Empires won by conquest have always fallen either by revolt within or by defeat by a rival.

Our civilization has evolved through the continuous adjustment of society to the stimulus of new knowledge.

Science has produced such powerful weapons that in a war between great powers there would be neither victor nor vanquished. Both would be overwhelmed in destruction.

As we have seen, the wireless and the airplane have made the world so small and nations so dependent on each other that the only alternative to war is the United States of the World.

There can be no peace in the world so long as a large proportion of the population lack the necessities of life and believe that a change of the political and economic system will make them available. World peace must be based on world plenty.

Knowledge acquired in biological research is seldom directly applicable to human beings ... The results of scientific research, obtained under these conditions, cannot be applied directly to human beings who vary widely in their hereditary make-up, in their environment, and in their past health record.

In the last fifty years science has advanced more than in the 2,000 previous years and given mankind greater powers over the forces of nature than the ancients ascribed to their gods.