From cartoons of Muhammad in a Danish newspaper to displays of the Confederate battle flag over the South Carolina statehouse, acts of cultural significance have set off political conflicts and sometimes violence. These and other expressions and enactments of culture--whether in music, graffiti, sculpture, flag displays, parades, religious rituals, or film--regularly produce divisive and sometimes prolonged disputes. What is striking about so many of these conflicts is their emotional intensity, despite the fact that in many cases what is at stake is often of little material value. Why do...