This thesis proposes a new reading of the Cosmographia of Bernardus Silvestris and a reconsideration of the work's place in the intellectual history of the twelfth century. A complex allegory of creation, the Cosmographia depends on a wide variety of scientific, literary and theological traditions. This thesis seeks to identify the classical, patristic and early medieval traditions to which Bernardus was indebted, and it argues that the Cosmographia deployed the resources of these traditions to respond to the changing intellectual conditions of the schools of northern France where Bernardus worked.