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 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)

In this paper, I develop an essentialist model of the semantics of slurs. I defend the view that slurs are a species of kind terms: Slur concepts encode mini-theories which represent an essence-like element that is causally connected to a set of negatively-valenced stereotypical features of a social group. The truth-conditional contribution of slur nouns can then be captured by the following schema: For a given slur S of a social group G and a person P, S is true of (...) P iff P bears the “essence” of G—whatever this essence is—which is causally responsible for stereotypical negative features associated with G and predicted of P. Since there is no essence that is causally responsible for stereotypical negative features of a social group, slurs have null-extension, and consequently, many sentences containing them are either meaningless or false. After giving a detailed outline of my theory, I show that it receives strong linguistic support. In particular, it can account for a wide range of linguistic cases that are regarded as challenging, central data for any theory of slurs. Finally, I show that my theory also receives convergent support from cognitive psychology and psycholinguistics. (shrink)

It is often thought that a notion of general term rigidity could help explain the particular behavior of natural kind terms in modal contexts. An influential strategy for developing a non-trivial account of general term rigidity appeals to essential properties of the things to which such terms apply. I show that essentialism cannot underpin a notion of rigidity that can play the expected explanatory roles. Essentialists are committed to presuppositions that themselves play those roles without implying essentialism.

There is a line of reasoning in metaepistemology that is congenial to naturalism and hard to resist, yet ultimately misguided: that knowledge might be a natural kind, and that this would undermine the use of conceptual analysis in the theory of knowledge. In this paper, I first bring out various problems with Hilary Kornblith’s argument from the causal–explanatory indispensability of knowledge to the natural kindhood of knowledge. I then criticize the argument from the natural kindhood of knowledge against the method (...) of conceptual analysis in the theory of knowledge. A natural motivation for this argument is the following seemingly plausible principle: if knowledge is a natural kind, then the concept of knowledge is a natural kind concept. Since this principle lacks adequate support, the crucial semantic claim that the concept of knowledge is a natural kind concept must be defended in some more direct way. However, there are two striking epistemic disanalogies between the concept of knowledge and paradigmatic natural kind concepts that militate against this semantic claim. Conceptual analyses of knowledge are not affected by total error, and the proponents of such analyses are not subject to a priori conceptual obliviousness. I conclude that the argument from natural kindhood does not succeed in undermining the use of conceptual analysis in the theory of knowledge. (shrink)

One type of deflationism about metaphysical modality suggests that it can be analysed strictly in terms of linguistic or conceptual content and that there is nothing particularly metaphysical about modality. Scott Soames is explicitly opposed to this trend. However, a detailed study of Soames’s own account of modality reveals that it has striking similarities with the deflationary account. In this paper I will compare Soames’s account of a posteriori necessities concerning natural kinds with the deflationary one, specifically Alan Sidelle’s account, (...) and suggest that Soames’s account is vulnerable to the deflationist’s critique. Furthermore, I conjecture that both the deflationary account and Soames’s account fail to fully explicate the metaphysical content of a posteriori necessities. Although I will focus on Soames, my argument may have more general implications towards the prospects of providing a meaning-based account of metaphysical modality. (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)

Kripke holds the thesis that identity statements containing natural kind terms are if true, necessarily true; these statements can be denominated theoretical identities. Kripke alleges that the necessity of theoretical identities grounds on the linguistic feature that natural kind terms are rigid designators. Nevertheless, I argue that the conception of natural kind terms as rigid designators, in one of their most natural views, hinders the establishment of the truth of theoretical identities and thus of their necessity. However, in Kripke’s works (...) another proposal, not linguistic but metaphysical, is found to justify the presumed necessity of theoretical identities; it grounds on essentialism concerning natural kinds. In this regard, I question some of Kripke’s main claims, focusing on one of the main examples of theoretical identities put forward by Kripke, i.e., “Water is H2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}O”. I challenge his a priori claims concerning what should be the essence of a natural kind like water. Furthermore, I adduce that the character of that theoretical identity is not that claimed by Kripke, since in the term flanking the right side of the identity sign it has to be resorted to the notion of similarity or it should have the form of a disjunction of a cluster of substances. (shrink)

Posttraumatic stress disorder is a debilitating condition that results from the experience of a traumatic event. Natural kinds are mind-independent entities found in nature and are the objects of scientific inquiry. It is common to deny that PTSD is a natural kind, but extant denials assume a thesis of natural kinds that can be called “essentialism”. According to essentialism, many entities are not natural kinds that one would expect should be natural kinds. The homeostatic cluster view of natural kinds offers (...) an alternative that accommodates these cases, including, superficially, the claim that PTSD is a natural kind. I introduce two novel objections to this claim and recommend a distinction aimed to resolve the newly introduced problems. (shrink)

It is often thought that some general terms or kind terms, in particular natural kind terms, are rigid designators, and that a properly extended notion of singular-term rigidity can help explain the behaviour of such general terms. In this article, I argue that the only legitimate notion of general-term rigidity is a trivial one and identify some crucial asymmetries between a posteriori necessary truths involving names and a posteriori necessary truths involving general terms. If we pay attention to these asymmetries, (...) it becomes clear that attempts to draw a non-trivial rigid/non-rigid distinction for general terms are bound to fail to offer the explanations we expected. As opposed to singular terms, what is interesting about the behaviour of natural kind terms, even in modal contexts, cannot be accounted for by modal distinctions like rigidity/non-rigidity but must rather track non-modal features. (shrink)

I first focus on Gomez-Torrente’s defense of a neo-Kripkean treatment of theoretical identification statements like “Water is H2O” against objections that ‘water’ is vague and that ‘H2O’ does not designate a genuine explanatory kind. On my reading, Gomez-Torrente accepts and while interpreting the identity statement as correctly attributing vague identity to the pair consisting of the vague natural kind water and the related kind H2O. My discussion sketches a framework for making sense talk of vague objects, properties, and identities that (...) seems to fit his discussion. Next I focus on his treatment of a problem posed by seemingly conflicting perceptual reports of secondary qualities, like being hot, or red, made by equally competent observers. Since the observers are equally competent, it is hard to explain the apparent inconsistency. Whereas Gomez-Torrente treats the reports as so fine-grained as not to conflict, I suggest dispensing with ultrafine-grained semantic contextual parameters in favor of richer pragmatic parameters determining negotiated asserted contents. Next I question whether his plausible individually sufficient but not disjunctively necessary rules for uses of names and demonstratives should be understood as providing speaker referents versus contributions to illocutionary contents of uses of sentences containing those terms. Finally, I explain why I take the crowning jewel of the book to be the account in chapter 4 of natural numbers as plural cardinality properties, and of verbal, and Arabic, numerals as Millian names of those properties, the referents of which are fixed by genuinely semantic reference-fixing expressions. (shrink)