DARWIN 



supply can increase only by an arithmetical ratio; 

 thus the world is bound to become overpopulated and 

 fall a prey to misery and suffering owing to the strug- 

 gle for existence which must ensue. This postulate is 

 based on what he asserted to be two imperative in- 

 stincts of the human being, — the desire for food, and 

 to procreate. Thus, it is a mistake to relieve suffering 

 since the only means to reduce population, and so to 

 postpone the debacle of civilization, is to foster vice, 

 misery, and war, the three greatest causes of death. 

 Since each person has two parents, it must follow 

 that the number of anyone's ancestors doubles with 

 each generation as we go backwards in time, and they 

 form a geometrical series with the number two as a 

 multiplying factor. It is quite another matter when 

 we attempt to estimate the number of posterity any- 

 one will have in successive future generations; that 

 would be a pure guess. All persons have had the same 

 number of ancestors, counting an equal number of 

 preceding generations, and we may apply the law of a 

 geometrical series; but some will have no descend- 

 ants, others will have a few, and others will have 

 many. And so the population of any country, or even 

 of the whole race, may increase, remain stationary, or 

 decrease in number; there can be no law relating to 

 the future number of a population and no law of 

 future increase or decrease. We accept as a general 

 fact that many species of animals have increased in 

 number for a time and have afterwards decreased 



C 205 ;] 



