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Ideas and Mechanism
Essays on Early Modern Philosophy
By Margaret Dauler Wilson PRINCETON UNIVERSITY PRESS
Copyright © 1999 Princeton University Press
All rights reserved.
ISBN: 978-0-691-00471-6
CHAPTER 1
Skepticism without Indubitability
In Philosophy and the Mirror of Nature Richard Rorty traces the emergence of "foundationalist epistemology ... as the paradigm of philosophy." According to Rorty, a key step in this development was Descartes's un-Aristotelian construal of sensory grasp of particulars" as "mental" (54). The resulting conception of the mind as "an inner arena with its inner observer" "permitted" the seventeenth century "to pose the problem of the veil of ideas, the problem which made epistemology central to philosophy" (51). Thus Descartes, by "carving out inner space," "simultaneously made possible veil-of-ideas skepticism and a discipline devoted to circumventing such skepticism" (140).
In seeking to account for Descartes's fateful introduction of an account of sense perception focused on ideas of sense, Rorty tentatively appeals to an apparently idiosyncratic Cartesian preoccupation with "indubitability" (55). Although Descartes himself sought the foundations of knowledge in distinct ideas of reason rather than in sensory particulars, the move to empiricistic foundationalism was readily accomplished by Locke, on Rorty's account. On the Cartesian model, adapted by Locke, the Eye of the Mind is restricted to surveying the ideas or representations in inner space, "hoping to find some mark which will testify to their fidelity" to extra-mental reality (45).
Rorty is surely right that a strong distinction or contrast between sensations or "ideas of sense," on the one hand, and external physical things on the other hand, emerges as central doctrine in seventeenth-century philosophy. Further, the distinction is, as he indicates, closely connected with both the modern mind-body problem and certain sorts of skeptical reasoning. It is also true that both Descartes and Locke speak of knowledge as requiring a "foundation" in indubitable ideas. Nevertheless, there is a crucial element missing from Rorty's account of seventeenth-century concerns: an element that is also omitted or slighted by many other critics who either look back on the period from the dubious vantage of twentieth-century sense-data theories, or look forward (so to speak) from the standpoint of ancient skepticism. I have in mind the fact that the seventeenth-century contrast between ideas of sense and physical things at least partly derives from the conception of material reality provided by mechanistic science, and the disparity between this conception of reality and the seeming givens of ordinary perceptual experience.
I
Underlying seventeenth-century accounts of perception is the metaphysical view that "real and physical" qualities include just extension, figure, motion, and (for some) impenetrability or solidity (together with structural qualities such as texture, which result from combining extended particles in various ways). Proceeding from this conception of material reality, philosophers of the period espouse a broad theory of perception that includes the following basic tenets:
1. In ordinary sense experience certain entities arise "in us" or "in the mind." These entities are variously referred to as "ideas of sense," "sensations," "images," "phantasms," or (rarely) "species."
2. These sensory ideas (as I shall call them) are formed in the mind as the result of mechanistic processes, involving (characteristically) material things external to our bodies, and the sensory-systems of our bodies themselves.
3. Sensory ideas correlate with discrete sensible qualities, like blue, soft, putrid. In Locke's words, they "enter by the senses simple and unmixed," even though the qualities that produce them are "united and blended" in the things themselves.
4. Whole classes of the sensory ideas formed in our minds—ideas of colors and tastes, for instance—are completely "unlike" the material things we are ordinarily said to perceive, or any qualities really in the things. This tenet is universally regarded as contrary to common sense.
5. We do apprehend real qualities of material things, through our representations of size, shape, and motion. Not all philosophers clearly indicate whether our representations of the latter qualities are always sensory ideas, and there is not much unanimity among those who do take positions on this point.
The theory constituted by these five tenets is vigorously propounded by Hobbes, Malebranche, and Boyle, as well as Descartes and Locke. They commonly ascribe to the conception of physical reality that underlies this view of perception an a priori or essentialist grounding in "the concept of body." Descartes, Boyle, and others also stress the explanatory success of strictly mechanistic concepts in accounting for perception, as well as the other phenomena of nature.
The relations between this general account of perception and skeptical concerns are complex. Here I wish to distinguish two separate connections. In the next section I focus on the notion, implicit in tenet 4, that human beings in general are systematically and literally constantly deceived in ordinary sense experience. Seventeenth-century philosophers employ skeptical arguments in aid of this conviction: to this extent the arguments function instrumentally, and depend on a confident background conception of the true nature of material things. In the third section I consider more closely some relations among the characteristic seventeenth-century account of sense perception, the "veil-of-perception" position (which has its proponents today), and non-instrumental skepticism.
