Gary Hatfield

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

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. The emphasis on ‘folk psychology’ in arguments concerning the status of various concepts within scientific psychology is unfortunate, because it runs afoul of the ideal that the philosophy of psychology, by analogy with the philosophy of biology and the philosophy of physics, should have at its core the discussion of ongoing psychological theories. For while it may be admitted that the status of appeals to ‘folk psychology’ in order to justify a role for the belief-desire idiom within psychology proper is a matter that is of interest in its own right, it is not at all clear that mainstream experimental psychology has adopted either the language or the conceptions of ‘belief-desire’ psychology.

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.

This chapter deals with Immanuel Kant's remarks on touch and vision in the context of his pragmatic anthropology, by considering his views of the scope, aims, and methods of that fledgling discipline. Kant supports his discussion with appeals to observation and experience that form a kind of everyday phenomenology of sensory experience. The chapter considers Kant's notion of the relation between the pragmatic and the theoretical, including his remarks that a pragmatic anthropology does not present theoretical or scholastic knowledge but focuses on worldly knowledge. Kant derived the framework for his discussion of the five external senses from his lectures on metaphysics, especially those on empirical psychology. In both empirical psychology and anthropology he categorizes the senses into those that are comparatively objective and those that are comparatively subjective: the objective senses provide more cognition, and provide occasion for reflection, but the subjective senses have more sensation than reflection.

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.

We examine a number of investigations of perceptual economy or, more specifically, of minimum tendencies and minimum principles in the visual perception of form, depth, and motion. A minimum tendency is a psychophysical finding that perception tends toward simplicity, as measured in accordance with a specified metric. A minimum principle is a theoretical construct imputed to the visual system to explain minimum tendencies. After examining a number of studies of perceptual economy, we embark on a systematic analysis of this notion. We examine the notion that simple perceptual representations must be defined within the "geometric constraints" provided by proximal stimulation. We then take up metrics of simplicity. Any study of perceptual economy must use a metric of simplicity; the choice of metric may be seen as a matter of convention, or it may have deep theoretical and empirical implications. We evaluate several answers to the question of why the visual system might favor economical representations. Finally, we examine several accounts of the process for achieving perceptual economy, concluding that those which favor massively parallel processing are the most plausible.

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."

The chapter focuses on attributions of the transparency of thought to early modern figures, most notably Descartes. Many recent philosophers assume that Descartes believed the mind to be “transparent”: since all mental states are conscious, we are therefore aware of them all, and indeed incorrigibly know them all. Descartes, and Berkeley too, do make statements that seem to endorse both aspects of the transparency theses (awareness of all mental states; incorrigibility). However, they also make systematic theoretical statements that directly countenance “unnoticed” thoughts or mental states, that is, thoughts or mental states of which the subject is unaware and has no knowledge. Descartes, having identified the essence of mind with thought or representation, distinguishes bare states of mind from states of which we have reflective awareness, thereby providing a theoretical tool for understanding both his seeming endorsement of transparency and his actual denial of it: Descartes distinguished between a basic perceptual state, or a basic awareness, and reflectively conscious states that involve explicit noticing and cognizing on the part of the subject. Leibniz (as is better known) directly endorsed a similar distinction between bare perception and reflective consciousness, using the term “perception” for the first and “apperception” for the second. In these cases, bare perceptions are not transparently available to the subject, and so in fact the subject does not have knowledge, hence does not have incorrigible knowledge, of all its occurrent mental states. This chapter gives evidence to support these claims; elaborates the complex psychology of the subject found in Descartes and other early moderns; and notes some ways in which these early moderns contributed to the genesis of the modern subject. Finally, it compares McDowell’s conception of the Cartesian mind with the conceptions of mind found in the writings of Descartes, Berkeley, and Leibniz, finding that his characterization caricatures the positions of early modern philosophers. McDowell's characterization has four elements: consciousness as essence of mind; intentionality as exclusively mental; the veil of perception; and the transparency of mind. Only the second point, about intentionality, fully fits Descartes. As a consequence of his own misdirection, McDowell misses the actual basis of his difficulty in connecting mind with world, which arises from a point of agreement between him and Descartes: the removal of intentionality from material sensory systems. But whereas Descartes could relocate (nonconceptual) sensory intentionality in mental states, McDowell is left to account for it with his overly cognitivized scheme of perceptual content as exclusively conceptual. (Paper first given at the European Society for Early Modern Philosophy, 2007.)

