In this book, Benjamin Strosberg explores difficulties and anxieties inherent in studying, defining, and defending against anti-Semitism by tracing a concurrent difficulty in thinking about Jewishness, which has historically served as a limit case for central social categories such as outsider, religion, race, gender, and nation. Dr. Strosberg draws on Zygmunt Bauman’s concept of proteophobia—the anxious fear of what doesn’t fit into clear-cut categories—to think more carefully about anti-Semitism as response to the complex-realities of ambivalence and otherness. The book proposes ‘negative psychology’ as a methodology for studying anti-Semitism and proteophobia rooted in psychoanalysis and Theodor Adorno’s Critical Theory. Drawing from lived experiences, contemporary events, and debates in the field, this compelling work explores the broad implications of the investigation of anti-Semitism for politics, education, and psychoanalysis, as well as the specific implications for Jewish identity and resistance.