Some scientific categories seem to correspond to genuine features of the world and are indispensable for successful science in some domain; in short, they are natural kinds. This book gives a general account of what it is to be a natural kind and puts the account to work illuminating numerous specific examples.

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)

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 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 chapter discusses the distinction between natural kinds and natural properties. Some theorists deny the distinction, and claim that natural kinds can be identified with properties. For example, natural kinds might be understood as the perfectly natural properties, reducible to properties or the extensions of properties. Alternatively, one might argue that natural kinds and natural properties are distinct and that natural kinds could be considered as a sui (...) generis type of entity. For example, one might hold that natural kinds require a distinct kind of universal, substantival universal, or sortal. Alternatively, one might claim that properties themselves form natural kind groupings, in virtue of causal mechanisms. This chapter argues that classification into natural kinds can reflect real differences between natural groups, without the supplementary ontological distinction between properties and kinds. -/- . (shrink)

A large part of our exploration of the world consists in categorizing or classifying the objects and processes we encounter, both in scientific and everyday contexts. There are various, perhaps innumerable, ways to sort objects into different kinds or categories, but it is commonly assumed that, among the countless possible types of classifications, one group is privileged. Philosophy refers to such categories as natural kinds. Standard examples of such kinds include fundamental physical particles, chemical elements, and (...) biological species. The term natural does not imply that natural kinds ought to categorize only naturally occurring stuff or objects. Candidates for natural kinds can include man-made substances, such as synthetic elements, that can be created in a laboratory. The naturalness in question is not the naturalness of the entities being classified, but that of the groupings themselves. Groupings that are artificial or arbitrary are not natural; they are invented or imposed on nature. Natural kinds, on the other hand, are not invented, and many assume that scientific investigations should discover them. (shrink)

According to the received tradition, the language used to to refer to natural kinds in scientific discourse remains stable even as theories about these kinds are refined. In this illuminating book, Joseph LaPorte argues that scientists do not discover that sentences about natural kinds, like 'Whales are mammals, not fish', are true rather than false. Instead, scientists find that these sentences were vague in the language of earlier speakers and they refine the meanings of the (...) relevant natural-kind terms to make the sentences true. Hence, scientists change the meaning of these terms, This conclusions prompts LaPorte to examine the consequences of this change in meaning for the issue of incommensurability and for the progress of science. This book will appeal to students and professional in the philosophy of science, the philosophy of biology and the philosophy of language. (shrink)

The phrase "natural kind term" has come into the linguistic and philosophical literature in connection with well-known work of Kripke (1972) and Putnam (1970, 1975a). I use that phrase here in the sense it has acquired from those and subseqnent works on related topics. This is not the transparent sense of the phrase. That is, if I am right in what follows there are words for kinds of things existing in nature which are not natural kind terms (...) in the current sense - e.g. planet, woman, and weed. I use the term "nondescriptional", following Salmon (1981), to mean "lacking a Fregean sense", where a Fregean sense is taken to be a property or group of properties semantically associated with an expression which determines its denotation. I hope that the term "nondescriptional" will be clarified in subsequent discussion, but perhaps a few words about it and its opposite, "descriptional", would be useful here. These terms (as Salmon notes (p.15, n. 11)) should be taken as technical terms. The idea is that descriptional words, of which bachelor is the overwhelmingly favorite example, express a semantic content, or sense, which is what mediates their denotation. Entities fall in their denotation in virtue of possessing the property or properties expressed as their sense. (It is not necessary, however, that this sense be as easily paraphrasable with descriptive synonyms as it is typically held to be in the case of bachelor, or even that it be paraphrasable at all.) In the case of nondescriptional words there is no Fregean sense to mediate the link between word and object. Hence such terms are described by what Salmon, following Kaplan, calls "the theory of direct reference". What it is that does associate such terms with their denotations is another question which will be touched on briefly at the end. I have several aims in this paper. The first is to defend a conservative position on nondescriptionality. I will argue that relatively few natural language words have this property. My other aims are primarily clarificatory. Among the issues I would like to clarify are those connected with the determination of this property and flae explanation of why it exists, its relationship with other properties such as rigid designation and essentiality, and its significance for lexical semantics. The organization of the paper is as follows. The first section identifies the position taken here on the question of which expressions are nondescriptional and provides a general defense of it. The second section is a critical examination of criteria associated with nondescriptionality. In the third section provide further defense for the conservative position, and in the fourth section we turn to related issues in lexical semantics. (shrink)

