An oxymoron is a clever gambit in an exhibition title. The Whitechapel Gallery’s Radical Figures: Painting in the New Millennium is designed to trigger the reaction: ‘Radical? Figures?’ before revealing quite how radical the figure can be. But like all good marketing, it is deceptive. Figurative art may have been consigned to history by Clement Greenberg 80 years ago, but history since — neo-romanticism, school of London, neo-expressionism — has repeatedly proved him wrong.