In the last phase of Franciszek Karpiński's life as a writer (the first quarter of the 19th century), he practically gave up poetry and concentrated instead on writing memoirs. This article tries to find out to what extent his autobiographical work, especially his Historia mego wieku i ludzi, z którymi żyłem [A History of My Century and the People with Whom I Lived], is influenced by an attitude characteristic of the sentimentalism of the previous century. As this analysis shows Karpiński's narrative exhibits both a sensitivity much indebted to Rousseau's autobiographical method and skilful shifts of tone, from satire and irony to various shades of melancholy. For sentimentalist aesthetic and poetics the continual manipulation of tone is a means of alerting the reader to the world's complexity. As in the novels of Lawrence Sterne, that complexity is experienced by way of careful observation of fragments of reality, defined by the subjectivity of the observer and the truth of his emotions.