Approached from the perspective of theory of nature and the resulting conception of perceptual experience, the problem of sensory contact with the external world that arises in seventeenth-century thought appears both more readily intelligible and less tightly dependent on preoccupations with justification and certainty than is often supposed. Accordingly, the problem does not automatically vanish if we follow Rorty in rejecting, as anachronistic or artificial, attempts to "ground" empirical knowledge claims in an indubitable sensory given.
II
A typical statement of the distinction between ideas of sense and physical quality occurs in the following passage from Malebranche:
In order ... to judge soundly about light and colors, as well as all the other sensible qualities, one must distinguish with care the sensation [sentiment] of color from the movement of the optic nerve, and recognize by reason, that movements and impulsions are the properties of bodies, and that hence they can be encountered in the objects, and in the organs of our senses; but light, and the colors that we see, are modifications of the soul quite different from the others, and of which we also have quite different ideas.
Of course seventeenth-century writers often acknowledge interpretations of a statement like "the violet is blue" on which this statement comes out literally true: in saying that the violet is blue we may be predicating of it a certain superficial microstructure, or a "power" deriving from such a surface structure to affect sentient beings with a particular sort of sensation. Nevertheless they steadfastly maintain that such qualities in objects are utterly different from—fail to "resemble"—sensory appearances. Thus, they do deny that colors and so forth are in objects in the way that we normally take them to be—as real, discrete, irreducible qualities, manifest in sense experiences, and on a footing with size and shape. Contrary to Malebranche's admonition, we do not normally judge soundly about colors, smells, tastes, sounds, and the like, but (as Locke says) "by mistake attribute" reality to them. Indeed we are peculiarly obstinate in our error: "Men are hardly to be brought to think, that Sweetness and Whiteness are not really in Manna." The same point is expressed, in quite similar terms, by Descartes, Malebranche, Hobbes, and Boyle.
This sort of universal "deception" is of much more than passing concern. The widespread human error about the objectivity of sensible qualities is generally felt to require some kind of explanation, and even to raise problems of theodicy. Descartes elaborately traces such errors to habits arising in infancy, and to a tendency simply to conflate mere sensations—intended to alert us to things good or bad in the environment—with our "clear" perceptions of physically real qualities. Malebranche, who develops a quite complex analysis of perceptual judgment and error, locates a source of the basic problem in the fall of Adam. Hobbes offers a physical explanation of our tendency to project sensations on things in terms of the "endeavor outward" that he takes to be characteristic of sensory processes. (Some of these philosophers also discuss ways of overcoming such "error.")
The claim that the senses constantly—not just episodically—lead us into error about physical reality provides an important perspective for understanding the stress on skeptical arguments in seventeenth-century work. In Descartes and Malebranche, in particular, such arguments are overtly used to shake our faith in the senses, as purveyors of objective truth. "Detachment from sense" is of course not a professed aim of empiricists like Hobbes or Locke. Still Locke and other writers draw on the relativity considerations associated with traditional skepticism to underscore the subjectivity of certain broad classes of sensory states, to which their theory of reality independently commits them.
From this perspective, relativity arguments, Descartes's dreaming argument, and other attacks on the senses, appear to be propounded for a decent dogmatic purpose. Their role is neither to convert us to an equinanimous agnosticism, nor to focus our attention on our indubitable "inner sensory representations" with the aim of building from them to well-founded objective knowledge claims. They are intended to prepare us to accept the austere "new" truths about what the world around us is really like in the face of our natural resistance.
III
The tenets of the view of sense perception I outlined above do not explicitly include either the claim that sensory ideas are states of "mental substances" or the claim that the mind perceives (or immediately perceives) only its own ideas. In fact, historically, this conception of sense perception is not invariably accompanied by the latter claims. Hobbes, for example, definitely maintains that we perceive physical objects, not the sensory "phantasms" they produce in us. Further, he holds that all substances are bodies, and explicitly identifies phantasms with motions in the sensory system. Despite this fact, the account of perception that arises from the mechanistic picture of nature does help illuminate—more, I think, than any preoccupation with indubitability or epistemological foundations—the systematic origins of the veil-of-perception position.
