Does de Weldon's Iwo Jima Memorial do the same job as Donatello? Photograph: Pablo Martinez Monsivais/AP
I've just been in New York for a Global Creative Leadership Summit, set up by the Louise T Blouin Foundation, whose £20m cultural institute has just opened in London with a spectacular James Turrell show. Rubbing shoulders with Nobel prize winners in science and leaders in business and the arts is a potentially heady business - but only potentially. Egos can too easily obstruct exchange.
The panel into which I'm co-opted is posed the question: "Can art and design save the world?" As Ron Arad says at breakfast, the question might as well be the other way round. In any event, our chairman decides to redefine the question in terms of the relationship of art with money, or, more particular, business. The points I had rehearsed in my mind proved largely irrelevant. I do not do well in the ensuing debate.
One of the problems of such gatherings of the 'great' across such a spectrum is that one person becomes representative of some vast territory. Chuck Close stands for 'Art', Arad for 'Design'. I'm the only signed-up historian. People tend by their nature to be individual and idiosyncratic rather than representative and typical.
But there's a deeper problem. Once we deal in such gross categories as 'Art' and 'Science' and expect to deliver sharp analysis, we are in real trouble. Is there any reason that, say, a painter of academic portraits and a maker of anarchic installations should be thought of as being in the same business? Or are a theoretical physicist and student of animal behaviour doing anything remotely similar? The names 'Art' and 'Science' are no longer doing useful jobs, if, for example, we want to talk effectively about creativity. We first have to ask: what kind of art, what kind of science?
There's much to say in favour of David Hockney's argument that the mainstream of western art from the mid-19th century onwards progressively went into photography, film and television, and now computer graphics. 'Fine Art' became a kind of laboratory subject.
In art, it's a piece like Felix W de Weldon's Iwo Jima Memorial, based on a photograph by Joe Rosenthal, that does the same kind of job as Donatello in terms of public and political communication. It's certainly not David Smith's welded abstractions. I'm not saying that de Weldon is a great sculptor, but he's the heir to the great western sculptors in terms of function. The many reworkings of the photograph and sculpture - John Wayne in Sands of Iwo Jima, the Marine's website, the group of fire-fighters posed at Ground Zero, and now in Clint Eastwood's just-released film Flags of Our Fathers - testify to their efficacy in the wider public domain.
There's now a massive audience for the experimental outputs of the art laboratories. Picasso draws huge numbers. The latest experiment in the Tate Modern's turbine hall is a well-established spectator event. There are artists who are working urgently on big issues, such as the environment. But are their voices significant?
The art world has a great propensity to take its own incestuous circles of communication as exercising significant leverage on the 'real world'. At best we are part of a complex set of cultural voices that can sometimes build up sufficient mass to make those who matter take notice. But those who matter are more likely to listen to their own kind.
