By the time you read this, Gordon Brown should be close to completing his long, painful ascent of what Disraeli famously described as the 'greasy pole' of politics. Barring some unforeseen, seismic political event, Brown is a shoo-in for the top job. The only risk to his final success took the shape of David Miliband, and he shied away in April. I like and greatly admire Miliband, and am disappointed he chose not to run. But it seems that he did not, at the crucial moment, possess one of the most important ingredients of a leader - an unshakeable belief in his own superiority for the top job.
He is said to have reminded friends that the parallels with the Conservative leadership race were doubtful. 'Gordon,' he was reported as saying, 'is not David Davis.' True enough. It is hard to imagine the son of the manse posing with large-breasted models with T-shirts emblazoned with 'It's DD for me!'.
But more to the point, perhaps, is the difference between Miliband and David Cameron. Cameron believed that he was the best man to lead his party; and this belief became apparent to those who watched him. And he now seems to be relaxed about the idea of wielding ultimate power in No. 10. The other David was said to be uncertain. The bottom line is that if he had been asked in a press conference if he thought he would make a better prime minister than Brown - and, of course, he would have been asked - Miliband might not have been able to answer in the affirmative.
The level of self-belief required to sustain the opinion that you are the best person to run the country is, of course, pretty high. But the belief is absolutely necessary. Voters are able to distinguish between politicians with faith in their own capacity and those who land up leading their parties by historical or political accident. Authority is an intangible commodity - but you know it when you are near it. And followers want their leaders to exude authority and self-belief. They need them to inspire confidence. So there is a necessary arrogance to leadership.
In leadership theory, some of the most vogue-ish ideas are authenticity, emotional intelligence and empathy. It is not possible to find arrogance on a contemporary list of leadership qualities. This is in many ways a positive shift: business leaders, especially, need to engage their employees by using a richer palette than traditional, top-down, charismatic leaders do. But there is a danger of throwing the baby out with the bathwater. Leaders need to be open and emotionally sentient - but nobody is going to follow a self-scrutinising wimp. There are leaders who have the necessary self-belief but who may lack self-awareness. Macho, Jack Welch-style leaders can inspire people through the sheer force of their personality. But the danger is that their high regard for themselves is based on contempt for others.
The ideal leader is one who combines an utter confidence in their own ability to lead, along with a willingness to listen to and learn from others and admit mistakes - somebody who exhibits amiable arrogance. It is a tall order, but not an impossible one. Indeed, true self-confidence often permits a degree of humility and openness. Leaders who are uncertain of themselves often avoid criticism or dissent, as if afraid that they will be toppled from the citadel if they lose an argument or admit an error.
Sir Stuart Hampson, who has just vacated the chairmanship of John Lewis, is a good example from the business world: urbane, empathetic but - by all accounts - decisive and steely too. And Cameron, like Tony Blair, seems to possess some of this blend. A few around him attribute his confidence to his Old Etonian background, saying that he's a product of a class and set of institutions that have shaped him to believe he is born to rule. This is certainly overstated. It seems unlikely that Sir Alan Sugar would have higher self-esteem if he were an OE. Parents probably have more influence than dorm-masters. But whatever the mix of genetics, family background and education, some people emerge into the workplace with a strong sense of their own power and destiny.
This sense of self-belief does not have to be broadcast loudly from the front pages of the business sections or television. Amiable arrogance can be quietly expressed. How many of the following CEOs have you heard of?... George Cain, Alan Wurtzel, David Maxwell, Colman Mockler, Darwin Smith, Jim Herring, Lyle Everingham, Joe Cullman, Fred Allen, Cork Walgreen, Carl Reichhardt? Quite. But these were the 11 leaders who, according to business guru Jim Collins, took their company's performance from 'Good to Great'.
Collins emphasises the modesty of these highly successful leaders, but it is also clear that they were all certain about the steps necessary to improve their organisations, and about their own capacity to lead - building, in Collins' phrase, a 'culture of discipline'.
Arrogance is only a virtue in combination with amiability, openness and focus. But it is hard to do the top job convincingly without a deep-seated belief that you are the best person for it. And self-belief can propel great people into the fray even when the odds seem stacked against them - and then they change those odds. As Virgil put it, 'fortune sides with him who dares'.
Richard Reeves is director of Intelligence Agency, an ideas consultancy; e-mail: email@example.com.