ABSTRACT
If war is due to the fundamental aggressiveness of human beings, who tend to fight as individuals and in groups, then there are two solutions and two solutions only—either human beings must be changed or their aggressiveness must be restrained. Neither of these courses appear to us to be impracticable. To say that fighting has been a universal tendency in human behaviour in the past does not imply that it must always remain so in the future. People are what they are not only because of their inherited natures, but also because of the form of environment in which their inherited natures have developed. Hence it may be possible to change the character of adult behaviour by changing the environment in which our unchanged hereditary element develops. And, in a different way, it may be possible to ensure peace long before the slow process of individual change is complete.
