A belief in a firm correspondence between objects, ideas, and their representation in language pervaded the works of Anne Robert Jacques Turgot
(1727–1781) in 1750. This conviction is particularly manifest in Turgot’s sharp critique of Berkeley’s philosophical system and his remarks on Maupertuis’s reconstruction of the origin of language. During the 1750s Turgot’s epistemological views underwent a change, apparent in two of his contributions to the Encyclopédie: the entries Existence and Étymologie (1756). These articles included a reassessment of Berkeleyan immaterialism, facing an ultimate crisis of definition and representation. A similar development may be traced in contemporary works by Condillac and Diderot. Turgot’s Encyclopédie entries also envisaged a new science, an archeology of the human mind aided by the examination of linguistic development and change. This entailed the scientific verification of conjectures in any historical account of ideas, turning etymological
and psychological inquiries into what Turgot termed ‘experimental metaphysics’.