We’re continually assured that government policies are grounded in evidence, whether it’s an anti-bullying programme in Finland, an alcohol awareness initiative in Texas or climate change responses around the globe. Science itself, we’re told, is guiding our footsteps. There's just one problem: science is in deep trouble. Last year, Richard Horton, editor of The Lancet, admitted that "much of the scientific literature, perhaps half, may simply be untrue.

‘Bad policy.’ ‘No discernible impact on the key outcomes it was supposed to improve.’ ‘Deliberate misrepresentation of the data… a funding model that could have been designed to waste money’. ‘A waste of £1.3 billion’. ‘Failed’. The media’s treatment of the troubled families programme, whose evaluation has recently been made public, cannot have cheered David Cameron in his last week as an MP. History does not look likely to be kind to his great social policy.

Six months ago an old friend of mine was murdered on his doorstep. This week his killer was sentenced to life imprisonment. In both cases, the first I heard of it was when someone I follow on Twitter posted a joke with a link to a news story. Both jokes were whimsical rather than callous — both were, in fact, musing on which Sunday evening television detective would most likely solve the crime — but whimsy in these circumstances feels like callousness.

It all began with oysters. Londoners used to eat them as they walked along, throwing away the shells much as they do burger wrappers now. Lord George Cavendish, owner of Burlington House on Piccadilly (now the Royal Academy), was sick of shells littering his garden, and so in 1819 decided to open a shopping arcade down that side of his property to protect it from the ‘tossers’. Nearly 200 years later the place is thriving.