Writing a book about ‘natural classification’ is not a natural thing to do these days. As the authors of The Nature of Classification point out, classification as a stand-alone topic—separated from discussions of hypothesis testing, experimentation and concept formation—was all the rage in mid-nineteenth century philosophy of science, but interest has steadily dwindled ever since. In most twentieth century philosophy of science, classification was treated either as a pre-scientific endeavor, or as a product of (...) theory-driven science. The general attitude is nicely captured in Carl Hempel’s remarks from his 1966 textbook Philosophy of Natural Science:[I]f a particular way of analyzing and classifying empirical findings is to lead to an explanation of the phenomena concerned, then it must be based on hypotheses about how those phenomena are connected; without such hypotheses, analysis and classification are blind .This was about all Hempel had to say about classifica .. (shrink)

This paper addresses a central interpretive problem in understanding Pierre Duhem's philosophy of science. The problem arises because there is textual support for both realist and antirealist readings of his work. I argue that his realist and antirealist claims are different. For Duhem, scientific reasoning leads straight to antirealism. But intuition (reasons of the heart) motivates, without justifying, a kind of realism. I develop this idea to suggest a motivational realist interpretation of Duhem's philosophy.

Peirce was greatly influenced by Aristotle, particularly on the topic of final cause. Commentators are therefore right to draw on Aristotle in the interpretation of Peirce's teleology. But these commentators sometimes fail to distinguish clearly between formal cause and final cause in Aristotle's philosophy. Unless form and end are clearly distinguished, no sense can be made of Peirce's important claim that 'desires create classes.' Understood in the context of his teleology, this claim may be considered Peirce's answer to nominalists and (...) sceptics on the possibility and status of scientific knowledge. On the basis of an improved view of Peirce's teleology, the objection that inorganic physical events do not admit of teleological explanation can be answered. I argue that the non-teleological alternative leaves the laws of nature and the actions of inorganic matter unexplained. (shrink)

We develop conceptions of arguments and of argument types that will, by serving as the basis for developing a natural classification of arguments, benefit work in artificial intelligence. Focusing only on arguments construed as the semantic entities that are the outcome of processes of reasoning, we outline and clarify our view that an argument is a proposition that represents a fact as both conveying some other fact and as doing so wholly. Further, we outline our view that, with (...) respect to arguments that are propositions, (roughly) two arguments are of the same type if and only if they represent the same relation of conveyance and do so in the same way. We then argue for our conceptions of arguments and argument types, and compare them to alternative positions. We also illustrate the need for, and some of the strengths of, our approach to classifying arguments through an examination of aspects of two prominent and recent attempts to classify arguments using argumentation schemes, namely those of M. Kienpointner and D. Walton. Finally, we clarify how our conception of arguments and of argument types can assist in developing an exhaustive classification of arguments. (shrink)

Duhem is commonly held to have founded his view of history of science as continuous on the ‘metaphsical assertion’ of natural classification. With the help of a strict distinction between formal and material characterization of natural classification I try to show that this imputation is problematic, if not simply incorrect. My analysis opens alternative perspectives on Duhem's talk of continuity, the ideal form of theories, and the rôle of ‘bon sens’; moreover it emphasizes some aspects of (...) Duhem's realism that play an important part in his philosophy of science. (shrink)

Duhem's discussion of physical theories as natural classifications is neither antithetical nor incidental to the main thrust of his philosophy of science. Contrary to what is often supposed, Duhem does not argue that theories are better thought of as economically organizing empirical laws than as providing information concerning the nature of the world. What he is primarily concerned with is the character and justification of the scientific method, not the logical status of theoretical entities. The crucial point to notice (...) is that he took the principle of the autonomy of physics to be of paramount importance and he developed the conception of natural classification in opposition to accounts of physical theories that contravened it. (shrink)

