Abstract

The paper aims to show that Philoponus’ theory of sense-perception does not fit in with the spiritualist claim that the sensory process does not involve an extra material change in the sense-organ. Both the specific sense-organs and the primary sense-organ contract or expand in the perceptual process. On the other hand, the literalist claim needs to be modified as well since only the tactile sense-organ takes on the relevant qualities. Contraction or expansion in the sense-organ is triggered, not by physical changes in the medium, but by the formal activities arising from the perceptible objects: colours make the visual sense-organ contract or expand. At the level of sense-organs, the physiological process underlying sense-perception has three stages. The change in specific sense-organ will be transmitted to the primary sense-organ of the particular sense , and then reaches the common sense-organ, the pneuma. The primary sense-organs are spatially distinguishable parts of the common sense-organ which is otherwise homogeneous, not allowing for qualitative differences. The homogeneity of the pneuma establishes the unity of sense-perception at the level of physiological processes