Anselm Kiefer is putting the finishing touches to his exhibition Finnegans Wake with the help of a forklift truck. The huge gallery at White Cube Bermondsey has been all but filled with a mound of shattered concrete surrounded by barbed wire, like a bombed second world war bunker. I watch as the wiry, bespectacled 78-year-old lion of German art directs the drop of a final piece of rubble into place, sending a rusty chunk of metal crashing on its side. “Perfect,” he says. When we sit down to talk he tells me how he hacked out this broken mass from...