A surging movement for Catalan political independence from Spain has brought renewed urgency to questions about what it means, personally and politically, to speak or not to speak Catalan and to claim Catalan identity. This book develops a framework for analyzing ideologies of linguistic authority and uses it to illuminate the politics of language in Catalonia, where Catalan jostles with Castilian for legitimacy. Kathryn Woolard's longitudinal research across decades of political autonomy contextualizes this ethnographic study of the social meaning of Catalan in the 21st century. Part I lays out the ideologies of linguistic authenticity, anonymity, and naturalism that underpin linguistic authority in the modern western world, and gives an overview of a shift in the ideological grounding of linguistic authority in contemporary Catalonia. Part II examines discourses in the media surrounding three public linguistic controversies: an immigrant president's linguistic competence, a municipal festival, and an international book fair. Part III explores individuals' linguistic practices and views, drawing on classroom ethnographies and interviews with two generations of young people from the same high school. Woolard argues that there is an ongoing shift at both public and personal levels away from the ethnolinguistic authenticity that powered relations in the early transition to political autonomy, and toward new discourses of anonymity, rooted cosmopolitanism, and authenticity understood as a project rather than a matter of origins and essence.