The balance of organs and faculties in a race is a very delicate organic equilibrium.  How delicate we now know from thousands of examples, from the correlations of seemingly unlike parts, from the wide-spread effects of small conditions, from the utter dying out of races like the Tasmanians or the Paraguay Indians under circumstances different from those with which their ancestors were familiar.  What folly to interfere with a marvellous instinct which now preserves this balance intact, in favour of an untried artificial system which would probably wreck it as helplessly as the modern system of higher education for women is wrecking the maternal powers of the best class in our English community!

Indeed, within the race itself, as it now exists, free choice, aided by natural selection, is actually improving every good point, and is for ever weeding out all the occasional failures and shortcomings of nature.  For weakly children, feeble children, stupid children, heavy children, are undoubtedly born under this very regime of falling in love, whose average results I believe to be so highly beneficial.  How is this?  Well, one has to take into consideration two points in seeking for the solution of that obvious problem.

In the first place, no instinct is absolutely perfect.  All of them necessarily fail at some points.  If on the average they do good, they are sufficiently justified.  Now the material with which you have to start in this case is not perfect.  Each man marries, even in favourable circumstances, not the abstractly best adapted woman in the world to supplement or counteract his individual peculiarities, but the best woman then and there obtainable for him.  The result is frequently far from perfect; all I claim is that it would be as bad or a good deal worse if somebody else made the choice for him, or if he made the choice himself on abstract biological and ‘eugenic’ principles.  And, indeed, the very existence of better and worse in the world is a condition precedent of all upward evolution.  Without an overstocked world, with individual variations, some progressive, some retrograde, there could be no natural selection, no survival of the fittest.  That is the chief besetting danger of cut-and-dried doctrinaire views.  Malthus was a very great man; but if his principle of prudential restraint were fully carried out, the prudent would cease to reproduce their like, and the world would be peopled in a few generations by the hereditarily reckless and dissolute and imprudent.  Even so, if eugenic principles were universally adopted, the chance of exceptional and elevated natures would be largely reduced, and natural selection would be in so much interfered with or sensibly retarded.