Education, education, education? For shame, for shame, for shame. New Labour’s failure to rescue state education, let alone improve it, will be its most disgraceful legacy. The Conservatives should not crow; when in office they also failed to take on the forces destroying education.

Each week the news is full of reports of stagnating standards, more university dropouts (one in seven students, despite government “investment” of £1 billion since 2003), a shortage of teachers, particularly in maths and science, and a majority of underqualified teachers. However, two dismal stories stood out last week, both as symptom and explanation of what is wrong.

One of the three leading universities in the country, Imperial College London, announced that in 2010 it would introduce an entrance exam for applicants because it cannot rely on A-level results. Sir Richard Sykes, the college’s rector, suggested that grade inflation in A-levels made them almost “worthless” as a way of choosing between candidates: “Everybody who applies has got three or four As.”

That is hardly surprising, since it isn’t difficult to get an A; last year 25% of all A-level papers were given a grade A. Oddly enough, there are people in the education world who still deny that A-levels and GCSEs have been debased. They must be wilfully blind to the evidence; last week, for instance, many newspapers printed a comparison of an old maths O-level exam paper with the contemporary GCSE one. The fall from rigour was lamentable.

Also last week, Professor John White of the notoriously progressive Institute of Education told us that traditional lessons were too middle class. Instead, he said, schools should teach skills such as “energy saving and civic responsibility” through “theme or project-based learning”.

At a conference on the national curriculum he argued that while private schools historically focused on the classics and elementary schools for the working classes concentrated on the three Rs, middle-class schools taught academic subjects such as English, science, history, geography, modern languages and Latin as “mere stepping stones to wealth” via university, which “fed [sic] into the idea of academic learning as the mark of a well-heeled middle class”.

This, he feels, was the basis of the Conservatives’ attempt to impose middle-class values by introducing a national curriculum of traditional subjects in 1988. Subject-based education like this, he thinks, favours the middle class and alienates many children, especially the disadvantaged. White specialises in the philosophy of education and, readers may be irritated to know, was recently a member of a committee set up to advise ministers on the secondary school curriculum.

It is hard to say which of these two stories is more infuriating. The rector of Imperial College is right. Contemporary A-level results, debased as they are, reveal little about a student’s suitability for serious study at a top university, but they never did, even at their most rigorous. When I was a teenager, top marks at A-level, although difficult to achieve, were considered irrelevant to getting into Oxford or Cambridge. Passes at A-level were required but what mattered were the entrance exams that both universities set. These were much harder than A-levels – and different.

It was considered at the time too obvious to mention that this was suitable only for the brightest academic children. All this was hard for teenagers who couldn’t get into Oxbridge and automatically excluded gifted children from poor schools and deprived backgrounds.

However, if you want a world-class university, attended by students who are not only bright but also well prepared for study as undergraduates, with a well stocked memory and well trained habits of thinking, reading and writing, there is no substitute for selection, however harsh.

At 18, sadly, it makes little difference why a particular teenager is not a good candidate – whether her bog-standard comp or her family or her natural ability failed her. It is not the proper role of a university to do anything about any of that – for one thing it is too late. It’s not the role of a university to experiment with social engineering, although the government forces it on them. It’s not the role of a university to offer remedial teaching, although plenty do. Maddening though it is to see people reinventing the wheel, Imperial College is right.

So too, oddly enough, is the infuriating White, at least in one way. Beneath his old-fashioned class hatred and his atavistic loyalty to discredited progressive teaching, lurks an awkward truth. An academic school education – a traditional grammar school education – is not suitable for most people.

It was never a good idea to impose a grammar school-style curriculum on all children in the state sector and subject them to it in large, mixed-ability classes. That served neither the few who were suited to it, nor the many who were not. It has indeed alienated the disadvantaged. Plenty of them would be better served, as White says, by practical vocational subjects. That was the vision of the old secondary moderns and the technical colleges. Can it be that the progressive White is trying to reinvent this regressive wheel?

Behind the rector’s story and the professor’s story lies the obstinate folly of generations of teachers and theorists of education. Obsessed with equality and social engineering, they refused to recognise the simple truth that children and students vary. Children are born with different abilities, into different environments, which exaggerate those differences: ignoring those differences is no way to help them all, nor is clumsy social engineering.

Imposing one kind of school, one class and one syllabus on everyone, in an attempt to iron out those differences, has been tragically wrong. Encouraging everyone to think they can get a university degree is unforgivably discouraging to the majority of young people who can’t and don’t.

The result has been a school system that suits almost nobody and public exams that mean almost nothing. As these two stories demonstrate, quality has been sacrificed to the pursuit of equality. It is shameful.