Gary Hatfield

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).

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).

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.