452 THE POPULAR SCIENVE MONTHLY. 



Still, it may be said, this is, after all, only unscientific opinion. 

 Has Science, with her more careful method of investigating and prov- 

 ing, anything to say on this interesting theme ? It is hardly to he 

 supposed that she would have overlooked so fascinating a subject. 

 And, as a matter of fact, it has received a considerable amount of 

 attention from pathologists and psychologists. And here for once 

 Science appears to support the popular opinion. The writers who have 

 made the subject their special study agree as to the central fact that 

 there is a relation between high intellectual endowment and mental 

 derangement, though they differ in their way of defining this relation. 

 This conclusion is reached both inductively by a survey of facts, and 

 deductively by reasoning from the known nature and conditions of 

 great intellectual achievement on the one hand, and of mental disease 

 on the other.* 



What we require first of all is clearly as many instances as can be 

 found of men of genius who have exhibited intellectual or moral pe- 

 culiarities which are distinctly symptomatic of mental disease. Such 

 a collection of facts, if sufficient, will supply us with a basis for induc- 

 tion. In making this collection we need not adopt any theory respect- 

 ing the nature either of genius or of mental disease. It is sufficient to 

 ay that we include under the former term all varieties of originative 

 power, whether in art, science, or practical affairs. And as to the 

 latter term, it is enough to start with the assumption that fully devel- 

 oped insanity is recognizable by certain well-known marks ; and that 

 there are degrees of mental deterioration, and a gradual transition 

 from mental health to mental disease, the stages of which also can, 

 roughly at least, be marked off and identified. 



In surveying the facts which have been relied on by writers, we 

 shall lay most stress on mental as distinguished from bodily or nervous 

 symptoms. And of these we may conveniently begin with the less 

 serious manifestations : 



1. The lowest grade of mental disturbance is seen in that tempo- 

 rary appearance of irrationality which comes from an extreme state of 

 " abstraction " or absence of mind. To the vulgar, as already hinted, 

 all intense preoccupation with ideas, by calling off the attention from 

 outer things and giving a dream-like appearance to the mental state, 

 is apt to appear symptomatic of " queerness " in the head. But in 

 order that it may find a place among distinctly abnormal features this 

 absence of mind must attain a certain depth and persistence. The 

 ancient story of Archimedes, and the amusing anecdotes of Newton's 



* The principal authoritative utterances on the subject are Moreau, " La Psychologie 

 morbide," etc. ; Hagen, " Ueber die Verwandtschaft des Genies mit dem Irresein " 

 (" Zeitschrift fur Psychiatrie," Band 33) ; and Radestock, " Genie und Wahnsinn (Breslau, 

 1884). This last contains the latest review of the whole question, and is written in a 

 thoroughly cautious scientific spirit. I have derived much aid from it in preparing this 

 essay. 



