LAW OF PANMIXIA 261 



the slow, the sickly, the defenceless. And it is necessary, it 

 is indispensable to the species, that these useless members 

 should be eliminated; for otherwise, and by virtue of the 

 law of panmixia, organic deterioration of the whole species 

 would set in, and its extermination would be the ultimate 

 result. 



Thus, the law of selection is not only beneficial, it is indis- 

 pensable for the conservation of the species. In human societies, 

 to as great an extent as in animal societies, this law of selection 

 prevails. It may therefore be urged that those phenomena 

 which we consider as pathological elements in social life are 

 merely normal features, due to the rapidity of social evolution, 

 and determined by the law of selection. But this contention 

 is rendered untenable by a single consideration. Selection, 

 ,,_—— operating within a species living under natural conditions, 

 causes the extinction of weak and diseased members of the 

 species, and the survival of the better adapted members. But 

 in civUised society to-day precisely the contrary is the case. 

 Granted that only the morbidly predisposed fall victims to 

 mental disease, and that, in this way, a diseased element is 

 removed from social life — a contention which, however, is not 

 by any means universally valid — the fact remains that mental 

 disease is continually increasing, both absolutely and relatively. 

 Consequently, a diseased element is ever increasing, and in- 

 creasing at the expense of the non-diseased elements ; and 

 therefore a biological deterioration is in progress. Here we 

 have the diametrical converse of what ought to happen were 

 selection permitted to operate normally, by the extinction of 

 the unfit and the multiplication of the fit. It is the unfit who 

 are being multipHed — a result contrary to the basal principle 

 of the law of selection, and equally contrary to the fundamental 

 interests of the species — in this case, human society. 



We are thus justified in seeing in this increase of mental 

 disease a phenomenon of social pathology. It is not a case of 



