German expressionism, which flowered between the late 1800s and the collapse of the Weimar Republic in 1932, is the orphan of modern art: plaintive, clotted with turbulent emotion, snotty and—outside Germany—somewhat inaccessible. Its local significance was immense, its international resonance small; even today, the expressionist works that survive best seem to be in film (Fritz Lang) or theater (Brecht-Weill) rather than in painting.
A common attitude toward German expressionist artists like Emil Nolde, Ernst Kirchner, Franz Marc, Karl Schmidt-Rottluffor Max Pechstein used to be that their work was a talented but...