For this reason, I thought that the great problem of the limits might grow little by little, on board a transatlantic liner, out of a discussion about America. An Italian, who has made money in America, and who, like so many Europeans who have made their fortune thus, is an admirer of the New World, one evening launches out into a eulogy of young America at the expense of old Europe. He extols the civilisation of machinery, progress, and liberty, by contrast with what remains in Europe of the ancient civilisation whose efforts were directed to improving the quality of things rather than augmenting their quantity; which left the world poor while it created arts, religions, moralities, and rights. The discussion becomes heated, complicated, and diffuse until, under the guiding influence of an old savant who knows Europe and America too, it concentrates on this point: Granted that man was well-advised to exceed the ancient limits within which preceding civilisations had confined him, to hurl himself on the world and to conquer it; up to what point may man aspire to liberty in every department of life, without endangering in the long run the most precious fruits of his conquest? The book does not pretend to solve this formidable problem. No philosopher, no writer, no book could solve it. It can only be solved by a radical revolution in the ideas, sentiments, and interests of the masses. But the book which I have written purports to throw light on some, at least, of the essential aspects of the problem. It endeavours to make it clear to the men of our time, by harping on a principle of great antiquity, great simplicity, and great modesty, which may be perhaps usefully recalled to the memory of present generations, in Europe as well as in America. That principle is, that man is a being of limits; and that he ought, therefore, to observe in his desires a certain mean. A civilisation must remember that it is the sum of the efforts of a great many individuals; that these individuals may be very numerous, but that each one is a small limited being; and that the sum of their efforts cannot be infinite. Consequently, a civilisation must not let its desires and wishes extend untrammelled in every direction. It must learn to confine itself within limits. VI THE RIDDLE OF AMERICA