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)

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)

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)

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)

As is well known, the linguistic/philosophical reflection on natural kind terms has undergone a remarkable development in the early seventies with Putnam and Kripke’s essentialist approaches, touching upon different aspects of Kan’s slant. Preliminarily, however, it might be useful to review some of the theoretical stages in Locke and Leibniz’s approaches on natural kind terms in the light of contemporary reflections, to eventually pinpoint Kant’s contribution and see how some commentators have placed it within (...) the theory of direct reference. Starting with textual evidence even from the logical corpus, in the present essay I will attempt to discuss some of the arguments dismissing Kant’s adherence to this view. These assume that in his approach to the semantics of natural kind Kant appears to be still holding on to a nominalist/conceptualist position, though he seems to be well aware of a few key issues for the theorists of direct reference. (shrink)

According to the causal-historical theory of reference, natural kind terms refer in virtue of complicated causal relations the speakers have to their environment. A common objection to the theory is that purely causal relations are insufficient to fix reference in a determinate fashion. The so-called hybrid view holds that what is also needed for successful fixing are true descriptions associated in the mind of the speaker with the referent. The main claim of this paper is that the (...) objection fails: reference fixing of natural kind terms can be purely causal. The main argument draws inspiration from recent theoretical advances made in metaphysics of kinds by Marion Godman, Antonella Mallozzi, and David Papineau. The main claim is that their notion of super-explanatory properties may explain how reference of many kind terms can be fixed purely causally. (shrink)

Since Saul Kripke’s and Hilary Putnam’s groundbreaking work in the Seventies, the idea has emerged that natural kind terms are semantically special among common nouns. Stephen P. Schwartz, for example, has argued that an artifactual kind term like “pencil” functions very differently from a natural kind term like “tiger.” This, however, blatantly violates a principle that I call Semantic Uniformity. In this paper, I defend the principle. In particular, I outline a picture of how (...) natural kind terms function based on Kripke’s and Putnam’s considerations, and I use it to rebut Schwartz’s arguments, showing that if it works for natural kind terms, it can work for artifactual kind terms too, or at least that Schwartz did not provide good enough reasons to the contrary. (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)

This paper evaluates the Natural-Kinds Argument for cognitive extension, which purports to show that the kinds presupposed by our best cognitive science have instances external to human organism. Various interpretations of the argument are articulated and evaluated, using the overarching categories of memory and cognition as test cases. Particular emphasis is placed on criteria for the scientific legitimacy of generic kinds, that is, kinds characterized in very broad terms rather than in terms of their fine-grained causal roles. (...) Given the current state of cognitive science, I conclude that we have no reason to think memory or cognition are generic natural kinds that can ground an argument for cognitive extension. (shrink)

In lecture III of Naming and Necessity, Kripke extends his claim that names are non-descriptive to natural kind terms, and in so doing includes a brief supporting discussion of terms for natural phenomena, in particular the terms ‘light’ and ‘heat’. Whilst natural kind terms continue to feature centrally in the recent literature, natural phenomenon terms have barely figured. The purpose of the present paper is to show how the apparent (...) similarities between natural kind terms and the natural phenomenon terms on which Kripke focuses are outweighed by more significant differences. Thus, rather than providing additional support for non-descriptivism, natural phenomenon terms turn out to challenge that thesis. (shrink)

Philosophical treatments of natural kinds are embedded in two distinct projects. I call these the philosophy of science approach and the philosophy of language approach. Each is characterized by its own set of philosophical questions, concerns, and assumptions. The kinds studied in the philosophy of science approach are projectible categories that can ground inductive inferences and scientific explanation. The kinds studied in the philosophy of language approach are the referential objects of a special linguistic category—natural kind (...) class='Hi'>terms—thought to refer directly. Philosophers may hope for a unified account addresses both sets of concerns. This paper argues that this cannot be done successfully. No single account can satisfy both the semantic objectives of the philosophy of language approach and the explanatory projects of the philosophy of science approach. After analyzing where the tensions arise, I make recommendations about assumptions and projects that are best abandoned, those that should be retained, and those that should go their separate ways. I also recommend adopting the disambiguating terminology of “scientific kinds” and “natural kinds” for the different notions of kinds developed in these different approaches. (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)

