too slight to reach your consciousness. 

 We may thus be conscious of a transferred Aabration leading 

 to action or sensation, and yet be ignorant of the cause that 

 set it going. IMemories again Avill iiiA^oluntarily, and it may 

 be unconsciously, arouse both feelings and actions. I may 

 have smelt the strong scent of some flower Avhen some 

 •critical event took place, a proposal of marriage or some 

 sudden news ; henceforth, Avhenever the topic is touched on 

 the very scent or A'ibrations of the nerve of smell that repre- 

 sent it are exactly reproduced by my sub-conscious mind. 

 A certain field always recalls a certain song Ave used to sing 

 as Ave crossed it on our Avay to school. The smell o+ 

 saudal-Avood or the taste of chutnee may set the thoughts 

 of old Anglo-Indians in vibration Avith Eastern sights and 

 sounds stirred up again in the old centres. Observe in all 



