Gary Hatfield examines theories of spatial perception from the seventeenth to the nineteenth century and provides a detailed analysis of the works of Kant and Helmholtz, who adopted opposing stances on whether central questions about spatial perception were fully amenable to natural-scientific treatment. At stake were the proper understanding of the relationships among sensation, perception, and experience, and the proper methodological framework for investigating the mental activities of judgment, understanding, and reason issues which remain at the core of philosophical psychology (...) and cognitive science. (shrink)

According to the reading offered here, Descartes' use of the meditative mode of writing was not a mere rhetorical device to win an audience accustomed to the spiritual retreat. His choice of the literary form of the spiritual exercise was consonant with, if not determined by, his theory of the mind and of the basis of human knowledge. Since Descartes' conception of knowledge implied the priority of the intellect over the senses, and indeed the priority of an intellect operating independently (...) of the senses, and since, in Descartes' view, the untutored individual was likely to be nearly wholly immersed in the senses, a procedure was needed for freeing the intellect from sensory domination so that the truth might be seen. Hence, the cognitive exercises of the Meditations, modeled not on the sense- and imagination-based exercises of Ignatius of Loyola, but on the Augustinian procedure of turning away from the senses and imagination to perceive the unpicturable with the fleshless eye of the mind. In accordance with this reading, the function of Descartes' skeptical arguments is not to introduce skepticism so that it can be defeated but to aid the meditator in withdrawing the mind from the senses in order to attend to truths of the pure intellect. These truths then offer the basis for a new natural philosophy, including a new theory of the senses. (shrink)

This article seeks the origin, in the theories of Ibn al-Haytham (Alhazen), Descartes, and Berkeley, of two-stage theories of spatial perception, which hold that visual perception involves both an immediate representation of the proximal stimulus in a two-dimensional ‘‘sensory core’’ and also a subsequent perception of the three dimensional world. The works of Ibn al-Haytham, Descartes, and Berkeley already frame the major theoretical options that guided visual theory into the twentieth century. The field of visual perception was the first area (...) of what we now call psychology to apply mathematics, through geometrical models as used by Euclid, Ptolemy, Ibn al-Haytham, and Descartes (among others). The article shows that Kepler’s discovery of the retinal image, which revolutionized visual anatomy and entailed fundamental changes in visual physiology, did not alter the basic structure of theories of spatial vision. These changes in visual physiology are advanced especially in Descartes' Dioptrics and his L'Homme. Berkeley develops a radically empirist theory vision, according to which visual perception of depth is learned through associative processes that rely on the sense of touch. But Descartes and Berkeley share the assertion that there is a two-dimensional sensory core that is in principle available to consciousness. They also share the observation that we don't usually perceived this core, but find depth and distance to be phenomenally immediate, a point they struggle to accommodate theoretically. If our interpretation is correct, it was not a change in the theory of the psychology of vision that engendered the idea of a sensory core, but rather the introduction of the theory into a new metaphysical context. (shrink)

It is difficult to evaluate the role of activity - of force or of that which has causal efficacy - in Descartes’ natural philosophy. On the one hand, Descartes claims to include in his natural philosophy only that which can be described geometrically, which amounts to matter (extended substance) in motion (where this motion is described kinematically).’ Yet on the other hand, rigorous adherence to a purely geometrical description of matter in motion would make it difficult to account for the (...) interactions among the particles that constitute Descartes’ universe, since the notions of extension and kinematical motion do not in themselves imply any causal agency. There is, after all, no reason to expect that a particle whose single essence is extension, even if we suppose it to be moving, should impart motion to another particle, while conversely, there is no reason to expect a resting particle to hinder the motion of an impinging one. Descartes' hankering for an austere ontology of matter in motion is in danger of excluding causal agency (force, conceived dynmically) from matter. To the modern reader it may seem obvious that Descartes did not get himself into such a fix, since matter in motion so readily reminds us of kinetic energy or of some more primitive notion of force. Yet by no means is it obvious that Descartes attributed causal efficacy to matter in motion per se. Serious scholars have held opposite positions on this issue. Westfall, Gabbey, and others’ have argued that although on the metaphysical plane Descartes attempted to eliminate force from his mechanical universe, nonetheless ‘force is a real feature’ of his mechanical world. The thrust of this view is that Descartes conceived of force as ‘the capacity of a body in motion to act’, by means of impact, upon other bodies. An opposing interpretation, defended here, is that Descartes did in fact deny causal agency to moving matter per se, restricting agency to immaterial substances such as the human mind, angels, and God. The intention of this interpretation is not to de-emphasize the role of matter in motion in Descartes’ explanation of nature, but rather to stress the fact that Descartes did not conceive of this moving matter dynamically. -/- Reprinted in Descartes, ed. by J. Cottingham, Oxford Readings in Philosophy (Oxford: Oxford University Press, 1998), 281–310. (shrink)

Representation and content in some (actual) theories of perception -- Representation in perception and cognition : task analysis, psychological functions, and rule instantiation -- Perception as unconscious inference -- Representation and constraints : the inverse problem and the structure of visual space -- On perceptual constancy -- Getting objects for free (or not) : the philosophy and psychology of object perception -- Color perception and neural encoding : does metameric matching entail a loss of information? -- Objectivity and subjectivity revisited (...) : color as a psychobiological property -- Sense data and the mind body problem -- The reality of qualia -- The sensory core and the medieval foundations of early modern perceptual theory -- Postscript (2008) on Ibn al-Haytham's (Alhacen's) theory of vision -- Attention in early scientific psychology -- Psychology, philosophy, and cognitive science : reflections on the history and philosophy of experimental psychology -- What can the mind tell us about the brain? : psychology, neurophysiology, and constraint -- Introspective evidence in psychology. (shrink)

During the seventeenth century the major cognitive faculties--sense, imagination, memory, and understanding or intellect--became the central focus of argument in metaphysics and epistemology to an extent not seen before. The theory of the intellect, long an important auxiliary to metaphysics, became the focus of metaphysical dispute, especially over the scope and powers of the intellect and the existence of a `pure' intellect. Rationalist metaphysicians such as Descartes, Spinoza, and Malebranche claimed that intellectual knowledge, gained independently of the senses, provides the (...) framework for constructing a new theory of nature. Other writers, including Hobbes and the early Gassendi, denied the existence of a distinct intellectual faculty, and so challenged the metaphysicians' abilities directly to perceive the essences of substances. The theory of the senses, which had long been a part of philosophical discussion, took on a new urgency, for adherents of the new corpuscularian philosophy needed to replace the dominant Aristotelian theory of real sensory qualities and sensible species. The revival of skepticism and a renewed interest in method also brought the faculties into prominence, for skeptical challenges typically were directed toward the faculties of sense and understanding, and the theory of method was conceived as providing instructions for the proper use of one's cognitive equipment. The theory of the faculties, then, is an important key to theories of knowledge in the seventeenth century. Indeed, rather than speaking of seventeenth century epistemology, it would be less anachronistic and more informative to speak of theories of cognition. The familiar (and over-stated) point that epistemology became fundamental to metaphysics during that century can then be restated as the point that the theory of faculties became central in metaphysical dispute. (shrink)

