We have no right to attempt to impose on any human creature an exaggerated and one-sided development.

But it is not only our right, it is our duty, or rather one may say, the natural impulse of every rational and humane person, to seek that only such children may be born as will be able to go through life with a reasonable prospect that they will not be heavily handicapped by inborn defect or special liability to some incapacitating disease.

What is called "positive" eugenics--the attempt, that is, to breed special qualities--may well be viewed with hesitation.

But so-called "negative" eugenics--the effort to clear all inborn obstacles out of the path of the coming generation--demands our heartiest sympathy and our best co-operation, for as Galton, the founder of modern Eugenics, wrote towards the end of his life of this new science: "Its first object is to check the birth-rate of the unfit, instead of allowing them to come into being, though doomed in large numbers to perish prematurely." We can seldom be absolutely sure what stocks should not propagate, and what two stocks should on no account be blended, but we can attain reasonable probability, and it is on such probabilities in every department of life that we are always called upon to act.
It is often said--I have said it myself--that birth-control when practised merely as a limitation of the family, scarcely suffices to further the eugenic progress of the race.

If it is not deliberately directed towards the elimination of the worst stocks or the worst possibilities in the blending of stocks, it may even tend to diminish the better stocks since it is the better stocks that are least likely to propagate at random.