The issue addressed by this paper concerns one particular aspect of sociological theory and method in the analysis of social inequality. While not often made explicit, a temporal aspect is built into the sociological notion of social stratification as a general and comprehensive phenomenon, under which many observable forms of inequality may be subsumed. This recent advance in stratification analysis, consisting of more adequate and clearer formulations of the time dimension, is put forth and discussed. Among the various issues that are addressed are various conceptions or paradigms of social stratification, the usefulness of a biographical framework or life history as a tool of investigation, the concept of the cohort (or the age class of persons who move through the life cycle in the same span of calendar time) and models of inequality of social opportunity. Data are also presented for a research design that uses a retrospective life history, allowing for an analysis of equality of opportunity, or achievement, and of distribution of life chances very much within the temporal and causal framework of other models. This design is also able to estimate coefficients of the types of parameters suggested by other models. A causal temporal framework is not many steps removed from a confrontation with history - from which the study of social stratification should indeed not be remote. (Author/AM)