Spaces of Knowledge in Medieval Diagrams

The spatial structure of diagrams can be described in algebraic, geometric, cognitive or semiotic terms. Based on the ?Ur-diagram' of the Divided Line in Plato's ?Republic', diagrams can be understood as representations of the visible and the intelligible world. However, the knowledge thus conveyed is subject to the contingency of material and contextual, i.e., period-specific circumstances. How i...