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.

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.]

The chapter begins with a sketch of the empirical, theoretical, and philosophical background to nineteenth-century theories of perception, focusing on visual perception. It then considers German sensory physiology and psychology in the nineteenth century and its reception. This section gives special attention to: assumptions about nerve–sensation relations; spatial perception; the question of whether there is a two-dimensional representation in visual experience; psychophysics; size constancy; and theories of colour perception. The chapter then offers a brief look at the interaction between perceptual theory and philosophical issues in epistemology and the metaphysics of mind in Britain and America, focusing on: the notion of a muscle sense; the problem of the external world; and forms of perceptual realism. It ends with an overview of psychological theories of perception in the early twentieth century and the Gestalt reaction, culminating with J. J. Gibson.

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.)

As the word “optics” was understood from antiquity into and beyond the early modern period, it did not mean simply the physics and geometry of light, but meant the “theory of vision” and included what we should now call physiological and psychological aspects. From antiquity, these aspects were subject to geometrical analysis. Accordingly, the geometry of visual experience has long been an object of investigation. This chapter examines accounts of size and distance perception in antiquity (Euclid and Ptolemy) and the Middle Ages (Ibn al-Haytham), before turning to "natural geometry" in Kepler and Descartes. It finds a purely mechanical realization of natural geometry in Descartes (primarily in his L'Homme, 1664), in which he conceives states of the visual system as varying in accordance with distance, much as his geometrical compasses vary their spatial relations in accordance with geometrical proportions. This reading challenges the notion that a two-dimensional sensation (without three-dimensional phenomenality) was universally accepted prior to the nineteenth century by positing a direct psychophysiological account of the experience of distance in Descartes. It thereby challenges the interpretations of Descartes on natural geometry of George Berkeley, Nancy Maull, Margaret Wilson, Erwin Panofsky, and Jonathan Crary.

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.

The paper provisionally accepts the goal of Goldman's primary epistemics, which is to seek reliability values for basic cognitive processes, and questions whether such values may plausibly be expected. The reliability of such processes as perception and memory is dependent on other aspects of cognitive structure, and especially on one's "conceptual scheme," the evaluation of which goes beyond primary epistemics (and its dependence on cognitive science) to social epistemics, or indeed to traditional epistemology and philosophy of science. Two general arguments against the plausibility of determining reliability values for the basic cognitive architecture of humans are proposed, one applying Fodor's distinction between input and central systems, and the other invoking a point by Geertz about culture and evolution. Social epistemics is only briefly evaluated, as it is nascent.

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.)

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.

