This contribution to the sociology of sociology offers an empirical evaluation of a comprehensive class-analytic explanation for structured and temporal intellectual diversity in sociological theory and analysis. In an articulation of the arguments of Chertok (1990) and Szymanski (1985), it is suggested that the structured diversity of the discipline is a function of class structure, and that "metatheoretical shifts" — systematic changes in the paradigmatic underpinnings and the categorical structure of sociological theories and analyses — are a function of the vitality of social movements. A quantitative analysis of the conceptual content of the Sociological Abstracts on CD-ROM ("Sociofile") documents the existence, the nature, and the extent of a recent metatheoretical shift.