THE THREAT OF OVERPOPULATION I95 



ever, are rising— exploding is the better w^ord— and the third 

 method will eventually fail through the law of diminishing 

 returns. Populations have already, or will soon, pass the pos- 

 sible limits of production and technology. Then, say most 

 of those who are aware of the problem, the fourth method, 

 namely, birth control, must be applied or nature herself will 

 marshal her lethal weapons against us. 



It was Thomas Alalthus at the opening of the nineteenth 

 century who forcefully called attention to the danger of 

 a world-wide population increase. He pointed out that the 

 problem was to provide for those who were in want and 

 that as populations increased, it became more and more dif- 

 ficult, even impossible, for all to receive an adequate diet. 

 He thought that man's growth in numbers was largely 

 dependent on the supply of food, and we confirm this to a 

 certain extent even in our day. It is true that sometimes 

 devastating epidemics cut heavily into a population, but 

 often these killers are more or less directly connected with 

 food scarcity which has lowered the population's resistance 

 to disease. For the great hordes of people in China and India 

 one of the factors determining the death rate is the amount 

 of food. In his day Malthus had access to only limited and 

 inaccurate data on the problem; yet, nevertheless, he gave 

 us the fundamentally correct view of man and his food sup- 

 ply—a view which sets a limit to the possible world popula- 

 tion. 



Malthus could not foresee the great advances in science 

 and knowledge which were to make possible enormously 

 greater food supplies than he could have imagined. But he 

 did foresee that the greater the quantity of food available, 

 the greater will be the increase of individuals in the popula- 

 tion. He was well aware of a fact that has been verified 

 many times since his day; namely, that well-fed humans, 

 like any other animal, are more healthy, more resistant to 

 disease, and more liable to reproduce. In a well-fed popula- 

 tion the death rate falls and the birth rate rises. Here is the 



