You are listening to a programme from BBC Radio 4.

Rabbi Lord Sachs, good morning.

Good morning.

Yesterday, a major British dictionary named as its 2017 word of the year the phrase fake news.

At least I think it did, and that too was fake news.

And when you recall that last year another dictionary chose as its word

of the year post-truth, you realise that we're in trouble. It's all a long way from the lost

innocence of the Edwardian era when Bertrand Russell could say about the philosopher G.E. Moore

that he only once heard him tell a lie, which was when he asked him more,

have you ever told a lie and Moore replied, yes? Now, how has this change happened? Fake news is

his oldest time, and it can have devastating consequences. Jews suffered for centuries because of a fake

news item known as the blood libel, accusing them of using the blood of Christian children.

And despite the fact that it was denounced as untrue by several popes, that didn't stop it being told and believed.

Fake news is used as propaganda in war, and it was used to stoke fears in Bosnia and Rwanda,

where it led straight to bloodshed.

But it flourishes today because increasingly we're getting our news from the social media,

where it's hard to check whether a story is fact, fiction or fantasy.

And there's convincing evidence that it's increasingly being used by

foreign powers to manipulate opinion and distort the democratic process. And it works because the human

brain is ultra-sensitive to threats of danger, so it's easy to spread paranoia, and because of the

psychological phenomenon known as the confirmation bias, which leads us to believe stories that

confirm our prejudices. By the time truth emerges, the lie has already done its harm. The deepest insight into the fragility of truth

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