There’s nothing more annoying than a lay-man who ‘knows best’. What’s particularly annoying about it is that almost everyone I’ve ever met is culpable, myself particularly so. Barely a day goes by when I don’t fantasise about telling a trained professional in some remote and complicated field exactly how I feel he should be doing his job; when I don’t strut around informing all who’ll listen that I could do a better job than Emile Heskey if only Fabio would put me on the plane. The idea of competence is deeply unfashionable in a furiously enfranchised society. It is no longer possible to win an argument by asserting that I have a Ph.D in this subject whereas you have half a GCSE; that I have worked in Whitehall for forty years, you first googled ‘politics’ last Tuesday.

This sometimes saddens me. I would sometimes like to say ‘I’m right, because I know more about this than you’ or even ‘I agree with her because she knows more than me’, but it’s correct that I can’t, usually.

One of the main criticisms of the ‘amateur-who-knows-better’ is that it is in principle very easy to learn facts, but much harder to understand systems; anyone can have a narrow knowledge, but not everyone can have a broad understanding. You may have an opinion on feet, but this does not make you a podiatrist This feud is best illustrated in the Post Office queue: I would have no problem whatsoever explaining to the assistant how I might get what I need right now, but I’d be stumped if asked to come up with a system which could get everybody what they needed immediately.

That said, the reason ‘competence’ should remain a taboo, that lay-people should be allowed to express their annoying opinions freely and without prejudice is because it is democratic. The theory is that everybody’s narrow, self-centred opinions when combined and squashed into parliamentary form, should create a kind of meta-opinion, centred on the narrow self of the entire body of the franchise. This, of course, only works if everybody is actively enfranchised; lop a limb off the body politic and this system will no longer cater for them – not even in theory.

David Cameron and Michael Gove would do well to remember this before they push through their new ‘Do-It-Yourself Schools’ policy. In principle it sounds great: if everybody could work to create a school that was perfectly tailored to their child we might theoretically get a school system which worked for every child. But not everybody can.

The franchise only extends here to the sufficiently educated, or the sufficiently well off, or those with enough security to give up a stable job for such a project. In other words, the middle classes; more specifically, pushy parents. Yes, some particular visionaries will, with no professional background, create systems for the universal good. Equally, some methods that work for children from rich backgrounds also work for those from deprived homes. But let’s not be under any illusion: most won’t, most don’t. As a rule systems cater for those who create them. In basing his educational policy on DIY Schools, in allowing their existence at all, Cameron is in grave danger of creating anew a system that is well suited to the needs of the rich, and fails the disadvantaged.

Teaching professionals and Local Education Authorities – not parent pressure groups – are employed and trained to give the greatest educational benefit to the greatest number; that is the cornerstone of comprehensive education. Unless we can come up with a system in which everybody can genuinely contribute for the good of everybody, this is one area where the taboo of competence must be broken.