Both realist and anti-realist accounts of natural kinds possess prima facie virtues: realists can straightforwardly make sense of the apparent objectivity of the natural kinds, and anti-realists, their knowability. This paper formulates a properly anti-realist account designed to capture both merits. In particular, it recommends understanding natural kinds as ‘categorical bottlenecks,’ those categories that not only best serve us, with our idiosyncratic aims and cognitive capacities, but also those of a wide range of alternative (...) agents. By endorsing an ultimately subjective categorical principle, this view sidesteps epistemological difficulties facing realist views. Yet, it nevertheless identifies natural kinds that are fairly, though not completely, stance-independent or objective. (shrink)

It is commonly assumed that natural kind terms constitute a distinct semantic category. This idea emerged during the 1970's following Kripke's and Putnam's well-known remarks on natural kind terms. The idea has stayed with us, although it is now recognized that the issues are considerably more complex than initially thought. Thus, it has become clear that much of Kripke's and Putnam's discussions were based on rather simplified views of natural kinds. It also turns out that the (...) semantic issues are less straightforward than assumed - in particular, it is far from clear what it might mean to say that a kind term is rigid. Strikingly, however, these worries have not done much to undermine the confident assumption that natural kind terms form a special semantic category. In the paper I try to shake that confidence. I argue that although natural kind terms are no doubt important (for instance, from an explanatory point of view), we are certainly not warranted in concluding that they form a separate, semantic category among the kind terms. (shrink)

A paradigmatic case of rigidity for singular terms is that of proper names. And it would seem that a paradigmatic case of rigidity for general terms is that of natural kind terms. However, many philosophers think that rigidity cannot be extended from singular terms to general terms. The reason for this is that rigidity appears to become trivial when such terms are considered: natural kind terms come out as rigid, but so do all other general terms, and in (...) particular all descriptive general terms. This paper offers an account of rigidity for natural kind terms which does not trivialise in this way. On this account, natural kind terms are de jure obstinately rigid designators and other general terms, such as descriptive general terms, are not. (shrink)

In this paper I offer a unified causal account of natural kinds. Using as a starting point the widely held view that natural kind terms or predicates are projectible, I argue that the ontological bases of their projectibility are the causal properties and relations associated with the natural kinds themselves. Natural kinds are not just concatenations of properties but ordered hierarchies of properties, whose instances are related to one another as causes and effects (...) in recurrent causal processes. The resulting account of natural kinds as clusters of core causal properties that give rise to clusters of derivative properties enables us to distinguish genuine natural kinds from non-natural kinds. For instance, it enables us to say why some of the purely conventional categories derived from the social domain do not correspond to natural kinds, though other social categories may. (shrink)

Recently in the philosophy of psychology it has been suggested that several putative phenomena such as emotions, memory, or concepts are not genuine natural kinds and should therefore be eliminated from the vocabulary of scientific psychology. In this paper I examine the perhaps most well known case of scientific eliminativism, Edouard Machery’s concept eliminativism. I argue that the split-lump-eliminate scheme of con- ceptual change underlying Machery’s eliminativist proposal assumes a simplistic view of the functioning of scientific concepts. Conceiving (...) of scientific concepts as natural kind terms is an important reason for the impasse between Machery and anti-eliminativists, as both sides allude to properties of natural kinds in their contradicting arguments. As a solution I propose that, in order to develop a more satisfactory theory of conceptual change in science, one needs to distinguish between three different types of scientific concepts, hitherto conflated under the loaded notion of natural kind. (shrink)

