Tony Hall was appointed as the BBC Director-General after declining to participate in the selection process that threw up – and then threw out – his predecessor, George Entwistle. This has not dissuaded him from the questionable decision to appoint, without advertisement or interview, two new highly-paid members of his BBC executive, Anne Bulford and James Purnell. He is clearly of the “results, not process” school of management (which may not appeal to ambitious BBC executives hoping to climb the corporate tree, interview board by interview board). Now he has brought in a third top executive from outside, with minimal selection process: James Harding, recently ousted from the editor’s chair at The Times, is to be the new Director of News and Current Affairs.

The day Hall took up his position he circulated an email to the BBC staff. It is vapid to the point of tedium: but it is not on such pro forma announcements that he will be judged. His tasks include finding a way to exorcise the Savile legacy, adjusting the BBC to an income 16-20% lower than at its peak spending power (and now declining by the annual rate of inflation), and implementing the lessons of the Pollard Report into why Newsnight failed to broadcast its revelations about Jimmy Savile but did broadcast its libellous report on Lord McAlpine.

Nick Pollard’s key findings – explicitly endorsed by BBC Trust chairman, Lord Patten – were that both the BBC’s culture and its structure had been found unfit for purpose. Silo mentality had left senior executives reluctant to engage with each other, for fear of encroachment on the BBC’s journalistic independence. The mindset that pervaded the upper reaches of management was to avoid knowledge, and thereby responsibility.

George Entwistle’s predecessor as DG, Mark Thompson, insisted to Pollard that he knew nothing in detail about the Savile item, and that nobody told him about its contents. He read none of the many newspaper stories about the decision to drop the story, and across nine months none of his executive colleagues thought he ought to be told about them. His lofty preference for ignorance stretched to not even reading a threatening letter being sent on his behalf by a private lawyer to a newspaper that wanted to ask what he knew.

Now Thompson has slipped off to pastures new as chief executive of The New York Times, where some staff, given their investigative training, have questioned this apparent culture of ignorance. One hopes that Hall will install Harry Truman’s famous placard – “the buck stops here” – on his desk.

Yet it may be another US president that Hall most needs to emulate: Richard Nixon. The biggest structural fault that Pollard identifies in the BBC is the massive dysfunctionality of the monolithic news and current affairs department: a department which Hall himself was the first to run, after he and John Birt created it as a bureaucratic giant within the Corporation.

Just as only a powerfully anti-Communist Republican like Nixon could reach detente with Mao’s China, so perhaps someone who made the case for merging news and current affairs 25 years ago must now dismember the beast at its heart.

News and current affairs should be kept separate, as they are in many broadcasters, because they are subtly different. In the BBC, by contrast, they have been unified not only within but also across radio and television and between its domestic and international services.

The benefit is supposed to be a single voice in news and current affairs from the BBC. But this is an organisation responsible for over 60% of all news consumption in the UK, and growing. To safeguard our democracy, we need a wide range of views. The combination of a super-dominant BBC with a unified structure insisting on one voice is that it not only inhibits a range of views it deliberately squeezes it out. Apart from phone-in shows (which don’t count as journalism), at present all news reports and analysis pass through an editorial “sieve” to minimise differences of view. Without these tight controls, journalists would be able to follow their own lines of inquiry, even if it meant that sometimes conflicting views were broadcast.

So, step forward, Tony Hall. At the Royal Opera House, he showed considerable deftness in managing complex issues, and welcomed initiatives in finding new sources of income. It may be asking too much of even the most far-thinking DG to plan for a future for the BBC without the licence fee, but he should at least fulfil a Nixonian role by eliminating gigantism and inflexibility in BBC journalism.

The DG does not instigate a single television or radio programme – the core outputs by which most people judge the BBC: but he (there has never been a she) sets the tone at the top. Tony Hall is now “the Tone at the top”: he must not muff his opportunity.

To spell it out, current affairs on TV constitutes Panorama, Newsnight, This Week (the Andrew Neil show), Andrew Marr on Sunday, The Money Programme, Question Time and their ilk. News is bulletins and the news channel. Breakfast Time could be either.

