It must, however, be pointed out that, even assuming that the facts are as stated; it is a hazardous assumption that the best stocks are necessarily the stocks of high social class.
In the main no doubt this is so, but good stocks are nevertheless so widely spread through all classes—such good stocks in the lower social classes being probably the most resistent to adverse conditions—that we are not entitled to regard even a slightly greater net increase of the lower social classes as an unmitigated evil.
It may be that, as Mercier has expressed it, "we have to regard a civilized community somewhat in the light of a lamp, which burns at the top and is replenished from the bottom."
The soundness of a stock, and its aptitude for performing efficiently the functions of its own social sphere, cannot, indeed, be accurately measured by any tendency to rise into a higher social sphere.
On the whole, from generation to generation, the men of a good stock remain within their own social sphere, whether high or low, adequately performing their functions in that sphere, from generation to generation. They remain, we may say, in that social stratum of which the specific gravity is best suited for their existence.
Yet, undoubtedly, from time to time, there is a slight upward social tendency, due in most cases to the exceptional energy and ability of some individual who succeeds in permanently lifting his family into a slightly higher social stratum.14 Such a process has always taken place, in the past even more conspicuously than in the present. The Normans who came over to