Recent work on Natural Kind Essentialism has taken a deflationary turn. The assumptions about the grounds of essentialist truths concerning natural kinds familiar from the Kripke-Putnam framework are now considered questionable. The source of the problem, however, has not been sufficiently explicated. The paper focuses on the Twin Earth scenario, and it will be demonstrated that the essentialist principle at its core (which I call IDENT)—that necessarily, a sample of a chemical substance, A, is of the same (...) kind as another sample, B, if and only if A and B have the same microstructure—must be re-evaluated. The Twin Earth scenario also assumes the falsity of another essentialist principle (which I call INST): necessarily, there is a 1:1 correlation between (all of ) the chemical properties of a chemical substance and the microstructure of that substance. This assumption will be questioned, and it will be argued that, in fact, the best strategy for defending IDENT is to establish INST. The prospects for Natural Kind Essentialism and microstructural essentialism regarding chemical substances will be assessed with reference to recent work in the philosophy of chemistry. Finally, a weakened form of INST will be presented. (shrink)

In this chapter I lay out a notion of philosophical naturalism that aligns with pragmatism. It is developed and illustrated by a presentation of my views on natural kinds and my theory of concepts. Both accounts reflect a methodological naturalism and are defended not by way of metaphysical considerations, but in terms of their philosophical fruitfulness. A core theme is that the epistemic interests of scientists have to be taken into account by any naturalistic philosophy of science in (...) general, and any account of natural kinds and scientific concepts in particular. I conclude with general methodological remarks on how to develop and defend philosophical notions without using intuitions. (shrink)

SCIENTISTS HAVE DISCOVERED that water is H2O. Water is H2O is true. But is it a necessary truth? In other words, is it true in all possible worlds? Some people think it is. For example Hilary Putnam, in his well-known Twin Earth argument, concludes that "water is H2O" is necessarily true; thus a liquid which phenomenally resembles H2O and fits the description of water in almost all aspects, but has the chemical formula XYZ, cannot be water. Saul Kripke has made (...) a similar claim about the necessary identity between water and H2O. Because this type of truth is based on empirical discoveries, Kripke calls truths of this sort "necessary a posteriori." The thesis shared by Putnam and Kripke has two premises: a realist view that natural kinds exist independently of human cognition, and a theory of direct reference of natural kind terms. Opposing the view that natural kind terms pick out objects through descriptions, Putnam and Kripke hold that natural kind terms pick out natural kinds in the world in a direct way. Based on these two premises, they argue that, if two natural kind terms, A and B, designate the same thing in the world, "A = B" expresses a necessary identity. (shrink)

What, for Kant, is the semantic status of the proposition: Water is H2O? Is it analytic or synthetic? The question is not one of merely esoteric import since an answer to it would constitute a statement about the meaningfulness of all our scientific propositions. And, insofar as the Critique is a defense of the possibility of the natural sciences, it seems that we should be able to find in it the answer to our question. Further, we should be able (...) to find an answer to the question of whether or not Kant is a scientific essentialist. I attempt to show that he is not an essentialist despite the fact that his semantics of natural kind terms greatly resembles that of some contemporary authors who are essentialists and take their semantic theories to provide evidence for their views. One way to go about this would be simply to locate Kant's criteria for the analytic/synthetic distinction and then to place the proposition in the category dictated by those criteria. Rather than employ this method, I will examine instead some of Kant's own examples. The hope is that by means of the examples the criteria themselves will achieve a greater degree of clarity and that through this clarification Kant's position will emerge as a genuine alternative to contemporary positions. (shrink)

This paper considers the problem of assigning meanings to empty natural kind terms. It does so in the context of the Twin-Earth externalist-internalist debate about whether the meanings of natural kind terms are individuated by the external physical environment of the speakers using these terms. The paper clarifies and outlines the different ways in which meanings could be assigned to empty natural kind terms. And it argues that externalists do not have the semantic resources to assign them (...) meanings. The paper ends on a sceptical note concerning the fruitfulness of using the Twin-Earth setting in debates about the semantics of empty natural kind terms. (shrink)

I argue for the importance of clarifying the distinction between metaphysical, semantic, and meta-semantic concerns regarding what Emotion is. This allows us to see that those involved in the Scientific Emotion Project and the Folk Emotion Project are in fact involved in the same project – the Science of Emotion. It also helps us understand why questions regarding the natural kind status of Emotion, as well as answers to questions regarding the value of ordinary language emotion terms or concepts (...) to emotion research, will not help resolve the observed crisis in the Science of Emotion. (shrink)

