So I'm re-reading Asimov's The Caves of Steel, and as one of the Spacers is explaining the offworld way of life to our hero - no disease, great longevity, sparse population, plenty of robots for the dirty work - he drops this little bombshell:
"Logically, developing children are carefully screened for physical and mental defects before being allowed to mature."
Baley interrupted. "You mean you kill them if they don't -"
"If they don't measure up. Quite painlessly, I assure you. The notion shocks you, just as the Earthman's uncontrolled breeding shocks us."
"We're controlled, Dr. Fastolfe. Each family is allowed so many children."
Dr. Fastolfe smiled tolerantly. "So many of any kind of children; not so many healthy children. And even so, there are many illegitimates and your population increases."
"Who's to judge which children should live?"
"That's rather complicated and not to be answered in a sentence. Some day we may talk it out in detail."
I can't remember off the top of my head whether Asimov does explore this further in later novels. But holy flaming cow, the implications! What exactly does "allowed to mature" mean? Where's the cut-off point for the detection of "defects" - infancy? Puberty? Majority? Do acquired "defects" count, such as a lost limb? Do they do surgical repairs and/or gene therapy
in utero? The first signs of my chronic illnesses began to appear when I was about eighteen. How many of us would have made it to Spacer adulthood?
But the really extraordinary thing is this:
how did they install this system in the first place?! How do you convince people who have essentially unlimited space and resources (and again, shedloads of robots) to kill their own children? The only thing I can think of is that originally existence on the colony worlds was incredibly harsh, and they became so used to losing children that they began softly killing kids they knew wouldn't survive; if you iterated this for thousands of years, could you end up with a system in which "individual life is of prime importance", which could easily provide all the care the most disabled child could possibly need, and yet weeds out the imperfect? There are uneasy parallels here with our own world, which has enough resources for all, but lets children starve.