"Civilization has taught man how to live in dense crowds, and by that very fact those crowds are likely ultimately to constitute a majority of the world’s population. Already there are many who prefer this crowded life, but there are others who do not, and these will gradually be eliminated. Life in the crowded conditions of cities has many unattractive features, but in the long run these may be overcome, not so much by altering them, but simply by changing the human race into liking them."