The transformation of the human sciences into the social sciences in the third part of the 19th century was closely related to attempts to develop and implement methods for dealing with social tensions and the rationalization of society. This book studies the connections between academic disciplines and notions of Jewish assimilation and integration and demonstrates that the quest for Jewish assimilation is linked to and built into the conceptual foundations of modern social science disciplines. Focusing on two influential "assimilated" Jewish authors—anthropologist Franz Boas and sociologist Georg Simmel—this study shows that epistemological considerations underlie the authors’ respective evaluations of the Jews’ assimilation in German and American societies as a form of "group extinction" or as a form of "social identity." This conceptual model gives a new "key" to understanding pivotal issues in recent Jewish history and in the history of the social sciences.