While literary scholars and journalists casually speak of literary “generations,” they do so without a well-developed or precise understanding of the term. This essay investigates the emergence of the “generation” as a sociological concept in 19th century France and argues that the particular conditions of its emergence color its wider applicability as a tool of analysis. The golden age of generational theory in the 1920s is investigated and tied to a larger field of generational thinking in the popular imagination, and two case studies (the Spanish Generation of 1898 and a comparison between Henry Green and H.E. Bates) showcase the problematic nature of the term’s use.