Affordances and classification: On the significance of a sidebar in James Gibson's last book

This article is about a sidebar in James Gibson's last book, The ecological approach to visual perception. In this sidebar, Gibson, the founder of the ecological perspective of perception and action, argued that to perceive an affordance is not to classify an object. Although this sidebar has received scant attention, it is of great significance both historically and for recent discussions about specificity, direct perception, and the functions of the dorsal and ventral streams. It is argued that Gibson's acknowledgment of Wittgenstein's ideas of classification suggests a limited scope of his theory of direct perception—it cannot account for the classification of objects. The implications for both the specification debate and theorizing about the brain's dorsal and ventral pathways are explored. Based on a recent ecological conception of information and direct perception, we ultimately argue that both affordance perception and classification are direct.