There are many ways of construing the claim that some categories are more “natural" than others. One can ask whether a system of categories is innate or acquired by learning, whether it pertains to a natural phenomenon or to a social institution, whether it is lexicalized in natural language or requires a compound linguistic expression. This renders suspect any univocal answer to this question in any particular case. Yet another question one can ask, which some authors take (...) to have a bearing on the issue of the naturalness of categories, is whether a system of categories constitutes a unique way of organizing a particular set of entities or phenomena, or whether there are other legitimate classification schemes that can coexist with it. Another way of putting this is by asking whether systems of categories can cut across one another, and if so, under what circumstances. Some philosophers have claimed that crosscutting systems of categories cannot exist as genuine natural kinds. This paper examines that claim and puts forward some counterexamples, concluding that this notion of natural kind is not in tune with scientific classification and ought to be rejected in favor of an alternative. (shrink)

It has been argued recently that some basic emotions should be considered natural kinds. This is different from the question whether as a class emotions form a natural kind; that is, whether emotion is a natural kind. The consensus on that issue appears to be negative. I argue that this pessimism is unwarranted and that there are in fact good reasons for entertaining the hypothesis that emotion is a natural kind. I interpret this to mean (...) that there exists a distinct natural class of organisms whose behavior and development are governed by emotion. These are emoters. Two arguments for the natural kind status of emotion are considered. Both converge on the existence of emotion as a distinct natural domain governed by its own laws and regularities. There are then some reasons for being optimistic about the prospects for consilience in emotion theory. 1 The mantra 2 Griffiths on emotions as natural kinds 3 Panksepp on emotions as natural kinds 4 Emotion as a neurobiological kind 5 Emotion as a psychological kind 6 Response to the mantra 7 Unification or fragmentation? 8 Concluding remarks. (shrink)

Naturalism about natural kinds is the view that they are none other than the kinds discoverable by science. This thesis is in tension with what is perhaps the dominant contemporary view of natural kinds: essentialism. According to essentialism, natural kinds constitute a small subset of our scientific categories, namely those definable in terms of intrinsic, microphysical properties, which are possessed necessarily rather than contingently by their bearers. Though essentialism may appear compatible with naturalism, (...) and is indeed sometimes qualified with the epithet “scientific,” it has become increasingly clear in recent years that only a minority of categories posited by science satisfy those conditions. I will not try to argue against essentialism directly in this chapter. Instead, I will attempt to articulate an alternative, naturalist conception of natural kinds, according to which the mark of natural kinds is their discoverability by science, not just basic science but the special sciences and even the social sciences. (shrink)

It has recently been argued that the concept of natural kinds should be eliminated because it does not play a productive theoretical role and even harms philosophical research on scientific classification. We argue that this justification for eliminativism fails because the notion of ‘natural kinds’ plays another epistemic role in philosophical research, namely, it enables fruitful investigation into non-arbitrary classification. It does this in two ways: first, by providing a fruitful investigative entry into scientific classification; and (...) second—as is supported by bibliometric evidence—by tying together a research community devoted to non-arbitrary classification. The question of eliminativism then requires weighing off the benefits of retaining the concept against its harms. We argue that the progressive state of philosophical work on natural kinds tips this balance in favour of retaining the concept. (shrink)

The new externalist picture of natural kind terms due to Kripke, Putnam, and others has become quite popular in philosophy. Many philosophers of science have remained sceptical. Häggqvist and Wikforss have recently criticised this view severely. They contend it depends essentially on a micro-essentialist view of natural kinds that is widely rejected among philosophers of science, and that a scientifically reasonable metaphysics entails the resurrection of some version of descriptivism. It is argued in this paper that the (...) situation is not quite as dark for the new theory of reference as many critics suggest. There are several distinct questions here which should not be conflated and ought to be dealt with one by one. Descriptivism remains arguably problematic. (shrink)