The focus of this article is on the pragmatic presuppositions involved in the use of general terms in inductive practices. The main thesis is that the problem of characterizing the assumptions underlying the projection of predicates in inductive practices and the ones underlying the classification of crtain general terms as «natural kind terms» coincide to a good extent. The reason for this, it is argued, is that both classifications, «projectibility» and «natural kind term», (...) are attempts to answer to the same semantico-epistemological phenomenon, viz. underdertermination. It is proposed a «deflationary» reading of the so-called «theory of direct reference» as to enable an evaluation of its contribution to epistemological problems associated with this kind of phenomena, as well as it is argued that a purely de facto account of projectibility is not viable. The resulting hypothesis is that the conception of «natural kind terms» is only interesting insofar as they are seen as a kind of projectible general terms and thus as parts of classifications used in natural science, more generally, in inductive practices, and that this is a perspective that makes undue metaphysical readings avoidable. (shrink)

When we ask what natural kinds are, there are two different things we might have in mind. The first, which I’ll call the taxonomy question, is what distinguishes a category which is a natural kind from an arbitrary class. The second, which I’ll call the ontology question, is what manner of stuff there is that realizes the category. Many philosophers have systematically conflated the two questions. The confusion is exhibited both by essentialists and by philosophers who pose (...) their accounts in terms of similarity. It also leads to misreading philosophers who do make the distinction. Distinguishing the questions allows for a more subtle understanding of both natural kinds and their underlying metaphysics. (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)

What kind of reference (if any) do terms such as “pencil,” “chair,” “television,” and so on have? On the matter, a de-bate between directly referential theorists and descriptiv-ist theorists is open. It is largely acknowledged that natural kind terms (such as “water,” “gold,” “tiger,” etc.) are directly referential expressions (cf. Putnam,1975). That is, they are expressions whose reference is determined by their refer-ents' nature, independent of whether we know or will ever know what this nature (...) is. However, it does not seem like-wise convincing that all artifactual kind terms (like “pen-cil,” “chair,” “television,” etc.) semantically behave the same. Terms for artifactual kinds seem more likely to be subjected to a descriptivist view, that is, definable not by links to their extensions' nature but in terms of conjunctions or clusters of properties. In his celebrated “The Meaning of ‘Meaning’” (1975), Hilary Putnam originated the mentioned debate by arguing that artifactual kind terms also refer directly. Thus, the discussion ultimately revolves around establishing whether artifactual and natural kind terms are both directly referential expressions. The authors engaged in this debate have tried to argue in favor of (or against) Putnam's proposal by highlighting the similarities (or differences) between nat-ural vis-à-vis artifactual kind words and their respective ref-erents. This paper aims to provide a thorough and reasoned overview of the debate at stake, pointing out trends and problems associated with each proposed account. (shrink)

Traditional debate on the metaphysics of gender has been a contrast of essentialist and social-constructionist positions. The standard reaction to this opposition is that neither position alone has the theoretical resources required to satisfy an equitable politics. This has caused a number of theorists to suggest ways in which gender is unified on the basis of social rather than biological characteristics but is “real” or “objective” nonetheless – a position I term social objectivism. This essay begins by making explicit the (...) motivations for, and central assumptions of, social objectivism. I then propose that gender is better understood as a real kind with a historical essence, analogous to the biologist’s claim that species are historical entities. I argue that this proposal achieves a better solution to the problems that motivate social objectivism. Moreover, the account is consistent with a post-positivist understanding of the classificatory practices employed within the natural and social sciences. (shrink)

Millstein (2009) argues against conceptual pluralism with respect to the definition of “population,” and proposes her own definition of the term. I challenge both Millstein's negative arguments against conceptual pluralism and her positive proposal for a singular definition of population. The concept of population, I argue, does not refer to a natural kind; populations are constructs of biologists variably defined by contexts of inquiry.

Millstein argues against conceptual pluralism with respect to the definition of “population,” and proposes her own definition of the term. I challenge both Millstein’s negative arguments against conceptual pluralism and her positive proposal for a singular definition of population. The concept of population, I argue, does not refer to a natural kind; popula tions are constructs of biologists variably defined by contexts of inquiry.

