Introduction: Neuropsychiatry has generally been regarded as a hybrid discipline that lies in the borderland between the disciplines of psychiatry and neurology. There is much debate on its current and future identity and status as a discipline. Materials and Methods: Taking a historical perspective, the future of neuropsychiatry is placed within the context of recent developments in clinical neuroscience. Results: The authors argue that with the maturation of the discipline, it must define its own identity that is not dependent entirely (...) upon the parent disciplines. The requirements for this are the claiming of neuropsychiatric territory, a strong training agenda, an emphasis on treatments that are uniquely neuropsychiatric, and a bold embrace of new developments in clinical neuroscience. Conclusion: The exponential growth in neuroscientific knowledge places neuropsychiatry in an excellent position to carve out a strong identity. It is imperative that the leaders of the discipline seize the moment. (shrink)

Seeing, Doing, and Knowing is an original and comprehensive philosophical treatment of sense perception as it is currently investigated by cognitive neuroscientists. Its central theme is the task-oriented specialization of sensory systems across the biological domain. Sensory systems are automatic sorting machines; they engage in a process of classification. Human vision sorts and orders external objects in terms of a specialized, proprietary scheme of categories - colours, shapes, speeds and directions of movement, etc. This 'Sensory Classification Thesis' implies that sensation (...) is not a naturally caused image from which an organism must infer the state of the world beyond; it is more like an internal communication, a signal concerning the state of the world issued by a sensory system, in accordance with internal conventions, for the use of an organism's other systems. This is why sensory states are both easily understood and persuasive.Sensory classification schemes are purpose-built to serve the knowledge-gathering and pragmatic needs of particular types of organisms. They are specialized: a bee or a bird does not see exactly what a human does. The Sensory Classification Thesis helps clarify this specialization in perceptual content and supports a new form of realism about the deliverances of sensation: 'Pluralistic Realism' is based on the idea that sensory systems coevolve with an organism's other systems; they are not simply moulded to the external world. The last part of the book deals with reference in vision. Cognitive scientists now believe that vision guides the limbs by means of a subsystem that links up with the objects of physical manipulation in ways that bypass sensory categories. In a novel extension of this theory, Matthen argues that 'motion-guiding vision' is integrated with sensory classification in conscious vision. This accounts for the quasi-demonstrative form of visual states: 'This particular object is red', and so on. He uses this idea to cast new light on the nature of perceptual objects, pictorial representation, and the visual representation of space. (shrink)

How many senses do humans possess? Five external senses, as most cultures have it—sight, hearing, touch, smell, and taste? Should proprioception, kinaesthesia, thirst, and pain be included, under the rubric bodily sense? What about the perception of time and the sense of number? Such questions reduce to two. 1. How do we distinguish a sense from other sorts of information-receiving faculties? 2. By what principle do we distinguish the senses? Aristotle discussed these questions in the De Anima. H. P. Grice (...) revived them in 1967. More recently, they have taken on fresh interest as a result of a collection of essays edited by Fiona Macpherson. This entry reviews some approaches to these questions and advances some new ideas for the reader’s consideration. It proposes that the senses constitute an integrated learning system, membership in which answers question 1. It also proposes that the modalities can be distinguished from one another in two ways, by the means of information pick-up and by the kinds of activity that a perceiver undertakes to make use of them. (shrink)

The sense of touch provides us knowledge of two kinds of events. Tactile sensation (T) makes us aware of events on or just below the skin; haptic perception (H) gives us knowledge of things outside the body with which we are in contact. This paper argues that T and H are distinct experiences, and not (as some have argued) different aspects of the same touch-experience. In other words, T ≠ H. Moreover, H does not supervene on T. Secondly: In T, (...) we are aware of immanent, phenomenal qualities; in H, we come to know of transcendent qualities in things that exist independently of ourselves. Finally: T is non-spatial; it is indexed by parts of the body, but not by position in space. H, by contrast, is spatial. This brings to mind Kant’s contention that things are presented as existing objectively when they are represented spatially. (shrink)

