Collective identities are not only a current societal issue but also a fundamental concept in social and cultural sciences: What is a "collective" or a "society," and how does it come into being? How are individual and collective identities interconnected? This volume traverses various disciplines and debates, addressing both the urgency and relevance of collective identity as well as the diversity in which it is conceived, researched, and critiqued, culminating in the thesis of the necessity and impossibility of collective identity. The introduction is aimed at students of social and cultural sciences as well as anyone interested and engaged in societal issues.