"All those principles and rules which we call Morality are, in fact, mere rules of the game of life. We play the game or do not play it; we are fair or unfair. "On the whole, most of us try to be fair because it has been found that playing the game with a sense of fairness is the only way in which we can succeed in working together for common ends without the necessity of imposing upon ourselves coercive rules to hold our organization together for possible mass attack upon the end in view. "Social life, in this sense of playing the game fairly, has made man the superior of the brutes he sprang from. There is nothing mysterious or recondite about it. "In order to work together men must understand one another. Therefore, natural selection has picked out the intelligent for survival in the social world; and in order to work together intelligent men must depend on one another, abiding by their covenants. "Therefore, again, natural selection has picked out what we call Morality for survival in the social world. The whole further progress of mankind would seem to hang upon the possibility that we can find a way to limit and, if possible, to terminate wars between nations, for only in that contingency can we hope to develop a social system in which a supreme efficiency with a maximum of individual liberty can be combined upon a working basis." Application of the Facts. "These are incontrovertible facts, and they find their application to the existing European situation in various ways, the most important of which will appear in the discovery that, valuable as conventions and covenants of nation with nation may be, and intolerable as any violation of them surely is, we cannot hope for general and unfailing observance of them until the feeling of mankind and the whole attitude of the world in respect to international as well as private conduct shall be that the covenants and conventions shall become, in a degree, unnecessary. "Already it is apparent that the entire world, including the peoples of the nations at war as well as the peoples of the nations remaining happily at peace, have, begun to think these thoughts and reflect upon their momentous importance. "Shocked and stunned as never before by a calamity for which we find no measure in past human experience, mankind is bound to take at this moment a more sober view, a broader and more rational view, of the problems of responsibility and collective conduct than it hitherto has been able even to attempt. "The world is sure to ask what things make for sobriety of judgment and integrity of purpose. It is sure in future more carefully to weigh relative values, and will be disposed to count as unimportant many things for which hitherto the armed men of nations have rushed into war. "In a word, this war has made the whole world think as no one thing ever has made it think before, and, after all, it is upon the habit of thought that we must depend for all rational progress.