On radio, Today, The World At One, PM and The World Tonight are current affairs, though they include bulletins that come from news.

Documentaries are neither current affairs nor news, even if they are sometimes made by journalists. They have always sat outside the news and current affairs structures. Of course, the BBC needs to make more of them, covering domestic and international issues.

The skills involved in making the different types of programmes - including reporting - are subtly different. John Humphreys would not make a good news reporter. Some correspondents - eg Robert Peston, Nick Robinson - could work in either format, and can also make documentaries. The key difference is that news reports and bulletins are driven by: a) a news "agenda" that looks at many possible stories and places them in a certain order, and b) a reporting style which is strictly factual, even if stories may include sound bites from opinionated people such as politicians.

By contrast, current affairs editors zero in on stories that they think: a) are particularly important and/or b) where they think they can add significantly to public understanding of those stories. They want reporters who are persistent and probing, and who can sustain more than a 2-4 minute report. They are not afraid of reaching conclusions - indeed, definitive statements are positively sought out.

The Pollard Report identified some key failings of the combined news/current affairs structure, stretching across radio and television. It led, for example, to the appointment of a radio producer to run Newsnight. That could never have happened in a separated structure. Peter Rippon had never worked in television. Many of his Newsnight colleagues consequently doubted his ability to make the right editorial decisions. He failed even to view the key interview in the Savile film, as he did not trust the emotional reaction he might have to it.

The second problem was that the top executives in the combined department were primarily experienced in news, not current affairs. They lacked the urgency that typifies current affairs production. Instead of a head of current affairs sitting down with Rippon and his team to judge what to do with the Savile material, the Deputy Director of News and Current Affairs - an extremely busy executive hopping between locations and tasks - offered intermittent feedback, the detail of which he was pretty vague about when quizzed by Pollard a year later.

The original decision by John Birt 15 years ago to bring the departments together was part of the managerialism that he imposed on the BBC. He had been shocked by the lack of discipline and impartiality in current affairs when he joined the BBC as deputy DG, and his structure - combined with the infamous imposition of "bi-mediaism" (requiring all reporters to work for both TV and radio) - allowed far more control to be imposed from above. It also squeezed out what was seen as undesirable variations in BBC reporting. More and more emphasis came to be placed on consistency in reporting, such that the BBC "position" on any issue could be better defended. This, in turn, invited more pressure on the BBC, as settled positions not leaving room for doubt (global warming, Middle East, Northern Ireland, immigration, EU, NHS cuts) came under attack from particular interests.

In ITV, news and current affairs remain separate, though the halcyon days of many contractors, with current affairs split up between Granada, Thames, Yorkshire, LWT and Central, whilst ITN looked after news, are a distant memory.

The BBC merged radio, TV and online, and news and current affairs, under a single structure, because it could. But its doing so is certainly to the detriment of the audience and democracy. We need the different skills required by radio and television to be nurtured, not blurred. We need news and current affairs to be much more distinct, not arms of a single directorate. Ideally, the BBC news channel should also be given its independence, so that it can compete more coherently with Sky News.

We will end up with some bits of BBC output disagreeing with others; but that is no bad thing. Indeed, an editorial in The Times last year called for just such a dispersal of power and control through disentangling the different elements within the news and current affairs directorate. Let us hope that Harding read, and took to heart, that editorial before publishing it. If he turns out to be an overseer of diversity, rather than an imposer of conformity, he will have done us all a favour.

After years of persistently turning a blind eye to the problem, Ofcom recently called for more plurality in BBC output, to offset the overwhelmingly dominant BBC position in news consumption. Actually, variations in output will only come with variations in input, which in turn requires the disassembling of the news and current affairs directorate, as recommended by The Times. That way, reporters and producers can follow their instincts without worrying about BBC "positions", and the audience (and democracy) can benefit from a fuller range of journalistic instincts, interests, methods and stories. That's what it's all about.