Scientific practice involves two kinds of induction. In one, generalizations are drawn about the states of a particular system of variables. In the other, generalizations are drawn across systems in a class. We can discern two questions of correctness about both kinds of induction: what distinguishes those systems and classes of system that are ‘projectible’ in Goodman’s sense from those that are not, and what are the methods by which we are able to identify kinds that are likely to be (...) projectible? In answer to the first question, numerous theories of ‘natural kinds’ have been advanced, but none has satisfactorily addressed both questions simultaneously. I propose a shift in perspective. Both essentialist and cluster property theories have traditionally characterized kinds directly in terms of the causally salient properties their members possess. Instead, we should focus on ‘dynamical symmetries’, transformations of a system to which the causal structure of that system is indifferent. I suggest that to be a member of natural kind it is necessary and sufficient to possess a particular collection of dynamical symmetries. I show that membership in such a kind is in turn necessary and sufficient for the presence of the sort of causal structure that accounts for success in both kinds of induction, thus demonstrating that has been answered satisfactorily. More dramatically, I demonstrate that this new theory of ‘dynamical kinds’ provides an answer to with methodological implications concerning the discovery of projectible kinds. (shrink)

We need to distinguish two sorts of natural kinds, scientific and common NKs, because the notion of NK, which has to satisfy demands at three different levels—ontological, semantic and epistemological—, is subject to two incompatible sets of constraints. In order to prove this, I focus on the much-discussed case of jade. In the first part of the paper, I show that the current accounts are unsatisfactory because they are inconsistent. In the process, I explain why LaPorte’s analysis of “jade” as (...) a vernacular NK-term with an open-texture meaning does not offer a way out. Using a reductio ad absurdum argument, I conclude that according to the main tenets of NK-term theories, today’s “jade” has to be an NK-term, and jade thereby an NK. In the second part of the paper, I argue for this conclusion in a positive manner. First, I present a series of thought experiments demonstrating that today’s “jade” has the specific features of an NK-term. Then, I show that the kind that we presently call “jade” exhibits the typical ontological and epistemological features of an NK. More generally, I expound on why common NKs are more than mere classes, and why categories such as “jade” are useful in many inferences and explanations. (shrink)

In recent years both philosophers and scientists have asked whether or not our current kinds of mental disorder—e.g., schizophrenia, depression, bipolar disorder—are natural kinds; and, moreover, whether or not the search for natural kinds of mental disorder is a realistic desideratum for psychiatry. In this dissertation I clarify the sense in which a kind can be said to be “natural” or “real” and argue that, despite a few notable exceptions, kinds of mental disorder cannot be considered natural kinds. Furthermore, I (...) contend that psychopathological phenomena do not cluster together into kinds in the way that paradigmatic natural kinds do; and, in light of this fact, I conclude that the normative ideal of natural classification—i.e. classifying real or natural kinds—is not appropriate as a general strategy for psychiatry. In the conclusion to this dissertation I propose an alternative way forward. Rather than assuming a priori that psychopathological phenomena cluster together into kinds, a more tractable and theoretically promising approach would be to first explain how particular kinds of experiences and behaviours—e.g, hallucinations, delusions, disorganized thinking, mania, low mood, etc.—are produced. (shrink)

A number of areas of biology raise questions about what is of value in the natural environment and how we ought to behave towards it: conservation biology, environmental science, and ecology, to name a few. Based on my experience teaching students from these and similar majors, I argue that the field of environmental ethics has much to teach these students. They come to me with pent-up questions and a feeling that more is needed to fully engage in their subjects, and (...) I believe some exposure to environmental ethics can help focus their interests and goals. I identify three primary areas in which environmental ethics can con- tribute to their education. The first is an examination of who (or what) should be considered to be part of our moral community (i.e., the community to whom we owe direct duties). Is it humans only? Or does it include all sentient life? Or all life? Or ecosystems considered holistically? Often, readings implicitly assume one or more of these answers; the goal is to make the student more sensitive to these implicit claims and to get them to think about the different reasons that support them. The second area, related to the first, is the application of the different answers concerning the extent of the ethical community to real environmental issues and problems. Students need to be aware of how the different answers concerning the moral community can imply conflicting answers for how we should act in certain cases and to think about ways to move toward conflict resolution. The third area in which environmental ethics can contribute is a more conceptual one, focusing on central concepts such as biodiversity, sustainability, species, and ecosystems. Exploring and evaluating various meanings of these terms will make students more reflective and thoughtful citizens and biologists, sensitive to the implications that different conceptual choices make. (shrink)

