178 THE POPULAR SCIENCE MONTHLY. 



parts of the nervous system morbidly affected being exceedingly dif- 

 ferent. 



I have so far almost ignored the distinction between nervous states 

 and mental states. Now, if the case of insanity be considered as a 

 series of mental phenomena only, it would be absurd to compare or 

 even to contrast it with progressive muscular atrophy, which is a 

 series of physical phenomena only. But no difficulty can arise if it 

 be understood that insanity, or " disease of the mind," is with medical 

 men disease of the highest nervous centers revealing itself in a series 

 of mental phenomena. We compare and contrast disease of the high- 

 est centers with disease of some anterior horns (some lowest centers) 

 revealing itself in atrophy of certain muscles. But, acknowledging 

 this, it may be said that the two things are so exceedingly different 

 that it is frivolous to compare or even to contrast them on any basis. 

 Yet, no one denies that each is a morbid affection of the central nerv- 

 ous system ; this being granted, the rejoinder to those "who insist on 

 the extreme uulikeness is that the lesion in one is at the very bottom, 

 in the other at the very top, of the central nervous system ; two lesions 

 can not possibly be farther apart in the central nervous system. Still 

 it may be said that classification, on the principle of dissolution, if 

 true, is of no value ; that it is of no use making an orderly ascending 

 series from progressive muscular atrophy to insanity — of no use show- 

 ing that progressive muscular atrophy is redaction to a more auto- 

 matic condition in a small corner on the lowest level, that hemiplegia 

 is such reduction on a larger scale higher up, and that insanity is such 

 a reduction on the topmost level, and on the largest scale — that even 

 if this kind of work could be thoroughly well done it is not worth any 

 ane's while to do it. I grant that such a classification is not of direct 

 value, but yet I think it of much indirect value for clinical purposes. 

 We require in our profession two kinds of classification. The use of 

 two classifications may be easily illustrated. There is a classification, 

 or strictly an arrangement, of plants by the farmer for practical pur- 

 poses, and there is a classification of plants by the botanist for the 

 advancement of biology. I submit that there is no more incongruity 

 in classing together progressive muscular atrophy and insanity upon 

 the basis mentioned than there is in classifying the bamboo with 

 common grass, or the hart's-tongue with the tree-fern in a botanist's 

 garden. Such kind of classification of plants would be absurd in a 

 farm or kitchen-garden, and so would a classification of diseases of 

 the nervous system upon the principle of dissolution be absurd in an 

 asylum or in the wards of a hospital. I know of no other basis on 

 which cases of insanity, diseases of the highest centers, can be studied 

 comparatively with non-mental diseases of the nervous system — dis- 

 eases of lower centers. 



I next speak of different depths of dissolution. The deeper the 

 dissolution the shallower the level of evolution remaining. In hemi- 