One common response to the knowledge argument is the ability hypothesis. Proponents of the ability hypothesis accept that Mary learns what seeing red is like when she exits her black-and-white room, but they deny that the kind of knowledge she gains is propositional in nature. Rather, she acquires a cluster of abilities that she previously lacked, in particular, the abilities to recognize, remember, and imagine the color red. For proponents of the ability hypothesis, knowing what an experience is like (...) simply consists in the possession of these abilities. Criticisms of the ability hypothesis tend to focus on this last claim. Such critics tend to accept that Mary gains these abilities when she leaves the room, but they deny that such abilities constitute knowledge of what an experience is like. To my mind, however, this critical strategy grants too much. Focusing specifically on imaginative ability, I argue that Mary does not gain this ability when she leaves the room for she already had the ability to imagine red while she was inside it. Moreover, despite what some have thought, the ability hypothesis cannot be easily rescued by recasting it in terms of a more restrictive imaginative ability. My purpose here is not to take sides in the debate about physicalism, i.e., my criticism of the ability hypothesis is not offered in an attempt to defend the anti-physicalist conclusion of the knowledge argument. Rather, my purpose is to redeem the imagination from the misleading picture of it that discussion of the knowledge argument has fostered. (shrink)

In this chapter, I present the first systematic trope nominalist approach to natural kinds of objects. It does not identify natural kinds with the structures of mind-independent entities (objects, universals or tropes). Rather, natural kinds are abstractions from natural kind terms and objects belong to a natural kind if they satisfy their mind-independent application conditions. By relying on the trope theory SNT (Keinänen 2011), I show that the trope parts of a simple (...) object determine the kind to which it belongs. Moreover, I take the first steps to generalize the trope nominalist theory to the natural kinds of complex objects. (shrink)

Do neurobiologists aim to discover natural kinds? I address this question in this chapter via a critical analysis of classification practices operative across the 43-year history of research on long-term potentiation (LTP). I argue that this 43-year history supports the idea that the structure of scientific practice surrounding LTP research has remained an obstacle to the discovery of natural kinds.

Recent treatments of imagination have increasingly treated imagining as a skill. Insofar as imaginative accuracy is one of the factors that underwrites this skill, it is important to understand what it means to say that an imagining is accurate. This paper takes up that task. The discussion proceeds in four parts. First, I address two worries that may naturally arise about the coherence ofthe notion of imaginative accuracy. Second, with those worries addressed, I turn to an exploration of what is (...) meant by imaginative accuracy. My discussion relies on two key points: first, that accuracy is best understood in terms of aim; and second, that imaginings aim at the representation of fictional states of affairs. I call this line of thought _the fictionality approach_. Third, I look more closely at six different types of imaginings in an effort to develop and clarify the fictionality approach. Finally, I turn to what I call the calibration objection. Given the nature of imagination, there seems to be no way to calibrate one’s judgments of imaginative accuracy. After showing how much of the force of the calibration objection can be defused, I offer some brief concluding remarks. (shrink)

How are we to understand the phenomenology of imagining? Attempts to answer this question often invoke descriptors concerning the “vivacity” or “vividness” of our imaginative states. Not only are particular imaginings often phenomenologically compared and contrasted with other imaginings on grounds of how vivid they are, but such imaginings are also often compared and contrasted with perceptions and memories on similar grounds. Yet however natural it may be to use “vividness” and cognate terms in discussions of imagination, it (...) does not take much reflection to see that these terms are ill understood. In this paper, I review both some relevant empirical literature as well as the philosophical literature attempt to get a handle on what it could mean, in an imaginative context, to talk of vividness. As I suggest, this notion ultimately proves to be so problematic as to be philosophically untenable. (shrink)

In this thesis I argue that the psychological study of concepts and categorisation, and the philosophical study of reference are deeply intertwined. I propose that semantic intuitions are a variety of categorisation judgements, determined by concepts, and that because of this, concepts determine reference. I defend a dual theory of natural kind concepts, according to which natural kind concepts have distinct semantic cores and non-semantic identification procedures. Drawing on psychological essentialism, I suggest that the cores consist (...) of externalistic placeholder essence beliefs. The identification procedures, in turn, consist of prototypes, sets of exemplars, or possibly also theory-structured beliefs. I argue that the dual theory is motivated both by experimental data and theoretical considerations. The thesis consists of three interrelated articles. Article I examines philosophical causal and description theories of natural kind term reference, and argues that they involve, or need to involve, certain psychological elements. I propose a unified theory of natural kind term reference, built on the psychology of concepts. Article II presents two semantic adaptations of psychological essentialism, one of which is a strict externalistic Kripkean-Putnamian theory, while the other is a hybrid account, according to which natural kind terms are ambiguous between internalistic and externalistic senses. We present two experiments, the results of which support the strict externalistic theory. Article III examines Fodor’s influential atomistic theory of concepts, according to which no psychological capacities associated with concepts constitute them, or are necessary for reference. I argue, contra Fodor, that the psychological mechanisms are necessary for reference. (shrink)

Do neurobiologists aim to discover natural kinds? I address this question in this chapter via a critical analysis of classification practices operative across the 43-year history of research on long-term potentiation. I suggest that this 43-year history supports the idea that the structure of scientific practice surrounding LTP research has remained an obstacle to the discovery of natural kinds as philosophers of science have traditionally conceived them.

