A friend moves into the 45th floor of a slick and shimmering tower in London’s Isle of Dogs. Up there, savouring bachelorhood in the heavens, watching pilots brave the steep glide path to City airport, it is unthinkable that his new neighbourhood served as a war zone within his lifetime. And here I do not resort to lurid tabloid metaphor. Stanley Kubrick used the rusting desolation of the 1980s Docklands to shoot Full Metal Jacket.

Because the resurgence of cities has been so stunning, what came before has passed into something more like rumour than history. The depopulation, the suburb as The Future, the fact that “inner city” was not an accolade: these realities of mid-century life take some believing now. What might persuade us is the regression of our swaggering cities into that forgotten gloom all over again. It could happen.

There are two contrasting futures for urban life after the coronavirus. In the sanguine version, people liberated from their homes re-form the great pullulating mass that has been shooed from the streets and sequestered of late. A century after the Roaring Twenties, we have?another.