Molyneux's Question (MQ) concerns whether a newly sighted man would recognize/distinguish a sphere and a cube by vision, assuming he could previously do this by touch. We argue that (MQ) splits into questions about (a) shared representations of space in different perceptual systems, and about (b) shared ways of constructing higher dimensional spatiotemporal features from information about lower dimensional ones, most of the technical difficulty centring on (b). So understood, MQ resists any monolithic answer: everything depends on the constraints faced (...) by particular perceptual systems in extracting features of higher dimensionality from those of lower. Each individual question of this type is empirical and must be investigated separately. We present several variations on MQ based on different levels of dimensional integration—some of these are familiar, some novel adaptations of problems known elsewhere, and some completely novel. Organizing these cases in this way is useful because it unifies a set of disparate questions about intermodal transfer that have held philosophical and psychological interest, suggests a new range of questions of the same type, sheds light on similarities and differences between members of the family, and allows us to formulate a much-augmented set of principles and questions concerning the intermodal transfer of spatiotemporal organization. (shrink)

The senses present their content in the form of images, three-dimensional arrays of located sense features. Peacocke’s “scenario content” is one attempt to capture image content; here, a richer notion is presented, sensory images include located objects and features predicated of them. It is argued that our grasp of the meaning of these images implies that they have propositional content. Two problems concerning image content are explored. The first is that even on an enriched conception, image content has certain expressive (...) limitations. In particular, it cannot express absolute location and time (as opposed to spatiotemporal relations) or logical complexity. Yet, perceptual experience does seem to express certain absolute locations—namely, here and now. How can it do so? Secondly, image content cannot exhaust the significance of perceptual states. This is proved by noting that perception, memory, and anticipation can have the same image content. Yet they have different significance. These problems show that some of the significance of sensory states comes from outside the image. (shrink)

The authors attempt to show that certain forms of behavior of the human immune system are illuminatingly regarded as errors in that system's operation. Since error-ascription can occur only within the context of an intentional/teleological characterization of the system, it follows that such a characterization is illuminating. It is argued that error-ascription is objective, non-anthropomorphic, irreducible to any purely causal form of explanation of the same behavior, and further that it is wrong to regard all errors of the immune system (...) as due to malfunction or maladaptation. <br>. (shrink)

The paper argues that material objects are the primary referents of visual states -- not places, as Austen Clark would have it in his A Theory of Sentience.

An artwork in one culture and form, say European classical music, cannot be evaluated in the context of another, say Hindustani music. While a person educated in the traditions of European music can rationally evaluate and discuss her response to a string quartet by Beethoven, her response to music in a foreign culture is merely subjective. She might "like" the latter, but her response is merely subjective. In this paper, I discuss the role of artforms: why response can be "objectively" (...) discussed within artforms, but is nonetheless subjective across them. My discussion falls into two parts. First, I offer a psychological account of aesthetic response to art: cultural learning stabilizes this response across individuals who are educated in an artform. Second, I offer a cultural-evolutionary account of the diversity of artforms, adapting Darwin's Principle of the Divergence of Character to explain the multiplicity of art forms. (shrink)

Sound like a philosopher’s controversy? I think so. In ‘Evolution,’ I argued that Anti-Individualism was committed to a ‘highly metaphysical’ proposition at odds with the methodology of population genetics. This infelicity gave me reason for rejecting it. In his recent article, Pust takes issue with Neander and me. Until Pust wrote, Sober felt some small pressure from Individualism, and had shifted, albeit microscopically, toward it—he thought that on a very broad conception of causation, there might be some reason to think (...) that selection explains individual traits. He is now convinced that he was right all along. So we are back where we were a few years ago, though with new arguments on each side. Such is the nature of progress in philosophy. The purpose of this paper is to offer some refinements of Individualism. (shrink)

In this short paper, I outline four philosophical arguments concerning the objects we perceive. These arguments build up to the conclusion that the objects of perceptual experience are material objects. I then show that the first three of these arguments parallel important psychological positions in vision science. Thus, (1) the notion of object used in Logical Atomism resembles the concept as it is defined in the Feature Integration Theory of Treisman and Gelade (1980). But (2) Frank Jackson's (1975) Many-Property Problem (...) leads to a substrate-quality structure for visual experience that corresponds to the structure of attended experience in Feature Integration Theory. A third philosophical argument (3) concerns the perception of movement. This argument culminates in the proposition that perceptual features are seen as belonging to material objects. There is a close resemblance between these objects and those of Zenon Pylyshyn's (1980) FINSTs. Finally, (4) I argue that material objects are the only substrates of multimodal perceptual experience. Perceptual psychology has yet to investigate this structure. (shrink)