The natural name theory, recently discussed by Johnson (2018), is proposed as an explanation of pure quotation where the quoted term(s) refers to a linguistic object such as in the sentence ‘In the above, ‘bank’ is ambiguous’. After outlining the theory, I raise a problem for the natural name theory. I argue that positing a resemblance relation between the name and the linguistic object it names does not allow us to rule out cases where the natural name (...) fails to resemble the linguistic object it names. I argue that to avoid this problem, we can combine the natural name theory with a type-realist metaphysics of language, and hold that the name is natural because the name is an instance of the kind that it names. I conclude by reflecting on the importance of the metaphysics of language for questions in the philosophy of language. (shrink)

This paper examines causal theories of reference with respect to how plausible an account they give of non-physical natural kind terms such as ‘gene’ as well as of the truth of the associated theoretical claims. I first show that reference fixism for ‘gene’ fails. By this, I mean the claim that the reference of ‘gene’ was stable over longer historical periods, for example, since the classical period of transmission genetics. Second, I show that the theory of partial (...) reference does not do justice to some widely held realist intuitions about classical genetics. This result is at loggerheads with the explicit goals usually associated with partial theories of reference, which is to defend a realist semantics for scientific terms. Thirdly, I show that, contrary to received wisdom and perhaps contrary to physics and chemistry, neither reference fixism nor partial reference are necessary in order to hold on to scientific realism about biology. I pinpoint the reasons for this in the nature of biological kinds, which do not even remotely resemble natural kinds (i.e., Lockean real essences) as traditionally conceived. (shrink)

Kinds that share historical properties are dubbed “historical kinds” or “etiological kinds,” and they have some distinctive features. I will try to characterize etiological kinds in general terms and briefly survey some previous philosophical discussions of these kinds. Then I will take a closer look at a few case studies involving different types of etiological kinds. Finally, I will try to understand the rationale for classifying on the basis of etiology, putting forward reasons for classifying phenomena on the basis (...) of diachronic features, thereby making a provisional case for considering at least some etiological kinds to be natural kinds. (shrink)

Discussions over whether these natural kinds exist, what is the nature of their existence, and whether natural kinds are themselves natural kinds aim to not only characterize the kinds of things that exist in the world, but also what can knowledge of these categories provide. Although philosophically critical, much of the past discussions of natural kinds have often answered these questions in a way that is unresponsive to, or has actively avoided, discussions of the empirical use (...) of natural kinds and what I dub “activities of natural kinding” and “natural kinding practices”. The natural kinds of a particular discipline are those entities, events, mechanisms, processes, relationships, and concepts that delimit investigation within it—but we might reasonably ask: How are these natural kinds discovered?, How are they made?, Are they revisable?, and Where do they come from? A turn to natural kinding practices reveals a new set of questions open for investigation: How do natural kinds explain through practice?, What are natural kinding practices and classifications and why should we care?, What is the nature of natural kinds viewed as a set of activities?, and How do practice approaches to natural kinds shape and reconfigure scientific disciplines? Natural kinds have traditionally been discussed in terms of how they classify the contents of the world. The metaphysical project has been one which identifies essences, laws, sameness relations, fundamental properties, and clusters of family resemblances and how these map out the ontological space of the world. But actually how this is done has been less important in the discussion than the resultant categories that are produced. I aim to rectify these omissions and suggest a new metaphysical project investigating kinds in practice. (shrink)

