“Phaedon” is the title of a philosophical work by Moses Mendelssohn (1729-1785), the German-Jewish philosopher and leader of the Haskalah (Enlightenment) movement. The treatise, published in 1767, derives its title from one of the "Dialogues" of Plato. The fluttering butterfly on the skull symbolizes the "immortality of the spirit" (Phaedon).
Benjamin, Chaya, The Stieglitz Collection: Masterpieces of Jewish Art, The Israel Museum, Jerusalem, 1987, English / Hebrew
The Stieglitz Collection: Masterpieces of Jewish Art, Israel Museum, Jerusalem, 30/11/1987 - 21/04/1987