Here’s an everyday story about BBC internal politics. BBC presenter Naga Munchetty is pressed by her Breakfast colleague Dan Walker for her views on an offensively racist statement by Donald Trump. She gives a relatively calm, guarded answer. A single viewer writes in and the complaint is, partially, upheld. The outrage, letters and petitions generated by this judgement force the BBC’s director-general Lord Tony Hall to intervene. He wisely reverses the decision.

This sequence of events should be no surprise. Anyone trying to read the BBC’s editorial guidelines would be struck by how confused they have become. The corporation once dominated a tiny number of TV channels in an age when such organisations were controlled by a disciplined hierarchy and online communication didn’t exist. The style of its news was impersonal and much of its audience thought that increased its authority.

The BBC now employs 20,000 people, costs £4bn a year and operates in a less formal world in which most people on earth can command a torrent of information to flow through a small device in their pocket.

The editorial guidelines make a brave attempt to sound clear and consistent with the founding traditions of a public service broadcaster. But the spread of digital communications has changed the impact of information, weakened the authority of expertise, encouraged sinking popular papers to abandon accuracy completely and provided dozens of points of view which any consumer of news and opinion can compare and contrast at will. It’s hardly surprising that public service broadcasters are finding it ever harder to set down stable and consistent rules which preserve impartiality.

The guidelines try to take account of the fact that a broadcaster must be able to express some personality without expressing opinions of the wrong sort. The part of the complaint originally upheld against Munchetty did not object to her giving an opinion about racism but criticised her for speculating about Trump’s motives – a delicate distinction to say the least.

BBC rules bend over backwards to give presenters and journalists wriggle room for judgements, but are complex and vague about exactly what is off limits. They say more than once that opinions ought to be “reasoned” and supported by facts. If someone is making a film for the documentary series Panorama over several weeks, that might reasonable. For a presenter needing to keep up the pace of an on-air conversation and compelled to reply in a few words, that is unrealistic.

Lost in the noise

A much larger and more dangerous issue lurks underneath rows such as the one over Munchetty’s brief words. It is painful to record this, but the world’s politicians are learning a lot from Donald Trump. Trump realised some time ago that in an age saturated by information, only certain assertions and images stand out well enough to be remembered.

He campaigned in the 2016 presidential election by saying several tendentious or untrue things on Twitter every day. Facebook shares and likes then gave him a real-time read-out about which of those eruptions was striking enough to stick. Then he doubled down on it the next day. If he was caught or corrected, he switched topics and the incident was swiftly forgotten in the ceaseless flood of words and images. Accuracy or inaccuracy was not the point – blurring certainty was the aim.

For many politicians, truth is less important than that old marketing idea of “cut-through” – the phrase or allegation which sticks when others fade. A few years ago, an ambitious interviewer asked Salman Rushdie: “What is the biggest problem of all?” He replied:

Our collective inability to agree on the nature of reality. There are such conflicting descriptions of how things are that it becomes difficult to make agreements that allow people to move forward.

The problem with truth

The shrinking space for agreement about how to establish the truth is a danger to every society which depends on the quality of public reason. But that assault on reason and facts is a special danger to organisations such as the BBC. And Brexit is currently the biggest risk of all to it.

Politicians have plenty to answer for but they did not create this problem. They are riding a tide of disillusion, resentment and national populism which has been building for years. Social media have helped to accelerate and amplify the idea that all opinions have equal value, that outrage gets you the most attention, that elites are self-preserving and corrupt and that global organisations are inherently bad.

Public service broadcasters depend on assumptions about how societies rest on shared values and on what those values are. They can survive certain changes – and the BBC, since its foundation just under a century ago has seen and weathered huge changes in attitudes to religion, social deference and diversity. But the planting of doubt about facts and how we go about relying on them generates unprecendented strain. Mark Damazer, a former controller of BBC Radio 4 made this comment in March.

Every senior editorial manager I spoke to believes that it has become more difficult to persuade both the public and politicians that the BBC is doing its impartial duty on Brexit.

In the face of these dangers, Lord Hall has taken the only line he can. The BBC, he says, is as close to a journalistic gold standard as we have – so value and preserve it. The BBC is backing a scheme, shared with the hi-tech giants, to detect and stop misinformation, particularly at election times. There is talk of a BBC-backed foundation to promote journalism of quality.

Hi-tech companies such as Google, Facebook and Twitter have a role to play as well. They are not, strictly speaking, media organisations – but they are part of the infrastructure of free speech. Neither they nor anyone else foresaw that an enormous increase in peoples’ power to communicate could be used to damage truth and reason.

These new players should control the amplification of material that can do harm (even if they do not suppress the original expression), they should base their own guidelines more closely on international human rights laws and they will have to devote yet more resources to “curation”, otherwise known as editing. They have moved in these directions, but they need to go further, faster. The hi-tech platforms are wrestling with problems which most editors have faced for centuries and which the director-general of the BBC faces every day.

George Brock, Visiting Professor of Practice (Journalism), City, University of London

This article first appeared on The Conversation.