The article is devoted to Denis Diderot’s Salons, which laid the foundations of art criticism, one of the biggest gifts of the French Enlightenment to world culture. The paper provides a brief overview of the history of the salon as a genre that appealed to many French writers (Stendhal, T. Gautier, C. Baudelaire, and É. Zola). Like Diderot, they would weaponize their descriptions of paintings and sculptures for a polemic  against the outmoded and in favour of a sweeping renewal of art. The scholar considers Diderot’s evolution as an art critic: he becomes increasingly proficient in the subject, offering informed analyses of aesthetic categories such as harmony, composition, symmetry, colouring, and drawing. The article dwells on the dialogic style of Salons — a quality that famously typifies Diderot’s entire output. His critical verdicts proved accurate over time: his opponents have faded into obscurity, while the contributions of the artists he championed (Greuze, Chardin, and David, among others) are recognized to this day. The philosopher himself considered Salons his best work, making these reviews an invaluable reference for better understanding Diderot’s philosophical and aesthetic creed.