Modern historians of science often discuss the twelfth-century “discovery of nature” as a milestone in our relations with the environment. This article explores medieval scientific, literary, and theological writers who contributed to this distinctive set of attitudes even as it documents the significant continuities between these writings and those of classical and late antique authorities on the natural world. It traces how the encyclopedic imagination provided a hierarchical framework for understanding the world, and how this ontological scaffolding, in turn, underpinned the twelfth-century revival of Neoplatonic thought, as medieval Christian writers would enthusiastically adopt an earlier tradition of personifying nature. In the thirteenth century, this magisterial Natura came to reflect advances in the “new” Aristotelian science that would become the foundation of the medieval university curriculum. While the synthesis of Christian Neoplatonism and Aristotelian physis would remain the predominant model of nature for several centuries, it also occasioned polemical debates over how God related to the universe that he created and how knowledge of the natural world was to be valued and instrumentalized. This medieval vision of a human-scaled, personified nature would prove philosophically durable up to the Scientific Revolution.