HOW THE GLANDS INFLUENCE THE MIND 173 



mind. But the dynamo is the more ancient possession of the 

 animal, the vegetative apparatus. In short, what must always be 

 remembered is that a wish is never cerebral, but always sub- 

 cerebral, visceral, in its origins. 



The sub-cerebral makes the cerebral. Activities in the nervous 

 system below the brain and especially the vegetative system, 

 force upon it its function of the active verb. It has to be, to do, 

 and to suffer, and then to manipulate the environment to satiate 

 the insatiable viscera, insatiable because the local chemistry is 

 continually raising the tension of one or the other of them. 

 A physics of human behaviour becomes possible with the aid of 

 these concepts of endocrine regulation of intra-visceral pressure, 

 and intervisceral equilibrium, an intramuscular pressure and an 

 intermuscular equilibrium, with the brain as the shifting fulcrum 

 of the system. 



The sensation of hunger, as we have seen, serves as good an 

 exemplar as any of this mechanism of the wish. Hunger is 

 preceded and accompanied by contractions of the stomach of in- 

 creasing intensity. Those contractions must be brought about 

 by a substance acting upon the nerve endings in the wall of 

 the stomach. As it closes down upon itself, waves pass up and 

 down. With each wave, the pressure within it rises. The exact 

 amount of the pressure may be accurately measured by means 

 of a small balloon swallowed and then inflated. When the pres- 

 sure rises above a certain figure, the sensation of hunger breaks 

 into the consciousness of the individual. We infer that certain 

 sensory impulses sent up to the brain attain a strength that 

 finally forces itself into the conscious field of feeling. The sen- 

 sation of hunger varies from individual to individual because 

 of variation in the reaction throughout the vegetative system. 

 Most often it is a sense of movement or even an itch in the upper 

 abdomen. Let some cause produce a weakening or cessation of 

 the movements of the stomach — as fear and anger — and the sen- 

 sation of hunger disappears coincidently with the drop in the 

 pressure within it. As the mathematicians would say, the wish 

 is a function of the pressure, and so of the concentration of 

 substance behind the pressure. 



We have in hunger the wish reduced to the lowest terms, the 

 most primitive form of it. Yet we may resolve all wishes, even 

 the most idealistic, into the same terms. As the vegetative sys- 

 tem becomes habituated by repeated experience to react in the 

 same way to the same stimulus, permutations and combinations of 



