There is a steady check in an old civilisation upon the fertility of the abler classes: the improvident and unambitious are those who chiefly keep up the breed. So the race gradually deteriorates, becoming in each successive generation less fit for a high civilisation.
I have already spoken in Hereditary Genius of the large effects of religious persecution in comparatively recent years, on the natural character of races, and shall not say more about it here; but it must not be omitted from the list of steady influences continuing through ancient historical times down, in some degree, to the present day, in destroying the self-reliant, and therefore the nobler races of men.
A really intelligent nation might be held together by far stronger forces than are derived from the purely gregarious instincts. A nation need not be a mob of slaves, clinging to one another through fear, and for the most part incapable of self-government, and begging to be led; but it might consist of vigorous self-reliant men, knit to one another by innumerable ties, into a strong, tense, and elastic organisation.
All male animals, including men, when they are in love, are apt to behave in ways that seem ludicrous to bystanders.
The following question had been much in my mind. How is it possible for a population to remain alike in its features, as a whole, during many successive generations, if the average produce of each couple resemble their parents? Their children are not alike but vary...
One of the effects of civilization is to diminish the rigour of the application of the law of natural selection. It preserves weakly lives that would have perished in barbarous lands.