In this paper, I examine a longstanding theological approach to the natural world known as the Book of Nature, which invites us to see God as the author of two distinct yet complementary books—the natural world and the Bible—and thus to imagine nature as in some sense readable, intelligible, and a source of revelation about God. Whilst the Book of Nature is often read as a source of general revelation, many authors have highlighted the potential for it to be read as a prompt for aesthetic contemplation. It is in this context that my paper will explore St Augustine's writings on the Book of Nature. Augustine draws a connection between the contemplation of beauty in creation and the contemplation of God as creator or 'author' of the Book of Nature. I explore two features of Augustine's discussion. First, I highlight the connection he draws between aesthetic contemplation of the natural world and the development of moral virtue—specifically, the virtue of humility. Second, I highlight Augustine's contemplative approach to reading the 'two books' of nature and scripture, which are treated as complementary rather than competing sources of revelation. Finally, I assess the potential for Augustine's insights on the Book of Nature to be applied to contemporary work in eco-theology, and whether the ancient metaphor of the Book of Nature can be rehabilitated for an ecological age.