One fine day, however, Europe discovered a vast continent in the midst of the ocean. Then it dawned upon her that Prometheus had been but a clumsy thief, for he had stolen only a tiny spark of fire; she discovered mines, coal, and electricity. She created the steam-engine and all the other machines which have been derived from it. She succeeded in multiplying riches with a rapidity unimagined by remoter ancestors. From that moment, man no longer contented himself with dreaming of the Promised Land. He wished to go there. He destroyed all the traditions, the laws, and institutions which place limitations upon the store of human energy. He learned to work swiftly. At a single stroke, he conquered liberty and riches, and he conceived the idea of progress. If America seems to-day to symbolise this movement, which has turned the world topsy-turvy, the movement was derived from Europe. After having conceived the idea of such a revolution, could Europe remain untouched by it? * * * * * It would appear then that the riddle of America is very simple. The answer contains nothing to make us uneasy. The riches of the New World threaten no catastrophe to the noblest traditions of our civilisation. For New York’s wealth is only a part of the riches produced in the same economic development in the two worlds. The ultimate development of these mighty riches might be merely a general advance, both material and ideal, of Europe and America. Rich and prosperous Americans might try to assimilate the culture of Europe, and on her part Europe, in her effort to increase her own riches, might seek to equal America. But a historian of antiquity who returns from America cannot share this optimism. In the lap of modern civilisation, there are twin worlds struggling with each other for leadership. But these two worlds are not, as people are apt to think, Europe and America. Their names are Quality and Quantity.