The rosy dawn of my title refers to that optimistic time when the logical concept of a natural kind originated in Victorian England. The scholastic twilight refers to the present state of affairs. I devote more space to dawn than twilight, because one basic problem was there from the start, and by now those origins have been forgotten. Philosophers have learned many things about classification from the tradition of natural kinds. But now it is in disarray and (...) is unlikely to be put back together again. My argument is less founded on objections to the numerous theories now in circulation, than on the sheer proliferation of incompatible views. There no longer exists what Bertrand Russell called ‘the doctrine of natural kinds’—one doctrine. Instead we have a slew of distinct analyses directed at unrelated projects. (shrink)

Theoretical identity statements of the form "water is H2O‟ are allegedly necessary truths knowable a posteriori, and assert that nothing could be water and not be H2O. The necessary a posteriori nature of these identity claims has been taken by Kripke, Putnam and Donnellan to justify a move from talk of reference (language) to talk of essence (metaphysics), and has motivated much of contemporary essentialism. In this paper I will contest this move from reference to essence, and argue that (i.) (...) the only way to derive essentialism from semantics (specifically direct reference) is to assume it as a premise, (ii.) that contemporary essentialism is a metaphysical assumption not a thesis, and (iii.) – assuming the accuracy of the analogy between proper names and natural kind terms – present an alternative version of natural kinds classification that is interest-relative, dependent on practical application and reflects the contingent state of affairs which is our world. (shrink)

What is a natural kind? This old yet lasting philosophical question has recently received new competing answers (e.g., Chakravartty, 2007; Magnus, 2014; Khalidi, 2013; Slater, 2015; Ereshefsky & Reydon, 2015). We show that the main ingredients of an encompassing and coherent account of natural kinds are actually on the table, but in need of the right articulation. It is by adopting a non-reductionist, naturalistic and non-conceptualist approach that, in this paper, we elaborate a new synthesis of all (...) these ingredients. Our resulting proposition is a multiple-compartment theory of natural kinds that defines them in purely ontological terms, clearly distinguishes and relates ontological and epistemological issues —more precisely, two grains of ontological descriptions and two grains of explanatory success of natural kinds—, and which sheds light on why natural kinds play an epistemic role both within science and in everyday life. (shrink)

Realist accounts of natural kinds rely on an account of causation where the relata of causal relations are real and discrete. These views about natural kinds entail very different accounts of causation. In particular, the necessity of the causal relation given the instantiation of the properties of natural kinds is more robust in the fundamental sciences (e.g. physics and chemistry) than it is in the life sciences (e.g. biology and the medical sciences). In this (...) paper, I wish to argue that there is a difference in kind between the putative natural kinds of the fundamental sciences and those of the life sciences, such that a uniform account of causation cannot capture both. The upshot is that we must either reject the claim that the kinds of the life sciences are genuine natural kinds, or accept that there are different kinds of causal relations involving the relata of natural kinds. I accept the latter. I reject the objection that the true causal relations that relate macro-level kinds are to be found by “going down a level” to causal relation at the fundamental kind, because the relevant causal mechanisms are not at the fundamental level. Since, autonomous mechanistic accounts of causal relations at the macro-level can be provided (e.g. in Biology and medicine), I argue that realism about the natural kinds of the life sciences is justified. I address the problem of negative causation as a counterexample to the positive account of causation that is entailed by realism about natural kinds in the life sciences. I argue that an acceptance of realist accounts of two different kinds of natural kind makes a uniform analysis of causation look unpromising. (277 words). (shrink)

It is commonly held that objects in the world form natural kinds. Rabbits form a natural kind and so do all pieces of gold. The traditional account of natural kinds asserts that the members of a kind share a common essence. The essence of gold, for example, is its unique atomic structure. That structure occurs in all and only pieces of gold, and it is a property that all pieces of gold must have.

