This book focuses on political presuppositions animating modern historical reflection in Germany that underwent sharp radicalization in the post-World War I context of the Weimar Republic. It is in this context that a novel polemical use of political concepts, nourished by radical forms of reflection on the historical character of human existence, brought to the fore interpretations of collective mentalities or group perspectives that crystallized in specific conceptions of “ideology” and of “political myth”. By centering analysis on the insight of a variety of twentieth-century thinkers whose works are of central importance for the elucidation of this topic, the author examines different interpretations of the role of reflection on human historicity in the elaboration of this novel polemical use of political concepts. Beyond an historical inquiry into this topic, this work aims to provide a theoretical investigation to elucidate the complex range of significations of the concepts of “ideology” and of “political myth”, the province of each of these concepts in the delineation of group perspectives, and the problematic legacy that the polemical use of these concepts has bequeathed to the contemporary world.