In this essay, I’ll argue, first, that an art object's aesthetic value (or merit) depends not just on its intrinsic properties, but on the response it evokes from a consumer who shares the producer's cultural background. My question is: what is the role of culture in relation to this response? I offer a new account of aesthetic pleasure that answers this question. On this account, aesthetic pleasure is not just a “feeling” or “sensation” that results from engaging with a work (...) of art. It is rather a mental state that facilitates engagement with an artwork, and (in the long run) enables a consumer to learn how to maximize this kind of pleasure. This is where culture comes in. If you belong to a culture, you know how to engage pleasurably with an artwork that is produced so you can engage with it in just this way. The aesthetic value of an artwork is that it plays into such a culture-pleasure nexus. -/- . (shrink)

Argues that Aristotle regarded the universe, or Totality, as a single substance with form and matter, and that he regarded this substance together with the Prime Mover as a self-mover.

Vision is organized around material objects; they are most of what we see. But we also see beams of light, depictions, shadows, reflections, etc. These things look like material objects in many ways, but it is still visually obvious that they are not material objects. This chapter articulates some principles that allow us to understand how we see these ‘ephemera’. H.P. Grice’s definition of seeing is standard in many discussions; here I clarify and augment it with a criterion drawn from (...) Fred Dretske. This enables me to re-analyse certain ephemera that have received counter-intuitive treatments in the work of Kendall Walton (photographs), Brian O’Shaughnessy (light), and Roy Sorenson (occlusions). (shrink)

Throughout this research, imposing the training of an Artificial Neural Network (ANN) to play tic-tac-toe bored game, by training the ANN to play the tic-tac-toe logic using the set of mathematical combination of the sequences that could be played by the system and using both the Gradient Descent Algorithm explicitly and the Elimination theory rules implicitly. And so on the system should be able to produce imunate amalgamations to solve every state within the game course to make better of results (...) of winnings or getting draw. (shrink)

Aristotle held that perception consists in the reception of external sensory qualities (or sensible forms) in the sensorium. This idea is repeated in many forms in contemporary philosophy, including, with regard to vision, in the idea (still not firmly rejected) that the retinal image consists of points of colour. In fact, this is false. Colour is a quality that is constructed by the visual system, and though it is possible to be a realist about colour, it is completely misleading to (...) think of it as received by the retina. Moreover, such supposedly “charitable” interpretations of Aristotle’s doctrines, based on miscon- ceptions of perception-science, distort our understanding of his historical context. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Omissions and Chronological ComplexitiesJyoti Mohan (bio)The stated purpose of Chinese and Indian Ways of Thinking in Early Modern European Philosophy: The Reception and the Exclusion by Selusi Ambrogio is "to examine the European understanding of China and India within the histories of philosophy from 1600 to 1744."1 Specifically, Ambrogio sets out to investigate the antecedents of the "othering" of non-Western philosophies. How far back did the notion go, (...) that non-Western philosophies were inferior? While Ambrogio often extends his argument to non-Western philosophies in general, in this monograph he examines only what he defines as "orientalist" philosophies—the philosophies of India and China. Since Ambrogio is investigating the histories of philosophy written in Europe, this choice makes sense: India and China were the two philosophical giants that most European philosophers needed to include in their works in order to claim to be universalist. No philosopher who wrote about world philosophies—and by extension no historian of philosophy—could ignore India and China, whether it was to dismiss the philosophies emanating from these geographic regions as inferior, or to extol them as proof that Europe was not the birthplace of "original thought."Ambrogio has chosen a time span from 1600 to 1744 c.e. to represent "the year 1600 … [,] the publication of Barbaricae philosophae antiquitatum by Otto van Heurn[,] and 1744[,] the year of the publication of the last book of the Historia critica by Jakob Brucker."2 Within the limits of this time [End Page 220] span, Ambrogio examines the work of several scholars who included Indian and Chinese philosophies in their "world histories of philosophies" and delineates three major historiographical trends. His rationale for ending his study with Brucker's work is that after this eighteenth-century opus, "Asians were usually excluded from the histories of philosophy."3 This time span seems puzzling to me. I know that most, if not all, of the authors Ambrogio cites had successors in their individual traditions well into the nineteenth century, if not the twentieth. While many histories of philosophy focused solely on the Western and classical traditions (as they did during the period under review by Ambrogio as well), the work of historians and scholars on Orientalist philosophies continued to multiply. To the extent that Ambrogio diligently studies his sources and constructs his argument, his work is commendable, but as a historian my questions for Ambrogio have to do with the underlying rationale for the time span he has chosen, and, by that extension, by the choices of his sources. Below I collect evidence that Asians continue to be included in the histories of philosophy past 1744, and in so doing suggest that this fact has an impact on his historiographical model.For instance, I would like to understand why, in his choice of sources, he has omitted all colonial works, especially since he engages with the argument that descriptions and understandings of Indian and Chinese philosophies were meditated through lenses of proselytization and of conquest. Granted, he is beginning with historians of philosophy, but as the eighteenth and nineteenth centuries progressed, historians also diversified their writings—as Ambrogio acknowledges—into histories of religion for instance. The connections between, and descriptions of, non-Western religions and philosophies were so muddled that it is impossible to separate them, save by attending to the titles of individual authors' works as being about religion or philosophy, respectively.The contents of such works are so closely related, at least in the Indian context, that contemporary historians, especially of the colonial period and of Indology, do not quibble over whether these works are about religion or philosophy. For instance, Paul Masson-Oursel wrote in 1923 that the development of Indian philosophy was integral to and proceeded alongside the development of religion.4 Systems of philosophical thought in India operated within larger systems of religious practice. Based on this model, Masson-Oursel describes the development of Indian philosophy as proceeding from the needs of religion. So, for example, he theorized that the mix of an Indo-Iranian religion and a pastoral, fire-worshipping people with an older indigenous Dravidian culture of agriculture, Goddess worship, and belief in amulets, spells, talismans, and other... (shrink)