In this article, I argue that depression and suicide are natural kinds insofar as they are classes of abnormal behavior underwritten by sets of stable biological mechanisms. In particular, depression and suicide are neurobiological kinds characterized by disturbances in serotonin functioning that affect various brain areas (i.e., the amygdala, anterior cingulate, prefrontal cortex, and hippocampus). The significance of this argument is that the natural (biological) basis of depression and suicide allows for reliable projectable inferences (i.e., predictions) (...) to be made about individual members of a kind. In the context of assisted suicide, inferences about the decision-making capacity of depressed individuals seeking physician-assisted suicide are of special interest. I examine evidence that depression can hamper the decision-making capacity of individuals seeking assisted suicide and discuss some implications. (shrink)

A standard requirement on natural kinds is that they be mind independent. However, many kinds in the human and social sciences, even the natural sciences, depend on human thought. This article suggests that the mind independence requirement on natural kinds be replaced with the requirement that natural kind classifications be defeasible. The defeasibility requirement does not require that natural kinds be mind independent, so it does not exclude mind dependent scientific (...) class='Hi'>kinds from being natural kinds. Furthermore, the defeasibility requirement captures the idea that natural kind classifications are tools for investigating the empirical world. (shrink)

Despite the traditional focus on metaphysical issues in discussions of natural kinds in biology, epistemological considerations are at least as important. By revisiting the debate as to whether taxa are kinds or individuals, I argue that both accounts are metaphysically compatible, but that one or the other approach can be pragmatically preferable depending on the epistemic context. Recent objections against construing species as homeostatic property cluster kinds are also addressed. The second part of the paper broadens (...) the perspective by considering homologues as another example of natural kinds, comparing them with analogues as functionally defined kinds. Given that there are various types of natural kinds, I discuss the different theoretical purposes served by diverse kind concepts, suggesting that there is no clear-cut distinction between natural kinds and other kinds, such as functional kinds. Rather than attempting to offer a unique metaphysical account of ‘natural’ kind, a more fruitful approach consists in the epistemological study of how different natural kind concepts are employed in scientific reasoning. (shrink)

According to the New Theory of Reference, proper names (and indexicals) and natural kind terms are semantically similar to each other but crucially different from definite descriptions and “ordinary” predicates, respectively. New Theorists say that a name, unlike a definite description, is a directly referential nondescriptional rigid designator, which refers “without a mediation of the content” and is not functional (i.e. lacks a Carnapian intension). Natural kind terms, such as ‘horse’ and ‘water’, are held to have similar distinctions, (...) in contrast to other predicates. However, the New Theory contains some problems related to reference, descriptionality, content and meaning. In view of these problems, it will be argued that the distinctive shared feature of proper names and natural kind terms, while technically corresponding to nonfunctionality, is to be explicated in terms of independence of possible worlds, rather than in terms of reference and content: natural kind terms are world-independent predicates, making “worldless” predications. Just as, say, ‘Elvis’ names Elvis even with respect to “Elvisless” worlds, or, rather, names Elvis independently of worlds, natural kind terms are in an important sense “worldless” as well: to talk about Elvis is to talk about him irrespective of moments of time and possible worlds, and is to talk about a human, also irrespective of moments and worlds, while it is not to talk about, say, a drug-addict irrespective of moments, nor about a singer irrespective of worlds. There is no genuinely timeless and worldless predication of the sort “Elvis is (was) bald”, but there is, it seems, such a predication “Elvis is (was) human”. This notion of independence of times and worlds is detached from those of descriptionality and content mediation. (shrink)

Philosophers have long been interested in a series of interrelated questions about natural kinds. What are they? What role do they play in science and metaphysics? How do they contribute to our epistemic projects? What categories count as natural kinds? And so on. Owing, perhaps, to different starting points and emphases, we now have at hand a variety of conceptions of natural kinds—some apparently better suited than others to accommodate a particular sort of inquiry. (...) Even if coherent, this situation isn’t ideal. My goal in this article is to begin to articulate a more general account of ‘natural kind phenomena’. While I do not claim that this account should satisfy everyone—it is built around a certain conception of the epistemic role of kinds and has an obvious pragmatic flavour—I believe that it has the resources to go further than extant alternatives, in particular the homeostatic property cluster view of kinds. (shrink)

This paper discusses whether it can be known a priori that a particular term, such as water, is a natural kind term, and how this problem relates to Putnams claim that natural kind terms require an externalist semantics. Two conceptions of natural kind terms are contrasted: The first holds that whether water is a natural kind term depends on its a priori knowable semantic features. The second.

