T.J. Clark is one of the world's leading art historians. The books he has published since 1974 on 19th and 20th century modernism, and more recently on Poussin, have rerouted the whole study of art history. Having recently returned to his native England after many years teaching at Berkeley, Clark is currently completing a study of Picasso's work during the 1920s. Here he offers a response to the Tate Britain exhibition 'Picasso and Modern British Art', considering what light the show sheds on the nature of English art.