CHAPTER XII 



DOUBLEDAY'S THEORY AND RECENT 

 EXPERIMENTS 



I WAS fortunate enough some time ago to come across 

 an old copy of the now almost forgotten work of Thomas 

 Doubleday on The True Law of Population. My previous 

 knowledge of the work had been confined to a brief 

 criticism of Doubleday's theory by Herbert Spencer in 

 a footnote to his Principles of Biology. Never seeing the 

 theory mentioned elsewhere, I had attached no importance 

 to it. And probably the work is known to very few 

 students of the problem of the birthrate, since they are 

 not likely to become acquainted with the theory unless 

 they come across a copy of the book. It is but fair to 

 Thomas Doubleday to point out that as far back as the 

 year 1841, and even earlier in Blackwood's Magazine for 

 March 1837, in an article under the title " A Letter to 

 The Right Honourable Lord Brougham," he had per- 

 ceived and stated that the rise in the birthrate about 

 that period was closely connected with the fall in the 

 standard of living. And his argument distinctly implied 

 that the only way to check the excessively heavy birth- 

 rate was to improve the condition of the mass of the people. 

 Malthus had recently developed his famous theory that 

 the evils from which society suffers are, in the absence 

 of sexual restraint, necessary to keep down the numbers 

 of the population. Doubleday retorted that these evils 

 were the cause of the heavy birthrate, and that the chief 



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