The British Museum has tended to keep its lips sealed about its most controversial set of treasures: the sculptures removed from the Parthenon in Athens by Lord Elgin at the start of the 19th century. I know, because I’ve taken part in public debates to put its case – without anyone from the museum to back me up – most recently at University College London, which is so close to the museum that its curators would have only needed to pop around the corner to say their piece.

Hartwig Fischer, the director of the British Museum, has just broken with this policy of saying nothing and hoping the museum’s critics will go away. He has given an uninhibited interview to the Greek newspaper Ta Nea, in which he makes an intellectual argument for keeping the sculptures where they are. And he has used an incendiary word that has unleashed a torrent of outrage.

In the interview – and to avoid repeating any mistranslations, I am quoting a text provided to me by the British Museum – Fischer claims that moving these and other objects from their original place into a museum in another part of the world can be “creative”.

“When you move cultural heritage into a museum, you move it out of context,” he says. “Yet that displacement is also a creative act, and each encounter with it is potentially a creative act.”

This may seem provocative. Is he actually claiming that when Elgin got his workmen to physically remove a huge part of the sculptures from the Parthenon temple, after doing a dodgy deal with the Ottoman empire that was oppressing Greece at the time, and ship them to London, this act of daylight robbery was creative? Try asking that another way. Was it creative when British soldiers destroyed the royal city of Benin, west Africa, in 1897 and looted the great brass plaques from its palace, many of which are in the British Museum? Or when Hitler planned a new museum to house the looted art of Europe?

Emotion is easy and thinking is hard. The campaign to return Elgin’s booty to Greece has run on passion for 200 years, ever since Lord Byron denounced Elgin in Childe Harold’s Pilgrimage. Today, this oldest of all cultural property protests has become emblematic of a wider outrage that sees many museum treasures, such as the British Museum’s Rapa Nui stone figure, as nothing more than imperial theft. There is a mood to support any and all such restitution claims – Jeremy Corbyn would return the Parthenon sculptures, no question – so for Fischer to call museums’ appropriation of other peoples’ art “creative” is bound to start a fire.

Yet, if you don’t see his case, you are ultimately saying there shouldn’t be any world museums and every work of art should stay in its original location, as it only has meaning in its original context. If you follow this through to its logical conclusion, there should be no international sharing of images and ideas. Every altar piece in the National Gallery would have to go back to the church it was made for. That’s a terrifying plan to intellectually shrink our species in a myriad of mental Brexits.

Placing these sculptures in the British Museum was an act of reverence.

Those who argue for the return of the Parthenon sculptures and any other such restitution need to be clear that in attacking the dream of the world museum you are assaulting the heritage of the Enlightenment. Museums make us see more, they let us explore connections. Visit the British Museum’s Islamic gallery and you can see how Islamic art drew on the classical heritage of which the Parthenon sculptures are the summit. You can see the same influence in its early Buddhist art. Only a collection like that of the British Museum opens up these bigger ways of seeing.

Creative? Actually, yes. The generosity and scope of a museum on the British Museum’s scale expands our horizons. It seems to me that there are two fundamental errors in the case to return the Parthenon treasures. One is the notion that ancient Greece, a civilisation that flourished 2,500 years ago, is somehow the cultural possession of modern Greece, that its achievements belong to Greece in some narrow national way. If that were true, no one outside Greece would study mathematics, philosophy or history, see a play, or do a scientific experiment – for all these fundamental human pursuits were invented by the ancient Greeks.

Parthenon Selene from the east pediment of the Parthenon, part of the Parthenon marbles in the British Mmuseum Photograph: Steve Taylor ARPS / Alamy Stock/Alamy Stock Photo

The other is that placing these sculptures in the British Museum expressed contempt for Greece. In fact, it was an act of reverence. These masterpieces came to London at the height of neoclassicism, when the civilisation of ancient Greece was seen as the fount of all wisdom, beauty and truth.

There’s a simple proof that putting this art in the British Museum was indeed creative. John Keats, unlike the aristocratic Lord Byron, was neither rich nor healthy enough to sail to Greece. But when he saw the Parthenon frieze in London it inspired him, in his Ode on a Grecian Urn, to describe its tragic image of a cow being led to slaughter:

“To what green altar, O mysterious priest,

Lead’st thou that heifer lowing at the skies,

And all her silken flanks with garlands drest?”

If it’s not creative to inspire one of the greatest poets in the English language, what is? Greece has Byron on its side. The British Museum has Keats (not to mention Percy Bysshe Shelley, who in the same years wrote Ozymandias about another marvel in its collection).

Fischer has been brave to stick his head over the parapet and say what he thinks. He’s the internationalist liberal in this debate. The passionate proponents of Greece’s claim need to explain how their argument differs from any other variety of nationalist populism.