Malebranche holds that visual experience represents the size of objects relative to the perceiver's body and does not represent objects as having intrinsic or nonrelational spatial magnitudes. I argue that Malebranche's case for this body-relative thesis is more sophisticated than other commentators—most notably, Atherton and Simmons —have presented it. Malebranche's central argument relies on the possibility of perceptual variation with respect to size. He uses two thought experiments to show that perceivers of different sizes—namely, miniature people, giants, and typical human (...) beings—can experience the very same objects as having radically different sizes. Malebranche argues that there is no principled reason to privilege one of these ways of experiencing size over the others and, more specifically, that all three kinds of perceivers experience size veridically. From the possibility of this kind of veridical perceptual variation, Malebranche infers that visual experience represents only body-relative size. (shrink)

According to Kepler and Descartes, the geometry of the triangle formed by the two eyes when focused on a single point affords perception of the distance to that point. Kepler characterized the processes involved as associative learning. Descartes described the processes as a “ natural geometry.” Many interpreters have Descartes holding that perceivers calculate the distance to the focal point using angle-side-angle, calculations that are reduced to unnoticed mental habits in adult vision. This article offers a purely psychophysiological interpretation of (...) Descartes’s natural geometry. In his account of perceived limb position from the Treatise on Man, he envisioned a central brain state that controls ocular convergence and thereby co-varies with the distance from observer to object. A psychophysiological law relates the visual perception of distance to this brain state. Descartes also invokes more traditional theories of distance and size perception based on unnoticed judgments, yielding a hybrid account. (shrink)

Descartes first invokes the errors of the senses in the Meditations to generate doubt; he suggests that because the senses sometimes deceive, we have reason not to trust them. This use of sensory error to fuel a sceptical argument fits a traditional interpretation of the Meditations as a work concerned with finding a form of certainty that is proof against any sceptical doubt. If we focus instead on Descartes's aim of using the Meditations to lay foundations for his new science, (...) his appeals to sensory error take on a different aspect. Descartes's new science is based on ideas innate in the intellect, ideas that are validated by the benevolence of our creator. Appeals to sensory error are useful to him in undermining our naïve faith in the senses and guiding us to an appreciation of innate ideas. However, the errors of the senses pose problems in the context of Descartes's appeals to God's goodness to validate innate ideas and natural propensities to belief. A natural tendency to sensory error is hard to reconcile with the benevolence of our creator. This paper explores Descartes's responses to the problems of theodicy posed by various forms of sensory error. It argues that natural judgements involved in our visual perception of distance, size and shape pose a problem of error that resists his usual solutions. (shrink)

Nicolas Malebranche (1638–1715) holds that the senses, imagination, and passions aim at survival and the satisfaction of the body’s needs, rather than truth or the good of the mind. Each of these faculties makes a distinctive and, indeed, an indispensable contribution to the preservation of life. Commentators have largely focused on how the senses keep us alive. By comparison, the imagination and passions have been neglected. In this paper, I reconstruct Malebranche’s account of how the imagination contributes to the preservation (...) of the body by compensating for the limitations of the senses. First, the imagination represents non-actual states of affairs, such as probable or possible future states. Second, the imagination forges new and often helpful associations based on past experiences. Third, the imagination (mis)represents that objects will cause pleasure and pain, thereby imbuing them with emotional significance they would otherwise lack. Together, these features flesh out Malebranche’s view that the imagination is necessary for the preservation of life. (shrink)

How does Descartes characterize the peculiar way in which each of us is aware of our bodies? I argue that Descartes recognizes a sense of bodily ownership, such that the body sensorily appears to be one's own in bodily awareness. This sensory appearance of ownership is ubiquitous, for Descartes, in that bodily awareness always confers a sense of ownership. This appearance is confused, in so far as bodily awareness simultaneously represents the subject as identical to, partially composed by, and united (...) to her body, without distinguishing these relations. Finally, the appearance of ownership is grounded in multiple other ways in which the body sensorily appears: namely, in the fact that the body appears to be inescapable, modified by bodily sensations, and an object of special concern. (shrink)

It is natural to assume that the fine-grained and highly accurate spatial information present in visual experience is often used to guide our bodily actions. Yet this assumption has been challenged by proponents of the Two Visual Systems Hypothesis , according to which visuomotor programming is the responsibility of a “zombie” processing stream whose sources of bottom-up spatial information are entirely non-conscious . In many formulations of TVSH, the role of conscious vision in action is limited to “recognizing objects, selecting (...) targets for action, and determining what kinds of action, broadly speaking, to perform” . Our aim in this study is to show that the available evidence not only fails to support this dichotomous view but actually reveals a significant role for conscious vision in motor programming, especially for actions that require deliberate attention. (shrink)