During the first half of the twentieth century, Austrian socialist thinkers such as Otto Bauer, Rudolf Hilferding, Karl Renner, and Max Adler emerged from and helped transform Austrian Social Democracy into one of Europe's best organized and most effective political and social movements. Equipped with extensive introductions that outline the intellectual and political background within which the Austro Marxists worked, these volumes represent the most thorough effort to date to provide a representative sampling in English of the Austro-Marxists' key theoretical ideas and their approaches to politic action. Drawing on their writings from the early twentieth century until the collapse of Austrian Socialism in the 1930s, these volumes illustrate the conceptual richness of Austro-Marxist thought and the enduring challenge that socialists faced then and now in the realization of their hopes.