Natural Kind Thingamajigs

I criticize the treatment of natural kinds as some sort of object, advocated in a recent paper by Alexander Bird. The arguments he gives for regimenting an illustrative statement featuring chemical kinds in his preferred manner are not conclusive, and his criticisms of an alternative strategy involving universally quantified sentences fail. This is important because of the widespread but poorly supported assumption that expressions of natural kinds should be treated as singular referring terms.     

Many Many Problems

Supervaluationist solutions to 'the problem of the many' typically rely on two principles. First, the root of the problem is that singular terms can be vague, just as predicates can be. Secondly, the same resolution as the supervaluationist suggests for puzzles with vague predicates will resolve puzzles concerning vague singular terms. In recent years this second principle has been attacked from a number of fronts: it has been claimed that supervaluationist accounts of vague singular terms cannot explain the role of vague singular terms in propositional attitude reports, cannot explain penumbral connections between distinct singular terms, and cannot allow that vague singular terms are directly referential. While some of these arguments are successful against extant supervaluationist theories, I offer some natural modifications to supervaluationism which avoid the challenges.     

Social Construction and Achieving Reference1

One influential view is that at least some putatively natural human kinds are actually social constructions, understood as some real kind of thing that is produced or sustained by our social and conceptual practices. Category constructionists share two commitments: they hold that human category terms like “race” (and racial terms) and “sex” (and sexual terms) and “homosexuality” and “perversion” actually refer to constructed categories, and they hold that these categories are widely but mistakenly taken to be natural kinds. But it is far from clear that these two commitments are consistent. The sort of mismatch between belief and underlying nature constructionists’ suppose is often taken to indicate a failure of reference. Reliance on a causal‐historical account of reference allows the preservation of reference, but unfortunately, constructionists' appropriation of causal historical accounts of reference is beset by difficulties that do not attend natural kind theorists’ appeals to such accounts. Here, I set out these difficulties, but argue that they can be answered, allowing terms for apparently natural human kinds refer to some sort of social construction about which there is massive error.     

Language and metaphysics: the case of theoretical identities

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 H\(_2\)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.

     

Two approaches to natural kinds

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.

     

Rigidity and actuality-dependence

It is generally assumed that rigidity plays a key role in explaining the necessary a posteriori status of identity statements, both between proper names and between natural kind terms. However, while the notion of rigid designation is well defined for singular terms, there is no generally accepted definition of what it is for a general term to be rigid. In this paper I argue that the most common view, according to which rigid general terms are the ones which designate the same kind in all possible worlds, fails to deliver a posteriori necessities. I also present an alternative view, on which the work of explaining a posteriori necessities is not done by rigidity, but by a related metasemantic notion, which I call actuality-dependence.     

Authority and Natural Kind Essence

If natural kinds have microstructural essences they have them independently of rules for the application of kind terms. This suggests that what those rules are should make no difference to the essences being discoverable. I present two thought-experiments that suggest otherwise, however. Each shows an authority’s application of rules creates the appearance of there being kind essences; absent those rules, the appearance vanishes. This suggests natural kind essences are not independent of authority-sanctioned rules.     

Diseases as natural kinds

In this paper, I focus on life-threatening medical conditions and argue that from the point of view of natural properties, induction(s), and participation in laws, at least some of the ill organisms dealt with in somatic medicine form natural kinds in the same sense in which the kinds in the exact sciences are thought of as natural. By way of comparing two ‘divisions of nature’, viz., a ‘classical’ exact science kind (gold) and a kind of disease (Graves disease), I show that there is no justifiable ‘ontological gap’ between disease kinds and exact sciences kinds. We have instead a difference of degree.     

A Biological Alternative to Moral Explanations

Some moral realists claim that moral facts are a species of natural fact, amenable to scientific investigation. They argue that these moral facts are needed in the best explanations of certain phenomena and that this is evidence that they are real. In this paper I present part of a biological account of the function of morality. The account allows the identification of a plausible natural kind that could play the explanatory role that a moral kind would play in naturalist realist theories. It is therefore a candidate for being the moral kind. I argue, however, that it will underdetermine the morally good, that is, identifying the kind is not sufficient to identify what is good. Hence this is not a natural moral kind. Its explanatory usefulness, however, means that we do not have to postulate any further (moral) facts to provide moral explanations. Hence there is no reason to believe that there are any natural moral kinds.     

Kinds, General Terms, and Rigidity: A Reply to LaPorte

Joseph LaPorte in an article on `Kind and Rigidity'(Philosophical Studies, Volume 97) resurrects an oldsolution to the problem of how to understand the rigidityof kind terms and other general terms. Despite LaPorte'sarguments to the contrary, his solution trivializes thenotion of rigidity when applied to general terms. Hisarguments do lead to an important insight however. Thenotions of rigidity and non-rigidity do not usefullyapply at all to kind or other general terms. Extendingthe notion of rigidity from singular terms such as propernames to general terms such as natural kind terms is amistake.     

Teleological Essentialism: Generalized

Natural/social kind essentialism is the view that natural kind categories, both living and non-living natural kinds, as well as social kinds (e.g., race, gender), are essentialized. On this view, artifactual kinds are not essentialized. Our view—teleological essentialism—is that a broad range of categories are essentialized in terms of teleology, including artifacts. Utilizing the same kinds of experiments typically used to provide evidence of essentialist thinking—involving superficial change (study 1), transformation of insides (study 2), and inferences about offspring (study 3)—we find support for the view that a broad range of categories—living natural kinds, non-living natural kinds, and artifactual kinds—are essentialized in terms of teleology. Study 4 tests a unique prediction of teleological essentialism and also provides evidence that people make inferences about purposes which in turn guide categorization judgments.     