Recent interest in the idea that there can be scientific understanding without explanation lends new relevance to Duhem's notion of natural classification. According to Duhem, a classification that is natural teaches us something about nature without being explanatory. However, Duhem's conception of naturalness leaves much to be desired. In this paper, I argue that we can measure the naturalness of classification by using an amended version of the notion of unification as defined by Schurz and (...) Lambert. If this thesis is correct, it both leads to a better conceptual understanding of scientific understanding, and also gives the nascent literature on this topic some much-needed precision. (shrink)

Realism in Duhem's Natural Classification. Pierre Duhem is an outstanding exponent of empiricism. According to the empiricist view scientific laws and theories merely describe formal relations between observable phenomena. Duhems' important notion of natural classification is intended to explain the predictive success of science. I shall argue that it can only be interpreted realistically. Besides the success of science, two further arguments are put forward in favor of realism: the fact that laws of nature are necessary, (...) and the extension of observation by using instruments. (shrink)

In response to Quinn we identify cladistics to be about natural classifications and their discovery and thereby propose to add an eighth cladistic definition to Quinn’s list, namely the systematist who seeks to discover natural classifications, regardless of their affiliation, theoretical or methodological justifications.

To consider Pierre Duhem’s conception of natural classification as the aim of physical theory, along with his instrumentalist view on its nature, sets up an inconsistency in his philosophy of science which has not yet been solved. This paper argues that to solve it we have to take Duhem on his own terms and that a solution can only be found by interpreting his philosophy as an articulated system which necessarily involves the following connections: 1. The association of (...) natural classification to the thesis of historical continuity as an essential condition to the possibility of assigning a goal to the evolution of physical theory, 2. The connection of Pascal’s esprit de finesse to Duhem’s conception of analogy as a heuristic criterion to the conception of hypotheses that are able to lead physical theory to an end that aims to approach the real structure of the world. (shrink)

The notion of 'natural kinds' has been central to contemporary discussions of metaphysics and philosophy of science. Although explicitly articulated by nineteenth-century philosophers like Mill, Whewell and Venn, it has a much older history dating back to Plato and Aristotle. In recent years, essentialism has been the dominant account of natural kinds among philosophers, but the essentialist view has encountered resistance, especially among naturalist metaphysicians and philosophers of science. Informed by detailed examination of classification in the (...) class='Hi'>natural and social sciences, this book argues against essentialism and for a naturalist account of natural kinds. By looking at case studies drawn from diverse scientific disciplines, from fluid mechanics to virology and polymer science to psychiatry, the author argues that natural kinds are nodes in causal networks. On the basis of this account, he maintains that there can be natural kinds in the social sciences as well as the natural sciences. (shrink)

The idea that nature is governed by laws and that the goal of science is to discover and formulate these laws, rose to prominence during the Scientific Revolution of the seventeenth century. It was manifestly held by the most significant actors of that revolution such as Galileo, Descartes, Kepler, Boyle, and Newton. But this idea was not new. In fact, it made an appearance in the Middle Ages, and it is likely to have emerged already in Antiquity.1In this paper we (...) pay close attention to the concept of law of nature in the writings of Roger Bacon, the outspoken Franciscan who promoted experimental science. We will be using Bacon as a test case to show that long before the... (shrink)

