In a Parisian café, the philosopher meets a curious and contradictory man, who resembles nothing less than his own self. The dialogue that opens between them, with the unparalleled grace, light humor, and wit of Diderot, gradually expands to cover all the central themes of modernity: virtue and knowledge, love and money, genius and faith, politics and art.

The gap between the two versions of self that Diderot stages, the primary split of the ego into two distinct but sometimes complementary positions, constitutes a pivotal moment in the history of thought, a moment of rupture, a bomb, as Goethe described it, the fragments of which scatter across the entire field of literature to this day.