Democritus' perspectival theory of vision

AbstractDemocritus' theory of vision combines the notions of images (εἴδωλα) streaming from objects and air imprints, which gives him the resources to account for the perception of the relative size and distance of objects, not just their characteristics. This perspectival explanation of the visual theory accommodates important but overlooked evidence from Vitruvius. By comparing Democritus' theory with ancient developments in visual representation, my analysis provides a new approach to the evidence of atomist vision. I begin with the process of vision before turning to the Peripatetic objections, showing how a unified theory of vision takes into account all of the ancient testimony and provides possible atomist responses to the criticisms raised against it. I also identify the importance of vision via air imprints as an important metaphor for the conventionality of sensible qualities. Understanding these fundamental issues puts us in a better position to assess Democritus' place in the development of ancient optics and of atomist approaches to sense perception.