Sociological traditions engender not theoretical uniformity but diversity. This is clearly evident in neo-Weberian statements of class formation and relations. Frank Parkin's development of the social closure notion in class analysis provides an implicit critique of Giddens' account of mobility closure in class structuration. The model of class contained in Parkins's elaboration of the concept of social closure posits a direct relation between class formation and social power relations, provides an account of exploitation in class relations, explains intra-class divisions through the concepts used in understanding inter-class divisions, and contains a unified statement of communal and class divisions. In each of these endeavours to contribute to our understanding of class relations, Parkin's formulations are found wanting.