Introduction

THE purpose of this article is to examine the bearing of some recent biological and psychological work upon the theories of the cause of war. The authors hold that war-or organized fighting between

large groups of adult human beings-must be regarded as one species of a larger genus, the genus of fighting. Fighting is plainly a common, indeed a universal, form of human behaviour. It extends beyond the borders of humanity into the types of mammals most closely related in the evolutionary classification to the common ancestors of man and other apes. War between groups within the nation and between nations are obvious and important examples of this type of behaviour. Since this is so, it must of necessity follow that the simplest and most general causes of war are only to be found in the causes of fighting, just as the simplest and most general causes of falling downstairs are to be found in the causes of falling down.