‘Wider still and wider, may thy bounds be set,’ the ecstatic throng sang at the Last Night of the Proms. They were partying like it was 1902, even though it seemed like the moral territory occupied by hope (not to mention glory) was growing narrower. Perhaps it has been ever thus, but it seems apparent that there are two versions of Britain on offer right now: Britannia Promlandia and Tate Britain, as in Catherine Tate: the commonwealth of ‘Am I Bovvered?’

Promlandia’s celebrations were cued up this time by David Cameron’s St Petersburg impersonation of Hugh Grant, schoolboyishly ticking off all...