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 examines a recent, influential argument for individualism in psychology defended by Jerry Fodor and others, what I call the argument from causal powers. I argue that this argument equivocates on the crucial notion of "causal powers", and that this equivocation constitutes a deep problem for arguments of this type. Relational and individualistic taxonomies are incompatible, and it does not seem in general to be possible to factor the former into the latter. The distinction between powers and properties plays (...) a central role in my argument. (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.

Humeans and non-Humeans reasonably agree that there may be necessary connections between entities that are identical or merely partly distinct—between, e.g., sets and their individual members, fusions and their individual parts, instances of determinates and determinables, members of certain natural kinds and certain of their intrinsic properties, and (especially among physicalists) certain physical and mental states. Humeans maintain, however, that as per “Hume’s Dictum”, there are no necessary connections between entities that are wholly distinct;1 and in particular, no necessary causal (...) connections between such entities (even when the background conditions requisite for causation are in place). The Humean’s differential treatment appears principled, in reflecting that commonly accepted necessary connections involve constitutional relations, whereas wholly distinct entities (notably, causes and effects) do not constitute each other. I’ll argue, however, that the appearance of principle is not genuine, as per the following conditional: Constitutional→Causal: If one accepts certain constitutional necessities, one should accept certain causal necessities. This result provides needed leverage in assessing the two main frameworks in the metaphysics of science, treating natural kinds, causes, laws of nature, and the like. These frameworks differ primarily on whether Hume’s Dictum is taken as a working constraint on theorizing; and it has proved difficult for either side to criticize the other without presupposing their preferred stance on the dictum, hence talking past one another. The arguments for Constitutional→Causal are based, however, in general and independent considerations about what facts in the world might plausibly warrant our beliefs in certain constitutional necessities involving broadly scientific entities. The Humean can respond to these arguments, which reveal a deep tension in their view, at attendant costs of implausibilty and adhocery. The non-Humean framework doesn’t face any such tension between constitutional and causal necessities, however, and so in this respect comes out ahead. (shrink)

Whether or not the particular view of generic sentences articulated above is correct, it is quite clear that the study of generic terms and the truth-conditions of generic sentences touches on the representation of other parts of the grammar, as well as on how the world around us is reflected in language. I would hope that the problems mentioned above will highlight the relevance of semantic analysis to other apparently distinct questions, and focus attention on the relevance of linguistic problems (...) to other already established areas of inquiry. (shrink)

According to a doctrine that has been popularized by Kripke and Putnam, a natural kind term like 'bird' rigidly designates the kind with the microstructure of sample birds. This microstructure is the essence of birdhood, so our learning what the relevant microstructure is our discovery of the kind's essence. We have discovered that some statement like 'The bird is the taxon with such and such DNA structure' is true. Further, it is commonly added, the discovered microstructure is essential to each (...) particular bird. ;I argue that this general picture is mistaken. I do accept and defend the view that terms like 'bird' are rigid designators. However, the picture at issue has other difficulties. Individual birds are not essentially birds. And the view that biologists have discovered or will discover that the bird kind is identical to some DNA structure or other type of structure seems wrong. We don't discover just what particular characteristic a kind is to be identified with. Rather, the meaning of natural kind terms changes; as science advances, more sophisticated concepts attending kind terms replace older ones. So the Kripke-Putnam account of our discovering the truth of theoretical identity statements seems wrong. ;Fortunately, the account retains some interest despite its falsity, because of its association with the claim that statements like 'The bird is the taxon with such and such DNA structure' are necessary but a posteriori. The above sentence does not express a truth, much less a necessary truth, but the idea that it could have expressed the sort of necessary a posteriori truth it is supposed to express is epistemologically interesting. The very possibility of such necessary a posteriori knowledge deserves some account. I offer an account, arguing that this sort of knowledge is no more impressive from an epistemological standpoint than is knowledge of analytic necessity: indeed, I argue, it is best understood as knowledge of a species of analytic necessity. Independently of this claim, I argue in a concluding discussion that analyticity ought to be accepted by proponents of the necessary theoretical identity statements in question. (shrink)

The phrase "natural kind term" has come into the linguistic and philosophical literature in connection with well-known work of Kripke (1972) and Putnam (1970, 1975a). I use that phrase here in the sense it has acquired from those and subseqnent works on related topics. This is not the transparent sense of the phrase. That is, if I am right in what follows there are words for kinds of things existing in nature which are not natural kind terms in the current (...) sense - e.g. planet, woman, and weed. I use the term "nondescriptional", following Salmon (1981), to mean "lacking a Fregean sense", where a Fregean sense is taken to be a property or group of properties semantically associated with an expression which determines its denotation. I hope that the term "nondescriptional" will be clarified in subsequent discussion, but perhaps a few words about it and its opposite, "descriptional", would be useful here. These terms (as Salmon notes (p.15, n. 11)) should be taken as technical terms. The idea is that descriptional words, of which bachelor is the overwhelmingly favorite example, express a semantic content, or sense, which is what mediates their denotation. Entities fall in their denotation in virtue of possessing the property or properties expressed as their sense. (It is not necessary, however, that this sense be as easily paraphrasable with descriptive synonyms as it is typically held to be in the case of bachelor, or even that it be paraphrasable at all.) In the case of nondescriptional words there is no Fregean sense to mediate the link between word and object. Hence such terms are described by what Salmon, following Kaplan, calls "the theory of direct reference". What it is that does associate such terms with their denotations is another question which will be touched on briefly at the end. I have several aims in this paper. The first is to defend a conservative position on nondescriptionality. I will argue that relatively few natural language words have this property. My other aims are primarily clarificatory. Among the issues I would like to clarify are those connected with the determination of this property and flae explanation of why it exists, its relationship with other properties such as rigid designation and essentiality, and its significance for lexical semantics. The organization of the paper is as follows. The first section identifies the position taken here on the question of which expressions are nondescriptional and provides a general defense of it. The second section is a critical examination of criteria associated with nondescriptionality. In the third section provide further defense for the conservative position, and in the fourth section we turn to related issues in lexical semantics. (shrink)