How, and why, does Earth (the element) move to the centre of Aristotle's Universe? In this paper, I argue that we cannot understand why it does so by reference merely to the nature of Earth, or the attractive force of the Centre. Rather, we have to understand the role that Earth plays in the cosmic order. Thus, in Aristotle, the behaviour of the elements is explained as one explains the function of organisms in a living organism.

Molyneux addressed his question to Locke in two forms. The question that is most often discussed in the literature is the 1693 version–about whether a newly sighted man could distinguish a globe and a cube when they are presented to his sight alone. But in 1688, he asked whether this man could know which was the globe. While Locke and Molyneux probably thought this an unnecessary add-on, we argue that it changes the question. Locke had no account of how one (...) could know a contingent singular fact by sight or by vision. We argue that we know in these ways by using a process of active sensory exploration that employs the modality in question. A new form of Molyneux’s question emerges from this understanding of perceptual knowledge. While the variety of sensory exploration methods within and across modalities raises considerable difficulties for a positive answer, the original question, like the later version, can ultimately be answered only by empirical investigation. (shrink)

In this Handbook entry, I review how colour similarity spaces are constructed, first for physical sources of colour and secondly for colour as it is perceptually experienced. The unique hues are features of one of the latter constructions, due initially to Hering and formalized in the Swedish Natural Colour System. I review the evidence for a physiological basis for the unique hues. Finally, I argue that Tye's realist approach to the unique hues is a mistake.

Denis Dutton died a day or two after Christmas in 2010. I had the good fortune to meet him in February 2010, when I participated in an Author-Meets-Critics session on The Art Instinct at the American Philosophical Association, Central Division. (The Critical Notice that follows is a development of my comments there.) Dennis was a passionate, intelligent, influential, and well connected man, who had a vigorous philosophical mind, fully on display in The Art Instinct. Outside of academic philosophy, he was (...) famous as founder of the Arts and Letters Daily, the pre-eminent content-aggregating blog for intellectuals. It is in that capacity that he was obituarised in many of the world’s leading English-language .. (shrink)

This is a comment on Frances Egan's paper, "How to Think About Mental Content." Egan distinguishes mathematical and cognitive content; she accepts the former and rejects the latter. In this comment, which was delivered at the Oberlin Colloquium in 2012, I defend cognitive content.

This chapter contains sections titled: Artifacts and the Four Causes Goals vs. Functions The Argument from Non‐Coincidence Craft, Form, and Spontaneity Non‐bodily Causes Global Teleology Note Bibliography.

It is argued that according to Aristotle the universe is a single substance with its own form and matter.