Necessity and Rigidly Designating Kind Terms

Kripke claims that certainkind terms, particularly natural kind terms,are, like names, rigid designators. However,kind terms are more complicated than names aseach is connected both to a principle ofinclusion and an extension. So, there is aquestion regarding what it is that rigidlydesignating kind terms rigidly designate. Inthis paper, I assume that there are rigidlydesignating kind terms and attempt to answerthe question as to what it is that they rigidlydesignate. I then use this analysis of rigidlydesignating kind terms to show how Kripke'sreasoning regarding the necessity of `Hesperusis Phosphorus' can be extended to statementsinvolving kind terms like `Water is H₂O'and `Tigers are mammals'.     

‘Knowledge’ as a natural kind term

Naturalists who conceive of knowledge as a natural kind are led to treat ‘knowledge’ as a natural kind term. ‘Knowledge,’ then, must behave semantically in the ways that seem to support a direct reference theory for other natural kind terms. A direct reference theory for ‘knowledge,’ however, appears to leave open too many possibilities about the identity of knowledge. Intuitively, states of belief count as knowledge only if they meet epistemic criteria, not merely if they bear a causal/historical relation to the term. I will develop this objection and show that it is grounded in modal considerations central to Kripke’s work on reference. I will also argue that a more plausible externalist semantics for natural kind terms disarms the objection.     

Two Ways to Smoke a Cigarette

In the early part of the paper, I attempt to explain a dispute between two parties who endorse the compositionality of language but disagree about its implications: Paul Horwich, and Jerry Fodor and Ernest Lepore. In the remainder of the paper, I challenge the thesis on which they are agreed, that compositionality can be taken for granted. I suggest that it is not clear what compositionality involves nor whether it obtains. I consider some kinds of apparent counterexamples, and compositionalist responses to them in terms of covert indexicality and unspecific meanings. I argue that the last option is the best for most of the cases I consider. I conclude by stressing, as against Horwich and Fodor and Lepore, that the appropriate question concerns the extent to which compositionality obtains in a natural language, rather than whether it obtains or not, so that the answer is essentially messy, requiring detailed consideration of a wide range of examples.     

The subject of “We intend”

This paper examines and compares the ways in which intentions of the singular kind (“I intend”) and the plural kind (“we intend”) are subjective. Are intentions of the plural kind ours in the same way intentions of the singular kind are mine? Starting with the singular case, it is argued that “I intend” is subjective in virtue of self-knowledge. Self-knowledge is special in that it is self-identifying, self-validating, self-committing, and self-authorizing. Moving to the plural form, it is argued that in spite of apparent differences, attitudes of the form “we intend” are subjective in the same way. The self-knowledge at work here is plural rather than singular. This supports a plural subject account of collective intentionality. It is argued that the worries sometimes raised in the literature against the metaphysical “spookiness” of plural subjects are due to a fundamental misconception of the way in which attitudes of either kind –singular and plural – are subjective.     

Revising the concept of lawhood: special sciences and natural kinds

The Kripkean conception of natural kinds (kinds are defined by essences that are intrinsic to their members and that lie at the microphysical level) indirectly finds support in a certain conception of a law of nature, according to which generalizations must have unlimited scope and be exceptionless to count as laws of nature. On my view, the kinds that constitute the subject matter of special sciences such as biology may very well turn out to be natural despite the fact that their essences fail to be microphysical or micro-based. On the causal conception of natural kinds I privilege, the naturalness of a kind is a function of the fact that it figures prominently in at least one causal law. However, there is a strong tendency prevailing among contemporary philosophers to assume that, in order to count as proper laws generalizations must be expectionless. Since most generalizations tracked down by the special sciences turn out not to fulfill these criteria, what this conception of a law implies is that most of the generalizations the special sciences trade in are not proper laws. It follows that, on this view, most if not all of the kinds the special sciences dealing with turn out not to constitute natural kinds, understood as kinds to which bona fide laws apply. In order to establish that the non-microstructurally defined kinds that fall within the domain of enquiry of the special sciences are eligible for the status of natural kind, I must therefore establish that generalizations needn’t have unlimited scope and be exceptionless to count as laws of nature. This is precisely what I seek to do in this paper. I begin by arguing that the question “what is a law of nature?” is most naturally interpreted as the question “what features must generalizations exhibit in order to ground scientific explanations?” and by offering reasons to believe that generalizations needn’t be exceptionless and have unlimited scope to play the crucial role laws have been thought to play in scientific explanation. Drawing on Sandra Mitchell [Mitchell, S. (2000). Philosophy of Science, 67, 242–265] and James Woodward’s [Woodward, J. (1997). Philosophy of science, 64 (proceedings), 524–541; Woodward, J. (2000). British Journal for the philosophy of science, 51(2), 197–254; Woodward, J. (2001). Philosophy of science, 68, 1–20] work, I subsequently develop an alternative account of the criteria generalizations must satisfy in order to count as laws of nature, which at least some of the generalizations of the special sciences turn out to fulfill. I thus give credence to the idea that at least some of the kinds that fall within the domain of the special sciences figure in laws of nature, and I thereby restore the possibility that some special science kinds deserve to be deemed natural.