At such times the collection is unable to follow the continuities it is looking for. Similarly, Gainsborough is tied to the Californian resident Hockney not by some mythologised shared national background, but by their posing of portrait models. At its best, Hatoum's work addresses exactly the question of the arbitrariness of national identity and the ease with which it can be suppressed. Here, a map of the world created in iron filings is swept from below by a magnetic arm. The effect is of watching countries ripple like cornfields.
Displaying work according to themes has certain benefits.
When you do find a familiar piece, it is often made surprising and fresh by the unfamiliar context in which it is viewed. But this also works against any understanding of the historical context in which different schools of paintings and sculpture emerged. There is an interesting room of British art acquisitions made over the last 10 years, containing some important older pieces as well as some curios from well-known artists. Not everything is as vacuous as the work displayed here by Tracey Emin, but much of it has little to say. Chris Ofili's No Woman No Cry , his response to the murder of Stephen Lawrence, is a large work, and the much-vaunted elephant dung base works very well as part of the work.