Are acids natural kinds? Or are they merely relevant kinds? Although acidity has been one of the oldest and most important concepts in chemistry, surprisingly little ink has been spilled on the natural kind question. I approach the question from the perspective of microstructural essentialism. After explaining why both Brønsted acids and Lewis acids are considered functional kinds, I address the challenges of multiple realization and multiple determination. Contra Manafu and Hendry, I argue that the (...) stereotypical properties of acids are not multiply realized. Instead, given the equivalence between the proton-donating and electron-accepting mechanisms of Brønsted and Lewis, respectively, I show that acidity as a property type can be identified with a unique microstructural property, namely the presence of a LUMO or other low energy empty orbital. In doing so, I defend the view that the Lewis theory encompasses Brønsted--Lowry, and that all Brønsted acids are also Lewis acids. Contra Hacking and Chang, I thus maintain that the different concepts of acidity do not crosscut, and that the hierarchy requirement is met. Finally, by characterizing natural kinds as powerful objects and by adopting a dispositional view of functions, I illustrate how the microessentialist can make sense of the latent and relational character of most acids. In sum, I contend that acids are genuine natural kinds, even for the microstructural essentialist. (shrink)

The identity of a natural kind can be construed in terms of its causal profile. This conception is more appropriate to science than two alternatives. The identity of a natural kind is not determined by one causal role because one natural kind can have many causal roles and several functions and because some functions are shared by different kinds. Furthermore, the microstructuralist thesis is wrong: The identity of certain natural kinds is not determined by (...) their microstructure. It is true that if A and B have the same microstructural composition then a sample of a chemical substance A is of the same chemical substance as a sample of B. However, the reverse does not hold. It is not the case that if a sample of a chemical substance A is of the same chemical substance as a sample of B then A and B have the same microstructural composition. This is because a macroscopic NK can be “multiconstituted” by different microstructures. (shrink)

Biological species are often taken as counterexamples to essentialist accounts of natural kinds. Essentialists like Ellis (2001) agree with nominalists that because biological kinds evolve, any distinctions between kinds of biological kind must ultimately be arbitrary. The resulting vagueness in the extension of natural kind predicates in the case of species has led to the claim that species ought to be construed as individuals rather than kinds (Ghiselin 1974, 1987; Hull 1976, 1978). I examine (...) the possibility that causal features extrinsic to the properties of natural kinds are responsible for establishing the unity of the properties of a natural kind. I reject the intuitive idea that laws of nature might act as such an external mechanism because this would entail an account of ceteris paribus biological laws, where there are no plausible truthmakers in terms of kinds or properties. I suggest instead that symbiosis is a plausible external causal mechanism, which explains the evolution of homeostasis in natural kind clusters. This involves the acceptance of an expanded account of evolutionary development as cooperative symbiosis. (shrink)

Natural-kind essentialism faces an important but neglected difficulty: the problem of complex essences (PCE). This is the question of how to account for the unity of an instantiated kind-essence when that essence consists of multiple distinct properties, some of which lack an inherent necessary connection between them. My central goal here is to propose an essentialism-friendly solution to this problem. Along the way I also employ some points from that solution to argue for the necessary truth of essentialism (necessary, (...) that is, in all possible worlds in which there are material objects), and to support the essentialist ontology of laws over and against a major rival. (shrink)

The article examines the role of natural kinds in semantic theorizing, which has largely been conducted in isolation from relevant work in science, metaphysics, and philosophy of science. We argue that the Kripke–Putnam account of natural kind terms, despite recent claims to the contrary, depends on a certain metaphysics of natural kinds; that the metaphysics usually assumed—micro-essentialism—is untenable even in a ‘placeholder’ version; and that the currently popular homeostatic property cluster theory of natural (...) class='Hi'>kinds is correct only to an extent that fails to vindicate the Kripke–Putnam account. This undermines the metasemantics required for anti-descriptivist semantics. _1_ Introduction _2_ From Semantics to Metaphysics _3_ Metaphysics, Part I: The Demise of Micro-essentialism _3.1_ Original micro-essentialism _3.2_ Placeholder essentialism _4_ Metaphysics, Part II: Homeostatic Property Cluster Theory _5_ Prospects for Natural Kind Term Semantics. (shrink)