Philip Guston’s “Head II,” 1969, one of the works in the postponed show. (National Gallery of Art, Washington, Gift of Edward R. Broida) From the Washington Post's art critic, Sebastian Smee In postponing Guston exhibition, the National Gallery and three other museums have made a mistake From the article: "In the art world, the culture war is playing out as a question of how big a role art can and should play in bringing about certain kinds of social change. Many on the left want our idea of art to become so instrumentalist — so subservient to political imperatives — that they are willing to jettison large parts of what art means to people who love it and truly need it. I am referring to its ambiguities, its contradictions, its connection to the richness and freedom of our inner lives, to beauty and pain, and its ability to speak to confusions within and without. I’m talking about all the things you find in Toni Morrison, in Frank Ocean, in Anton Chekhov or Alice Munro, in Sho...