Visual representations were deeply involved in medieval traditions related to the dissemination and teaching of philosophy and science. Consequently, they were not only examples of theological or philosophical interpretation, but rather brought together manifold intellectual activities, illuminating various perceptual, cognitive, and spiritual concerns. Visual tools, which appear frequently in medieval manuscripts, have often been considered as "illustrative material" intended to facilitate the comprehension and interpretation of texts. These "visual aids" offer something more than a straightforward correspondence between a conceptual interpretation and its figurative depiction. They are, in fact, key to understanding the methods of acquiring and shaping knowledge through visual frameworks with didactical, disputational or heuristic purposes. The aim of this volume is to deepen our understanding of medieval visual tools that represented and demonstrated philosophical and scientific knowledge and, to an extent, the accumulation of empirical information.