This edited volume of 13 new essays aims to turn past discussions of natural kinds on their head. Instead of presenting a metaphysical view of kinds based largely on an unempirical vantage point, it pursues questions of kindedness which take the use of kinds and activities of kinding in practice as significant in the articulation of them as kinds. The book brings philosophical study of current and historical episodes and case studies from various scientific disciplines to bear on (...) class='Hi'>natural kinds as traditionally conceived of within metaphysics. Focusing on these practices reveals the different knowledge-producing activities of kinding and processes involved in natural kind use, generation, and discovery. -/- Specialists in their field, the esteemed group of contributors use diverse empirically responsive approaches to explore the nature of kindhood. This groundbreaking volume presents detailed case studies that exemplify kinding in use. Newly written for this volume, each chapter engages with the activities of kinding across a variety of disciplines. Chapter topics include the nature of kinds, kindhood, kinding, and kind-making in linguistics, chemical classification, neuroscience, gene and protein classification, colour theory in applied mathematics, homology in comparative biology, sex and gender identity theory, memory research, race, extended cognition, symbolic algebra, cartography, and geographic information science. -/- The volume seeks to open up an as-yet unexplored area within the emerging field of philosophy of science in practice, and constitutes a valuable addition to the disciplines of philosophy and history of science, technology, engineering, and mathematics. -/- Contributions from a diverse group of established and junior scholars in the fields of Philosophy and History and Philosophy of Science including Hasok Chang, Jordi Cat, Sally Haslanger, Joyce C. Havstad, Catherine Kendig, Bernhard Nickel, Josipa Petrunic, Samuli Pöyhönen, Thomas A. C. Reydon, Quayshawn Spencer, Jackie Sullivan, Michael Wheeler, and Rasmus Grønfeldt Winther. (shrink)

This paper addresses philosophical issues concerning whether mental disorders are natural kinds and how the DSM should classify mental disorders. I argue that some mental disorders (e.g., schizophrenia, depression) are natural kinds in the sense that they are natural classes constituted by a set of stable biological mechanisms. I subsequently argue that a theoretical and causal approach to classification would provide a superior method for classifying natural kinds than the purely descriptive approach adopted by the (...) DSM since DSM-III. My argument suggests that the DSM should classify natural kinds in order to provide predictively useful (i.e., projectable) diagnostic categories and that a causal approach to classification would provide a more promising method for formulating valid diagnostic categories. (shrink)

Classifications of animals and plants have long been represented by hierarchical lists of taxa, but occasional authors have drawn diagrammatic versions of their classifications in an attempt to better depict the "natural relationships" of their organisms. Ornithologists in 19th-century Britain produced and pioneered many types of classificatory diagrams, and these fall into three groups: (a) the quinarian systems of Vigors and Swainson (1820s and 1830s); (b) the "maps" of Strickland and Wallace (1840s and 1850s); and (c) the evolutionary diagrams (...) of the post-Darwin authors (1860 on). The quinarians distinguished between affinity and analogy and used both in their classifications, whereas Strickland rejected the quinarians' belief in numerical regularity and their use of analogy. Wallace's "maps" are easily given an evolutionary interpretation, and his approach was taken up and modified by later evolutionary anatomists. Sharpe returned to Strickland's methods and merely appended a superficial evolutionary interpretation. Contrary to common belief systematics has a rich conceptual history, and many of the conceptual developments in 19th-century systematics were made by ornithologists. (shrink)

The Nature of Classification discusses an old and generally ignored issue in the philosophy of science: natural classification. It argues for classification to be a sometimes theory-free activity in science, and discusses the existence of scientific domains, theory-dependence of observation, the inferential relations of classification and theory, and the nature of the classificatory activity in general. It focuses on biological classification, but extends the discussion to physics, psychiatry, meteorology and other special sciences.

The notion of natural kinds has been widely criticized in philosophy of science but also appears indispensable for philosophical engagement with classificatory practices. Rather than addressing this tension through a new definition of “natural kind”, this article suggests materiality as a substitute for naturalness in philosophical debates about scientific classification. It is argued that a theory of material kinds provides an alternative and more inclusive entry point for analyzing classificatory practices, which is specified through an account of (...) “restricted malleability” of materiality and further analyzed as (1) gradual, (2) multi-dimensional, (3) scalable, (4) interactive, and (5) purpose sensitive. (shrink)

This article uses the case study of ethnobiological classification to develop a positive and a negative thesis about the state of natural kind debates. On the one hand, I argue that current accounts of natural kinds can be integrated in a multidimensional framework that advances understanding of classificatory practices in ethnobiology. On the other hand, I argue that such a multidimensional framework does not leave any substantial work for the notion “natural kind” and that attempts to (...) formulate a general account of naturalness have become an obstacle to understanding classificatory practices. (shrink)

