When the ideology that spoke about "human degeneracy" was all the rage. Tens of thousands, maybe hundreds of thousands, of good people who would have made excellent parents were sterilised, because they were simple, or they looked wrong in the eyes of some medical bureaucrat on the make. And because they were poor and powerless. People with learning difficulties, Gypsies, people of mixed race.

It happened in all the "forward looking countries". It happened especially in America. And it was the good progressive liberal-minded people who were most in favour of it. For example Bernard Shaw and H.G.Wells in Britain, the equivalents in other countries. It's a horrible and shameful chapter in history, and it's been brushed under the carpet, and most people never even get to hear about it.

And when the Nazis came along, there were plenty of respectable people in democratic countries who saw this as one policy that they had got right - a sort of eugenic equivalent of the programme for building autobahns. The Nazis didn't invent it, they adopted it, largely as a way of getting some good public relations.

There aren't simple technical fixes for the nightmare situations that spaw talked about. You can't just identify who is going to be suitable parents in some simple infallible way. There have tragically been many cases where carefully vetted foster parents and adoptive parents have gone on to abuse the children placed in their care.

People who are "severely mentally challenged can make wonderful parents. So can people who are "physically ugly". And beautiful people with college degrees and high professional standing have done horrible things to their children, including murder.

And there are a lot of people who don't manage, but who could do a great job if they had the kind of help and support which they don't get. So many of the natural and traditional support and guidance systems have been swept away in a fragmented society.

And of course there are some people who are not capable of looking after children under any circumstances, and there have to be better ways of identifying when that is happening, and moving fast to protect the children.

And in those paragraphs I'm talking about people with college degrees well as people with learning difficulties.