It is, as we've seen, an explicit feature of the widely shared seventeenth-century view that we err in thinking of colors-as-experienced (for example) as real qualities of bodies. What are they then? Hobbes's bold identification of sensory experiences with material states of the sentient organism was a far from unproblematic move—as recent decades of debate of the materialist identity thesis have surely made clear. It seems understandable enough that Descartes and some of his successors should conclude that colors and other "mere sensations" are no more to be identified with states of the nervous system than with "external" physical qualities—and see no alternative to construing them as merely mental entities. Further, while Descartes does connect this interpretation of the status of sensations with indubitability in the Meditations, consideration of the early parts of the Treatise on Light and the Dioptrics (for instance) shows that he by no means invariably does so. (Malebranche is merely restating Cartesian assumptions when he remarks that the true understanding of the difference between mind and body was achieved only "in the last few years," when it came to be appreciated that "sensible qualities" are not contained in the idea of matter.)
The view that we do not perceive—or immediately perceive—physical objects is sometimes said to be a "presupposition" or a logical consequence of the seventeenth-century distinction between sensory ideas of color and the like, on the one hand, and the real qualities of bodies on the other hand. I believe that this is an overstatement: one can consistently give a Hobbesian account of perceptual experience in terms of phantasms, without taking the step of holding that we perceive phantasms. But there is a fairly simple path to the view that what the Eye of the Mind perceives are its own ideas, from the account of perception summarized above. The key notion is that when we think we are looking at, listening to, touching (etc.) the world we after all do perceive colors, sounds, warmth, and cold, etc. But colors, sounds, warmth, and cold, etc. are merely ideas or sensations in the mind. Therefore, what we perceive in these cases, at least, are (properly) ideas. This, I take it, is the viewpoint behind the following classic Cartesian statement of the veil-of-perception position:
... [B]esides the extension, figures, and motion of bodies, I also sensed in them hardness, and heat, and other tactile qualities; and further light, and colors, and odors, and tastes, and sounds, from the variety of which I distinguished heaven, earth, sea, and other bodies from each other. And surely it was not without reason, on account of the ideas of all these qualities which offered themselves to my thought, and which alone I properly and immediately sensed, I thought I sensed certain things completely different from my thought, namely bodies from which these ideas proceeded.
Admittedly, the reasoning sketched so far does not explicitly cover figure, motion, and other qualities that (on the mechanistic hypothesis) "are not otherwise sensed or understood by us than they are, or at least can be in objects." There are various considerations that would tend to support the inclusion of perceptions of such qualities in the "veil" theory: the consideration, for instance, that sensibly experienced shapes and so on are pervaded by the qualities regarded s thoroughly subjective, like color. As mentioned under tenet 5, however, this is a textually complex issue; and I cannot fully deal with it here.
The account so far offered indicates why—apart from preoccupation with indubitability or foundationalism—Descartes and his successors would tend to treat sensory grasp of particulars as falling within the realm of the mental; why they might tend to consider our immediate perceptions as failing to provide direct cognitive contact with physical reality; and why they would seek to instill doubt of the senses. The question that remains to be considered is whether this perspective on the veil-of-perception position suggests any connection with skepticism of a noninstrumental sort.
Now, I think in fact concern with "circumventing" veil-of-perception skepticism or seeking internal marks of "fidelity" in inner representations of sense—is far from rampant in seventeenth-century philosophy. (Incidentally, such concern is arguably more noticeable in Descartes and Malebranche than in Locke.) This observation fits with the tendencies to untroubled perceptual realism which have often been discerned in the period and with the notion that the veil-of-perception position is correlative to a positive theory of nature. Nevertheless, it seems to me that the position does permit—even, ultimately, support—a very perplexed attitude toward our sensory contact with the world, whether or not seventeenth-century theorists themselves exhibit serious perplexity about this problem. Berkeley put his finger on the crucial point when he objected that the materialists, for all their emphasis upon explanatory success, in fact could offer no intelligible explanation of how sensory ideas are produced by matter.
Suppose that someone who accepts the proposition that the immediate objects of perception are mental, requests an account of how exactly the sensory particulars that he immediately perceives are connected with, serve to relate him cognitively to, real things out there. The cheerful Boylean or Lockean answer—heard again in recent years—is that the things produce the ideas via our sensory systems; Descartes, in his more searching moments, holds that changes in the brain serve as signs to the mind, giving it "occasion" to generate sensations. The latter view leaves unilluminated the central step of the mind's receiving signs from the brain, and to this extent seems dismissible as a vague metaphor. The simpler language of causal production seems more plausible, more commonsensical, even scientific. However, I am inclined to think that this appearance is deceptive.
(Continues...)
Excerpted from Ideas and Mechanism by Margaret Dauler Wilson. Copyright © 1999 Princeton University Press. Excerpted by permission of PRINCETON UNIVERSITY PRESS.
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