Finding a governor of all the talents Sir Mervyn King's looming retirement will create a dauntingly hard-to-fill job vacancy at the helm of the Bank of England. So demanding is the role that observers have taken to talking about the need to find some central banking "superman" to shoulder it. While this is hyperbole, it is indisputable that the list of qualities needed to run Threadneedle Street's Old Lady, always lengthy, has expanded since the financial crisis. So much so that it is hard to see any single likely candidate fitting the entire bill. Editorial Governors have always needed to possess attributes such as discretion, political nous and a strong grasp of economics. But with the BoE's annexation of wide new powers over the financial system, the demands have mushroomed. Britain's top central banker should now possess the sort of intellectual heft and virtuosity in policy making needed to co-ordinate the various unconventional tools the BoE has employed in recent years to combat the economic downturn. Allied to this are the advocacy skills required to present and justify often complex policies not only to the chancellor of the exchequer and his colleagues, but to the wider public. He or she should also be able to defend the BoE's independence against all comers while maintaining a co-operative relationship with Westminster. This is not easy. At times of economic peril, political pressures can be extreme. Sir Mervyn's relationship with the last Labour chancellor, Alistair Darling, was notoriously prickly. Nor does the list end there. The successful candidate would ideally be an excellent manager, capable of running the sort of large institution the BoE is well on the way to becoming as it completes its merger with the Financial Services Authority. And lastly, he or she should have the intellectual honesty and detachment to make a proper accounting for the BoE's role so far in the crisis. This is an institution that has not acquired more and more power because of its exemplary performance over the past few years. It needs to learn from its mistakes. Embodying all these virtues in a single candidate is nigh on impossible. The government has wisely chosen to cast its net widely, eschewing the sort of discreet coronation that Sir Mervyn enjoyed when he was drawn from a shortlist of one. Candidates will face the rigours of competitive selection. The government is also right to look beyond the curtain walls of Threadneedle Street. While there is a strong internal candidate in the shape of Paul Tucker, one of the deputy governors, there is also a good case appointing externally. An outsider might, for instance, find it easier to appraise the BoE's recent performance than someone intimately involved in the decisions under scrutiny. But even with an open field, the ideal candidate looks elusive. True, some of the mooted applicants tick many of the boxes: Lord Turner, the chairman of the Financial Services Authority, certainly has the intellectual heft and detachment; while Lord O'Donnell, the former cabinet secretary, possesses a formidable managerial skills. Neither, however, ticks them all. Compromises can be made. This newspaper's instinct would be to favour intellectual leadership over organisational zip. But another way round the dilemma might be to split the roles, reflecting the complexity of the task the government has bequeathed Sir Mervyn's successor with its reforms. In such a model the governor might provide the intellectual firepower, while the deputy could play the part of a chief operating officer. This would alleviate the need to find a "superman." It might also provide a better governance framework for a more complicated institution. Sir Mervyn has at times run his fiefdom like an absolute monarch. This is not a model the next governor should follow.