The Traicté de la proportion naturelle et artificielle des choses par Jean-Pol Lomazzo (1649), written by Hilaire Pader, is one of the earliest pieces of writing on art published in seventeenth century France. It is the first of the seven books that composed Lomazzo's Trattato della pitttura (1584). It concerns proportion. Pader hoped to translate the other six books of Lomazzo's treatise if the first was successful. Although the translation of the Trattato was never completed, Pader nevertheless followed up the ideas it contained in other works. In 1658, he published his Treatise on Painting in two parts: the Peinture parlante and the Songe énigmatique sur la peinture universelle. The aim of this article is to discuss the social and artistic stakes of Lomazzo's translation.