‘ELITISM is rife at the top of Scottish society,” the Social Mobility and Child Poverty Commission has recently concluded, and few would disagree. Indeed, elitism in Scotland can be quantified more or less precisely. According to the Commission’s figures, only six per cent of Scots went to private school, but that tiny minority account for 45 per cent of senior judges, 29 per cent of elite media professionals and 28 per cent of Scottish business leaders who were educated in the UK.

Everyone can admit that’s staggeringly unfair. “There can be few people in Scotland who believe that the sum total of talent resides in just six per cent of pupils in the country’s schools,” notes ex-Labour MP Alan Milburn, the Commission’s chair. No indeed.

It’s cold comfort to know that England’s figures are ever-so-slightly worse. In Scotland, we often congratulate ourselves on our elevated collectivist impulses, and hardly a day passes without a million social media graphics disparaging the Eton-educated toffs down south. All of which is perfectly good fun, except that, at the top, Scotland runs a social apartheid, a self-replicating caste system, nearly as cruel as England’s.

And this in a country that’s had control over education under “social democratic” governments for 17 continuous years, with no centre-right opposition. Which prompts the question: why is there no political debate about the system that allows rich parents to buy privilege for their children?

After all, politicians from the Blairite Milburn to Nick Clegg and John Major are obsessed with “social mobility”. And everyone with half a brain knows that private schools are the most brazenly obvious impediment to it: that’s why we measure injustice in top jobs by looking at rates of private education. That’s why we’re forever complaining about UK Cabinet ministers who learned their stuff on the playing fields of Eton. If public schools are such a menace, why not abolish them?

You don’t have to be Chairman Mao, or even John McDonnell, to acknowledge the logic of this. Warren Buffet, the billionaire American investor, has suggested that the only way to make education systems fair is to “make private schools illegal and assign every child to a school by random lottery”.

When looked at objectively, on intellectual and moral grounds, the arguments for allowing private education are staggeringly weak. “Parental choice” is probably the most popular principle used to defend it. But that “choice” is unevenly distributed: two parents earning the average salary of £23,000 simply cannot spend upwards of £10,000 per year educating each child. Choice, then, belongs only to the haves, and the have-yachts.

Yes, private schools admit entrance to a few “able” ordinary children every year. Lovely; except they only do this because it blocks debate about their tax-exempt status as “charities”. Yes, private schools “save the taxpayer money” because the state isn’t paying for privileged children’s schooling.

But the cartel that rules our society should simply pay more tax for schooling; and they would, if their children went to the same schools as the rest of us.

And yes, perhaps international law might be a barrier to abolishing “choice” in education. Perhaps. Except Finland has outlawed fee-paying schools already. Incidentally, they’ve also outlawed streaming by ability and most testing, and they’ve got some of the world’s best schools.

The arguments in favour of abolishing or severely curbing private schools are endless. To take one small example, they perpetuate miserable political attitudes. The National Centre for Social Research (NCSR) has concluded that, politically, elite schools “produced Conservative partisans”.

Asked by NCSR how much a company chairman should earn, private school-educated people suggested an average figure of £237,000 per year, £88,000 higher than the figure suggested by everyone else. Why should we expect anything different? Privileged elites like to look after their own.

By abolishing fee-paying education, we could ensure, at the very least, that the elites who run society have some semblance of the “humanity” of those they govern.

To take another example, private schools inherently promote the idea of competition between schools and, thus, league tables. After all, if you’re a parent paying a six-figure sum to buy your child success, you want assurances they’ll end up at Oxbridge.

This encourages these schools to “teach to the test”, creating exam-passing machines. That explains why privately educated kids often do badly at university: they are accustomed to being “spoon fed” knowledge. Independent learning is not in their nature.

This atmosphere of testing and competition, which stems from private schools’ economic needs, infects the public system too. We train kids to pass tests, not to solve problems, because teaching professionals are terrified by the tyranny of league tables.

Just in case there’s any confusion, I’m not judging everyone who got a private education. Some people from a posh background are lovely and, despite growing up in a conformist, snobby atmosphere, show no signs of pomposity themselves. I know many “posh” people who hated every minute of their private education. And it’s not even the parents who are at fault: many simply know that buying access is the only way for their children to succeed. The system, by rewarding injustice and competitive parenting, fostering anti-social, often delusional attitudes among the well-off, is the problem.

Nor am I pretending that you’d have perfect “social mobility” by scrapping private education. You need much more equality of outcome before you can have equality of opportunity. But if you want a quick, painless route to social mobility, there’s only one answer. Get rid of the schools that perpetuate ruling-class privilege.

So I have a challenge for everyone standing for Holyrood this year. If you’re going to bang on about social mobility, have the courage to talk about private education, or don’t speak at all. If you’re going to waffle on about social justice, have a little nerve to confront Scotland’s institutions of social apartheid, or stay silent. Every year that passes, with another rich father passing power to another well-fed son, is a political choice; and we can choose to end it.