The Active Nature of the Soul in Sense Perception: Robert Kilwardby and Peter Olivi

This article discusses the theories of perception of Robert Kilwardby and Peter of John Olivi. Our aim is to show how in challenging certain assumptions of medieval Aristotelian theories of perception they drew on Augustine and argued for the active nature of the soul in sense perception. For both Kilwardby and Olivi, the soul is not passive with respect to perceived objects; rather, it causes its own cognitive acts with respect to external objects and thus allows the subject to perceive them. We also show that Kilwardby and Olivi differ substantially regarding where the activity of the soul is directed to and the role of the sensible species in the process, and we demonstrate that there ar…