Gary Hatfield

This chapter examines the question of Kant's relation to Hume's skepticism and then considers the evidence for Kant's attitude toward Hume in three contexts: the A Critique, the Prolegomena, and the 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 what he said it 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).

L’Homme presents what has been termed Descartes’ “physiological psychology.” It envisions and seeks to explain how the brain and nerves might yield situationally appropriate behavior through mechanical means. On occasion in the past 150 years, this aim has been recognized, described, and praised. Still, acknowledgement of this aspect of Descartes’ writing has been spotty in histories of neuroscience and histories of psychology. In recent years, there has been something of a resurgence. This chapter argues that Descartes ascribed a range of active functions to the brain acting on its own in seeking to explain psychological functions such as sense perception, attention, memory, and emotional response.

This chapter discusses Decartes as a rationalist and an experimentalist, as a philosopher-metaphysicist who also relies on experiment and observation as an essential activity of knowledge. It explains deduction in terms of intuition, its connection between one proposition and another as the only way to knowledge and method, as some sets of rules, easy rules that should someone follow them, will lead to the truth. It further explains Descartes concept of the anaclastic which depends on the angle of incidence and the angle of refraction. This chapter also explains Decartes thought that intuition and deduction are the immediate grasping of the propositions and inferential connection between propositions. Finally this chapter explains how certain experiments are needed to arrived at certain knowledge through deduction.

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.

This volume, originally published in 2002, assembles the historical sequence of writings that Kant published between 1783 and 1796 to popularize, summarize, amplify and defend the doctrines of his masterpiece, the Critique of Pure Reason of 1781. The best known of them, the Prolegomena, is often recommended to beginning students, but the other texts are also vintage Kant and are important sources for a fully rounded picture of Kant's intellectual development. As with other volumes in the series there are copious linguistic notes and a glossary of key terms. The editorial introductions and explanatory notes shed light on the critical reception accorded Kant by the metaphysicians of his day and on Kant's own efforts to derail his opponents.

This article first refines the question of Kant's relation to Hume's skepticism, and then considers the evidence for Kant's attitude toward Hume in three contexts: the A Critique, the Prolegomena, and the B Critique. My thesis is 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 Kant succeeded 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 what he said it 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).

Seeking to avoid the typical binary choices between symbolic representations and no representations, or between functionally decomposable psychological processes and no psychological processes, or between direct perception of mind-independent physical properties and indirect perception of sense data, this article proposes that even a clear-thinking friend of Gibson can accept that perception of the environment is mediated by appearances and that such appearances are produced by functionally decomposable, rule-instantiating psychological processes. In so doing, it avoids both hyper-intellectualization of the perceptual process and the positing of sense data as immediate objects of perception. It considers notions of perceptual mediation from classical Gestalt psychology, while referencing recent phenomenological arguments showing that perception does not simply conform to mind-independent physical properties. Perception presents objects and scenes under a phenomenal aspect, in a manner suitable to be action-guiding. Finally, it examines neuroscientific decompositions of Gibsonian information pickup mechanisms, finding that such mechanisms are reasonably described as effecting processes of construction. As a separate point, such mechanisms are usefully described as including subpersonal, non-symbolic representations and processes of information integration.

This chapter considers the development of experimental psychology as a distinct discipline from philosophy, a result that arrived more slowly in Britain than in Germany or the United States. The chapter first considers more closely the question of what it means to chart the ‘emergence’ of psychology as a separate discipline. It finds that the usual criteria applied by historians of psychologh, that a discipline arises through institutional structures such as professorships (a specialist career path), journals, and professional socieites, does not fit the British scene. It then surveys some actors’ taxonomies of psychological trends or schools in Britain, looking back from the first quarter of the twentieth century. Finally, it examines connections between philosophy and psychology in the decades surrounding the turn of the twentieth century, involving the problem of the external world and the use of psychology in epistemology.

This edited volume of newly commissioned papers aims to further understanding of the philosophy of perception and its history. It seeks a broad historical coverage, to include works outside the Western tradition and figures only newly prominent within the Western tradition. Its principal theme is the problem of perceptual error, which it asserts has been understudied, at least in antiquity and the middle ages, as has, allegedly, the history of theories of perception more generally. The individual chapters are typically of high quality and add to the extant literature. The focus, as is usual, is on visual perception, but blindness and touch come forward in three chapters on Molyneux's...

