HUMAN IMPLICATIONS 8I5 



and perhaps less occupied planets. And there is a 

 rapidly expanding human population, which is even 

 now becoming uncomfortably dense in the crowded 

 nations. It is often said that this is a fundamental 

 cause of tension which makes wars inevitable, as 

 hard-pressed dense populations seek food in more 

 amply-provided areas. 



The desirable biological results of wars so induced 

 have been, and still are, supposed to be two: 



1. The dense populations are thinned to the bear- 

 able point as a result of the fighting, or 



2. Superior nations, or races, are victors. They 

 expand at the expense of the defeated inferior group 

 and so occupy more of the limited space which is 

 available for men. 



Let us test these theories against the known facts. 

 Roughly speaking, there are about fifty-two million 

 square miles of land surface on the earth. (95) This 

 includes the habitable plains of the temperate re- 

 gions; it also includes the relatively uninhabited 

 deserts, tropical jungles, and mountains. Approxi- 

 mately one-fourth of these fifty-two million square 

 miles is desert or semi-desert and can support only 

 a sparse population of men. This leaves roughly 

 forty million square miles of non-arid land theoreti- 

 cally open to human habitation. 



On this land there are living at present, accord- 



