Perception and common sense: a study of twentieth century direct realism

This thesis is a critical examination of the direct realist theory of perception. A common-sense analysis of perception is defended against arguments which are widely believed to rule out the direct realist's notion of a direct contact with external physical reality. I argue that a common-sense version of direct realism can adequately account for hallucinations, perceptual relativity, perceptual illusions, severe time-lags and the causal processes involved in perception. The views of prominent twentieth-century direct realists are critically examined, with the intention of identifying constraints on any plausible direct realist theory of perception. I maintain that there are representationalist tensions in the work of leading twentieth-century direct realists, and that a principal source of these representationalist tensions is their adherence to the common element thesis, the notion that hallucinations and genuine perceptions are the very same experience. Appealing to recent cognitive science experiments on the imagination, I defend a disjunctivist analysis of experience, one which holds that hallucinations and genuine perceptions involve fundamentally different experience-types, rather than sharing a common, world-independent experience. The analysis which emerges is nonepistemic in its denial that perceptual experiences are essentially cognitive. A nonintentional and non-propositional species of perceptual representational content is proposed, one which recognises qualia of perceptual experience. Recent attempts by direct realists to apply Russellian acquaintance to the direct perception of external physical reality are rejected as inconsistent with the central ideas in Russellian acquaintance. Traditional Humean difficulties about the elusiveness of the self in introspection, and the question of how we could know we perceive if we are never acquainted with the self, are addressed by appeal to Russell's largely overlooked notion of learning to be acquainted with objects