Gary Hatfield

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).

Descartes’ accounts of sensory perception have long troubled his interpreters, for their lack of clear and explicit statements on some fundamental issues. His readers have wondered whether he allows spatial sensory ideas (spatial qualia); whether sensory ideas such as color or pain are representations and, if so, what they represent; and what cognitive value Descartes attributed to sense perception. Recent discussions take differing stands on the questions just mentioned, and also disagree over Descartes’ account of the externalization of sensory qualities, on the origin and correct analysis of the “material falsity” he attributes to some sensory ideas, and on the value of the “teachings of nature.” Such disagreement should not be surprising, for although sensory perception was an important topic for Descartes, his treatment of these particular issues is not systematic – or at least not apparently so. Generally, there are no proof texts that unequivocally settle questions about Descartes’ views on spatial qualia, the representationality of sensory ideas, their cognitive value, externalization, material falsity, and the status of the teachings of nature. Yet these questions and topics naturally arise from matters about which Descartes is explicit and (reasonably) consistent, regarding the role of the senses in philosophy and everyday life and concerning the nature of minds and ideas. It is, therefore, worthwhile to ask what his positions might have been. This chapter develops answers by considering Descartes’ systematic doctrines on the nature of the mind and its ideas and by combing his statements on sensation and perception for hints about how to apply such principles. The first section reviews some key texts. Succeeding sections develop positions on representationality, cognitive value, externalization, material falsity, and the teachings of nature. Ultimately, I favor an interpretation in which, for Descartes, all sensory ideas represent by resemblance, different kinds of sensory ideas vary in cognitive value, externalization arises through spatial localization, and, with sensory ideas of color and the like, as materially false they do not intrinsically misrepresent but afford occasion for false judgments, which arise as merely apparent, and so not actually legitimate, teachings of nature.

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.

This chapter focuses on the notion of color as a property of the surfaces of objects. It considers three positions on what colors are: objectivist, subjectivist, and relationalist. Examination of the arguments of the objectivists will help us understand how they seek to reduce color to a physical property of object surfaces. Subjectivists, by contrast, seek to argue that no such reduction is possible, and hence that color must be wholly subjective. This chapter argues that when functional considerations are taken into account, a relationalist position best accommodates the primary data concerning color perception, and permits a better understanding of the ways in which color is both objective and subjective. The chapter ends with a reconsideration of the notions of objectivity and subjectivity themselves, and a consideration of how modern technology can foster misleading expectations about the specificity of color properties.

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.

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.

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.

This article argues that many (often Anglophone) interpreters of the Deduction have mistakenly identified Kant's aim as vindicating ordinary knowledge of objects and as refuting Hume's (alleged) skepticism about such knowledge. Instead, the article contends that Kant's aims were primarily negative. His primary mission (in the Deduction) was not to justify application of the categories to experience, but to show that any use beyond the domain of experience could not be justified. To do this, he needed to show that their proper use in attaining metaphysical knowledge was restricted to (actual and possible) experience. The central theoretical claims of previous metaphysics were thus rendered void. Kant was not out to save ordinary knowledge from the skeptic, at least not originally, since he did not think such knowledge was in danger. Rather, he wanted to sustain the skeptical claim that we cannot justify metaphysical claims about things in themselves, hence that we cannot gain metaphysical knowledge about the existence of God, the immortality of the soul, the beginning of time, and the least parts of matter. He wanted to achieve this result in a more theoretically satisfying manner than had skeptical authors. Doing so would also allow him to curb certain forms of skeptical empiricism, by showing that we cannot disprove, or rule out as unintelligible, human freedom, an afterlife, or divine providence. The article ends by considering the retrospective rereadings of the Deduction by Hermann Cohen and P. F. Strawson, concluding that these rereadings force Kant's text into an alien mold, thereby diminishing its philosophical value as a work with its own distinctive aims and methods.

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.

