Visible Figure and Reid's Theory of Visual Perception

Hume Studies Volume 28, Number 1, April 2002, pp. 49-82 Visible Figure and Reid's Theory of Visual Perception RYAN NICHOLS 1. Inconsistency in Reid We can make a good prima facie case for the inconsistency of Reid's theory of perception with his rejection of the Ideal Theory. Most scholars believe Reid adopts a theory on which the immediate object of perception is a physical body. Reid is thought to do this in order to avoid problems generated by the veil of perception in the Ideal Theory, a conjunction of commitments Reid closely associates with Hume and Locke. Reid explains that the Ideal Theory "leans with its whole weight upon a hypothesis. . .[t]hat nothing is perceived but what is in the mind which perceives it" (I 96a; B 4).1 Reid attributes to the Ideal Theory thesis (1): (1) No immediate objects of perception are mind-independent. Let's leave (1) at this level of generality for the time being and show how Reid's rejection of the Ideal Theory conflicts with his theory of perception. Reid's attempt to banish perceptual intermediaries in his analysis of visual perception does not obviously succeed. This is because he recognizes that what he dubs "visible figures" are the immediate objects of our visual systems . With sight, "we perceive originally the visible figure and colour of bodies only" and not, for instance, their extension (I 185a; B 171). It seems that visible figures are perceptual intermediaries. At least, they don't share Ryan Nichols is at the Department of Philosophy, University of Aberdeen, Old Brewery, High Street, Old Aberdeen AB24 3UB, Scotland e-mail: r.nichols@abdn.ac.uk 50 Ryan Nichols the ontological status of middle-sized dry goods. This indicates that the objects of acts of visual perception are actually visible figures. So, interpreting 'originally' as meaning 'immediately,' Reid affirms that (2) The immediate objects of visual perception are only ever visible figures. Reid's repudiation of the Ideal Theory in (1) and the nature of his account of visual perception in (2) seem to be in conflict. Specifically, they are inconsistent with the following description of visible figure: (3) Visible figures are not mind-independent objects. The secondary literature on Reid's theory of perception that takes Reid to endorse a type of direct perception—the thesis that the objects of immediate perception are mind-independent—also takes Reid's theory of direct perception to apply to all sense modalities. But if Reid is taken to endorse a direct theory of perception for all our sense modalities, then Reid cannot deny (1) and affirm both (2) and (3). Were he to do so, his theory of visual perception would be structured in a radically different way. In addition to differing sharply with received wisdom, such a hybrid theory—on which touch is direct and vision indirect—is at least counterintuitive, and may be philosophically problematic. Reid did not fully appreciate this conflict, though he notices that vision presents unique difficulties for his overall theory of perception. He does analyze the nature of the representational relations between visible figures, which he occasionally calls "perspectival appearances," and what he calls "real" and "tangible" figures, i.e., the surface properties of physical objects.2 The result of this analysis, Reid's "geometry of visibles," is used to show that the faculty of visual perception can give us reliable information about three-dimensional objects.3 Unfortunately, the implications of Reid's geometry of visibles and his implementation of the notion of visible figure have not been examined in the context of Reid's theory of perception. They have instead remained a curiosity in the history of geometry. This state of affairs isn't surprising because Reid's analysis of visual figure and his theory of visual perception are a royal mess. The key question for resolving this conflict is: What is visible figure? In other words, what properties does visible figure possess? Only if an answer to this question enables Reid to differentiate visible figures from the Ideal Theory's ideas will he evade the puzzle I've articulated. However, it is not enough to avoid the puzzle for Reid to...