ABSTRACT: As Smith freed moral philosophy from former control bodies (the Church, the state), the Scottish philosopher opened the field for a scientific political economy. In his Adam Smith. Philosophie et économie (Paris, Presses universitaires de France, 1990, p. 45), Jean Mathiot asked : «Should then one wonder that his [Smith’s] audacious stand became the historical grounding stone for political economy, then bringing recognition as an objectively-grounded field of knowledge?» Mathiot’s text and thought have been little debated to this day; this essay is meant to fill that gap, in particular with regard to the history of Smith’s reception in France. Mathiot sought to understand better the “impartial spectator” using a new character whom he claimed Smith was implicitly sketching, and whom he called “the impartial laborer”. To Mathiot’s mind, from the Theory of moral sentiments (1759) to the Wealth of Nations (1776), the link is nothing else than Smith’s own philosophy.