On the World and Religious Life (c. 1381) is the first surviving treatise of Coluccio Salutati (1332–1406), chancellor of the Florentine Republic (1375–1406) and the leader of the humanist movement in Italy in the generation after Petrarch and Boccaccio. The work was written for a lawyer who had left secular life to enter the Camaldulensian monastery of Santa Maria degli Angeli, located in the heart of Florence. The new monk prevailed on Salutati to write a treatise encouraging him to persevere in the religious life. His request led to this wide-ranging reflection on humanity’s misuse of God’s creation and the need to orient human life in accordance with a proper hierarchy of values. This work is here translated into English for the first time.