Listen to Neil MacGregor's lecture celebrating the 250th anniversary of the public opening of the British Museum

The fox knows many things; the hedgehog knows one big thing. Neil MacGregor, director of the British Museum, is a hedgehog. The one big thing he knows is what his museum is for: “What the collection is about is truth, and one way to the truth is comparison; and comparison is an enormous weapon in the struggle towards truth. That holds across everything. A comparative collection, as opposed to a national collection, offers access to different kinds of truth.”

He has just laid out his big hedgehog idea in an important anniversary lecture. It is a text by which future museum policy, here and elsewhere, will be defined. It represents a new, deeper, global statement of what the hedgehog knows. He wants to turn the BM into “the private collection of every citizen in the world”.

There are national museums all over the world, telling local stories, but there are only a handful of museums in which national cultures can be compared. Of these, the BM is the most comprehensive and, thanks to Hedgehog MacGregor (now in the seventh year of his reign), the most ambitious. He wants to create a worldwide network of curators trained to know the contents of the BM.

He even wants to turn it into a “lending library”, so these curators can pick and choose their objects and make their own exhibitions in their own countries. “This vision . . . ” I say tentatively. He interrupts. “It’s really a quotation rather than a vision. It's what people in the 18th century, when the museum was founded, thought they were doing.” “Vision” was a bit strong for him. He is famously reticent, curiously understated for a man widely regarded as the greatest museum boss in the world. But I’ll come back to this matter of his psychology.

Underlying this and other plans is not some new hedgehog knowledge. He’s said it all to me before. But he’s saying it again, in more detail and with more passion, because the times require it. “The need to use this resource has become more acute. As a result of what’s happened in the Middle East and Africa, the need to engage with the historical dimensions of identities, societies and conflicts is greater than ever. The stakes have got higher and higher. In Palestine and Iran, the stakes are higher than they were five years ago; the same is true in Sudan or in central Africa or west Africa. The construction of civil society in more and more of these areas looks endangered, and the implications for our societies are more evident than they were.”

The transcultural, transnational, transhistorical comparisons that can be made in the BM’s collection subvert the crude rhetoric of contemporary politics and tribal division. They prompt us, as MacGregor says, “to slow down conclusions, to complicate the questions, to make the hasty judgment harder”. Things — shoes, statues, coins, whatever — tell stories we may not want to hear. Iran is not what our leaders say it is; nor are we what the Iranians are told by theirs.

MacGregor is big on Iran. Next month he has a new exhibition — Shah Abbas: The Remaking of Iran — about Abbas I, who, in the 17th century, stabilised and globalised his country. Iran tended to be written out of eurocentric history. Not any more, if the Hedgehog has anything to do with it. He’s also currently showing an exhibition about Babylon, to make it clear that that city was not the barbaric den of iniquity of thoughtless history and Bob Marley songs; and he’s got Montezuma in the autumn, to show that indigenous Latin American culture was not destroyed by the Spanish conquistadors, another myth of thoughtless history. He wants us to look again: “It’s a way of using objections to challenge not so much misconceptions . . . (reticence again) . . . as accepted assumptions. That is central to the position of the museum.”

“Are you not,” I ask, “letting your exhibitions policy be dominated by contemporary politics?”

“No,” he says, surprisingly quickly — he normally takes a while to formulate his answers. “We are saying the collection is so rich that it enables us to look at these things. After Montezuma, we’re doing Florentine Renaissance drawings, and one after that on the journey of the soul in the Egyptian afterlife. It would be a bit of a stretch to fit that in with contemporary politics.”

He laughs wildly, convulsing in his chair. He does that a lot. Yet, in spite of his reluctance to define his role as political, it is. Very. Take, for example, the Lewis Chessmen. These are 12th-century chess pieces found in the 19th century in the Outer Hebrides. A few are on display in Edinburgh, but most are in the BM. Some Scots have been saying they should all be in Edinburgh, that they are an essential part of national identity. The Glasgow-born Hedgehog becomes withering: “The question is, in what sense can an object made in Norway for export to Ireland, then buried, credibly become a vector of Scottish identity? If we are going to construct new support for national identities, it’s important to question whether they are valid ones — or fantasies.”

The Parthenon (Elgin) Marbles, of course, cannot be quite so easily dismissed. They are Greek to the core. But MacGregor has been down this road many times before — by having them in the BM, by removing them from the purely national context of Greece, he exalts them by fitting them into the wider story of global civilisations.

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