The text explores the medieval concept of liber mundi, the idea of ​​the world as a book to be deciphered. The perspective of St. John is discussed, emphasizing the reason inherent in the world as a reflection of God, and that of St. Peter, seeing the world as a system of divine signs. The ideas of authors such as St. Bonaventure, Sir Thomas Browne, Plotinus and Hermes Trismegistus are examined, exploring how understanding the natural world relates to understanding the divine, and the influence of the Corpus Hermeticum on Renaissance philosophy is highlighted.