This chapter considers philosophical problems concerning non-human (and sometimes human) animals, including their metaphysical, physical, and moral status, their origin, what makes them alive, their functional organization, and the basis of their sensitive and cognitive capacities. I proceed by assuming what most of Descartes’s followers and interpreters have held: that Descartes proposed that animals lack sentience, feeling, and genuinely cognitive representations of things. (Some scholars interpret Descartes differently, denying that he excluded sentience, feeling, and representation from animals, and I consider (...) the evidence for these interpretations as well.) Given that Descartes denied any sort of soul to animals, his other philosophical commitments entailed that he must explain the vital and sensitive powers of non-human animals through purely material causes. Indeed, he welcomed this task, for he was engaged in the larger project of providing purely mechanistic explanations for all natural phenomena of the material world. Animal bodies form functional unities that are adapted to environmental circumstances. In his new physics, Descartes sought to discover or hypothesize material mechanisms that would explain the physiological and behavioral capacities of animals, including how they maintain themselves by seeking food and drink, reproduce themselves, and modify their behavior to fit current circumstances. Metaphysically, his new perspective raised the problem of accounting for the functional unity of the animal body considered as a purely material construction, devoid of an active, organizing power such as the sensitive soul. Descartes’s project becomes even more challenging if we ask whence come such mechanisms that are capable of performing the functions of living things. Officially, Descartes endorsed the accepted theological orthodoxy, that God designed and created the bodily mechanisms of humans and animals. However, in his natural philosophy he set himself the task of explaining the origin of animals as part of the natural development of the universe out of an original chaotic soup of material particles. Within this naturalistic perspective, he must explain how, through purely material processes, the functionally organized bodies of living things (plants and animals) could be produced from non-living matter. Without a designing creator, how do animal bodies arise that are capable of digesting food, growing, reproducing, and performing the behaviors needed to preserve life and health? (shrink)

In preparation for examining the place of introspective evidence in scientific psychology, the chapter begins by clarifying what introspection has been supposed to show, and why some concluded that it couldn't deliver. This requires a brief excursus into the various uses to which introspection was supposed to have been put by philosophers and psychologists in the modern period, together with a summary of objections. It then reconstructs some actual uses of introspection (or related techniques, differently monikered) in the early days (...) of experimental psychology. It distinguishes broader and narrower conceptions of introspection and argues that recent critics have tended to misdescribe how introspection was supposed to work. Drawing upon the broader conception of introspection, it argues that introspective reports are ineliminable in perceptual psychology. It concludes with some examples of such ineliminable uses of introspective reports in both earlier and recent perceptual psychology. (shrink)

Descartes understood the subject matter of physics (or natural philosophy) to encompass the whole of nature, including living things. It therefore comprised not only nonvital phenomena, including those we would now denominate as physical, chemical, minerological, magnetic, and atmospheric; it also extended to the world of plants and animals, including the human animal (with the exception of those aspects of the human mind that Descartes assigned to solely to thinking substance: pure intellect and will). Descartes wrote extensively on physiology and (...) on the physiology and psychology of the senses. This chapter examines the notions of *physiology* and *psychology* in medical and natural philosophical works of Descartes' day; follows his efforts to bring physiology into his mechanistic idiom; considers the relation between physiology of the animal machine and psychological functions that yield functionally appropriate behavior; goes into his physiology and psychology of vision; and elaborates the tension in Descartes' works between his metaphysically supported micro-corpuscularism and his discussion of the animal machine as an organic unity comprising various functionally and teleologically characterized systems. The chapter draws on Descartes' works in both metaphysics and natural philosophy, including his Treatise on Man (originally published as L'Homme, 1664). (shrink)

Psychology considered as a natural science began as Aristotelian "physics" or "natural philosophy" of the soul, conceived as an animating power that included vital, sensory, and rational functions. C. Wolff restricted the term " psychology " to sensory, cognitive, and volitional functions and placed the science under metaphysics, coordinate with cosmology. Near the middle of the eighteenth century, Krueger, Godart, and Bonnet proposed approaching the mind with the techniques of the new natural science. At nearly the same time, Scottish thinkers (...) placed psychology within moral philosophy, but distinguished its "physical" laws from properly moral laws. British and French visual theorists developed mathematically precise theories of size and distance perception; they created instruments to test these theories and to measure visual phenomena such as the duration of visual impressions. By the end of the century there was a flourishing discipline of empirical psychology in Germany, with a professorship, textbooks, and journals. The practitioners of empirical psychology at this time typically were dualists who included mental phenomena within nature. Accordingly, psychology as a natural scientific disciplines was not invented in the 18th and 19th centuries, but *remade* from the extant empirical psychology. (shrink)

Descartes developed an elaborate theory of animal physiology that he used to explain functionally organized, situationally adapted behavior in both human and nonhuman animals. Although he restricted true mentality to the human soul, I argue that he developed a purely mechanistic (or material) ‘psychology’ of sensory, motor, and low-level cognitive functions. In effect, he sought to mechanize the offices of the Aristotelian sensitive soul. He described the basic mechanisms in the Treatise on man, which he summarized in the Discourse. However, (...) the Passions of the soul contains his most ambitious claims for purely material brain processes. These claims arise in abstract discussions of the functions of the passions and in illustrations of those functions. Accordingly, after providing an intellectual context for Descartes’s theory of the passions, especially by comparison with that of Tho- mas Aquinas, I examine its ‘machine psychology’, including the role of habituation and association. I contend that Descartes put forth what may reasonably be called a ‘psychology’ of the unensouled animal body and, correspondingly, of the human body when the soul does not intervene. He thus conceptually distinguished a mechanistically explicable sensory and motor psychology, common to nonhuman and human animals, from true mentality involving higher cognition and volition and requiring (in his view) an immaterial mind. (shrink)

