This book intends to renovate the view of social sciences in the German-speaking world. It explores the intellectual tension in the social science in Austria and Germany in the late-nineteenth and early-twentieth centuries. It deals with how the emergence of the new school (Austrian School) changed the focus of social science in the German speaking world, and how it prepared the introduction of an evolutionary perspective in economics, politics, and sociology. Based on (mostly hitherto unknown) primary evidence, this development is lively described in a series of encounters and decisions by each social scientists.