The Encyclopédie, ou Dictionnaire raisonné des sciences, des arts et des métiers (1751-1772) is the laboratory of experience of the new technical-rational values produced by the 18th century and the philosophie. Science and the mechanical 'arts', labor, invention, industry and trade; and, following on from these, freedom of conscience, tolerance, dialogue etc., in their controversial relations, give a representation of the conflicts of the newly-born bourgeois society. Exponents of the 'enlightened', learned and anticlerical nobility (Jaucourt, d'Holbach, Hélvetius); of the intellectual petty bourgeoisie (Diderot, Rousseau, Marmontel, Deleyre); of the 'liberal clergy' (the abbés De Prades, Yvon, Pestré and many others). Work and the representation (also figurative) of the productive operations of the mechanical arts are the central point, the main means through which the Enlightenment's enterprise of human emancipation is accomplished.