The historical role of the working class has recently been subject to reassessment. Frequently repudiated are the Marxist views that the proletariat constitutes either, as Marx's and Engels' classic scheme would have it, the revolutionary social force in capitalist societies, or, as Lenin believed, the pre-eminent element in a revolutionary alliance with the poorest strata of the peasantry, or, finally, as Mao holds, the leadership cadres needed to mobilize the downtrodden peasant masses into conscious, revolutionary action. Consider, for instance, the meager role attributed to the working class in Barrington Moore's brilliant effort, in Social Origins of Dictatorship and Democracy, to delineate three historical routes to modernity.