262 HEREDITY AND SELECTION IN SOCIOLOGY 



the " elimination of the waste matters of the social organism " ; 

 for precisely these elements, morbid in the extreme, are Tiot 

 eliminated as they should be, but are retained and allowed to 

 multiply. The diseased member is not removed from active 

 social life, but is permitted to mix freely with it, contaminating 

 those who are not diseased. In civilised States, owing to the 

 changed conditions brought about by social evolution, the sur- 

 vival of the individual no longer depends on the perfection of his 

 vision, as did that of the members of the primeval tribes seeking 

 their prey in the forests. Individuals, therefore, in whom the 

 faculty of vision is less well developed — such as the short-sighted 

 — are allowed to survive and multiply on equal terms with those 

 in whom it is more highly developed. When this is the case, 

 a progressive deterioration of the faculty of vision in the whole 

 race must set in, in accordance with the law of panmixia. This 

 law may be defined as the equalisation of conditions for the 

 more evolved and the less evolved. The consequence is obvious : 

 when the more evolved have no advantage, and when the less 

 evolved are able to survive and multiply as freely as they, then 

 the standard of development attained by the more highly evolved 

 — which, under natural conditions, is necessarily attained by 

 all the survivors of the species — must inevitably be lowered. 

 It will no longer be common to the species as a whole ; those 

 individuals who possess it will not be selected ; and, finally, it 

 will become a rarity. No doubt exists as to the deterioration 

 of the visual faculty under the artificial conditions created by 

 social evolution. There is probably not a species among verte- 

 brates whose visual faculty is not infinitely greater than that of 

 civilised man. 



It is the same with any faculty. If a faculty is to be main- 

 tained at a certain degree of development, all those individuals 

 possessing a regressive variation of it must be rigidly exter- 

 minated before attaining maturity. For it is obviously useless 

 to exterminate such individuals if we permit them first of all to 



