The Portrait of a Young Man (1656, Hermitage), is presumed to be a self-portrait showing a young man in a melancholy pose. It was previously believed that the sitter's mood was connected to his financial difficulties. The current view is that the painting is a pensieroso (pensive) portrait, a motive going back to the 15th-century Neoplatonic concept that melancholy is the distinguishing feature of the creative character. The allegorical significance of the objects in the painting such as old books, empty purse, gold coins, and inkwell is consistent with this interpretation. The portrait also has a moralizing inscription, RATIO QUIQUE REDDENDA (Every man must give an accounting). This allegorical strain is characteristic of Sweerts' art. (https://en.wikipedia.org/wiki/Michiel_Sweerts)