There is disagreement over the notion of representation in cognitive science. Many investigators equate representations with symbols, that is, with syntactically defined elements in an internal symbol system. In recent years there have been two challenges to this orthodoxy. First, a number of philosophers, including many outside the symbolist orthodoxy, have argued that "representation" should be understood in its classical sense, as denoting a "stands for" relation between representation and represented. Second, there has been a growing challenge to orthodoxy under (...) the banner of connectionism. Although this connectionist challenge has evoked emotionally-charged rebukes from the symbolist camp, connectionists as a group have not articulated a conception of representation to replace the symbolist view. Nonetheless, most agree on the need for a nonsymbolic notion of representation. This paper advances a "stands for" sense of representation as primary by incorporating it into a general approach to cognitive science consonant with the connectionism. The idea is to marry connectionism to a particular version of functionalism, viz., one that builds its notion of "function" on the similarity between functional analysis in biology and in psychology. It builds on my earlier work adapting and revising Marr's tri-level approach to cognition. My proposal frees Marr's analysis from its moorings in the orthodox symbolic view of representation and allies it with a notion of functional analysis akin to that proposed by Cummins, developed further by Haugeland, and invoked by Millikan and Dretske. Unlike these authors, however, I do not wed representation to a general belief-desire analysis of behavior. Rather, I follow what I take to be the lesson of psychological practice, according to which the investigator does not seek to explain behavior in general but seeks to analyze the cognitive capacities that underlie behavior, such as vision, memory, learning, and linguistic capacities. Accordingly, ascriptions of representational content are made not by working back from belief-desire ascriptions, but in the context of forming psychological models to account for specific cognitive capacities. Because conceptions of representation in cognitive science typically are embedded in a general approach to the study of cognition, arguments for the comparative plausibility of a particular conception of representation must scout these larger frameworks. I therefore begin by characterizing the interlocking set of assumptions that gave life to the orthodox symbolist approach, paying special attention to the complementarity between representation and process that naturally arises from those assumptions. I then consider two versions of an alternative approach to representation: Dretske's and my own. Finally, I urge the merits of the "cognitive capacities" over the "belief-desire" approach to the subject-matter of cognitive science. (shrink)

The concept of representation has become almost inextricably bound to the concept of symbol systems. the concepts is nowhere more prevalent than in descriptions of "internal representations." These representations are thought to occur in an internal symbol system that allows the brain to store and use information. In this paper we explore a different approach to understanding psychological processes, one that retains a commitment to representations and computations but that is not based on the idea that information must be stored (...) and manipulated in symbol systems. In particular, we suggest that the notion of a symbol system as currently understood construes psychological processes in terms of a specific type of computational system, in which a control function "reads," "interprets," and manipulates discrete entities called "symbols." We argue that other types of computational systems may provide a more appropriate characterization of psychological processes. One implication of our argument is the need to consider the constraints placed on computational theories in psychology by the nature of the computing device itself, the human brain. Perhaps surprisingly, this implication leads us to the conclusion that a "functionalist" conception of psychological processes (discussed below) does not entail that physiology is irrelevant to psychology, as has been maintained by prominent adherents of the symbol-systems approach. (shrink)

In this chapter I examine past and recent theories of unconscious inference. Most theorists have ascribed inferences to perception literally, not analogically, and I focus on the literal approach. I examine three problems faced by such theories if their commitment to unconscious inferences is taken seriously. Two problems concern the cognitive resources that must be available to the visual system (or a more central system) to support the inferences in question. The third problem focuses on how the conclusions of inferences (...) are supposed to explain the phenomenal aspects of visual experience, the looks of things. Finally, in comparing past and recent responses to these problems, I provide an assessment of the current prospects for inferential theories. (This paper is reprinted in Hatfield 2009, Perception and Cognition: Essays in the Philosophy of Psychology, Clarendon Press, 124-152.). (shrink)

Descartes' Meditations is one of the most widely read philosophical texts and has marked the beginning of what we now consider as modern philosophy. It is the first text that most students of philosophy are introduced to and this Guidebook will be an indispensable introduction to what is undeniably one of the most important texts in the history of philosophy. Gary Hatfield offers a clear and concise introduction to Descartes' background, a careful reading of the Meditations and a methodological investigation (...) of its main themes. As with all the Guidebooks, this is an exemplary companion to any reading of the Meditations. (Note: This edition has been superseded by Gary Hatfield (2014), The Routledge Guidebook to Descartes' Meditations.). (shrink)

An understanding of the relationship between metaphysics and natural philosophy - or, as we might now say, between philosophy and science - is fundamental to understanding the rise of the "new science" of the seventeenth century. Twentieth-century scholarship on this relationship has been dominated by the thoughbt of Ernst Cassirer, E. A. Burtt, A. N. Whitehead, and Alexandre Koyre. These authors found a common core in the mathematization of nature, which they ascribed to a common Platonic or Pythagorean metaphysical presupposition, (...) on the part of Copernicus, Kepler, Galileo, and Descartes, that the book of nature is written in mathematical characters. Taking Burtt as its primary stalking horse, this chapter challenges this view by finding significant differences in the relations to metaphysics of major actors such as those just named. It does this in part by recognizing that, in the seventeenth century, metaphysics was an intellectual practice that one engaged in wittingly. By contrast, Burtt adopted a historiographical approach in which metaphysics consists of the nonempirical presupposition of an age (a position advanced by R. G. Collingwood). That approach, although valid within its limits, distorts or omits from consideration the witting practice of metaphysics by figures such as Kepler and Descartes. And it makes metaphysicians of Copernicus and Galileo, who are better classified as a mathematical astronomer and a mathematical natural philosopher and writer on astronomy. The chapter ends with some reflections on purportedly aphilosophical history of science. (shrink)

Descartes was both metaphysician and natural philosopher. He used his metaphysics to ground portions of his physics. However, as should be a commonplace but is not, he did not think he could spin all of his physics out of his metaphysics a priori, and in fact he both emphasized the need for appeals to experience in his methodological remarks on philosophizing about nature and constantly appealed to experience in describing his own philosophy of nature. During the 1630s, he offered empirical (...) support for the basic principles of his natural philosophy, while also promising to provide a metaphysical justification. He offered the metaphysical justification in the Meditations and Principles. and claimed absolute certainty for it. At the same time, he recognized that the particular postulated mechanisms of his natural philosophy did not reach that standard of certainty. These mechanisms were supported by empirical testing or confirming of causes through observed effects. (shrink)