This article is Part II in a pair of articles on racial realism. In Part I, I defined “racial realism” and discussed the major attempts in the past twenty years among metaphysicians of race and biologists to defend racial realism from the viewpoint of what biologists mean by “race.” In this article, I continue discussing and critiquing how metaphysicians of race have conceived of and defended racial realism, but with a focus on how ordinary people use “race.” I focus on (...) two broad groups of racial realisms in this article: biological racial realism and social racial realism. After defining each one, I summarize a representative sample of recent attempts from metaphysicians of race to defend both types of racial realism. I also discuss major criticisms against each attempt. I end by sketching a new, radical pluralist way of being a racial realist, and I provide some empirical motivation for why it's promising. (shrink)

The aim of this article is to illustrate how a belief in the existence of kinds may be justified for the particular case of natural kinds: particularly noteworthy in this respect is the weight borne by scientific natural kinds (e.g., physical, chemical, and biological kinds) in (i) inductive arguments; (ii) the laws of nature; and (iii) causal explanations. It is argued that biological taxa are properly viewed as kinds as well, despite the fact that they have been by some alleged (...) to be individuals. Since it turns out that the arguments associated with the standard Kripke/Putnam semantics for natural kind terms only establish the non-descriptiveness of natural kind terms and not their rigidity, the door is open to analyze these terms as denoting traditional predicate-extensions. Finally, special issues raised by physical and chemical kinds are considered briefly, in particular impurities, isotopes and the threat of incommensurability. (shrink)

There is a perennial philosophical dream of a certain natural order for the natural kinds. The name of this dream is ‘the hierarchy requirement’. According to this postulate, proper natural kinds form a taxonomy which is both unique and traditional. Here I demonstrate that complex scientific objects exist: objects which generate different systems of scientific classification, produce myriad legitimate alternatives amongst the nonetheless still natural kinds, and make the hierarchical dream impossible to realize, except at absurdly great cost. Philosophical hopes (...) for a certain order in nature cannot be fulfilled. Natural kinds crosscut one another, ubiquitously so, and this crosscutting spells the end of the hierarchical dream. (shrink)

A long-standing debate has dominated systematic biology and the ontological commitments made by its theories. The debate has contrasted individuals and the part – whole relationship with classes and the membership relation. This essay proposes to conceptualize the hierarchy of higher taxa is terms of a hierarchy of homeostatic property cluster natural kinds (biological species remain largely excluded from the present discussion). The reference of natural kind terms that apply to supraspecific taxa is initially fixed descriptively; the extension of those (...) natural kind terms is subsequently established by empirical investigation. In that sense, classification precedes generalization, and description provides guidance to empirical investigation. The reconstruction of a hierarchy of (homeostatic property cluster) natural kinds is discussed in the light of cladistic methods of phylogeny reconstruction. (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)

I propose that we approach the epistemology of modality by putting modal metaphysics first and, specifically, by investigating the metaphysics of essence. Following a prominent Neo-Aristotelian view, I hold that metaphysical necessity depends on the nature of things, namely their essences. I further clarify that essences are core properties having distinctive superexplanatory powers. In the case of natural kinds, which is my focus in the paper, superexplanatoriness is due to the fact that the essence of a kind is what causes (...) all the many properties and behaviors that are typically shared by all the instances of the kind. Accordingly, we know what is necessarily true of kinds by knowing what is essential to them in the sense of actually playing such causal-explanatory roles. Modal reasoning aimed at discovering metaphysical necessity thus proceeds via essentialist deduction: we move from essentialist truths to reach necessary truths. (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.

