Adam Sopuck, in Philosophy, presents from his paper, which discusses the role of sensations and the nature of perceptual directness in Reid’s doctrine of perception.

In an influential work, Pappas argues that the “double-tier” interpretation of Reid’s doctrine, according to which sensation and perception are distinct causally related psychological events, is incompatible with perceptual direct realism. On the other hand, Madden and Copenhaver, for example, argue that perception is direct for Reid precisely because sensation and perception are discrete psychological events. At the crux of these diametrically opposed views are competing conceptions of epistemic mediation. I address Pappas’ objection to the double-tier interpretation of Reid’s doctrine