Two stories have dominated the historiography of early modern philosophy: one in which a seventeenth century Age of Reason spawned the Enlightenment, and another in which a skeptical crisis cast a shadow over subsequent philosophy, resulting in ever narrower "limits to knowledge." I combine certain elements common to both into a third narrative, one that begins by taking seriously seventeenth-century conceptions of the topics and methods central to the rise of a "new" philosophy. In this revisionist story, differing approaches to (...) the central subject matter of early modern metaphysics--knowledge of substances through their essences and causal powers--arise as a result of disagreements about the powers of the human cognitive faculties. Methodological writings are seen as attempts to direct readers in the proper use of their cognitive faculties. The early modern rejection of the Aristotelian theory of cognition ranks equally in importance with rejection of Aristotelian doctrines about nature. Skepticism is more often than not a tool to be used in teaching the reader the proper use of the cognitive faculties, or indeed in convincing the reader of the existence or inexistence of certain cognitive faculties or powers. Instead of early modern "epistemology" or "theory of knowledge," one speaks, with seventeenth century writers, of theories of the cognitive faculties and their implications for the possibility of human knowledge. The early modern rejection of Aristotelian logic can then be seen as reflecting a negative assessment about the fit between syllogistic reasoning and logic as an art of reasoning or thinking which refines the use of the cognitive faculties. -/- Central to this new historiography is the story of the relation between the intellect and senses as cognitive faculties or powers. The development of philosophy from Descartes to Kant can be portrayed as a series of claims about the power of the intellect to know the essences of things, with resulting consequences for ontology and the foundations of natural philosophy. I illustrate this revised narrative by comparing three conceptions of the intellect in three philosophical settings, provided by several late scholastic Aristotelians, Descartes, and Locke. I have two aims: first, to exhibit the central role played by the conception of intellect or understanding in these authors, and, second, to locate their discussions of the cognitive faculties in relation to recent understandings of psychology, epistemology, logic, mind, and their relations. Early modern writings do not easily fit into the modern categories of epistemology and psychology; more generally, the early modern concern with the workings of mind does not coincide with recent conceptions of naturalism. These findings can help us to see problems with our current categories. (shrink)

This paper develops an appearance view of perception. When we see an object, we see it by having it appear some way to us. We see the object, not the appearance; but we see the object via the appearance. The appearance is subjectively conditioned: aspects of it depend on attributes of the subject. We mentally have the appearance and can reflect on it as an appearance. But in the primary instance, of veridical perception, it is the object that we focus (...) on and experience. I contrast this view with naive realism and with intentionalist or representationalist views, which I call the physical content view. I agree with these views in rejecting sense-data intermediaries and in affirming direct perception, but I argue that direct perception occurs via appearances, making mine a critical direct realism. The other views attempt to explain the spatial content of perception entirely through the physical properties of objects and their physical relation to the perceiver. I argue instead that there are ineliminably subjective aspects of normal spatial perception, which are systematically manifested as a lack of full phenomenal constancy. This systematic underconstancy can’t be accounted for at all by a consistent naive realism; for the physical content view, it requires that most of our ordinary perception is classified as illusory, violating the spirit of that view. Accepting phenomenal underconstancy as pervasive, I suggest that our ability to perceive the mind-independent properties of objects depends on developed conceptual abilities. In the final section, I compare my appearance view with the adverbialism of Chisholm and the critical direct realism of Roy Wood Sellars. (shrink)

Shape and slant judgments of rotated or frontoparallel ellipses were elicited from three groups of 10 subjects. A masking stimulus was introduced to control processing time. Backward masking trials were presented with interstimulus intervals of 0, 25, and 50 msec, Reduction of processing time altered shape judgments in the direction of projective shape and slant judgments in the direction of frontoparallelness. This finding is consistent with the shape-slant invariance hypothesis. In order to study the effects of processing load, one group (...) of subjects was given prior knowledge of the kind of judgment to be made on each trial, one group had no prior knowledge, and a third group made both judgments on each trial. The effects of the processing load manipulation were interpreted in terms of the role of attention in perceptual encoding. Consistent with previous findings, allocation of attention did not affect perceptual encoding. (shrink)

The Gestalt psychologists adopted a set of positions on mind-body issues that seem like an odd mix. They sought to combine a version of naturalism and physiological reductionism with an insistence on the reality of the phenomenal and the attribution of meanings to objects as natural characteristics. After reviewing basic positions in contemporary philosophy of mind, we examine the Gestalt position, characterizing it m terms of phenomenal realism and programmatic reductionism. We then distinguish Gestalt philosophy of mind from instrumentalism and (...) computational functionalism, and examine Gestalt attributions of meaning and value to perceived objects. Finally, we consider a metatheoretical moral from Gestalt theory, which commends the search for commensurate description of mental phenomena and their physiological counterparts. (shrink)

Twelve subjects provided shape and orientation judgments for a set of projectively equivalent, variously rotated rectangles under three viewing conditions—monoptic, dichoptic, and binocular—with and without the presence of a pattern mask. In the absence of the mask, partial constancy was exhibited under the first two conditions and near perfect constancy under the binocular condition. Orientation was discriminated. Presence of the mask produced projective shape matching and diminished orientation discrimination. It is argued that the site of masking was postchiasmal, and the (...) results are related to previous work with pattern masking of projectively equivalent ellipses. (shrink)

Some experiments in perceptual psychology measure perceivers’ phenomenal experiences of objects versus their cognitive assessments of object properties. Analyzing such experiments, this article responds to Pizlo’s claim that much work on shape constancy before 1985 confused problems of shape ambiguity with problems of shape constancy. Pizlo fails to grasp the logic of experimental designs directed toward phenomenal aspects of shape constancy. In the domain of size perception, Granrud’s studies of size constancy in children and adults distinguish phenomenal from cognitive factors.