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)

One primary goal for metaphysical theories of natural kinds is to account for their epistemic fruitfulness. According to cluster theories of natural kinds, this epistemic fruitfulness is grounded in the regular and stable co- occurrence of a broad set of properties. In this paper, I defend the view that such a cluster theory is insufficient to adequately account for the epistemic fruitfulness of kinds. I argue that cluster theories can indeed account for the projectibility of natural kinds, but not for (...) several other epistemic operations that natural kinds support. Natural kinds also play a role in scientific explanations and categorizations. A theory of natural kinds can only account for these additional kind-based epistemic practices if it also analyzes their causal structure. (shrink)

Natural Categories and Human Kinds is a recent and timely contribution to current debate on natural kinds. Because of the growing sophistication of this debate, it is necessary to make careful distinctions in order to appreciate the originality of Khalidi’s position. Khalidi’s view on natural kinds is naturalistic: if we want to know what Nature’s joints really are, we should look at the actual carving job carried out by our best scientific practices. Like LaPorte, Khalidi is a fallibilist: our best (...) scientific theories may be revised or abandoned and so can our current classifications of natural kinds. Unlike LaPorte, however, Khalidi is an anti-essentialist: he argues against the idea that membership in a natural kind is a matter of possessing an essential set of necessary and sufficient properties. Like Dupré, Khalidi is a pluralist and anti-reductionist: he does not believe that there is only one true classification system and that there are natural kinds only at the so-called "fundamental level" of microphysics. Khalidi develops his pluralistic and anti-reductionistic position on the basis of a deep appreciation for the special sciences but, unlike Dupré, he thinks that only the scientific inquiry, which is driven by epistemic purposes, discover natural kinds and that, therefore, there are important differences between scientific and folk classifications. Khalidi’s conception of natural kinds has both an epistemic and a metaphysical component. (shrink)

Although the category “race” fails as a postulated natural kind, racial, ethnic, national, linguistic, religious, and other group designations might nonetheless be considered projectible insofar as they support inductive inferences in biomedicine. This article investigates what it might mean for group concepts in population genetics and genomics to be projectible and whether the projectibility of such predicates licenses the representation of their corresponding classes as natural kinds according to currently prevailing projectibility-based accounts of natural kinds. The article draws on a (...) case study from cancer genetics, specifically, breast cancer risk in Ashkenazi Jewish women. (shrink)

Are persons substances or modes? Two currently dominant views may be characterized as giving the following rival answers to this question. According to the first view, persons are just biological substances. According to the second, persons are psychological modes of substances which, as far as human beings are concerned, happen to be biological substances, but which could in principle be non-biological. There is, however, also a third possible answer, and this is that persons are psychological substances. Such a view is (...) inevitably associated with the name of Descartes, and this helps to explain its current unpopularity, since substantial dualism of his sort is now widely rejected as ‘unscientific’. But one may, as I hope to show, espouse the view that persons are psychological substances without endorsing Cartesianism. This is because one may reject certain features of Descartes's conception of substance. Consequently, one may also espouse a version of substantial dualism which is distinctly non-Cartesian. One may hold that a person, being a psychological substance, is an entity distinct from the biological substance that is his or her body, and yet still be prepared to ascribe corporeal characteristics to this psychological substance. By this account, a human person is to be thought of neither as a non-corporeal mental substance, nor as the product of a mysterious ‘union’ between such a substance and a physical, biological substance. This is not to deny that the mind—body problem is a serious and difficult one, but it is to imply that there is a version of substantial dualism which does not involve regarding the ‘mind’ as a distinct substance in its own right. (shrink)