 In a later paper (1956) Ryle corrects this. The idea that perceiving involves “having sensations” is called into question with an investigation of the ordinary concepts of sensation and feeling and their relation to the technical notions of sense-impression and sense-data. (Arguably, today’s notion of “perceptual experiences” – conceptual or non-conceptual—also figure as a target of Ryle’s arguments.) In this section, I shall discuss the negative thesis that perception does not require the postulation of sensations construed in its ordinary sense and why one motivation for postulating sense-data or sense-impressions should be resisted. In the next, I discuss a different motivation and show why the thickness of perceptual concepts thwarts attempts to discover the “nature” of perception in physiological, optical, acoustic, etc. phenomena.