Gandhi’s notion of passive-resistance is critical in two ways and defines swaraj and swadeshi, leading to his assertion that India alone is the land of redemption for the world afflicted with modern civilization, “the sheet-anchor of our hope”. “Sound at the foundation”, “India remains as it was before”, while the world speeds on, “usurp[ing] the function of Godhead” and indulg[ing] in novel experiments”. This paper aims at elaborating Gandhi’s definition of nature in terms of the scalar, speed, as found in (...) Hind Swaraj and other writings in order to demonstrate that India as hind swaraj is critical nation. (shrink)

This book offers an original intersection of concepts from Immanuel Kant’s moral command ethics and Søren Kierkegaard’s existential ethics. The Kantian formulation of moral law is based on theoretical ground while Kierkegaardian ethics of the quest for selfhood views it as the very act of living. The present work provides an account of both these perspectives and questions whether these approaches to morality are mutually exclusionary. Using Slavoj Žižek’s ‘parallax view’ in the realm of morality, it argues that moral philosophy (...) must engage with a constant critique of ‘difference’ around which the transformation of our various perspectives to morality revolves. This work appeals for furtherance of the conversation model and participation of perspectives to transcend ‘positional confinement’. It advocates the traversing of the ethical parallax to allow for intellectual openness and an empathetic perception of the ‘other’. (shrink)

Byrne & Hilbert are right that it might be an objective fact that a particular tomato is unique red, but wrong that it cannot simultaneously be yellowish-red (not only objectively, but from somebody else's point of view). Sensory categorization varies among organisms, slightly among conspecifics, and sharply across taxa. There is no question of truth or falsity concerning choice of categories, only of utility and disutility. The appropriate framework for color categories is Nominalism and Pluralistic Realism.

A brief comment on Mark Bedau's critique of naturalist theories of teleology. A positive account is offered in "Teleology and the Product Analogy".

Are color categories the evolutionary product of their usefulness in communication, or is this an accidental benefit they give us? It is argued here that embodiment constraints on color categorization suggest that communication is an add-on at best. Thus, the Steels & Belpaeme (S&B) model may be important in explaining coordination, but only at the margin. Furthermore, the concentration on discrimination is questionable: coclassification is at least as important.

A main point of my article, as I see it, is that we can solve Putnam's problem, as articulated in the first paragraph of section three, without recourse to the definition of “natural-kind term” as “rigid designator of a natural kind”. I had three main objections to this definition: It makes the classification of a term as a natural-kind term dependent on one's metaphysics, i.e., on the status given to natural kinds. However, Putnam's argument seems to be independent of such (...) metaphysical considerations, and the sort of natural kinds it establishes should be “read off its face”, not set down in advance. It permits the derivation of “exotic necessary truths” such as “If water is H20 then necessarily water is H20”. Putnam's main point appears to be about the independence of a term's extension from a linguistic community's beliefs. Why should this point affect the theory of designation? Kripke's argument about names establishes the non-descriptiveness of names while leaving undisturbed the classical conception of names designating individuals. Why should we not take his and Putnam's parallel arguments as establishing the non-descriptiveness of natural-kind terms while leaving undisturbed the classical conception of general terms designating classes? (shrink)

A review of Paul Thompson's semantic interpretation of evolutionary theory.

John Campbell argues that visual attention to objects is the means by which we can refer to objects, and that this is so because conscious visual attention enables us to retrieve information about a location. It is argued here that while Campbell is right to think that we visually attend to objects, he does not give us sufficient ground for thinking that consciousness is involved, and is wrong to assign an intermediary role to location. Campbell’s view on sortals is also (...) queried, as is his espousal of the so-called Referential View of Experience. (shrink)

Mazviita Chirimuuta proposes a new “adverbialist” ontology of color. I argue that ontological disputes in the philosophy of color are uniformly terminological. Chirimuuta's proposal too is a terminological variant on others, though it has some hortatory value in directing attention to aspects of color science that have hitherto been neglected. On a side note, I also take issue with Chirimuuta's laudatory take on early modern theories of color.