According to Kepler and Descartes, the geometry of the triangle formed by the two eyes when focused on a single point affords perception of the distance to that point. Kepler characterized the processes involved as associative learning. Descartes described the processes as a “ natural geometry.” Many interpreters have Descartes holding that perceivers calculate the distance to the focal point using angle-side-angle, calculations that are reduced to unnoticed mental habits in adult vision. This article offers a purely psychophysiological interpretation of Descartes’s natural geometry. In his account of perceived limb position from the Treatise on Man, he envisioned a central brain state that controls ocular convergence and thereby co-varies with the distance from observer to object. A psychophysiological law relates the visual perception of distance to this brain state. Descartes also invokes more traditional theories of distance and size perception based on unnoticed judgments, yielding a hybrid account

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

Seeing happens effortlessly and yet is endlessly complex. Among the most fascinating aspects of visual perception is its stability and constancy. As we shift our gaze or move about the world, the light projected onto the retinas is constantly changing. Yet the surrounding objects appear stable in their properties. Psychologists have long been interested in the constancies. They have asked questions such as: How good is constancy? Is constancy a fact about how things look, or is it a product of our beliefs and judgments about how things look? How can the contents of visual experience be studied experimentally? Philosophers have long been interested in characterizing visual experience and have become widely interested in the constancies more recently. As psychologists and philosophers have interacted, new questions have arisen: If experience is not as of retinal stimulation (proximal mode), but does not always exhibit constancy (or at least not in all respects), how shall we describe this intermediate state? Also, should we regard any departure from constancy as a failure of the visual system, or might it be a reasonable or adaptive response? In what circumstances is seeing highly conditioned by cognitive factors such as background assumptions, and in what circumstances not? Our volume focuses on size constancy and color constancy. It considers methodologies for studying conscious visual perception, efforts to describe visual experience in relation to constancy, what it means that constancy is not always perfect, and the conceptual resources needed for explaining visual experience.

This paper examines the claims of the Gestalt psychologists that there was a crisis in experimental psychology ca. 1900, which arose because the prevailing sensory atomism excluded meaning from among psychological phenomena. The Gestaltists claim that a primary motivation of their movement was to show, against the speculative psychologists and philosophers and Verstehen historians, that natural scientific psychology can handle meaning. Purportedly, they revealed this motivation in their initial German-language presentations but in English emphasized their scientific accomplishments for an American audience. The paper finds that: there was a recognized crisis in the new experimental psychology ca. 1900 pertaining especially to sensory atomism; that the Gestaltists responded to the crisis with new experimental findings and theoretical concepts that challenged atomism; in both languages, they raised problems of meaning and discussed the contest with speculative psychology and philosophy only after presenting their scientific case; that they introduced phenomenological observations on meaning and perceptual organization into their psychology but did not develop a theory of meaning or solve philosophical problems; that they argued ‘‘philosophically,’’ that is, using abstract, conceptual arguments; and that this aspect of their cognitive style was not received well by some prominent members of their American audience.

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.

This chapter challenges the view that psychology emerged from philosophy about 1900, when each found its own proper sphere with little relation to the other. It begins by considering the notion of a discipline, defined as a distinct branch of learning. Psychology has been a discipline from the time of Aristotle, though with a wider ambit, to include phenomena of both life and mind. Empirical psychology in a narrower sense arose in the eighteenth century, through the application (in Britain and elsewhere) of the observational attitudes of the physical and life sciences to mental phenomena. The experimental psychology of the latter nineteenth century was a transformation of this empirical psychology, although the British version was characterized by new theoretical conceptions (including evolutionary ideas) as well as new empirical techniques. After surveying psychology in and out of universities in this period, the chapter reviews a taxonomy of “schools” of psychology from 1923. Notice of anti-psychological attitudes in British philosophy before and after 1900 is balanced by considering positive conceptions of psychology’s role in connection with epistemology and the problem of the external world.

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."

This paper examines the origins and legacy of Titchener’s notion of stimulus error in the experimental study of sensory experience. It places Titchener’s introspective methods into the intellectual world of early experimental psychology. It follows the subsequent development of perceptual experimentation primarily in the American literature, with notice to British and German studies as needed. Subsequent investigators transformed the specific notion of a “stimulus error” into experimental questions in which subjects’ attitudes toward their perceptual tasks became independent variables to be manipulated experimentally. Ultimately, these manipulations support a distinction between accessing phenomenal as opposed to cognitive aspects of subjects’ responses to perceived objects.

