MENTAL LIFE 



special thought-organs (phroneta) at certain parts of the 

 cortex, and these again are built up into a large har- 

 monious system of wonderful regularity and capacity. 

 Each phronetal cell is a small chemical laboratory, con- 

 tributing its share to the unified central function of the 

 mind, the conscious action of reason. Scientists are 

 still very far from agreement as to the extent of the 

 phronema in the cortex and its delimitation from the 

 neighboring sense-centres (sensoria). But they are all 

 agreed that there is such a central organ of mind, and 

 that its normal anatomic and chemical condition is the 

 first requisite for the life of the human mind. This 

 belief — one of the foundations of monistic psychology — 

 is confirmed by the study of psychiatry. 



The study of the diseased organism has greatly 

 furthered our knowledge of the normal frame. Diseases 

 are so many physiological experiments made by nature 

 herself under special conditions, which experimental 

 physiology would often be unable to arrange artificially. 

 The thoughtful physician or pathologist can often obtain 

 most important knowledge of the function of organs by 

 carefully observing them during disease. This is espe- 

 cially true of diseases of the mind, which always have their 

 immediate foundation in an anatomical or chemical 

 modification of certain parts of the brain. Our advanc- 

 ing knowledge of the localization of mental functions, or 

 of their connection with special phroneta or organs of 

 thought, is for the most part based on the experience 

 that the destruction of the one is foUowed.by the extinc- 

 tion of the other. Modem psychiatry, the empirical 

 science of mental disease, has thus become an important 

 element of our monistic psychology. If Immanuel Kant 

 had studied it and had visited the asylum wards for a 

 few months, he would certainly have escaped the dualist 

 errors of his philosophy. We may say the same of the 

 modern metaphysical psychologists who built up a mystic 



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