Without Paul F. Lazarsfeld the social sciences would not be what they are today. In his work on unemployment, voting, consumer behaviour, and social influence, among other subjects, his methodological emphasis on vigorously controlled scientific language and structures transformed social research worldwide. His criticism of observational, conceptual, and inferential procedures in sociology led to the formation of universally applied observational and analytical techniques. The 18 essays in On Social Research and Its Language illustrate the diversity of Lazarsfeld’s substantive, methodological, and organizational interests. Spanning the years 1933 to 1972, they encompass his own works of social research, as well as writings on methodology and the history and sociology of social research. In addition, Raymond Boudon provides a revealing biography of Lazarsfeld and his influence on sociology.