This essay explores the relation between nature and culture and analyses it from the perspective of contemporary evolutionary theory. Both animals and humans are conceived of as attaining both natural and cultural features that interact with each other on a number of levels of varying complexity: nature as cultural, nature as influenced by culture, culture as natural, and culture as influenced by nature. “Nature as cultural” is meant to express a decoupling of behavioral/phenotypic changes of an organism from (...) its genetic determination. “Nature as influenced by culture” is the idea of niche construction, wherein such decoupled changes can causally feedback to genetic reality, thereby influencing the evolutionary features of downstream species. “Culture as natural” portrays how cultural structures of humans and animals persist through the generations, accumulate incurred changes, and evolve in analogous ways to biological natural selection. “Culture as influenced by nature” is the notion that the cultural/linguistic capacities of animals and humans have evolutionarily emerged from precultural history. All this is meant to evaluate the viability of constructing a nature/culture divide. The conclusion is made that the divide seems arbitrary within and between human and animal life when considering how the differences between the natural and cultural dynamics of humans and animals are modelled as differences of degree, not kind. A potential approach in using the concept of consciousness to recontextualize a nature/culture divide in terms of the possession of consciousness is proposed at the end. (shrink)

The paper discusses whether the color terms should be given an externalist semantics. In the literature on the semantics of color terms externalism is standardly taken for granted, and Twin Earth style arguments play a central role. This is notable given that few people would claim that semantic externalism applies across the board, to all types of terms. Why, then, should the color terms belong with this group of terms? I argue that the standard externalist (...) strategies, introduced by Tyler Burge and Hilary Putnam, do not apply to these terms: The color terms do not function like natural kind terms, and the idea of semantic reliance on others does not apply to them. I conclude that the externalist arguments fail and that a version of internalism, more properly called ‘individualism’,applies to the color terms. (shrink)

On Kripke’s intended definition, a term designates an object x rigidly if the term designates x with respect to every possible world in which x exists and does not designate anything else with respect to worlds in which x does not exist. Kripke evidently holds in Naming and Necessity, hereafter N&N (pp. 117–144, passim, and especially at 134, 139–140), that certain general terms – including natural-kind terms like ‘‘water’’ and ‘‘tiger’’, phenomenon terms like ‘‘heat’’ and (...) ‘‘hot’’, and color terms like ‘‘blue’’ – are rigid designators solely as a matter of philosophical semantics (independently of empirical, extra-linguistic facts). As a consequence, Kripke argues, identity statements involving these general terms are like identity statements involving proper names (e.g., ‘‘Clark Kent=Superman’’) in that, solely as a matter of philosophical semantics, they express necessary truths if they are true at all. But whereas it is reasonably clear what it is for a (first-order) singular term to designate, Kripke does not explicitly say what it is for a general term to designate. General terms are standardly treated in modern logic as predicates, usually monadic predicates. There are very forceful reasons – due independently to Church and Godel, and ultimately to Frege – for taking predicates to designate their semantic extensions. But insofar as the extension of the general term ‘‘tiger’’ is the class of actual tigers (or its characteristic function), it is clear that the term does not rigidly designate its extension, since the class of tigers in one possible world may differ from the class of tigers in another. What, then, is it for ‘‘tiger’’ to be rigid? (shrink)

The present thesis explores some metaphysical issues concerning biochemical kinds and the relations between chemical and biological properties and phenomena. The main result of this thesis is that there is something sui generis about biochemical kinds. This result is motivated by two theoretical steps. The first is characterising biochemical functions as weakly emergent from the chemical structure [Chapter 3, Chapter 6]. The second is via an account for which biochemical kinds are natural categories [Chapter 4, Chapter 7]. The thesis (...) comprises four parts. Part I [Chapter 1, Chapter 2] aims to offer the methodological and conceptual tools that underpin this research. Chapter 1 presents the debate on the unity of science and the motivation of the research. Chapter 2 presents the account of natural kinds that will be used throughout the thesis. Part II [Chapter 3, Chapter 4] offers a detailed metaphysical analysis of the molecular gene. Chapter 3 argues that molecular genes are weakly emergent from nucleic acids. Chapter 4 argues that the category "molecular gene" can be deemed a natural kind, following the account presented in Chapter 2. Part III [Chapter 5, Chapter 6, Chapter 7] explores some of the themes related to biochemical kinds and generalises some of the results from Part II. Chapter 5 considers biochemical functions and how functional attribution should be interpreted for biochemical molecules. Chapter 6 considers the relation between biochemical functions and structure, spelt in terms of weak emergence and explores unity in biochemistry. Chapter 7 considers the topic of biochemical kinds per se and argues that biochemical kinds are natural categories. Part IV [Chapter 8] elucidates the main outcome and the implications that this research can have for future discussion in the philosophy and metaphysics of biochemistry and the unity of science. (shrink)