Throughout his career, Wundt recognized Völkerpsychologie (VP) as (at first) ancillary to experimental psychology or (later) as its required complement. New scholarship from around 1979 highlighted this fact while claiming to correct a picture of Wundt as a pure associationist, attributed to Boring’s History of Experimental Psychology, by instead emphasizing apperception in Wundt’s scheme (sec. 2). The criticisms of Boring, summarized by Blumenthal in 1980, overshot the mark. Boring’s Wundt was no pure associationist. Both Boring and the seventy-niner historians emphasized psychic activity in Wundt. Section 3 considers Wundt’s endorsements of mental chemistry, elements, association, and psychological explanation via combinations of elements. Section 4 follows Wundt’s changing conceptions of VP; looks into the relations between VP and experiment, especially as regards “higher” mental processes; examines the (sometimes cooperative) interactions between individual (including experimental) psychology and VP; and considers how method, not type of mental process, distinguishes the two branches of psychology. Finally, section 5 acknowledges Wundt’s unification of VP and individual psychology and concludes that although he objected to the Würzburgers’ experimental methods in treating higher mental processes, he did not generally exclude the latter from experimental investigation, contrary to the seventy-niner narrative, which has been widely adopted.

Abstract. Classical constructivists such as Rock and Hoffman contend that the processes of perception are intelligent and construct perceptual experience by going beyond the stimulus information or by creating a percept that deviates from the physical properties of the object. On these terms, Gibson’s theory of perception is anti-constructivist. After reviewing classical constructivism, this article maintains, first, that the phenomenology of visual space shows a deviation from physical spatial properties, by being contracted in depth, even under full cue conditions, a fact that makes trouble for Gibson’s version of direct realism. Second, independently of the first argument, it contends that perception is pervasively constructed in the sense that stimulus information must be transformed to yield perception. Accordingly, perception is radically constructed in its very bones.

This article considers Helmholtz’s relation to philosophy, including Fichte’s philosophy. Recent interpreters find Fichtean influence on Helmholtz, especially concerning the role of voluntary movement in distinguishing subject from object, or “I” from “not-I.” After examining Helmholtz’s statements about Fichte, the article describes Fichte’s ego-doctrine and asks whether Helmholtz could accept it into his sensory psychology. He could not accept Fichte’s core position, that an intrinsically active I intellectually intuits its own activity and posits the not-I as limiting and determining that activity, because that account requires cognitive abilities that conflict with Helmholtz’s claim that the development of spatial perception relies primarily on associative memory and involves no direct awareness of the ego’s activity as such. Helmholtz would have known various accounts of the distinction between subject and object, or self and world, from sensory physiology, including associative accounts invoking voluntary motor movements and accounts describing checks on the perceiver’s activity. Some of the accounts cite Fichte on the I and not-I, but most do not, and none adopt Fichte’s Idealism. Finally, the article examines Helmholtz’s relation to metaphysics, finding that in all periods he rejected Fichtean Idealism and that the modest metaphysics of his mature period is a version of structural realism.

L’Homme presents what has been termed Descartes’ “physiological psychology”. It envisions and seeks to explain how the brain and nerves might yield situationally appropriate behavior through mechanical means. On occasion in the past 150 years, this aim has been recognized, described, and praised. Still, acknowledgement of this aspect of Descartes’ writing has been spotty in histories of neuroscience and histories of psychology. In recent years, there has been something of a resurgence. This chapter argues that, in seeking to explain psychological functions such as sense perception, attention, memory, and emotional response, Descartes ascribed a range of active functions to the brain acting on its own (independently of mind).

Descartes analysed the mind into various faculties or powers, including pure intellect, imagination, senses, and will. This article focuses on his account of the sensory power, in relation to its Aristotelian background. Descartes accepted from the Aristotelians that the senses serve to preserve the body by detecting benefits and harms. He rejected the scholastic Aristotelian sensory ontology of resembling species, or ‘forms without matter’. For the visual sense, Descartes offered a mechanistic ontology and a partially mechanized account of sensory processes, including some previously ascribed to judgement. He did this in the context of his theory of brain signs that prompt sensations. The article contends that Descartes’s use of the sign-relation was modelled on standard discussions of non-resembling signs in commentaries on Aristotle’s De interpretatione. It follows three uses of the sign-relation: brain states that cause colour sensations; brain states that cause experiences of spatialized contents, such as shapes; and brain states that realize a ‘natural geometry’. It argues that Descartes’s natural geometry does not involve mental operations but physiological mechanisms that co-vary with the distance to seen objects. While retaining the language of sensory powers, Descartes offered a partial mechanization of those powers.