The article discusses the formal classification of natural sciences, which is based on several propositions: (a) natural sciences can be separated onto independent and dependent sciences based on the gnosiologic criterion and irreducibility criteria (principal and technical); (b) there are four independent sciences which form a hierarchy: physics ← chemistry ← terrestrial biology ← human psychology; (c) every independent science except for physics has already developed or will develop in the future a set of final paradigms formulated (...) in the terms of the science one step above it in the hierarchy; (d) some paradigms in physics will never become final; (e) each independent natural science has dependent sciences with paradigms already expressed in the terms of the respective independent sciences. Existing paradigms of independent natural sciences are listed and discussed with respect to the degree of their approach to the final state. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}. (shrink)

The notion of natural kinds has been widely criticized in philosophy of science but also appears indispensable for philosophical engagement with classificatory practices. Rather than addressing this tension through a new definition of “natural kind”, this article suggests materiality as a substitute for naturalness in philosophical debates about scientific classification. It is argued that a theory of material kinds provides an alternative and more inclusive entry point for analyzing classificatory practices, which is specified through an account of (...) “restricted malleability” of materiality and further analyzed as (1) gradual, (2)multi-dimensional, (3) scalable, (4) interactive, and (5) purpose sensitive. Such 1. (shrink)

Making use of our prescientific understanding of things, as well as relevant scientific theories, this book presents original arguments for monism with respect to the concept of a natural kind, for essentialism with respect to the members of a natural kind, and for natural-kinds realism with respect to a few chemical, physical, and biological kinds.

How do-or how should-we parse the world into kinds of things? Going back at least to Plato, most philosophers have done so with respect to some notion or other of natural kinds. And many analyses of natural kinds have been essentialistic-that is defining those kinds with respect to universals, or some set of intrinsic properties, or necessary and sufficient conditions. And there's a long-standing dispute between thinkers who regard scientific categories as natural kinds with essential properties fixed (...) by nature-those that "cut nature at its joints"-and thinkers who maintain that our classifications and categories have no essence and instead merely reflect human interests and values. A typical example of the former would be "having a mass of 1.7 × 10-27," and examples of the latter would be the categories of "ADHD," "race," or "child abuse." Khalidi aims for an epistemic, naturalistic, non-essentialist, account of natural kinds, one which comfortably embraces not only the usual candidates favored by essentialists (e.g., elementary particles, chemical elements, biological species), but also categories in the social and behavioral sciences. Drawing on cases from many scientific fields, from fluid mechanics and polymer science to virology and psychiatry, Khalidi argues that "natural kinds are investigative or epistemic kinds, in the sense that they are the categories revealed by our systematic attempts to gain knowledge of nature" (p. 43). Moreover, he claims that natural kinds can be "fuzzy" (i.e. have indefinite boundaries), satisfy epistemic virtues to varying degrees, and be mind-dependent in a way that doesn't detract from their reality or objectivity. Although the book is pitched for a sophisticated and philosophically informed audience (and, needless to say, too complex to be adequately summarized in a brief notice such as this), it's clearly written, nuanced, compellingly argued, and worth the effort for JSE readers curious about the unavoidable metaphysical dimensions of doing science of any kind. (shrink)

Classification in eighteenth-century natural history was marked by a battle of systems. The Linnaean approach to classification was severely criticized by those naturalists who aspired to a truly natural system. But how to make oneself nature''s spokesman? In this article I seek to answer that question using the approach of the French anthropologist of science Bruno Latour in a discussion of the work of the French naturalists Buffon and Cuvier in the eighteenth and early nineteenth century. (...) These naturalists followed very different strategies in creating and defending of what they believed to be a natural classification in zoology. Buffon failed, whereas Cuvier''s work appeared to be very successful. My argument will be that, to explain Buffon''s failure and Cuvier''s success, we should not focus on the epistemological or theoretical concerns and justifications of these naturalists, but on the concrete and heterogeneous means or tools through which animals were mobilized, stabilized and combined into ever more comprehensive systems of classification. (shrink)