During the 1630s Descartes recognized that he could not expect all legitimate claims in natural science to meet the standard of absolute certainty. The realization resulted from a change in his physics, which itself arose not through methodological reflections, but through developments in his substantive metaphysical doctrines. Descartes discovered the metaphysical foundations of his physics in 1629-30; as a consequence, the style of explanation employed in his physical writings changed. His early methodological conceptions, as preserved in the Rules and sketched (...) in Part Two of the Discourse, pertained primarily to his early work in optics. By the early 1630s, Descartes was concerned with new methodological problems pertaining to the postulation of micro-mechanisms. Recognition of the need to employ a method of hypothesis led him to lower the standard of certainty required of particular explanations in his mature physics. (shrink)

The first two sections of the paper characterize the nineteenth century respect for the phenomenal by considering Helmholtz’s position and James’ and Russell’s move to neutral monism. The third section displays a moment’s sympathy with those who recoiled from the latter view -- but only a moment’s. The recoil overshot what was a reasonable response, and denied the reality of the phenomenal, largely in the name of the physical or the material. The final two sections of the paper develop a (...) third way, which retains a healthy respect for the mental and for the mind–body relation, does not attempt to equate objects with congeries of sensations, and does not attempt to deny the reality of the phenomenal. In fact, I will claim that on some conceptions (and not merely idealist-phenomenalist conceptions), the phenomenal is a fact of nature, and hence a part of the natural world. Some aspects of this third way are familiar in the various representational and critical realisms of the twentieth-century. But the realization -- or, more neutrally, the conception -- that the natural might include the phenomenal is less familiar. Yet this position has its predecessors too, not only among the physicists and psychologists of the nineteenth century, but among major physicists (as opposed to physicalist philosophers) and psychologists of the twentieth. [A re-edited version of this paper appears in Gary Hatfield, Perception and Cognition: Essays in the Philosophy of Psychology, Clarendon Press, 2009.]. (shrink)

Descartes is widely regarded to be the father of modern philosophy and his Meditations is among the most important philosophical texts ever written. _The Routledge Guidebook to Descartes’ Meditations_ introduces the major themes in Descartes’ great book and acts as a companion for reading this key work, examining: The context of Descartes’ work and the background to his writing; Each separate part of the text in relation to its goals, meanings and impact; The reception the book received when first seen (...) by the world; The relevance of Descartes’ work to modern philosophy, it’s legacy and influence. With further reading included throughout, this text follows Descartes’ original work closely, making it essential reading for all students of philosophy, and all those wishing to get to grips with this classic work. This edition revises the earlier guidebook entitled _Descartes and the Meditations_ (2003). It has been thoroughly revised, and contains expanded treatment of the method of doubt, theory of ideas, and new discussion of Descartes' theory of vision. (shrink)

Challenges the revised standard historiography on Wundt as a psychologist. Considers the concept of psychology as a natural science. Examines the relations between psychology and philosophy before and after 1900. Reflects on the notion of disciplinehood as it affects historical narratives.

This chapter considers Kant's relation to Hume as Kant himself understood it when he wrote the Critique of Pure Reason and the Prolegomena. It first seeks to refine the question of Kant's relation to Hume's skepticism, and it then considers the evidence for Kant's attitude toward Hume in three works: the A Critique, Prolegomena, and B Critique. It argues that in the A Critique Kant viewed skepticism positively, as a necessary reaction to dogmatism and a spur toward critique. In his (...) initial statement of the critical philosophy Kant treated Hume as an ally in curbing dogmatism, but one who stopped short of what was really needed: a full critique of reason, to establish the boundaries of metaphysical cognition. Kant found fault with Hume's analyses of cognition and experience, and specifically his failure to see the crucial importance of synthetic a priori cognition in metaphysics. In particular, he held that Hume's empiricist account of cognition could neither explain the synthetic a priori cognition actually found in mathematics and natural science, nor provide a principled account of the limits on what can be known--and what can be thought--through the pure concepts of the understanding. According to Kant, Hume therefore failed in his attempt to determine the limits of metaphysics, whereas he was able to succeed because his transcendental philosophy provided a thorough account of cognition, its structure and limits. In the Prolegomena and the B Critique Kant distinguished his position more sharply from Hume's. He also adopted a more negative attitude toward "skeptical idealism" than before; but he attributed such skepticism to Descartes, not Hume. Prior to the B Critique Kant did not see Hume as attacking natural science or ordinary cognition. In none of the three works was Kant's main aim to "answer the skeptic." His primary aim was to firmly establish the boundary of metaphysics, by discovering the elements of human cognition and fixing its proper domain. His purported discoveries about the limits of metaphysical cognition meant that the traditional objects of metaphysical knowledge, God, the soul, and the world as it is in itself, are unknowable, hence that traditional metaphysics itself is impossible. Besides settling the possibility or impossibility of metaphysics, his findings would also prevent the illegitimate extension of principles of sensibility to God and the noumenal self, an extension that would threaten the metaphysics of morals by incorrectly denying the thinkability of noumenal freedom, and that might otherwise lead to "materialism, fatalism, atheism, and freethinking unbelief" (B xxxiv). (shrink)

The chapter begins with an initial survey of ups and downs of contextualist history of philosophy during the twentieth century in Britain and America, which finds that historically serious history of philosophy has been on the rise. It then considers ways in which the study of past philosophy has been used and is used in philosophy, and makes a case for the philosophical value and necessity of a contextually oriented approach. It examines some uses of past texts and of history (...) that reveal limits to noncontextual history, including Strawson's Kant, Rorty's grand diagnosis of the Western tradition, and Friedman on Kant's philosophy of mathematics. It then considers ways in which the history of philosophy may become philosophically deeper by becoming more historical, and instances in which history of philosophy of various stripes has or may deliver a philosophical payoff. Along the way, it urges historians of philosophy to attend not only to individual philosophers and their problems and projects, but also to the larger shape of the history of philosophy and its narrative themes. (shrink)

Review of THEO C. MEYERING, Historical Roots of Cognitive Science : The Rise of a Cognitive Theory of Perception from Antiquity to the Nineteenth Century. Boston: Kluwer, xix + 250 pp. $69.00. Examines the author's interpretation of Aristotelian theories of perceptual cognition, early modern theories, and Helmholtz's theory.

