Really high-minded people are indifferent to happiness, especially other people's.
If a Black Death could be spread throughout the world once in every generation survivors could procreate freely without making the world too full.
...impregnation will be regarded in an entirely different manner, more in the light of a surgical operation, so that it will be thought not ladylike to have it performed in the natural manner.
There are three ways of securing a society that shall be stable as regards population. The first is that of birth control, the second that of infanticide or really destructive wars, and the third that of general misery except for a powerful minority.