302 PSYCHIATRY 



manent deteriorating psychosis and the transitory phases (melan- 

 cholic, maniacal, and paranoid) of the functional psychosis. This 

 principle accounts also for the fact of there being maniacal as 

 well as melancholic types, and the "paranoid conditions," in the 

 "involution psychoses;" this principle is already well recognized 

 in respect to the neurasthenic, melancholic, and maniacal modes of 

 onset of paresis; and to the same types of functional disorder, and 

 tendency to obsessing suspicious and delusional ideas, in senile insan- 

 ity in which active symptoms may measurably or wholly disappear. 

 All the psychoses called functional for purposes of classification, 

 and being nearest to normal, constitute the main division of the 

 psychoses (considered as mental disorders); all the psychoses 

 called deteriorating, and being exceptions to the others, constitute 

 the minor division. In these the fact that in some particulars the 

 reductions of functional efficiency remain permanently deterior- 

 ating constitutes dementia, which implies some form of structural 

 change, though none strictly characteristic has yet been found. 

 The pathological principle here suggested leads to a practical method 

 of analysis of the symptom-factors of all possible forms of deteri- 

 orating psychoses. The first step is the distinction of the purely 

 functional modifications referable to physiological sources; these 

 relate to variations of the fundamental irritability as explanatory 

 of changes of motility and of the sensibilities and emotional tone, 

 all being comprehended broadly in relation with the "somatic 

 group of senses;" closely kindred with these are the reductions 

 of function of the processes of association, memory, attention, 

 inhibition, etc. Holding apart these phenomena of the main di- 

 vision of psychoses as being included in the functional conception 

 of their pathology, and as explainable through their genetic and 

 developmental character, there remain, of the symptom-factors 

 of a deteriorating psychosis, those that point to the causes of the 

 special deterioration. This helps to define the problem of research 

 for anatomical explanations. It should not escape observation 

 that when there is "innate constitutional weakness" in cases be- 

 longing to the main group of functional psychoses, special modi- 

 fications may be noted in the symptom-factors, especially of the 

 attention and inhibition element whose reduction is the most con- 

 stant and characteristic fact of constitutional insufficiency. It is 

 in these conditions that the law of habit has its most potent and 

 perpetuating influence. The functional psychoses, including those 

 answering to the definition of "a typical form of insanity," present 

 some points of special interest when analyzed in accordance with the 

 method and principles examined in the foregoing pages. Refer- 

 ence has been made to Griesinger's descriptive definitions of melan- 

 cholia as "states of mental depression" and mania as "states of 



