Who would want to be a politician? The hours are long, the material rewards moderate, the responsibilities great and the scrutiny utterly relentless and unforgiving. Gone is the deference, as if towards our ‘masters’, that characterised the relationship between the media and the political establishment some decades ago. Today’s politicians are derided, harried, hectored, mocked, and despised as if their motives are always questionable, their judgement too often poor, their good faith always in doubt. We demand that they be selfless and infallible, but we treat them as less than human. They may never admit to tiredness, hurt or strain.

Why would anyone want to be a politician?

I am far from being an uncritical fan of David Cameron and his Tory Cabinet, but I felt sorry for him last week, and sorry to see him stumble rather foolishly as he came clean too slowly, with a gradual drip feed of revelations about his shares in his father’s offshore fund. He’d done nothing wrong, as far as I understand, having paid the tax due on his income from the fund, and on the gain he made from the sale of his shares in the fund, early in 2010.

Offshore doesn’t necessarily mean dodgy. Of course, it can mean dodgy, if the beneficial owners of the fund conceal their earnings and gains. But those who do so are probably a minority. As many experts testified last week when asked sensible questions, most of our pension funds, and all sorts of other institutions, including trades unions, are invested in offshore funds. Such funds are sometimes set up to enable tax evasion, but the majority are set up because offshore funds are more flexible and easier to manage.

So, there was nothing dodgy at all about David Cameron’s ownership of shares in his father’s offshore fund. Moreover, he sold all his shares on becoming Prime Minister. I doubt that all Prime Ministers have rid themselves of vested interests so thoroughly and promptly.

And then there’s the issue of his mother’s gift of 200,000 pounds, a perfectly legal gift that any of us might make or receive. Nothing dodgy about that either.

David Cameron’s mistake was only in not explaining everything immediately, but rather in issuing guarded statements that sounded slightly evasive and that led, inevitably, to further more intrusive and aggressive questioning.

What makes politicians do the jobs they do?

The worst seek opportunities for personal gain through the corrupt and cynical abuse of power. Many politicians and leaders in the developing world, on more or less paltry salaries, are quite inexplicably wealthy. Here in Central and Eastern Europe the scandals are breath-taking in their cynicism. Too few of these corrupt politicians end up in jail.

Others are driven by ideology, religion, or a wish to forge or save a nation. Too many of these end up as intolerant, repressive dictators with a sense of their own near-divinity and entitlement.

But in our more open democracies, where politicians are expected to be selfless, unrewarded, dutiful, humble and tireless public servants, subject to meticulous scrutiny, and exposed to relentless scorn, what makes it all worthwhile?

In all management roles there is a kind of pleasure in the exercise of power, in the wielding of influence and the responsibility that derives from it. We all like to get our own way with things. We earn respect in virtue of the responsibility we accept, especially if it’s wielded successfully, and this, I suppose, is reward of a kind. In politics, though, success is only ever grudgingly recognised and is always only partial. On the other hand, disrespect and disdain always follow from failure, and, as we are often reminded, most political careers end in failure .

Deriving satisfaction from the wielding of power should not in itself be a disqualification, and some are very good at it. I admire politicians’ capacity to consider issues from many different points of view, and decide, albeit on insufficient evidence, on the least bad course of action, sometimes even on a good course. I could not do it. I like to sit on the fence. It would be unreasonable to expect our politicians to be reluctant to wield power. The traditional dragging of the ‘reluctant’ Speaker to the Speaker’s chair in the House of Commons after his or her election is symbolic theatre. A Parliament full of disinterested philosopher kings would be a tired, incompetent, ignorant and conservative body.

We want the impossible. We want our politicians and officials to be motivated only by a sense of public duty, but we also want them to be knowledgeable, clever, energetic, humble, perfect in judgement, never swayed by malign influence, unsullied by scandals past and physically in the prime of their lives. If they are also to be denied any form of satisfaction, what is to prevent them from pursuing lucrative careers in the private sector?

Self-belief is no sin (unless it morphs into pride), and without it no one could manage a household, or a company, let alone a nation. True, self-belief must always be tempered with humility and a sense of potential fallibility. The fawning respect of acolytes and the media are liable to discourage healthy self-awareness, but on the other hand, habitual contempt is undeserved.

Is it perhaps another symptom of the growing inequality of our societies that the ‘alienated’ poor automatically despise those with money or power, believing they can never get there themselves, and believing that those with money or power have no interest other than preserving it.

I was amused by an article I read yesterday on the few admissions of error made by Presidents of the United States. It was triggered by Obama’s admission that he screwed up the aftermath of US action against Libya. I admire Obama, and was delighted to read that he could be honest, even whilst still in office. But the writer concluded that it is never wise for a President to admit error – not ever. A political leader shouldn’t ever admit uncertainty or fallibility. We depend on our leaders being inhumanly perfect. We demand it of them.

In a good democracy we must maintain a healthy disrespect for politicians. When I visited India a few years ago, I was astonished by the noisy, cantankerous, disrespectful argument that characterised political talk shows. It took disrespect to a level even beyond the BBC’s Hard Talk or Newsnight. Compare that with the stage-managed personality-cult political debate of China and Russia.

But healthy disrespect should also be balanced with a little admiration and respect when it’s due. If not, there will be far too few of us willing to take on the dreadful task of governing others.