A verbal contract, as Sam Goldwyn observed, isn't worth the paper it's written on.

But it seems that a "legally binding pledge" isn't much better.

In the first three months of this year, more than five per cent of patients were not treated within the 12-week time limit which the SNP government made a legal obligation. That's up almost 90 per cent to 4,499 patients - the worst figure since the legislation came in.

What is being done about this flagrant breach of the law? Well, some waffly assurances from Shona Robison that steps are being taken, more "investment" is on the way, that last winter was "extremely challenging" - why, she didn't say - and the usual guff. I suppose the Health Secretary has to say something along those lines; I'd expect much the same from most politicians, whether or not I believed they had either the intention or the ability to improve matters.

Shouldn't there be the expectation of something more, though? Not, mind you, because I have any faith that anyone is likely to square the fanatically sentimental attachment to the NHS as an idea with the financial and logistical realities of delivering provision that satisfies everyone. But because - look! - we have a law!

Ignoring Cicero's exhortation ollis salus populi suprema lex esto, the Scottish Government decided it needed actual legislation, too. But the breach of the legislation has resulted in precisely no sanctions. Fines, community service orders, arrests, Asbos? None of that, just a politician saying she'll try to do better.

I suppose that since so many petty offenders get let off with a stern talking-to, the government thinks the same can apply to them. But in that case, what was the point of introducing the law into the issue of targets at all?

Of course, it isn't just the NHS. Providing accommodation for everyone who is unintentionally homeless and emission targets for climate change, for example, are also "enshrined in law". Something that makes not a whit of difference to meeting those aspirations, as it turns out.

There are targets for apprenticeships, for reducing waste, for improving educational attainment, for expanding digital infrastructure, for almost anything you can think of. There is, indeed, a whole section of the Scottish Government website, ludicrously entitled "Scotland Performs", where you can see them not being performed.

But it isn't just the SNP that's to blame. The Conservatives announced before the election they would legislate to ban a rise in income tax, VAT or National Insurance until 2020. It's hard to think of anything more pointless.

Either you believed the Tories when you said they wouldn't raise taxes if they won the election, or you didn't. And if they won the election (which you may have noticed they did), they could not only introduce such a law, but ignore it, or repeal it too.

Performance is the word, here. Not in the sense of the political parties achieving the targets which they've set, but in putting on a show that they mean to. Putting cynicism aside, we can all believe the SNP and the Tories, and no doubt the other parties, do intend to achieve their aims. That seems obvious, even if you disapprove of the aims, or if you think the policies employed to achieve them are misguided or even counter-productive.

No politician thinks that promising a popular measure, such as improving health or education, and then spectacularly failing to deliver it is a sure-fire way to get re-elected - though many of them end up doing just that. But that is because we already have, in elections, a means by which we can express our view that a government has made a hash of things.

Targets themselves may be a reasonable enough way to assess whether a party has done what it set out to do - though there are plenty of people who feel they can as easily camouflage failure to produce what ought to be the genuine objective. If short waiting lists were to mean poorer life expectancy, or better publication rates amongst lecturers meant worse university teaching, you might conclude the target was wrong, even if it were being met.

But at least that's a judgment we can make. And at least if a government sets a target that it then fails to meet we can conclude it has failed on its own terms. What is entirely gestural is to waste breath and ink on legislating to hold yourself to account, incur no penalty when you do, and then absolve yourself from blame. That's not politics, it's merely performance.

The proper purpose of laws, if we nip back to Cicero's De Legibus for a moment, is "the safety of citizens, the preservation of states, and the tranquillity and happiness of human life". He omits any mention of their aim being to make politicians look good, by trying to kid us they are keeping their promises.

Individual policies may look as if they are designed to achieve these admirable aims, yet be undesirable for other reasons. To go back to the NHS targets, one blindly obvious reason why they are not being met is the Scottish Government's provision of free social care for an ageing population. That is a wholly reasonable priority for government spending and one that the Scottish public overwhelmingly support - but the bed-blocking in hospitals is one unintended result. So either we need more money or to rethink the policy. A law about the targets doesn't help at all.

Or take free university tuition fees - again, a sensible and popular measure. But there are fewer students from poorer backgrounds in Scottish universities than English ones - another unintended outcome. At schools level, Scotland spends more but achieves worse, and socially much more unequal, results than England. Laws allowing politicians to congratulate themselves on reaching targets make it more likely that they will lose sight of the real desired outcomes.

Similarly, the Conservatives' plans to create more free schools and academies are only desirable if they make better schools; their integration of social care and health in Manchester will only matter if it improves results for patients.

The ultimate arbiters of such issues are voters. Both the Tories and the SNP were much more successful than many imagined they would be at the general election, but both parties now have an obligation to remember what it is that actually holds a government to account.

The pointless charade of constructing targets and laws to impose them does no good at all if the electorate concludes any of the following: that the government is failing on its own definition, that it is ignoring the law, that the law is pointless, that the targets are the wrong ones, that the targets are a distraction from delivering services or outcomes, or that, however desirable they seem, they are creating unintended outcomes which are even worse. All of this voters can, and do, make their own minds up about, without some pointless fig-leaf of a law guaranteeing "effectiveness" - especially when it doesn't, and can't.

In other words, instead of banging on about enshrining things in law, governments might confine themselves to legislating on the stuff the electorate gave them a mandate for. And then see if the voters still like them.