In “The Book of Nature,” Rebecca Davis traces the development theological trope of the book of nature in the twelfth-century Neoplatonic allegories of Bernard Silvestris and Alan of Lille as well as in Augustinian theology. After exploring Natura’s role as God’s vicaria dei in the allegories of Alan and Bernard, Davis turns to the book of nature’s role in later medieval vernacular poems like Dante’s Divine Comedy and William Langland’s Piers Plowman. Davis argues that medieval authors utilize the book of nature to call attention to issues of interpretation at points when authors attempt to establish or contest literary authority. The book of nature calls on us to interpret the world just as we interpret texts. The chapter closes with later manifestations of the book of nature in the works of Milton, Wordsworth, Emerson, and Rachel Carson.