In this paper I distinguish three kinds of kinds: traditional philosophical kinds such as truth, knowledge, and causation; natural science kinds such as spin, charge and mass; and social kinds such as class, poverty, and marriage. The three-fold taxonomy I work with represents an idealised abstraction from the wide variety of kinds that there are and the messy phenomena that underlie them. However, the kinds I identify are discrete, and the three-fold taxonomy is useful when it comes to understanding (...) claims about the normativity, scope, and implementation of conceptual engineering. In particular it reveals: first, that conceptual engineering in a broad sense is not distinctively normative; but second, that there is a distinctive normativity present in conceptual engineering in the narrow sense of amelioration; third, that conceptual engineering in the narrow sense of amelioration is only possible for terms that refer to kinds whose grounds we can change; and fourth, that the amelioration of such kind terms can be brought about as a result of changing the grounds of those kinds. The overall aim is to draw attention to the differences between kinds of kinds to make sense of the diverse and often conflicting claims in the conceptual engineering literature, both from its proponents and from its detractors. The hope is that paying attention to the differences between kinds of kinds will provide a better understanding of the landscape. (shrink)

Several philosophers have recently tried to define natural kinds in epistemic terms only. Given the persistent problems with finding a successful metaphysical theory, these philosophers argue that we would do better to describe natural kinds solely in terms of their epistemic usefulness, such as their role in supporting inductive inferences. In this paper, I argue against these epistemology-only theories of natural kinds and in favor of, at least partly, metaphysical theories. I do so in three (...) steps. In the first section of the paper, I propose two desiderata for a theory of natural kinds. In the second section, I discuss one example of a ‘general’ epistemology-only theory, proposed by Marc Ereshefsky and Thomas Reydon, and argue that theories like theirs fail to provide adequate criteria of natural kinds. In the third section, I focus on one example of a ‘specific’ epistemology-only theory, proposed by P. D. Magnus, and use it to show why such theories cannot justify the claim that the proposed epistemic criteria account for the naturalness of kinds. (shrink)

Experimental philosophy of language uses experimental methods developed in the cognitive sciences to investigate topics of interest to philosophers of language. This article describes the methodological background for the development of experimental approaches to topics in philosophy of language, distinguishes negative and positive projects in experimental philosophy of language, and evaluates experimental work on the reference of proper names and natural kind terms. The reliability of expert judgments vs. the judgments of ordinary speakers, the role that ambiguity (...) plays in influencing responses to experiments, and the reliability of metalinguistic judgments are also assessed. (shrink)

Theorists analyzing the concepts of race and gender disagree over whether the terms refer to natural kinds, social kinds, or nothing at all. The question arises: what do we mean by the terms? It is usually assumed that ordinary intuitions of native speakers are definitive. However, I argue that contemporary semantic externalism can usefully combine with insights from Foucauldian genealogy to challenge mainstream methods of analysis and lend credibility to social constructionist projects.

Penelope Mackie and Scott Soames argue, contrary to my Reference and Essence (R&E), that Hilary Putnam was correct that the direct-reference theory of natural-kind terms, taken in conjunction with empirical or otherwise uncontroversial premises, yields non-trivial essentialism, such as the conclusion that water is essentially two-parts hydrogen, one-part oxygen. A controversial distinction is drawn between rigid and non-rigid general terms. A new criterion for general-term rigidity is proposed, and Putnam’s ostensive definition of ‘water’ is reformulated accordingly (...) to generate the consequence that ‘water’ rigidly designates. Mackie and Soames propose a reformulation of Putnam’s ostensive definition that putatively yields the desired result. This reformulation, however, does not correctly explain the meaning of ‘water’ as a substance designator. Furthermore, if taken instead as a redefinition of ‘water’, the essentialism thereby generated is trivial. (shrink)

In this paper, we present and discuss the findings of two experiments about reference change. Cases of reference change have sometimes been invoked to challenge traditional versions of semantic externalism, but the relevant cases have never been tested empirically. The experiments we have conducted use variants of the famous Twin Earth scenario to test folk intuitions about whether natural kind terms such as ‘water’ or ‘salt’ switch reference after being constantly (mis)applied to different kinds. Our results indicate (...) that this is indeed so. We argue that this finding is evidence against Saul Kripke’s causal-historical view of reference, and at least provisional evidence in favor of the causal source view of reference as suggested by Gareth Evans and Michael Devitt. (shrink)