This chapter examines a question at the intersection of the mind-body problem and the analysis of mental representation: the question of the direction of constraint between psychological fact and theory and neurophysiological or physical fact and theory. Does physiology constrain psychology? Are physiological facts more basic than psychological facts? Or do psychological theories, including representational analyses, guide and constrain physiology? Despite the antireductionist bent of functionalist positions, it has generally been assumed that physics or physiology are more basic than, and hence contraining on, psychological fact and theory. Section 1 sketches the intuitions that would lead one to adopt such a view. The chapter then examines whether one-sided constraint has been and should be found in practice. It argues that philosophical analysis of psychological science shows that rigorous functional analyses can be carried out in advance of physiological knowledge. Indeed, in the investigation of sensory perception, ascription of psychological function leads the way in the individuation and investigation of neurophysiology. We shall look at several cases in visual perception (binocular single vision, stereopsis, and color vision), in which psychological results have provided a basis for physiological research. It is tempting to think that the psychological functions that enable physiological investigation would be Wrightian teleofunctions. It is, thus, natural to suppose that psychologists and neurophysiologists have proceeded with a conception of the purpose of a given neural structure, and have viewed neural anatomy and neural activity as the substrate for or instantiation of various properly psychological functions. For example, neuroscientists surely understand that the eye and visual system are for seeing, rather than for detecting an electric discharge in the vicinity of the retina (which sighted humans can do, via the subjective light produced by such discharges), and they guide their investigations of the eye, visual cortex, and intervening pathways accordingly. As a result, they will view rods and cones in the eye as photoreceptors, even though these structures will produce "output" (will respond with hyperpolarization) to other forms of energy. At the same time, there may be cases in which the functions that have guided research are in fact precisely determined input-output functions, whose teleofunctional status is absent or misdescribed. I will argue that in the case of trichromatic color matches, the psychological function involved is an input-output function, and that this result has implications for the description of color vision as a psychological capacity.

In the early modern period, many authors held that sensation or sensory reception is in some way passive and that perception is in some way active. The notion of a more passive and a more active aspect of perception is already present in Aristotle: the senses receive forms without matter more or less passively, but the “primary sense” also recognizes the salience of present objects. Ibn al-Haytham distinguished “pure sensation” from other aspects of sense perception, achieved by “discernment, inference and recognition,” which included perception of properties such as size and distance as well as similarity, difference, and beauty. Descartes regarded light and color as experiences passively caused in the mind by bodily processes, but he also included distance, perceived through accommodation and convergence, as an immediately caused sensory idea. On the perception side, most theorists held that size and distance perception occurs through unnoticed psychological operations, whether mediated by judgment or associative processes. Association is, in a sense, passive, as it occurs through nonreflective habit formation. But such habits mark a contribution of the subject to perception and are in that way active. The decision of whether sensation and perception are active or passive is highly sensitive to what counts as activity and to what is included as sensation or perception. There is no simple formula, but the generalization that sensation is for the most part passive and perception for the most part active may stand as an imprecise summary of early modern thought on the topic

The chapter concerns some aspects of Russell’s epistemological turn in the period after 1911. In particular, it focuses on two aspects of his philosophy in this period: his attempt to render material objects as constructions out of sense data, and his attitude toward sense data as “hard data.” It examines closely Russell’s “breakthrough” of early 1914, in which he concluded that, viewed from the standpoint of epistemology and analytic construction, space has six dimensions, not merely three. Russell posits a three-dimensional personal or “perspective” space that is inhabited by sense data. This space then forms the basis for constructing the three dimensional space of physics (and of public things). I am concerned with the specifics of this construction: with the properties of the private spaces, the relations among those spaces, and their relation to physical space and to constructed “things,” such as pennies or tables. There are difficulties of interpretation with respect to these relations, which stem from the difficulty of finding a coherent interpretation of Russell’s claim that objects such as tables and pennies look smaller at a greater distance (or look trapezoidal or elliptical from some points of view). I don’t mean to challenge the phenomenal claim that objects do, in some sense, look small in the distance. Rather, I raise difficulties with Russell’s analysis of this fact, in which he appeals to both phenomenal experience and the findings of sensory psychology. I hold that if he wishes to maintain his phenomenal claim about objects appearing smaller with greater distance, he must alter or redescribe aspects of his construction of ordinary things. However, if his construction of things and physical space is based on a problematic description of the private spaces, then his claim that private or perspective spaces are very well known and provide the hard data for knowledge of the physical world faces a challenge.

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.

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

This chapter first discusses psychology in the eighteenth century as the background to nineteenth-century psychology. It then recounts developments within German psychology, British psychology, evolutionary psychology, and American psychology, followed by a discussion of introspective methods in the laboratory. The final three sections discuss conflicting opinions on the existence of unconscious mental states, review relations between philosophy and psychology, and survey the state of psychology in the early twentieth century.

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.