The chapter places Kant's discussions of empirical and rational psychology in the context of previous discussions in Germany. It also considers the status of what might be called his "transcendental psychology" as an instance of a special kind of knowledge: transcendental philosophy. It is divided into sections that consider four topics: the refutation of traditional rational psychology in the Paralogisms; the contrast between traditional empirical psychology and the transcendental philosophy of the Deduction; Kant's appeal to an implicit psychology in his (...) taxonomy and theory of cognitive faculties throughout the Critique of Pure Reason; and his new definitions of and support for empirical and rational psychology in the Doctrine of Method. (shrink)

Analytic philosophy arose in the early decades of the twentieth century, with Bertrand Russell and G. E. Moore leading the way. Although some accounts emphasize the role of logic and language in the origin of analytic philosophy, of equal importance is the theme of perception, sense data, and knowledge, which dominated systematic philosophical discussion in the first two decades of the twentieth century in both Britain and America. This chapter examines work on perception and sense data as well as the (...) external world in the analytic tradition in the first half of the twentieth century. After sketching the situation before and just after 1900, it turns to Moore, Russell, and their interlocutors in the teens and twenties, addresses the American scene, looks to subsequent developments in the 1930s and beyond, and finally considers the fates of sense data and the ‘given’ and of the topic of perception more generally. (shrink)

This chapter poses questions about the existence and character of the Scientific Revolution by deriving its initial categories of analysis and its initial understanding of the intellectual scene from the writings of the seventeenth century, and by following the evolution of these initial categories in succeeding centuries. This project fits the theme of cross cultural transmission and appropriation -- a theme of the present volume -- if one takes the notion of a culture broadly, so that, say, seventeenth and eighteenth (...) or nineteenth century European intellectual cultures are deemed sufficiently distinct that one can speak of the "transmission" of texts and ideas from the one to the other as cross cultural. I maintain that a process of transforming and assimilating seventeenth century achievements manifests itself in two distinct cultures of interpretation, one developed by historians of philosophy, the other by scientists and historians of science. The first, following actor's categories, interprets the revolution in the seventeenth century as a philosophical displacement, partly fomented by a radical change in astronomical theory; the second, retrospectively applying the post nineteenth century sense of the term "science" to seventeenth century events, finds a "scientific" revolution, or the birth of modern science. The chapter proposes interpreting the Scientific Revolution as a revolution in natural philosophy and metaphysics. (shrink)

It seems intuitively obvious that metameric matching of color samples entails a loss of information, for spectrophotometrically diverse materials appear the same. This intuition implicitly relies on a conception of the function of color vision and on a related conception of how color samples should be individuated. It assumes that the function of color vision is to distinguish among spectral energy distributions, and that color samples should be individuated by their physical properties. I challenge these assumptions by articulating a different (...) conception of the function of color vision, according to which color vision serves to partition object surfaces into discrimination classes. (shrink)

Visual space can be distinguished from physical space. The first is found in visual experience, while the second is defined independently of perception. Theorists have wondered about the relation between the two. Some investigators have concluded that visual space is non-Euclidean, and that it does not have a single metric structure. Here it is argued that visual space exhibits contraction in all three dimensions with increasing distance from the observer, that experienced features of this contraction are not the same as (...) would be the experience of a perspective projection onto a fronto-parallel plane, and that such contraction is consistent with size constancy. These properties of visual space are different from those that would be predicted if spatial perception resulted from the successful solution of the inverse problem. They are consistent with the notion that optical constraints have been internalized. More generally, they are also consistent with the notion that visual spatial structures bear a resemblance relation to physical spatial structures. This notion supports a type of representational relation that is distinct from mere causal correspondence. The reticence of some philosophers and psychologists to discuss the structure of phenomenal space is diagnosed in terms of the simple materialism and the functionalism of the 1970s and 1980s. (shrink)

This chapter examines the relations between psychology and neuroscience. There is a strong philosophical intuition that direct study of the brain can and will constrain the development of psychological theory. When this intuition is tested against case studies from the psychology of perception and memory, it turns out that psychology has led the way toward knowledge of neurophysiology. The chapter presents an abstract argument to show that psychology can and must lead the way in neuroscientific study of mental function. The (...) opposing intuition is based on mainly weak arguments about the fundamentality or objectivity of physics or physiology in relation to psychology. The chapter argues that psychological phenomena are methodologically prior to neurophysiological concepts and descriptions, that psychology provides the functional descriptions that guide the behavioral brain sciences, that psychological concepts are not reducible, but that neurophysiological data and concepts are nonetheless evidentially and explanatorily relevant for psychology. (shrink)

There is disagreement over the notion of representation in cognitive science. Many investigators equate representations with symbols, that is, with syntactically defined elements in an internal symbol system. In recent years there have been two challenges to this orthodoxy. First, a number of philosophers, including many outside the symbolist orthodoxy, have argued that "representation" should be understood in its classical sense, as denoting a "stands for" relation between representation and represented. Second, there has been a growing challenge to orthodoxy under (...) the banner of connectionism. Although this connectionist challenge has evoked emotionally-charged rebukes from the symbolist camp, connectionists as a group have not articulated a conception of representation to replace the symbolist view. Nonetheless, most agree on the need for a nonsymbolic notion of representation. This paper advances a "stands for" sense of representation as primary by incorporating it into a general approach to cognitive science consonant with the connectionism. The idea is to marry connectionism to a particular version of functionalism, viz., one that builds its notion of "function" on the similarity between functional analysis in biology and in psychology. It builds on my earlier work adapting and revising Marr's tri-level approach to cognition. My proposal frees Marr's analysis from its moorings in the orthodox symbolic view of representation and allies it with a notion of functional analysis akin to that proposed by Cummins, developed further by Haugeland, and invoked by Millikan and Dretske. Unlike these authors, however, I do not wed representation to a general belief-desire analysis of behavior. Rather, I follow what I take to be the lesson of psychological practice, according to which the investigator does not seek to explain behavior in general but seeks to analyze the cognitive capacities that underlie behavior, such as vision, memory, learning, and linguistic capacities. Accordingly, ascriptions of representational content are made not by working back from belief-desire ascriptions, but in the context of forming psychological models to account for specific cognitive capacities. Because conceptions of representation in cognitive science typically are embedded in a general approach to the study of cognition, arguments for the comparative plausibility of a particular conception of representation must scout these larger frameworks. I therefore begin by characterizing the interlocking set of assumptions that gave life to the orthodox symbolist approach, paying special attention to the complementarity between representation and process that naturally arises from those assumptions. I then consider two versions of an alternative approach to representation: Dretske's and my own. Finally, I urge the merits of the "cognitive capacities" over the "belief-desire" approach to the subject-matter of cognitive science. (shrink)

This article critically examines the views that psychology first came into existence as a discipline ca. 1879, that philosophy and psychology were estranged in the ensuing decades, that psychology finally became scientific through the influence of logical empiricism, and that it should now disappear in favor of cognitive science and neuroscience. It argues that psychology had a natural philosophical phase (from antiquity) that waxed in the seventeenth and eighteenth centuries, that this psychology transformed into experimental psychology ca. 1900, that philosophers (...) and psychologists collaboratively discussed the subject matter and methods of psychology in the first two decades of the twentieth century, that the neobehaviorists were not substantively influenced by the Vienna Circle, that the study of perception and cognition in psychology did not disappear in the behaviorist period and so did not reemerge as a result of artificial intelligence, linguistics, and the computer analogy, that although some psychologists adopted the language-of-thought approach of traditional cognitive science, many did not, and that psychology will not go away because it contributes independently of cognitive science and neuroscience. (shrink)

