Historicism: The theory that to understand a historical event, you must understand the philosophical context that it took place in, rather than explain it with supposedly timeless or fundamental ideas.
What is art for? "L'art pour l'art" wrote Théophile Gautier as a slogan in 1835. And today's bohemians continue to repeat the creed "Art for art's sake." It's a catchy slogan, still what most people unreflectively tell themselves when confronted with the question: "What is the purpose of art?"