The homeostatic property cluster theory is widely influential for its ability to account for many natural-kind terms in the life sciences. However, the notion of homeostatic mechanism has never been fully explicated. In 2009, Carl Craver interpreted the notion in the sense articulated in discussions on mechanistic explanation and pointed out that the HPC account equipped with such notion invites interest-relativity. In this paper, we analyze two recent refinements on HPC: one that avoids any reference to the (...) causes of the clustering of properties and one that replaces homeostatic mechanisms with causal networks represented by causal graphs. We argue that the former is too slender to account for some inductive inference in science and the latter, thicker account invites interest-relativity, as the original HPC does. This suggests that human interest will be an un-eliminative part of a satisfactory account of natural kindness. We conclude by discussing the implication of interest-relativity to the naturalness, reality, or objectivity of kinds and indicating an overlooked aspect of natural kinds that requires further studies. (shrink)

A dominant strand of philosophical thought holds that natural kinds are clusters of objects with shared properties. Cluster theories of natural kinds are often taken to be a late twentieth-century development, prompted by dissatisfaction with essentialism in philosophy of biology. I will argue here, however, that a cluster theory of kinds had actually been formulated by William Whewell (1794-1866) more than a century earlier. Cluster theories of kinds can be characterized in terms of three central commitments, all (...) of which are present in Whewell’s work on classification. Like contemporary cluster theorists, Whewell claims that kinds are united by similarity, that many kinds do not have essences, and that there are “gaps” between kinds. Moreover, Whewell advises taxonomists to look for consilience (roughly, convergence) between different classificatory schemes, a recommendation that reinforces the identification of natural classes with property clusters. Thus Whewell was not only an early cluster theorist, but one with important insights into what a cluster theory of kinds means for the practice of classification. (shrink)

What does it mean for a general term to be rigid? It is argued by some that if we take general terms to designate their extensions, then almost no empirical general term will turn out to be rigid; and if we take them to designate some abstract entity, such as a kind, then it turns out that almost all general terms will be rigid. Various authors who pursue this line of reasoning have attempted to capture Kripke’s intent (...) by defining a rigid general term as one that applies to the objects in its extension essentially. I argue that this account is significantly mistaken for various reasons: it conflates a metaphysical notion (essentialism) with a semantic one (rigidity); it fails to countenance the fact that any term can be introduced into a language by stipulating that it be a rigid designator; it limits the extension of rigid terms so much that terms such as ‘meter’, ‘rectangle’, ‘truth’, etc. do not turn out to be rigid, when they obviously are; and it wrongly concentrates on the predicative use of a general term in applying a certain test offered by Kripke to determine whether a term is rigid. (shrink)

The paper presents two objections against Putnam’s Twin Earth argument, which was intended to secure semantic externalism. I first claim that Putnam’s reasoning rests on two assumptions and then try to show why these assumptions are contentious. The first objection is that, given what we know about science, it is unlikely that there are any natural-kind terms whose extension is codetermined by a small set of microstructures required by Putnam’s indexical account of extension determination. The second objection (...) is that there may not be a plausible concept of a speech community whose adoption would classify Oscar and Twin Oscar as members of different speech communities and, at the same time, render Oscar and Twin Oscar as being in the same psychological state. I contend that Putnam’s argument fails because both objections are justified. (shrink)

In this chapter, it is suggested that our epistemic access to metaphysical modality generally involves rationalist, a priori elements. However, these a priori elements are much more subtle than ‘traditional’ modal rationalism assumes. In fact, some might even question the ‘apriority’ of these elements, but I should stress that I consider a priori and a posteriori elements especially in our modal inquiry to be so deeply intertwined that it is not easy to tell them apart. Supposed metaphysically necessary identity statements (...) involving natural kind terms are a good example: the fact that empirical input is crucial in establishing their necessity has clouded the role and content of the a priori input, as I have previously argued. For instance, the supposed metaphysically necessary identity statement involving water and its microstructure can only be established with the help of a controversial a priori principle concerning the determination of chemical properties by microstructure. The Kripke-Putnam framework of modal epistemology fails precisely because it is unclear whether the required a priori element is present. My positive proposal builds on E. J. Lowe’s work. Lowe holds that our knowledge of metaphysical modality is based on our knowledge of essence. Lowe’s account strives to offer a uniform picture of modal epistemology: essence is the basis of all our modal knowledge. This is the basis of Lowe’s modal rationalism. I believe that Lowe’s proposal is on the right lines in the case of abstract objects, but I doubt that it can be successfully applied to the case of natural kinds. Accordingly, the case of natural kinds will be my main focus and I will suggest that modal rationalism, at least as it is traditionally understood, falls short of explaining modal knowledge concerning natural kinds. Yet, I think that Lowe has identified something of crucial importance for modal epistemology, namely the essentialist, a priori elements present in our modal inquiry. The upshot is that rather than moving all the way from modal rationalism to modal empiricism, a type of hybrid approach, ‘empirically-informed modal rationalism ’, can be developed. (shrink)

