But who cares about the pupils who fail?

It is a pity that downward mobility is an inescapable part of the social mobility that everyone is so fervently recommending. In all the fuss about grammar schools and selection there is a distinctly nasty undertone. Some of the most passionate defenders of grammar schools seem to me to take a somewhat heartless view, possibly because many owe their own success to a good grammar.

It is my experience that there is nobody more dismissive of the underprivileged than people who have fought their way up and out of modest backgrounds. “I’m all right, Darren” is what they’re saying in code. If not quite that, they are at least expressing a concentration on the brightest children and their upward mobility, rather like their own. But what about all the rest? After all, the rest make up much more than half the school population.

The ardent defenders of grammar schools often have little to say about those children, and perhaps little interest in them. I too am all in favour of doing everything possible to offer the brightest children the best possible education for the country’s benefit as well as their own; I am all in favour of upward mobility and I am all in favour of the selection needed (in some form) to produce it for them.

But what about the real pain involved for the children who failed the 11-plus and were consigned, so young, to a second-rate secondary modern and a third-rate future? And what about the inevitable downward mobility, which is an inescapable part of the social mobility that everyone is so fervently recommending? Besides, it’s better understood now that intelligence is too varied and too complex to be properly assessed by a fairly crude IQ test at 11.

Any morally respectable education policy ought to be equally concerned about the average child, the less bright child and the late developer and, for that matter, all the bright children who would, for all their obvious gifts, have failed the old 11-plus.

There are some distinguished people today (whom I won’t name) who fall into that category, and who, like the not so distinguished John Prescott, have never got over it. Paying careful attention to all schoolchildren and how best to teach them in their own interests is not just a matter of what we call social justice these days, or what is morally right.

The political calculation that the public won’t wear grammar schools may well be wrong, but all the same the Cameroons are broadly right. If we are to have a monolithic state education system, it cannot be one that separates the wheat from the chaff at 11. What was more or less acceptable just after the war, in much less egalitarian and aspirational times, is no longer acceptable today in a publicly funded universal state system, as David Willetts says.

It’s true that grammar schools generally worked well for the chosen, and it is usually a mistake to destroy something that works. Margaret Thatcher to her shame has the distinction of closing more grammar schools than anyone else. But now that there are so few grammar schools left – and why not leave them alone as Conservatives propose? – this is a moment to reform our disastrous education system in a humane and imaginative way.

The Cameroons are at least trying to catch the moment and it is rapidly becoming a defining moment for them. Not surprisingly they are finding it difficult. They accept what all but the most diehard socialists now admit: that children need to be taught with other children of similar ability. Children cannot learn well in classes of mixed ability. That’s been demonstrated beyond denial. But this involves selection, somehow, and the Cameroons are anxious that selection should not mean segregation.

I do not believe that most Conservative supporters, even those clamouring for grammars, want segregation either, in practice; it has, after all, a nasty way of segregating one’s own children in ways one might not like or expect. But in practice it is difficult to select without segregating.

Willetts speaks enthusiastically of setting and streaming as the way to square this circle but I am unconvinced. Until recently both were anathema in the “educationist” orthodoxy, which in great part explains the shocking failure of comprehensive schools. Nonetheless both have been brought back to a degree. However, as a total solution it seems unpromising. While I agree with Willetts’s general approach, I doubt whether he and his policy wonks have done the research on the numbers.

In any contemporary nonselective school, there is an obvious practical problem with trying to teach all children with their peers. In each year group of, say, 100, there will be a lot of children of roughly similar ability, clustering round the norm, who can indeed be settled and streamed well.

But there will also be a few children of high or very high ability along with some who are slow or intellectually impaired, and there won’t be enough of these children to form workable classes even in a large comprehensive. That’s simply a matter of numbers, because of the usual distribution of intelligence across the population.

Among 100 unselected children you would normally expect only nine or 10 of high or very high ability at the most, and only five or so of very low ability. When I say high ability, I mean – crude though this measure is – an IQ of 120 or more.

At both top and bottom it would be impossible to find enough children in a year group of 100 to put together a classful of like-minded pupils; you couldn’t have classes of two or three. Simply saying the magic words “setting and streaming” will not make this problem disappear. In theory one could have bigger schools, but huge schools are bad for children. Many comprehensives are simply too big.

The Conservatives will have to come up with subtle solutions to this problem to have a credible education policy. I think the answer is to abandon a monolithic school system and encourage a variety of different schools, including access to special schools for the few who need them, and great mobility between schools.

By its complexity this would take the sting out of any questions of selection – there would be no obvious educational sheep and goats, no obvious hierarchy of schools – and this is what the Conservatives are considering. Meanwhile, they are right about grammar schools.