Chapter 6 examines the politics of scientific fields at the level of micro-social interaction by analyzing intellectual conflict between RA members and their detractors in sustainability science. Data include firsthand observations of contentious interactions at academic conferences and detailed analyses of public debates, online forums, and scholarly publications. I identify the main groups in sustainability science with whom RA clashed and provide high-resolution accounts of key episodes of intellectual conflict. I show how RA used conferences to assert their theoretical faith, recruit new adherents, and challenge existing disciplinary boundaries. Competitor groups staged public performances (or “anti-rituals”) to re-establish these boundaries by questioning RA’s scientific faith, publicly shaming them, and desecrating their most sacred symbols. I conclude by showing how these conflicts over legitimacy altered RA’s ideas and those of their critics, leading to creative advances for RA and its competitors.