Moral realism and ethical naturalism are both highly attractive ethical positions but historically they have often been thought to be irreconcilable. Since the late 1980s defenders of Cornell Realism have argued that the two positions can consistently be combined. They make three constitutive claims: (i) Moral properties are natural kind properties that (ii) are identical to (or supervene) on descriptive functional properties, which (iii) causally regulate our use of moral terms. We offer new arguments against the feasibility (...) of Cornell realism and then show that there is a way to be a naturalistic realist that avoids internal inconsistency and uniquely provides for moral normativity. (shrink)

It is a truism that humans are social animals. Thus, it is no surprise that we understand the world, each other, and ourselves in terms of social kinds such as money and marriage, war and women, capitalists and cartels, races, recessions, and refugees. Social kinds condition our expectations, inform our preferences, and guide our behavior. Despite the prevalence and importance of social kinds, philosophy has historically devoted relatively little attention to them. With few exceptions, philosophers have given pride of (...) place to the kinds studied by the natural sciences, especially physics. However, philosophical interest in social kinds is growing in recent years. I critically examine answers to a cluster of related questions concerning the metaphysics of social kinds. Are social kinds natural kinds? Do social kinds have essences? Are social kinds mind dependent? Are social kinds real? (shrink)

A minimal essentialism (‘intrinsic biological essentialism’) about natural kinds is required to explain the projectability of human science terms. Human classifications that yield robust and ampliative projectable inferences refer to biological kinds. I articulate this argument with reference to an intrinsic essentialist account of HPC kinds. This account implies that human sciences (e.g., medicine, psychiatry) that aim to formulate predictive kind categories should classify biological kinds. Issues concerning psychiatric classification and pluralism are examined.

The aim of this thesis is to discuss whether general terms are rigid and if they are, how their rigidity should be interpreted. To this end, I first present the problems related to the rigidity of general terms. The most important ones among them are the following: What do general terms refer to? Is there any difference between the terms called “natural kind terms” and other general terms? After that, I discuss the (...) arguments of three competent interpretations which try to overcome these problems. The first interpretation holds that general terms refer to (or apply to) each and every object in their extensions. According to this view, only general terms related to essential properties like “cat”, “gold” turn out to be rigid. After I try to expose the drawbacks of this view, I examine the arguments of the second interpretation which holds that general terms refer to abstract kinds. I also argue for this interpretation. According to this interpretation general terms which refer to the same kind in all possible worlds turn out to be rigid. The main objection to this view is that this interpretation makes so many general terms rigid and it trivializes the notion of rigidity. Arguing that this is an unfair objection, I also focus on the philosophical importance of the subject and show that the interpretation I argue for realizes this philosophical importance. The third interpretation, on the other hand, rejects the rigidity of general terms. I also discuss the drawbacks of this view. -/- Another subject I discuss in the thesis is the rigidity of artifactual kind terms. The kinds of human made objects for specific purposes are usually called “artifactual kinds”. I argue that artifactual kind terms could rigidly refer to artifactual kinds. I reply to the critiques of this view with regard to the semantics of artifactual kind terms and metaphysics of artifactual kinds. (shrink)

For a period of several years the philosopher of science Hasok Chang has promoted various inter-related views including pluralism, pragmatism, and an associated view of natural kinds. He has also argued for what he calls the persistence of everyday terms in the scientific view. Chang claims that terms like phlogiston were never truly abandoned but became transformed into different concepts that remain useful. On the other hand, Chang argues that some scientific terms such as acidity have (...) suffered a form of “rupture”, especially in the case of the modern Lewis definition of acids. Chang also complains that the degree of acidity of a Lewis acid cannot be measured using a pH meter and seems to regard this as a serious problem. The present paper examines some of these views, especially what Chang claims to be a rupture in the definition of acidity. It is suggested that there has been no such rupture but a genuine generalization, on moving from the Brønsted-Lowry theory to the Lewis theory of acidity. It will be shown how the quantification and measurement of Lewis acidity can easily be realized through the use of equilibrium theory and the use of stability constants. (shrink)