The chapter traces the emergence of the ‘Promethean’ conception of knowledge and history in the long nineteenth century in France. First, it describes the environment in which Vichian ideas were resurrected. It explains why a reinvented Vico’s philosophy might have become indispensable in a bustling new epoch of inventions, political transformations, and industry. Then it focuses on Marx’s reading of Vico and Marx’s earlier formulation of ‘praxis epistemology’. Finally, it explores the philosophical synthesis of the French engineer Georges Sorel, who connected Vico, Marx, and the American pragmatists to formulate a new ‘praxis epistemology’ where human and natural sciences could find a convenient and consistent integration.