This book represents the first in-depth, comparative investigation of linguistic purism in modern French. It investigates the relative prevalence of purist ideology in France and Quebec. Both experience influence from English and have similar language legislation, but they differ in their social, political and economic history. Three different levels of society are examined (official, group and individual), allowing a comparison of the ‘voice from above’ and the ‘voice from below’. This is a key element in recent discussions of language planning but is rarely provided in studies of French. The study is also the first to apply to empirical data Thomas’s widely cited theoretical framework for describing linguistic purism (1991), and has evaluated and refined this, enhancing the theoretical underpinnings of the field. The book will be of interest not only to French scholars and sociolinguists, but also to scholars of language planning, language policy and language ideologies in all languages.