Naturalized sense data (Visual perception)

This paper examines and defends the view that immediate objects of visual perception, or what are often called sense data, are parts of the facing surfaces of physical objects-the naturalized sense data (NSD) theory. Occasionally defended in the literature on the philosophy of perception, most famously by G.E. Moore (1918-1919), it has not proved popular and indeed was abandoned by Moore himself. The contemporary situation in the philosophy of perception seems ripe for a revaluation of the NSD theory, however. The NSD theory allows us to accommodate the very real shortcomings in uncritical direct realism without postulating the existence of non-physical sense data in a way that has seemed to many incompatible with any robust form of philosophical naturalism. The argument to establish the NSD theory proceeds in two stages. In II I argue against the direct realist that we perceive three-dimensional material objects in virtue of perceiving parts of their surfaces. The argument for this conclusion involves clearly distinguishing (in I) between two notions that have tended to be run together in discussions of perception-namely, immediate perception and direct perception. In III I argue against the sense-datum theorist that those parts of the surface of those objects are not themselves perceived in virtue of the perception of anything else.