Online research in philosophy

The argument known as the 'McKinsey Recipe' tries to establish the incompatibility of semantic externalism (about natural kind concepts in particular) and _a priori _self- knowledge about thoughts and concepts by deriving from the conjunction of these theses an absurd conclusion, such as that we could know _a priori _that water exists. One reply to this argument is to distinguish two different readings of 'natural kind concept': (i) a concept which _in fact _denotes a natural kind, and (ii) a concept which _aims_ to denote a natural kind. Paul Boghossian has argued, using a _Dry Earth _scenario, that this response fails, claiming that the externalist cannot make sense of a concept aiming, but failing, to denote a natural kind. In this paper I argue that Boghossian's argument is flawed. Borrowing machinery from two-dimensional semantics, using the notion of 'considering a possible world as actual', I claim that we can give a determinate answer to Boghossian's question: which concept would 'water' express on Dry Earth?

The thought that diseases form natural kinds tends not to sit well with the essentialist treatment of natural kinds. The essentialist’s candidates for the essences of diseases—etiological properties—rarely satisfy the essentialist’s requirement that they be necessary and sufficient for membership within the kind. Consequently philosophers of medicine have tended to back away from treating diseases as natural kinds. However, this retreat was too hasty: there are good reasons for thinking that diseases form natural kinds. The problem lies with the essentialist treatment of natural kinds, and not with treating disease as forming natural kinds. A similar revolution has taken place within the species debate, where the notion of natural kind has been ‘taken back’ from the essentialist. Borrowing the revised treatment of natural kinds from the philosophers of species and modifying it slightly, I offer a proposed treatment of disease kinds in terms of homeostatic property clusters.

In defending semantic externalism, philosophers of language have often assumed that there is a straightforward connection between scientific kinds and the natural kinds recognized by ordinary language users.1 For example, the claim that water is H2O assumes that the ordinary language kind water corresponds to a chemical kind, which contains all the molecules with molecular formula H2O as its members. This assumption about the coordination between ordinary language kinds and scientific kinds is important for the externalist program, because it is what allows us to discover empirically the extensions of ordinary language kind terms.

Kripke and Putnam have convinced most philosophers that we cannot do metaphysics of nature by analysing the senses of natural kind terms -- simply because natural kind terms do not have senses. Neo-descriptivists, especially Frank Jackson and David Chalmers, believe that this view is mistaken. Merging classical descriptivism with a Kaplan-inspired two-dimensional framework, neo-descriptivists devise a semantics for natural kind terms that assigns natural kind terms so-called 'primary intensions'. Since primary intensions are senses by other names, Jackson and Chalmers conclude that we can and should do metaphysics of nature by analysing the natural kind concepts competent speakers possess. I argue that neo-descriptivism does not provide a suitable basis for doing this kind of metaphysics. I first of all give a detailed account of the neo-descriptivist semantics and deflate the intuitive support neo-descriptivists try to draw from their case of the XYZ-world. I then present three arguments -- the Argument from Ignorance, the Argument from Conceptual Analysis, and the Argument from Laziness. Taken together, these arguments undermine the neo-descriptivist analysis of natural kind terms. I conclude that natural kind terms do not have senses, that we cannot do metaphysics of nature by analysing the senses of our kind terms, and that the Kripke-Putnam account still provides the best semantics for natural kind terms we have.

Paul Boghossian has argued that Externalism is incompatible with privileged self-knowledge because (i) the Externalist can cite no property to be the reference of an empty natural kind concept such as the ether; (ii) without reference there is no content; hence (iii) either we do know on the basis of introspection alone whether an apparent natural kind thought has content or not, in which case we can infer from self-knowledge and a priori knowledge of Externalism alone to the existence in our environment of water, gold etc.; (iv) or we do not know, without empirical investigation, whether an apparent natural kind thought has content. An Externalist not wanting to accept either (iii) or (iv) can deny (i). All empty natural kind concepts refer to the necessarily uninstantiated property of being identical to nothing. Since they have different senses and self-knowledge is only held to extend to the existence and identity of sense, this is compatible with privileged self-knowledge, and Externalism is still true of the concepts.

It is widely held that the meaning of certain types of terms, such as natural kind terms, is individuated externalistically, in terms of the individual's external environment. Recently a more radical thesis has emerged, a thesis we dub 'a posteriori semantics.' The suggestion is that not only does a term's meaning depend on the external environment, but so does its semantics. One motivation for this is the aim to account for cases where a putative natural kind term fails to pick out a natural kind: The term may have a standard externalist semantics (if it picks out a natural kind) or a more descriptivist one (if it does not). Knowing which semantics applies will therefore require detailed empirical knowledge. This move has also been employed in cases where a singular term, such as a name, fails to have a reference. We argue that a posteriori semantics is inherently implausible, since the type of semantics common terms should be given ought not to be conditional on details of chemistry or physics. A number of difficulties for the position—'metaphysical,' epistemological, and methodological—are articulated. Finally, we suggest that a posteriori semantics misconstrues the way in which semantics is empirical.

, Lawrie Reznek argues that disease is not a natural kind term. I raise objections to Reznek's two central arguments for establishing that disease is not a natural kind. In criticizing his a priori, conceptual argument against naturalism, I argue that his conclusion rests on a weaker argument that appeals to the empirical diversity in the symptoms and manifestations of disease. I also raise questions about the account of natural kinds which Reznek utilizes and his point that conventions for classification are excluded by there being natural kinds. Keywords: Disease, natural kind, value judgement CiteULike Connotea Del.icio.us What's this?

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.

It has been suggested that the theory of reference advanced by Kripke and Putnam implies, or presupposes, an aristotelian vision of natural kinds and essences. I argue that what is in fact established is that there are degrees of naturalness among kinds. A parallel argument shows that there are degrees of naturalness among individuals. A subsidiary theme of the paper is that the definition of "natural kind term" as "rigid designator of a natural kind" is mistaken. Names and natural kind terms are defined by ostension to a spatiotemporal part of what they ostend. This helps us understand why 'Hesperus' and 'Phosphorus' are cognitively non-equivalent.

The main contribution of this paper is a new account of how a community may introduce a term for a natural kind in advance of knowing the correct scientific account of that kind. The account is motivated by the inadequacy of the currently dominant accounts of how a community may do this, namely those proposed by Kripke and by Putman. Their accounts fail to deal satisfactorily with the facts that (1) typically, an item that instantiates one natural kind instantiates several - 'the higher-level natural kinds problem', and (2) natural kinds often occur in nature in impure form - 'the composition problem' .On the account I propose, a term for a natural kind gains its reference by being associated with a recognitional capacity for that kind. I show how members of a scientifically ignorant community could have a recognitional capacity for a natural kind, say gold, as opposed to a certain kind of appearance, for instance the appearance that gold actually has. I argue that members of such a community can have recognitional capacities for particular natural kinds despite the actual or possible existence of duplicate kinds, e.g. water. After developing the account in detail, I show how it can deal with the two problems faced by Kripke's and Putnam's problem. The case of natural kind terms is crucial to the central debate in the philosophy of language and the philosophy of mind about whether we can refer non-descriptively to objects and kinds in the world. I take the account I propose to be a non-descriptive account of linguistic reference to natural kinds that can be used to support externalism in the philosophy of mind.