57o TEE POPULAR SCIENCE MONTHLY 



higher mental processes, they are obscurely purposeful. So also are the 

 impulsive acts of dementia prcecox as compared with those of general 

 paralysis. 



The psychology of feeling is one in which the standpoint of indi- 

 vidual differences has played very little part. The field is both tempt- 

 ing and difficult, and there has been the least progress in proportion to 

 the experimental work done in mood and emotional reaction. Common 

 observation shows that there are true individual differences, and for the 

 adaptation to life, these differences are of paramount significance. 



In many of the psychoses, the mood and emotional reactions are 

 markedly and fundamentally altered. Heightened emotional sensitive- 

 ness, or lability of mood, is especially characteristic of exophthalmic 

 goiter or Graves' disease. The source of intoxication here being internal 

 secretion, it is a noteworthy illustration of the interdependence between 

 mental activity and various extraneural processes. Functional atrophy 

 of the thyroid gland is accompanied by a converse picture showing 

 dulness and stupor, and with generally opposite symptoms, both physical 

 and mental, to Graves' disease. 



Still other psychoses are characterized by feelings of exaggerated 

 well-being. The manic excitement shows a typically active exhilara- 

 tion, often with no apparent diminution of intellect, manifesting itself 

 as we should expect to see it manifested in an exaggeratedly happy 

 normal person, with dancing, singing, jibing, half-jocular overestima- 

 tions of one's powers and the like. Another phase of the manic-depress- 

 ive psychosis shows a sort of mute transport, or silent ecstasy, in which 

 it is very difficult to get at the mental content at all ; it is termed the 

 manic stupor. The most genuinely beatific state of mind that is main- 

 tained in terrestrial relations is probably seen in general paralysis; a 

 state of easy-going, beaming euphoria, which the patient himself has 

 no words to describe, but which finds some expression in grandiose but 

 feeble delusions, scarcely if at all reacted to, as that he possesses count- 

 less millions, is king of the world, the super-god. It is interesting to 

 note that this unitary disease process is associated with a great variety 

 of mental pictures, sometimes with melancholic symptoms instead of 

 the euphoria. 



Simple, persistent depression of spirits is not a normal mental 

 reaction to any external cause, but it is a most common reaction of the 

 psychoses, where it is classified with the depressed phase of the manic- 

 depressive group. This is the correlate of the manic condition above 

 mentioned, sometimes alternating with it; though alone, it represents 

 much the more benign process of the two. As in exhilaration, a number 

 of delusions may arise secondarily to the emotional condition, which 

 here favors depressive or persecutory interpretations of the events about 

 one. These ideas are generally superficial and changeable; there is 