Names for colours or colour-related properties are ubiquitous among natural languages, and this has made linguistic colour classification a topic of interest: are colour classifications in natural languages language-specific, or is there a more general set of principles by which such classificatory terms are organized? This article focuses on a debate between cultural-linguistic, relativistic approaches, and universalistic approaches in this domain of research. It characterizes the central contemporary debates about colour naming, and the main research strategies currently (...) in use, as well as a novel, hybrid strategy. (shrink)

The more one reads about the topic of natural kinds, the more one is reminded of that famous scene in The Hitchhiker’s Guide to the Galaxy in which Deep Thought—after a mere 7.5 million years of doing calculations—reveals that the answer to the Ultimate Question of Life, the Universe and Everything was 42. Faced with bewildered reactions from the eager audience, Deep Thought explains: “I think the problem, to be quite honest with you, is that you’ve never actually known (...) what the question is” .In the case of the growing literature on natural kinds, it is easy to get a feeling that something similar is going on. While philosophers keep advancing novel accounts of natural kinds, at the same time there is considerable disagreement about what exactly the problem is that such accounts should solve. To some, natural kinds are real kinds in nature that exist in the world independently of human interests and practices. At the very least, they are human-made kinds that correspon .. (shrink)

This book argues that it is again appropriate to bring "the human" to the fore, to reclaim the singularity of the word as central to the anthropological ...

Nobody wants unnatural kinds. Just as we prefer all natural ingredients in our food, so also we prefer natural kinds in our ontology and epistemology. Philosophers contrast natural with merely “conventional” kinds, and scientists advocate for natural rather than artificial classification systems. A central plank of the desired naturalness is “mind independence”—the property of existing independent of human interests and desires. Natural kinds are discovered, not made. They reflect the structure of the world (“nature’s (...) joints”) and for this reason justify the practice of inductive inference. Conventional kinds, by contrast, are dependent on human classificatory activities. They are created with an end in view and therefore lack “a real existence in nature” (J. S. Mill, A System of Logic, Ratiocinative and Inductive [London: Longmans, 1843], 1:165). Since their existence is dependent on human activities, nominal kinds need not track nature’s joints. Because scientists are interested in groupings that really exist in nature—not those fabricated for human purposes—their classificatory practices aim to achieve natural-kind classifications. Achieving these classifications is crucial to the success of science. (shrink)

This paper analyses the place of natural history within Bacon's divisions of the sciences in The Advancement of Learning and the later De dignitate et augmentis scientiarum. It is shown that at various points in Bacon's divisions, natural history converges or overlaps with natural philosophy, and that, for Bacon, natural history and natural philosophy are not discrete disciplines. Furthermore, it is argued that Bacon's distinction between operative and speculative natural philosophy and the place of (...) natural history within this distinction, are discontinuous with the later distinction between experimental and speculative philosophy that emerged in the methodology of the Fellows of the early Royal Society. (shrink)

The value in Hartmann’s point of view can be watched from the perspective of some heteronymous plans - an ideal one, which would be “the modality of existence”, and a real one, which would be “the modality of knowing” the value. In Hartmann’s expression we deal with “the absolute character” 1 of values and “the apriority of knowing the values”. It’s interfering here the problem of the validity of values. The question is if the existence of values is reduced to (...) their validity, or if they exist without the dependence of the real states of the world. This validity, for Hartmann, is strictly referring to the second plan, the real one, which is dealing with values. The values are valid “for” – we have here the connection with the existing- but they have their own “world” beside this nip with reality that we call unbiased 2 . The validity of value is aprioristic, no matter the appreciation - like one “pure subjective”, arbitrary - the apriority of value is not depending of some constrain and converge at the level of the logical schemes of thinking. In the general conception of Hartmann’s philosophy the problem of value is diminishing in the analysis of the distinction between the theory of knowledge plan, which is aiming at the subject-object domain, and the ontological one, represented by the relation objective - trans-objective. Although the philosophical analysis will be done from the perspective of the theory of knowledge domain of the relation subject-object, the problem that will concern mostly Hartman will be the objective - trans-objective report seen from the angle of one “critic ontology”, trying to solve the problem of the report between general and specific in the way of being of the axiological structure. (shrink)

