Fin de siecle Vienna was once memorably described by Karl Kraus as a "proving ground for the destruction of the world." In the decades leading to the World War that brought down the Austro-Hungarian empire, the city was at once an operetta dream world masking social and political problems and tension, as well as a center for the far-reaching explorations and innovations in music, art, science, and philosophy that would help to define modernity. One of the most powerful critiques of the retreat into fantasy was that of the philosopher Ludwig Wittgenstein, whose early career in Vienna has...