This article identifies the source of Clemens Brentano’s tale ‚Die drei Nüsse‘ („The Three Nuts“), long sought by researchers. It goes back to a „curieuse“ case history by the Thuringian writer Melissantes (alias Johann Gottfried Gregorii, 1685–1770), which in turn refers to a Latin disputation by the ‚polyhistor‘ Daniel Moller (1642–1712), Professor at the University of Altdorf (Nuremberg). My paper examines how Brentano takes the traditional scholastic theme of the awakened conscience and creates a ‘Romantic’ work of art by composing a narrative following the rules of romantic poetology but based on an 18th century ‚exemplum‘ story. The final part of my paper re-examines the story’s literary reception.