In this paper I shall examine Aristotle's treatment of a certain puzzle concerning change. In section I, I shall show that within a certain standard framework for the semantics of subject-predicate sentences a number of things that Aristotle wants to maintain do not make sense. Then, I shall outline a somewhat non-standard account of the semantics for such sentences — arguably Aristotle's — and show how the proposals concerning change fit quite naturally into this framework. The results of this exercise (...) will enable us to say something quite precise about applications of some obscure but characteristically Aristotelian doctrines: that ‘is’ is ‘said in many ways,’ that his predecessors got the Law of Opposites wrong. They also shed some light upon Aristotle's ontology of predicables. (shrink)

In this paper, I examine Aristotle's notion of potentiality as it applies to the beginning of life. Aristotle’s notion of natural kinēsis implies that we should not treat the entity at the beginning of embryonic development as human, or indeed as the same as the one that is born. This leads us to ask: When does the embryo turn into a human? Aristotle’s own answer to this question is very harsh. Bracketing the views that lead to this harsh answer, his (...) theory of kinēsis still gives us reason for searching for a replacement answer. Aristotle’s own work unfortunately gives us no help in finding this answer. (shrink)

Christopher Gauker argues that no concept can be extracted from perceptual experience and that imagistic thought cannot draw boundaries between one kind and another. Here, it is argued, on the contrary, that images have extension and are consequently Fregean concepts. Hume’s theory of abstraction as indifference is offered as an account of extra-sensory concepts. Finally, it is argued that modern theories of sensory data processing run parallel to Kant’s idea of synthesis as a pre-condition for perception.

The standard interpretation of "Theaetetus" 152-160 has Plato attribute to Protagoras a relativistic theory of truth and existence. It is argued here that in fact the individuals of Protagorean worlds are inter-Personal. (thus the Protagorean theory has public objects, but private truth). Also, a new interpretation is offered of Plato's use of heraclitean flux to model relativism. The philosophical and semantic consequences of the interpretation are explored.

The author attempts here to sketch the beginnings of an adequate interpretation of Plato's treatment of the tall and the equal in the "Phaedo". The paper consists of seven sections (roman numerals). In I-II, he (a) argues that any attempt to solve the puzzle stated at "Phaedo" 102 bc within the parameters there set down would "eo ipso" be an attempted theory of relational statements; (b) formulates that puzzle; and (c) shows that Frege solved it by denying its presuppositions. In (...) IV the author proposes an interpretation of Plato's solution: that the "than y" in "x is taller than y" modifies the "is." In V-VI he shows how this theory fits in with and sheds light on other aspects of the theory of forms: the connection to Non-Contradiction, The doctrines of degrees of reality and of immanent characters. Finally in VII he shows that the puzzle of relational statements as formulated in the "Phaedo" need not extend to "equal." the paper also includes (iii) a discussion of H-N Castañeda's interpretation of Plato's theory. (shrink)

This chapter contains section titles: Introduction: Russell's Natural Kinds Is Biological Homeostasis Historical? Intrinsic Properties Redux Population Structure Conclusion: Are Species Duplicable?

Much recent work on Aristotle's Categories assumes that there is an ontological theory presented in that work and tries to reconstruct it on the basis of the slender evidence in the book. I claim that this is misguided. Using a distinction made by G.E.L. Owen between theory and the "phaenomena", I argue that the Categories is mainly concerned with setting out the phenomena -- the intuitions that any ontology must explain. This thesis has consequences for the interpretation of Aristotle's ontological (...) writings. I explore some of these. (shrink)

In Aristotle's cosmology, the nature of the elements is defined by their place in the Totality. Their cosmic motions keep the whole in motion, and this is their nature. Thus, the cosmos is an organized whole, a single substance directed to the good; this body constitutes together with its Prime Mover a composite substance that can be regarded as a self-mover.

In this review of Hutto and Myin's Radicalizing Enactivism, I question the adequacy of a non-representational theory of mind. I argue first that such a theory cannot differentiate cognition from other bodily engagements such as wrestling with an opponent. Second, I question whether the simple robots constructed by Rodney Brooks are adequate as models of multimodal organisms. Last, I argue that Hutto and Myin pay very little attention to how semantically interacting representations are needed to give an account of choice (...) and action. (shrink)

Homeostatic Property Cluster (HPC) theory suggests that species and other biological taxa consist of organisms that share certain similarities. HPC theory acknowledges the existence of Darwinian variation within biological taxa. The claim is that “homeostatic mechanisms” acting on the members of such taxa nonetheless ensure a significant cluster of similarities. The HPC theorist’s focus on individual similarities is inadequate to account for stable polymorphism within taxa, and fails properly to capture their historical nature. A better approach is to treat distributions (...) of traits in species populations as irreducible facts, explained in terms of selection pressures, genealogy, and other evolutionary factors. We call this view Population Structure Theory (PST). PST accommodates the view, implicit in biological systematics, that species are identified by reference to particular historical populations. (shrink)