Abstract

A theory of sense‐data is defended, which takes its cue from light. It is that the visual perception of outer physical objects is noticing visual sensations set in two‐dimensional body‐relative physical space, which stands in non‐deviant causal relation to outer phenomenal causes. The first leg of the argument is that there exist regular causally sufficient bodily conditions for the existence of a visual field of given colour‐bright spatial character, quite irrespective of the outer causes of those bodily causes. Now if those bodily conditions were caused by piecemeal scientific intervention we would deem the resulting visual field a psychological existent of type, visual sensations. Since they are also satisfied when the bodily conditions are caused by outer visibles, the same set of sensations must occur in perception of outer items. The theory is defended against the claim that the visual field has no separate existence from our awareness of it, through showing that the criteria for the content of visual field and of visual impression ensure divergence of content. Finally, an explanatorial argument is proposed for the view that sensations generally are psychological individuals, and are not to be understood as merely the internal objects of awareness‐experiences.