Menacing calls to decolonise art history loom large over the museum. But contrary to its stated ideological mission, the project is beneficial to everyone involved. At £20 per indulgence, this show absolves The Royal Academy of its original sin. An optional £2 donation excuses the visitor too.

But this more smoke and mirrors than a pious endeavour. One gallery parades John Singleton Copley – an academician painter forgettable save for his slave holdings – as the gift shop brand scapegoat. Another confusingly notes that the 1807 act of abolition had both supporters and opponents among artists. Later, US and British histories and art worlds mix with little discipline, laying the ground for claims that are as faddish as they are hyperbolic. A noxious mix of evidence and emotion dismisses any niggling doubts.

The show’s decisive weakness, however, is its aesthetic reliance to lift guilty souls from the gutter of history on a handful of already familiar works. The fragments of Himid, Locke, Walker, and Shonibare which frame the narrative have done so much ‘work’ in another parish that they are no witness to the Academy’s half-sincere contrition. Who could have thought that these mantras would turn into rote?