Um bei einer Wertung der Faktoren, die das Wachstum einer Population beeinflussen, zu einer richtigen Einsicht zu gelangen, empfiehlt es sich, nicht den relativen Wert dieser Faktoren in Bezug auf die in Rede stehende Insektenpopulation auszudrücken, sondern ihre absolute Grösse in Faktoreinheiten zum Ausdruck zu bringen — wie: Wärme in Grad Celsius, Luftfeuchtigkeit in Prozenten, Zahl der im Bevölkerungsmilieu vorgefundenen Raubinsekten oder Parasiten. Auf dieser Grundlage liessen sich Faktoren in folgender Weise aufteilen: Faktoren ersten Grades : Allgemeine Faktoren : Unabhängige (...) Faktoren : nicht mechanische Klimaeinflüsse , chemische Faktoren, Güte der Nahrung. Abhängige Faktoren : die internen Faktoren, die bei einer Zunahme der Dichtigkeit einen Rückgang des Zuwachses bewirken, mit Ausnahme des Kannibalismus, ferner die Menge der Nahrung. Selektive Faktoren : Unabhängige Faktoren : unersättliche Faktoren : mechanische Klimaeinflüsse, weitere mechanische Faktoren, Parasiten und Raubfeinde, die nicht mit töten aufhören, wenn sie gesättigt sind, insofern ihre Bevölkerungsdichte nicht durch die des fraglichen Insektes bedingt wird. ersättliche Faktoren: restliche Raubinsekten und Parasiten, insofern ihre Bevölkerungsdichte nicht durch die des fraglichen Insektes bedingt wird. Abhängige Faktoren : Kannibalismus. Wandelbare Faktoren : Raubinsekten und Parasiten, welche diesem Erfordernis entsprechen, pathogene Pilze und Bakterien. Faktoren zweiten Ranges . Faktoren des dritten Ranges .Afin d'obtenir une notion exacte de la valeur des facteurs qui influencent la croissance d'une population, il vaudra mieux ne pas exprimer ces facteurs en leur valeur relative quant à la population d'insectes en question, mais en unités de facteurs: degrés Celsius, pourcentage de l'humidité de l'air, nombre d'ennemis ou de parasites qui sont présents dans le milieu de la population. Sur cette base on pourra répartir les facteurs de la façon suivante: Facteurs du 1er ordre : Facteurs généraux : influences climatiques non mécaniques , facteurs chimiques, qualité de la nourriture. Facteurs dépendants : les facteurs internes qui font de sorte que la densité de la population diminue quand se présente une plus forte densité, en exceptant le cannibalisme, la quantité de nourriture. Facteurs selectifs ; seule une partie des individus est exposée à leur action; les animaux touchés sont mécaniquement endommagés et, dans la règle, tués. Facteurs indépendants : facteurs insatiables : des influences climatiques mécaniques, d'autres facteurs mécaniques, des parasites et des ennemis qui ne s'arrêtent pas de tuer quand ils sont rassasiés, pour autant que l'intensité de la population de l'insecte en question. facteurs rassasiables: autres ennemis et parasites pour autant que l'intensité de leur population ne se modifie pas sous l'influence de la densité de la population de l'insecte en question. Facteurs indépendants : cannibalisme. Facteurs modifiables : ennemis et parasites qui satisfont à cette exigence, champignons pathogènes, bactéries. Facteurs du 2ième ordre . Facteurs du 3iéme ordre. (shrink)

