This book offers a new perspective on the emergence of concepts that shaped the world, set against the dramatic background of political upheaval and crisis of scientific knowledge that characterized interwar Germany and Austria. On the one hand, the political-theoretical certainties of previous generations were rendered suddenly obsolete by the imperatives of total war. On the other hand, the old certainties of a reductive and deterministic conception of scientific knowledge had likewise been destabilized, in this case by the revolutionary discoveries of Relativity Theory and Quantum Mechanics. Among the philosophically literate intelligentsia of interwar Germany and Austria, the juxtaposition of such radical epistemic and political insecurity created fertile ground for the cross-pollination of ideas across disciplines. Using a network-oriented approach, this book traces key lines of influence, following the development, dissemination, and reinterpretation of concepts from domains of political thought to epistemology and back again. It is of interest and importance to a broad range of readers interested in learning how the ideas of physicist-philosophers like Albert Einstein and Werner Heisenberg shaped the paradigms within which major theorists like Walter Benjamin and Carl Schmitt opened up new horizons for political thought.