WHAT HAPPENED in 1910 that supposedly changed human nature? The event that stood out in Virginia Woolf’s recollection was a London exhibition of the paintings of the post-Impressionists, including Cézanne, Gauguin, Picasso, and van Gogh. It was an unveiling of the movement called modernism, and when Woolf wrote her declaration in the 1920s, the movement was taking over the arts.