Recent discussions in the philosophy of psychology have examined the use and legitimacy of such notions as “representation”, “content”, “computation”, and “inference” within a scientific psychology. While the resulting assessments have varied widely, ranging from outright rejection of some or all of these notions to full vindication of their use, there has been notable agreement on the considerations deemed relevant for making an assessment. The answer to the question of whether the notion of, say, representational content may be admitted into (...) a scientific psychology has often been made to hinge upon whether the notion can be squared with our “ordinary” or “folk” style of psychological explanation, with its alleged commitment to the idiom of beliefs and desires. In this article, I proceed the other way around, starting with experimental psychology itself and asking whether such notions as the above play a legitimate role within a particular area of contemporary theory, the psychology of perception. My conclusion will be that especially the first three have a legitimate place in theories of perception, albeit one that differs from that ascribed to them in a significant portion of the philosophical literature. Along the way I develop a notion of noncognitive functional analysis, which separates the notion of contentful perceptual processing and perceptual representation from cognitive or conceptual content. (This paper has been reprinted, with stylistic revisions, in Perception and Cognition, Essays in the Philosophy of Psychology, Oxford, Clarendon Press, 2009, pp. 50-87.). (shrink)

The problem of the Cartesian circle, as it is called, has sparked ongoing debate, which intersects several important themes of the Meditations. Discussions of the circle must address questions about the force and scope of the famous method of doubt introduced in Meditation I, and they must examine the intricate arguments for the existence of God and the avoidance of error in Meditations III to V. These discussions raise questions about the possibility of overturning skepticism, once a skeptical doubt has (...) been introduced. More generally, the problem of the circle resonates with recent questions about the foundations of knowledge: Must we be able to validate our methods of reasoning or of knowing before using them? If we must, wouldn't we be forever stuck at the beginning, unable to use our methods of reasoning or of knowing in their own validation? The problem of the Cartesian circle raises general questions about the validation of reason and the possibility of knowledge. This chapter examines the Cartesian circle in the context of Descartes' central project in the Meditations, to secure the foundations of metaphysics. In carrying out this project, Descartes felt the need, or adopted the strategy, of examining the possibility of human knowledge more generally. Such an examination can be interpreted in various ways. Depending on the interpretation given, the roles assigned to the method of doubt and the proofs about God may differ, thereby altering how we see the problem of the circle. We therefore need first to consider Descartes' metaphysical project along with the methods and strategies he adopted in carrying it out. Subsequently, I explain and evaluate several main approaches to the problem of the circle. The chapter concludes with some reflections on the relation of Descartes' metaphysics of knowledge to other prominent positions in the history of philosophy. (shrink)

Rene Descartes and William James had "body first" theories of the passions or emotions, according to which sensory stimulation causes a bodily response that then causes an emotion. Both held that this bodily response also causes an initial behavioral response (such as flight from a bear) without any cognitive intervention such as an "appraisal" of the object or situation. From here they differ. Descartes proposed that the initial processes that produce fear and running are entirely mechanical. Even human beings initially (...) run from the bear as a result of physiological processes alone, without mental contribution. These physiological processes also cause a mental passion, which is a cognitive representation of the situation (as regards novelty, benefit, or harm), and which motivates the will to continue the behavior already in progress. According to James, emotions are caused by instinctive bodily responses that are triggered by noncognitive but nonetheless conscious perceptual states. Emotions are bare feelings of internal physiological stirrings that accompany an instinctual response that has evolved through Darwinian natural selection. Jamesian emotions initially have no motivational or cognitive content, which they subsequently acquire through learning. The methodological legitimacy of comparing these positions across the centuries is defended, and the two theories are compared to recent theories. (shrink)

The theory of knowledge in early twentieth-century Anglo American philosophy was oriented toward phenomenally described cognition. There was a healthy respect for the mind-body problem, which meant that phenomena in both the mental and physical domains were taken seriously. Bertrand Russell's developing position on sense-data and momentary particulars drew upon, and ultimately became like, the neutral monism of Ernst Mach and William James. Due to a more recent behaviorist and physicalist inspired "fear of the mental", this development has been down-played (...) in historical work on early analytic philosophy. Such neglect assumes that the "linguistic turn" is a proper and permanent effect of twentieth-century philosophy, an assumption that distorts early analytic historiography, and begs a substantive philosophical question about thought and cognition. (shrink)

As British and American idealism waned, new realisms displaced them. The common background of these new realisms emphasized the problem of the external world and the mind-body problem, as bequeathed by Reid, Hamilton, and Mill. During this same period, academics on both sides of the Atlantic recognized that the natural sciences were making great strides. Responses varied. In the United States, philosophical response focused particularly on functional psychology and Darwinian adaptedness. This article examines differing versions of that response in William (...) James and Roy Wood Sellars. James viewed the mind as a “fighter for ends.” His neutral monism, by taming the mind-body problem and the problem of the external world, provided a secure metaphysics of mind as functional activity. In contrast, Sellars ’s scientific realism endorsed physical reality but was not mechanistic or reductionist. His critical realism and evolutionary naturalism offered novel metaphysical and epistemological positions in comparison with other American and British realisms. James and Sellars are distinguished from British philosophy in 1890–1918 in the types of realism they endorsed and in their success at introducing Darwinian evolutionary considerations and functional psychology into mainstream philosophy. (shrink)

This paper argues for the reality of qualia as aspects of phenomenal experience. The argument focuses on color vision and develops a dispositionalist, subjectivist account of what it is for an object to be colored. I consider objections to dispositionalism on epistemological, metaphysical, and 'ordinary' grounds. I distinguish my representative realism from sense-data theories and from recent 'representational' or 'intentional' theories, and I argue that there is no good reason to adopt a physicalist stance that denies the reality of qualia (...) as phenomenally available intentional contents in Brentano's original sense of 'intentionality'. (shrink)