Recent Cartesian scholarship postulates two Descartes, separating Descartes into a scientist and a metaphysician. The purpose varies, but one has been to show that the metaphysical Descartes, of the Meditations, is less genuine than the scientific Descartes. Accordingly, discussion of God and the soul, the evil demon, and the non-deceiving God were elements of rhetorical strategy to please theologians, not of serious philosophical argumentation. I agree in finding two Descartes, but the two I identify are not scientist and philosopher, but practitioner and methodologist of the mathematical sciences on the one hand, and metaphysician of a new, general science of nature on the other. This chapter examines the transition to the second Descartes, and especially the metaphysical turn. It proposes that although Descartes' doubt was methodological and he felt no serious threat from skepticism and absolute certainty was not his primary goal. Rather, the doubt was used to reform the intellect, or to teach the use of the pure intellect (and to obtain certainty in that domain). Further, Descartes' metaphysics was primarily in the service of his natural philosophy (where in the main he did not claim absolute certainty). He did not talk about God and the soul in order to fool the theologians. His discussion of the relation between God and human reason was part of a metaphysical strategy in which, through his doctrine on the eternal truths, he separated knowledge of the first principles of natural philosophy (gained by the natural light) from theological cognition (through the light of grace), thereby seeking to render his metaphysics distinct from the proper domain of theology.

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.

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.

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.)

This chapter examines the Helmholtz's changing conceptions of the relation between scientific cognition (the thought processes of the investigator) and artistic cognition. It begins with two case studies: Helmholtz's application of sensory physiology and psychology respectively to music and to painting. Consideration of these concrete cases leads to Helmholtz's account of the methodology of aesthetics, and specifically to his formulation of the distinction between the *Geisteswissenschaften* and *Naturwissenschaften*. It then examines the development of his comparative account of the thought processes of artist and scientist. This development parallels the development of his psychological theory of judgment into his famous theory of unconscious inference. The latter development exemplifies his classical "aesthetics of science."

Essay review of Daniel Garber, 1992, Descartes' Metaphysical Physics, University of Chicago Press, Chicago and London, xiv + 389 pp., and Michael Friedman,: 1992, Kant and the Exact Sciences, Harvard University Press, Cambridge, Mass., and London, xvii + 357 pp. These two books display the historical connection between science and philosophy in the writings of Descartes and Kant. They show the place of science in, or the scientific context of, these authors' central metaphysical doctrines, pertaining to substance and its properties, the metaphysics of force and causal agency, the relation of geometry to matter and to space, and the structure of cognition. In so doing, they provide an image of philosophy as an intellectually and culturally engaged enterprise, an image according to which it makes little sense to make pronouncements about the foundations of knowledge or the possibilities for science without direct engagement with the living practice of scientific and other cognitive enterprises. However, in some areas they did not engage the context as fully as needed; their interpretations of particular arguments and indeed of whole philosophical programs suffered thereby.

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.

This introductory chapter surveys some basic findings on primate evolution and the evolution of mind; examines socially transmitted traditions in relation to the concept of culture; recounts the sources of evidence regarding the evolution of mind and culture; charts the history of evolutionary approaches to mind and behavior since Darwin; reviews several prominent theoretical syntheses concerning the evolution of the human mind and behavior; and, along the way, introduces the specific questions examined in the individual chapters.

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.

Descartes boldly claimed: "I think, therefore I am." But one might well ask: Why do we think? How? When and why did our human ancestors develop language and culture? In other words, what makes the human mind human? _Evolution of Mind, Brain, and Culture_ offers a comprehensive and scientific investigation of these perennial questions. Fourteen essays bring together the work of archaeologists, cultural and physical anthropologists, psychologists, philosophers, geneticists, a neuroscientist, and an environmental scientist to explore the evolution of the human mind, the brain, and the human capacity for culture. The volume represents and critically engages major theoretical approaches, including Donald's stage theory, Mithen's cathedral model, Tomasello's joint intentionality, and Boyd and Richerson's modeling of the evolution of culture in relation to climate change. The volume contains chapters by: Peter Carruthers; Thierry Chaminade; Philip Chase; Merlin Donald; Peter Gardenfors; Gary Hatfield; Jody Hey; Steven Mithen; April Nowell; Peter Richerson and Robert Boyd; Theodore Schurr; Robert Seyfarth and Dorothy Cheney; Kim Sterelny; and Felix Warneken. ISBN 978-1-934536-49-0

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.