Good. Too good.

The problem with some political ideas is that they’re too good.

Take grammar schools. Grammar schools are clearly excellent. Everyone who went to one will tell you how great they are. It was the greatest contribution to social mobility, half a century before that phrase existed. It’s like a public school, but without the bills and the guilt.

They were small, local bundles of excellence, and everyone had a chance of getting in. People who went to them have risen to prominence in the land, based on nothing but their own excellence. And it provided a pleasant working environment for teachers, so the state sector didn’t lose all of its more delicate flowers to the independents.

How were grammar schools so wonderful? Because they selected which kids they wanted. This meant that some kids weren’t wanted, and they had to be taught somewhere else. And those schools, the ‘somewhere else’ which used to be called secondary moderns, are the reason why the grammar school system is a bad one.

The conversation goes like this. The left says, ‘The grammar school system was bad.’ The right says, ‘But grammar schools are wonderful.’ The left replies, ‘Yes, I know, that’s exactly the problem.’ And the right says, ‘You bloody lefties - you hate success.’

The way it turned out, the grammar schools system was horrible, and created social divisions. Society was now divided up based on how clever you were at age 11. And considering the stupidity of all 11-year-olds, that’s a pretty crazy measure.

There are worse ways of choosing how to divide up society - the size of your father’s house, or how many of your family’s generations can you count back, for example. So it was an improvement. And the proportion of people getting into the better bracket was larger than it had been before. But it was still a system based on dividing people up into the right kind and the wrong kind. And without any plan for what the wrong ’uns are then meant to do with their lives.

And, of course, vestiges of the old system remained. Wealthy families would give their children every support they could to pass the 11-plus. And if they failed, they would be shipped out to a public school that specialised in less academic pursuits such as rugby, dressing as a soldier, and geography. And however supportive poorer families want to be towards their 11-year-old scholars, there’s a limit to how much academic preparation they can do in a household short on spare rooms and tables.

It was a cruel system as it turned out, but it was never meant to be like that. The system was meant to be based on three types of school, not two. The idea was that if you wanted an academic schooling, you would go for a grammar school. If you wanted a practical schooling, you went to a technical school. And if you wanted a bit of both, you went to a secondary modern. Think of a grammar as a Lion bar, a technical as a Snickers, and a secondary modern as a Picnic.

They were all meant to be excellent schools. Two different kinds of specialists, and one generalist. But two things happened. First, everyone wanted to go the grammar schools. British parents want their children to go to university, get an arts degree, then settle into an uninspiring job in publishing. They do not want them to become plumbers, and retire a millionaire at 32. God knows why.

The other thing that happened, or more accurately didn’t happen, is that the government didn’t build enough technical schools. So, in practice, very few parents had the full choice. Grammar schools became where you wanted to go, secondary moderns were for the failures, and technical schools were little quirks of local history, like a oddly-coloured windmill or a church with a crooked spire. Confused tour guides would routinely point at technical schools and say, ‘I think it’s some kind of water tower.’

Grammar schools are a fairly small issue these days. Not many areas still have them, and there are bigger problems to deal with in education. The comprehensive school system that replaced it didn’t repeat the mistakes of the grammar school system - it made a whole load of brand-new ones.

So why bang on about grammar schools? Aren’t there enough real problems in politics without raking over generations-old disagreements?

The grammar school system is a very useful archetype. It is a clear example of when the well-meaning right do something which is partially wonderful, but detrimental overall. They then always use the same debating tactic: distraction. When an unfair system is attacked, the right can say, ‘But look at this beautiful, big, shiny, wonderful thing that everyone likes. Hey everyone, you know that brilliant thing you like? The left want to take it away. Boo.’

Of course, the right aren’t very fond of government at the best of times. They instinctively dislike the idea of a big central system controlling everything. Sometimes this means that they don’t have a big central system. But more often, they do have a big central system, but pretend it isn’t there. Then when the left object to the system, the right say, ‘What system? There’s no system here. This is just me and my friends relaxing and having fun - hey, don’t kill the buzz, man.’

The right knows that the electorate at large aren’t terribly interested in political theories, and if you object to a policy on national rather than local grounds, that sounds a lot like a theory. They encourage the thought, ‘Well, I don’t know much about your big fancy ideas, all I know is that the trains run on time.’

The right likes to pretend that their policies are better, because they can tell stories of individual people who benefit. Whereas the left have to talk in vaguer terms, because it’s not possible to have had a chat with everyone who would benefit from a more equal society. The right like to position themselves as the protectors of the individual. But the left looks after many more individuals than the right. They just may not be individuals you went to school or have played golf with.

Grammar schools were great; the grammar school system was terrible. It’s a very slightly complicated idea - that a single positive by-product cannot justify an entire unfair system - that the right love to pretend they cannot understand. And from the current government, each a beneficiary of an excellent (and often expensive) education, that feigned stupidity is not an edifying - or even particularly convincing - sight.