CHAPTER XV 

 ALCOHOL 



The essential constituents of alcoholic beverages The reasons why men 

 drink The types of men that drink for thirst, taste, and the cerebral effects 

 The question as to whether alcohol is beneficial or harmless The mental effects 

 produced by alcohol Normally no man drinks except for the pleasure that 

 drinking affords Inheritance and acqiiirement in relation to alcohol The hypo- 

 thesis that men drink in proportion as they do, or do not, exercise self-control 

 The causes that determine the extent of indulgence The inheritance of sus- 

 ceptibility to the charm of alcohol Individuals differ as regards susceptibility 

 Selection in relation to alcohol. 



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472. ~^~^ T'E see, then, that disease is the only factor, at any 

 rate the only clearly recognized factor, of selective 

 elimination sufficiently stringent amongst civilized 

 men to be a cause of progressive evolution. The racial changes 

 resulting from it have rendered many peoples of the Old World so 

 resistant to the endemic diseases of their own countries that they 

 are now able to dwell in large and settled communities and so 

 achieve civilization. On the'other hand, civilization, with its dense 

 populations and constant intercourse with distant peoples, has 

 conveyed to and rendered prevalent in every country the diseases 

 to which the environment is suitable. The races to which civiliza- 

 tion with its endemic diseases came so slowly that the birth-rate 

 tended to exceed the death-rate, are adapting themselves to the 

 new conditions. The rest have become extinct or are drifting 

 towards extinction. 



473. But parasitic micro-organisms are not the only causes of 

 selective disease amongst civilized men. Certain narcotics, of 

 which the principal are alcohol and opium, are causes of disease, 

 disablement, and death, as stringently selective and as widespread 

 as any parasitic species. Unfortunately, we now enter a region 

 of discussion which has ever been a playground of passion and 

 prejudice, born, on the one hand, of self-interest, and, on the other, 

 of a fanaticism as unreasoning as any that has been displayed in 

 religious controversy. Here the disputants have belonged mainly 

 to classes peculiarly unfitted for the calm discussion of what are 



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