Whenever politicians complain that the media is far too obsessed with personalities at the expense of issues, you can bet your bottom pound that party relations are in crisis and that personality is behind it. Think Margaret Thatcher and her problems with Nigel Lawson and Geoffrey Howe, or John Major and his troubles with the Eurosceptic "bastards". Of course policy issues were the occasion of argument, but it was the personal feelings that gave the crises their peculiar character.
So too today. If it were not for the strange, brooding character of the Chancellor, there would be very little fuss. At bottom, both the Prime Minister and his Chancellor are in accord on the politics of the euro referendum. It's simply not on before an election. A European recession is the worst possible time to consider it and anyway, the voters wouldn't buy it. So why take the risk? The huffing and puffing now is all about appearance - how to turn down the proposal today while displaying an ardour for tomorrow. And on that the Chancellor is as much pro-European in intention as his neighbour in Number 10. If it weren't for the peculiar partnership between the two, there wouldn't be much of a story.
So what does drive this hunched Scot in No 11, that makes him so enigmatic, belligerent even, to the average voter? Part of the problem, I think, is that while Mr Brown has a well-earned reputation as an iron Chancellor of prudence and competence, he actually isn't that interested in economics. Ask him about social policy or international relations and his eyes light up. Ask him about the state of sterling or the fall in the markets and he looks faintly confused that you should be interested - or think he would be. His mind roams the uplands of future society, not the marshlands of fiscal policy.
That economic disinterest helps to explain the unique position of Ed Balls, his chief economic adviser. To some, Mr Balls is a Svengali figure whose deep scepticism about the euro has determined the views of the Chancellor. But in fact Mr Balls is a relatively straightforward character whose job is to give the Chancellor the economic perspective to express his political instincts.
To Mr Balls, making the Bank of England independent was the route to better economic management. To Mr Brown its primary purpose was to break out of the reputation for incompetence that had dogged the Labour Party for the last two generations. No one could accuse New Labour of imprudence, or blame it for mismanagement, if the decisions were taken outside its control.
It is the same with the euro question. In a penetrating analysis of Mr Brown's time as Chancellor, The Prudence of Mr Gordon Brown, to be published this autumn, William Keegan shows just how deeply the Chancellor's view of currency policy has been dominated by his reaction to the débâcle of Black Wednesday and Britain's withdrawal from the ERM in 1992. Economically, the lesson was that you should go in at the right rate, not that the idea was intrinsically wrong. But politically, the lesson taken by Mr Brown, who as shadow Chancellor vigorously supported Mr Major's policy at the time, was that a government could be broken on the back of a market circumstances. Political risk far outweighed economic opportunity.
So it is with his view of the euro now. Mr Brown isn't against joining the currency at this time on grounds of the five economic tests, or even the sixth (a Europe fit for us to join) which he seemed to add in the CBI dinner this week. He is against it because there are too many electoral risks attached. His critics may demand deadlines and firm commitments. Tony Blair might like this as a means of proving his continued European commitment. But to Mr Brown the question is not when, but why? Why go against the grain of public opinion when Britain is managing quite happily outside the eurozone, its growth and employment far superior and its currency so far relatively well-positioned?
That may change in the future if British growth, currency movements or US-led deflation - about which he is surprisingly uninterested - dent his reputation for good management. But unless and until circumstances radically alter on the economic front, Mr Brown is content to avoid a referendum this year, next year, or beyond the next parliament after that if need be. Protected by the Bank of England, with an economy performing relatively better than the rest of Europe, he can sit on his hands for years to come.
In that sense, Peter Mandelson is right. The Chancellor is a politician to his fingertips. He's wrong that Mr Brown has necessarily outmanouvred his Prime Minister. It's a difference in positions. Mr Blair has to create a permanent sense of motion to show that he is doing something about hospital waiting lists, educational standards or Britain's place in Europe. Mr Brown need - so long as the economy goes all right - do nothing but wait. He has dreams of what he will do as Prime Minister, dreams that contain ironically some of the same vision of better society that Mr Blair, with his Christian rhetoric, subscribes to. But until then, the Chancellor waits.
And it is a foolish friend, colleague or commentator who thinks he can understand, let alone upset, the dynamic between the odd couple living at Numbers 10 and 11 Downing Street.