In 1936, Walter Benjamin defined the revolutionary class as being in opposition to a dense and dangerous crowd, prone to fear of the foreign, and under the spell of anti-Semitic madness. Today, in formations great or small, that sad figure returns--the hatred of minorities is rekindled and the pied-pipers of the crowd stand triumphant.

Class, by Andrea Cavalletti, is a striking montage of diverse materials--Marx and Jules Verne, Benjamin and Gabriel Tarde. In it, Cavalletti asks whether the untimely concept of class is once again thinkable. Faced with new pogroms and state racism,...