John of Jandun on Sense Perception and Instantaneous Change

Abstract

The aim of this paper is to show that John of Jandun, a French philosopher active in the first decades of the fourteenth century, defended an interesting interpretation of Aristotle’s theory of sense perception. His view on this topic could help us clarify some aspects of the contemporary debate among specialists of the Aristotelian tradition about the dependence of sense perception on physical changes in the medium and the organs. John of Jandun made use, much more than his contemporaries, of Alexander of Aphrodisias’ commentary on the De sensu, and Averroes’ commentaries on the De anima and the Physics. But his solution seems nonetheless original. This paper will focus on the nature of the changes involved in sense perception. I will try to show (1) that for Jandun sense perception is a kind of relational and qualitative change in the soul, which is not a mere Cambridge change; and (2) that for him sense perception is an activity of the soul, which is not reducible to the reception of a form in the organs.