Attention only "recently"--i.e. in the eighteenth century--achieved chapter status in psychology textbooks in which psychology is conceived as a natural science. This report first sets this entrance, by sketching the historical contexts in which psychology has been considered to be a natural science. It then traces the construction of phenomenological descriptions of attention from antiquity to the seventeenth century, noting various aspects of attention that were marked for discussion by Aristotle, Lucretius, Augustine, and Descartes. The chapter goes on to compare (...) selected theoretical and empirical developments in the study of attention over three time slices: mid eighteenth century (C. Wolff, C. Bonnet, J. F. Abel), turn of the twentieth century (E. B. Titchener), and late twentieth century. Significant descriptive, theoretical, and empirical continuity emerges when these developments are considered in the large. This continuity is open to several interpretations, including the view that attention research shows long-term convergence because it is conditioned by the basic structure of attention as a natural phenomenon, and the less optimistic view that theory making in at least this area of psychology has been remarkably conservative when considered under large grain resolution, consisting in the reshuffling of a few core ideas. (shrink)

The chapter advances two theses involving Descartes and the mind. The first concerns Descartes' conception of mental faculties, particularly the intellect. As I read the _Meditations_, a fundamental aim of that work is to make the reader aware of the deliverances of the pure intellect, perhaps for the first time. Descartes' project is to alter the reader's Aristotelian beliefs about the faculty of the intellect and its relation to the senses, while at the same time coaxing her to use the (...) pure intellect to perceive the first truths of metaphysics. His anti-Aristotelian understanding of the power of pure intellect undergirds his attempted revolution in metaphysics and physics. The second thesis pertains to Descartes' naturalism about the mind. Descartes typically is seen as having excluded mind from nature, thereby deanimating (literally, "de-souling") the physical world and making it safe for a full-scale mechanistic physics. This attitude effectively makes the mind into "a convenient receptacle for the chips and whittlings of science, rather than a possible object of scientific knowledge" (E. A. Burtt). In contrast, I argue that Descartes included (at least some functions and states of) mind as part of nature, that despite his dualism he continued an established tradition of treating the operations of the senses as open to empirical investigation, and that in virtue of his dualism he initiated a new line of thought leading to the search for specifically psychophysical laws, that is, laws linking non-mental bodily states to states of mind. The precise senses in which Descartes did and did not include *mind* under the rubric *nature* is problematic; but he did use language suggesting that even the intellect is a natural constituent of the human being, as when he ascribed intellectual cognitions to "the natural light.". (shrink)

This chapter finds two versions of the distinction between primary and secondary qualities in Galileo, Descartes, Boyle, and Locke. Although agreeing that primary qualities are physically basic properties of extended particles (including size, shape, position, and motion), these authors differed on whether secondary qualities such as color exist only in the mind as sensations or belong to bodies as powers to cause sensations. Kant was initially a metaphysical realist about primary qualities as spatialized forces (vs. bare extended particles), before placing (...) space among the appearances in his critical period. Space becomes the subjective form in which transcendently real forces and relations appear. Kant viewed color as a subjective sensation in the mind, whereas Helmholtz treated color as a power to cause sensations. Helmholtz was initially a realist about primary qualities as spatialized masses and forces, but he later adopted the epistemically modest view of space as the subjective form in which forces and relations appear. (shrink)

This chapter provides an overview of the phenomenology of size perception and the use of instructions to tease apart phenomenal and cognitive aspects. It develops his own recent proposals concerning the geometry of visual space. The chapter proposes that visual space is contracted along the lines of sight. This contraction would explain the apparent convergence of railway tracks, but without invoking a “proximal mode” experience. Parallel railway tracks receding into the distance project converging lines onto the retinas. A true proximal (...) mode representation would show these lines converging as if in a vertical plane. But we experience them as converging while also receding in depth along the ground. The chapter suggests that this calls for a third geometry of visual space, intermediate between a linear perspective projection and full phenomenal constancy. The chapter attributes reports of full constancy to cognitive factors. size perception, visual space, geometry, lines of sight, proximal mode, phenomenal constancy. (shrink)

During the period 1870-1914 the existing discipline of psychology was transformed. British thinkers including Spencer, Lewes, and Romanes allied psychology with biology and viewed mind as a function of the organism for adapting to the environment. British and German thinkers called attention to social and cultural factors in the development of individual human minds. In Germany and the United States a tradition of psychology as a laboratory science soon developed, which was called a 'new psychology' by contrast with the old, (...) metaphysical psychology. Methodological discussion intensified. New syntheses were framed. Chairs were established and Departments founded. Although the trend toward institutional autonomy was less rapid in Britain and France, significant work was done by the likes of Galton and Binet. Even in Germany and America the purposeful transformation of the old psychology into a new, experimental science was by no means complete in 1914. And while the increase in experimentation changed the body of psychological writing, there was considerable continuity in theoretical content and non-experimental methodology between the old and new psychologies. This chapter follows the emergence of the new psychology out of the old in the national traditions of Britain, Germany, and the United States, with some reference to French, Belgian, Austrian, and Italian thinkers. While the division into national traditions is useful, the psychological literature of the second half of the nineteenth century was generally a European literature, with numerous references across national and linguistic boundaries, and it became a North Atlantic literature as psychology developed in the United States and Canada. The order of treatment, Britain, Germany, and the US, follows the center of gravity of psychological activity. The final section considers some methodological and philosophical issues from these literatures. (shrink)

This chapter reconsiders the notion of perceptual constancy from the ground up. It distinguishes the phenomenology of perceptual constancy and stability from a functional characterization of perception as aiming at full constancy. Drawing on this distinction, we can attend to the phenomenology of constancy itself, and ask to what extent human perceivers attain constancy, as usually defined. Within this phenomenology, I distinguish phenomenal presentations of spatial features and color properties from categorizations, conceptualizations, and judgments that underlie verbal or other responses (...) to those presentations. Although phenomenal presentation and categorization commonly co-occur, they are distinct aspects of experience. After reviewing several standard descriptions of constancy, I present laboratory findings and my own phenomenological descriptions by way of confirming that, although perception "tends toward" constancy, human perceivers do not usually attain full constancy for either spatial or chromatic properties (as many investigators acknowledge). For spatial perception, I find that the phenomenology has been systematically misdescribed, and I offer a more adequate description of the phenomenology of everyday spatial perception. However, my greatest quarrel with previous theory concerns the functional aim of the constancies. I argue not only that perception does not achieve full constancy but that we should not characterize it as aiming for full constancy. Rather, perception seeks a stability of representation suitable for guiding our actions and which can also, as needed, enable us to classify and re-identify objects by phenomenally presented properties such as shape, size, or color. Further, I argue that theorists should not confuse these classifications with the qualitative character of phenomenal experience. My arguments underscore the need to distinguish phenomenal representation (better, "presentation") from conceptual categorization, and to distinguish perceptual presentations from subsequent processes that are involved in responding to them. (shrink)