In the introduction to his famous book, La Science et l’hypothèse, Poincaré remarks on the necessary role and legitimacy of hypotheses. He establishes a triple classification of hypotheses, dividing them into verifiable, useful, and apparent. However, in chapter 9, entitled ‘Les hypothèses en physique’, he gives a slightly different triadic classification: natural hypotheses, indifferent hypotheses, and real generalizations. The origin of this second classification is a lecture given at the International Congress of Physics, Paris, 1900. What (...) are the similarities and differences between these two classifications? My main purpose is to provide a possible equivalence between the two classifications in order to clarify the role of hypotheses in Poincaré’s epistemology of natural science. The discussion will be based on the two fundamental texts mentioned above and on the contrast between Poincaré’s use of the notion of hypothesis and that of some of his contemporaries. (shrink)

The notion of 'natural kinds' has been central to contemporary discussions of metaphysics and philosophy of science. In recent years, essentialism has been the dominant account of natural kinds among philosophers, but the essentialist view has encountered resistance. Informed by detailed examination of classification in the natural and social sciences, Prof. Muhammad Ali Khalidi argues against essentialism and for a naturalist account of natural kinds. By looking at case studies drawn from diverse scientific disciplines, from (...) fluid mechanics to virology and polymer science to psychiatry, the author argues that natural kinds are nodes in causal networks. On the basis of this account, he maintains that there can be natural kinds in the social sciences as well as the natural sciences. (shrink)

Both lay people and scientists organize the world around them by categorizing particular things as belonging to kinds. Scientists speak and theorize about various kinds of things, like hydrogen, gold, and water; electron and neutron; Canis lupus and Felis catus; igneous rock, sedimentary rock, and metamorphic rock; schizophrenia, psychopathy, and autism; Caucasian, African, and Amerindian. Given this variety of scientific kind categories, one fundamental question for philosophers of science is whether any of these kinds really are natural kinds, and (...) if so, what it is that constitutes their naturalness.nbsp;is to say, when we classify particular things as belonging to the same kind, is it ever the case that they really or naturally belong to the same kind? Do we ever carve the world at its joints, so to speak? Or, are there rather just many different ways in which we, humans, decide to classify particulars into kinds, each possible classification as conventional as any other? In this dissertation, a realist account of natural kinds is defended, according to which some kind classifications are more natural than others. It is argued that the naturalness of scientific kinds can be accounted for by the Causal Unification Theory. According to this view, the naturalness of a kind category lies in the contribution this category makes to our epistemic practices, as a result of accommodating these practices to a causally unified group of properties. Because the properties of natural kind-members are causally unified, they ground multiple causally sustained generalizations. Thus, natural kinds are the metaphysical grounds of systematic scientific research by allowing for multiple inductive generalizations and predictions, and for unified explanations. This view is developed in response to the historically most important theories about natural kinds and several more recent ones. The Causal Unification Theory of natural kinds is then put to work to elucidate the naturalness of two controversial humannbsp;classifications, namely the biological classification of human races and the social psychological classification of homophobes. The current metaphysical race debate is criticized for being too dependent on broad philosophical issues, and it is shown that asking about the naturalness of races, rather than about their existence, allows for a more nuanced debate that is to a larger extent dependent on empirical results. The example of homophobia is discussed in relation to the worry that the normative dimension of many human kinds diminishes the extent to which they can be considered natural kinds. It is argued that we should not be too pessimistic, but that there is indeed reason for concern. To illustrate this, a case is made that the measurement of homophobia is inflated as a result of the normative dimension of this kind. (shrink)

In 1934 Jaśkowski and Gentzen independently published their groundbreaking works on Natural Deduction. The aim of this paper is to provide some criteria for division of the diversity of existing systems on some natural subcategories and to show that despite the differences all these systems are descendants of original systems of Jaśkowski and Gentzen. Three criteria are discussed:The kind of items which are building-blocks of the proof.The format of proof.The kind of rules.The first leads to the division of (...) ND into two main classes: F-systems working on formulas and S-systems working on sequents. The second distinguishes between T-systems with tree-proofs and L-systems with linear proofs. Finally, the third leads to several minor divisions in the main categories. (shrink)