The Leveson inquiry has drawn our attention to a fundamental political problem which hasn't had the attention it deserves.

I'm referring to the fact that Jeremy Hunt supported News Corp's bid for BSkyB, before Cameron asked him to decide whether that bid should be referred to the Competition Commission. Harriet Harman says such an opinion meant that he did not act in a proper "quasi-judicial" manner in assessing the bid, and so should resign.

But if you want someone to act in a quasi-judicial manner, you should employ a (quasi-)judge, not a politician.

Expecting a politician to act as a quasi-judge is to expect that he will slough off his preconceptions, lobbyists and interests and become a different person.

There seems to be bipartisan agreement that this mental conjuring trick is possible. I'm not sure it is, and still less sure that it should be.

And this is what gets my goat. Everyone in this sorry episode - Labour, Tories and commentators - seems to assume that good decisions can be made, if only the minister has sufficient honour or judgment.This is silly. If you want good decisions to be made, you must put the right structures in place. So, if you want someone to act quasi-judicially, you ensure that he is legally - and culturally - independent. This requires much more than asking some guy to act a part, as Hunt was asked to.

My point here is not about the minutiae of Hunt's involvement in the News Corp bid, or even about the way in which takeovers are policed.

It's bigger than that. Tittle-tattle about whether Hunt should resign or not symbolises an ideology that disfigures our politics - the idea that what's needed for proper decision-making is men of the right character. But this is not enough. You also need the right systems. And these have not been in place.If Hunt does have to resign - and I can think of nothing I care less about - he will pay the price for a political system which over-rates the role of personality and under-rates the role of structure.

Alfred North Whitehead famously said that "civilization advances by extending the number of important operations which we can perform without thinking of them." By this standard, government hasn't advanced very much.