Here we go again. It’s normally not until August, with the publication of exam results, that the annual ‘let’s bash A-levels’ festival starts. It has come early this year, brought forward by the publication earlier this week of the recommendations of Mike Tomlinson, the former Chief Inspector of Schools.

Mr Tomlinson did what he was expected to do: propose the abolition of A-levels and their replacement with a diploma. His report has been greeted by some as unexpectedly radical. Given, however that the express purpose of his inquiry was to consider the need for a new exam system, it should hardly have come as a surprise that he recommended…a new exam system.

It’s easy – and, indeed, necessary – to attack the specifics of his proposals. The diploma, made up of various ‘credits’, will measure not achievement but ‘progress’. Pupils will be able to move up successive levels without attaining a given standard. They will simply, as Mr Tomlinson’s report puts it, have to transfer their credits on a “flexible ladder of progression”, whatever that might be.

This does not merely miss the real problem; it would make it far, far worse. Indeed, rather than rectifying the situation, the diploma exemplifies everything which has gone wrong with exams. The basic purpose of exams is to measure attainment. Measuring progress is all very well, but that is not what employers need or universities demand.

Indeed, quite apart from the flaws inherent in the diploma concept, the deeper problem is represented by the very fact that Mr Tomlinson was asked to produce such a report in the first place. We have a government which is obsessed with process and pays far too little attention to substance. Thus, instead at looking at why A-levels are no longer doing their job properly, the government moves to replace the entire structure with another – which, since the fundamental problems have been ignored, and the new mechanism is flawed, means that the end product will be far, far worse.

There is nothing wrong with A-levels as an idea. Employers and universities have more or less the same requirement – testing attainment - which A-levels are perfectly capable of meeting. They have been devalued by the use to which they have been put, and how they have been operated. It is not the mechanism of A-levels which is at fault but, rather, the conscious decision to change the way they are marked. Grade inflation has destroyed the reliability of A-levels because examiners have, quite deliberately, made it easier to achieve a given grade. And that has happened because of a misguided change in the use to which they have been put. Instead of testing ability, and being unafraid to fail where necessary, they have been contorted into a device for shunting fifty per cent of school leavers into university, to meet a pre-ordained target.

The Tomlinson proposals are thus typical of the government's belief in the opposite of the 'if it ain't broke, don't fix it' principle': if it's not broke, fix it; and if it is broke, leave it alone. An exam whose basic principles are the answer, not the problem, is being ripped up. Yet nothing is to be done to deal with what really lies behind the mess: the debasement of university education and, at root, the structure of the school system.

The same misguided approach seems to guide policy elsewhere, too. The National Health Service model of taxpayer funded healthcare is clearly broken, so the government is not fixing it, concentrating instead on pouring as much money as possible down the drain.

Welfare remains as broken as when Mr Blair came to office, promising to ‘think the unthinkable’ and cut a swathe through the bills. So, following the government’s ‘if it's not broken, fix it; and if it is broke, leave it alone’ mantra, nothing is being done.

But there is no clearer demonstration of this principle than the House of Lords. For all its oddities, the Lords was not broken: it was a fine revising chamber. So, because it wasn’t broken, the government started fixing it. As a result of those changes, it is now broken, with a membership which is widely derided. And, because it is now broken, it is being left alone. ‘Through the looking glass’ barely begins to describe what is going on.