The above analysis identified four conditions as necessary and sufficient for revolution in general and the Mexican revolution in particular: a favorable world context, an administrative and coercive crisis of the state, widespread rural rebellion, and dissident elite movement(s). The first three interact to produce a revolutionary situation; the fourth, given the near-automatic existence of alternate contenders, emerges to effect political and social transformation after military superiority is proved. Other conceptions of revolution - with their foci on expectations and deprivations, or dissensus and ideology, or political conflict, or change of “stage” and class struggle - were found wanting theoretically and to varying degrees unhelpful in making sense of the empirical realities of the Mexican case. The historically grounded, world-system informed structural explanation better fits the data. And theoretically, it integrates the two levels of description that analysts of revolution must comprehend: changes in social and political organization, and conscious human action. It preserves the distinction between revolution and other less far-reaching socio-political phenomena. And it suggests, sternly and surely, that in contemporary advanced societies the kind of conjuncture specified above cannot occur. Past revolutions may inspire but cannot serve as models for our own future.