The more firmly we believe that the diminution of the population is a natural process, the more strenuously, surely, we ought to guide it, so that it shall work without friction, and, so far as possible, tend to eliminate the undesirable stocks of man and preserve the desirable.

Clearly, the theory itself calls for much effort, since it is obvious that along natural lines the decline, if it is the result of high evolution, will affect the fit more easily than the unfit.
[29] The reader may point to the renewal of Militarism and Imperialism in France since the Great War.

That, however, has been an artificial product (in so far as it exists among the people themselves) directly fostered from outside by the policy of England and the United States, just as the same spirit in Germany before the war, in the face of a falling birth-rate, was artificially fostered from above by a military and Imperialistic caste.
[30] See especially Mathorez, _Histoire de la Formation de la Population Francaise_, Vol.

I, 1920, _Les Etrangers en France_.

The fecundity of French families, even among the aristocracy, till towards the end of the eighteenth century, was fabulous; in the third quarter of the seventeenth century the average number of children was five in Paris.
But the mortality was extremely high; under the age of sixteen, Mathorez estimates, it was 51 per cent., and infant mortality was terrible in all classes, small-pox being specially fatal.