According to the simple proposal about rigidity for predicates, a predicate is rigid (roughly) if it signifies the same property across the relevant worlds. Recent critics claim that this suffers from a trivialization problem: any predicate whatsoever would turn out to be trivially rigid, according to the proposal. In this paper a corresponding "problem" for ordinary singular terms is considered. A natural solution is provided by intuitions concerning the actual truth-value of identity statements involving them. The simple proposal for predicates (...) is then defended, by exploiting corresponding intuitions concerning statements involving their nominalizations, in an analogous manner. (shrink)

Natural kind essentialism is a specification of the intuitive idea that there are some mind-independent or objective categories in nature. These categories are thought to be characterised by a shared essence, which may involve intrinsic or extrinsic properties, mechanisms, or causal history. While the ontological basis of natural kinds has its roots in antiquity and especially Aristotle, the contemporary notion of a “natural kind” in philosophical discussion is often traced to William Whewell’s and John Stuart Mill’s work in the 1800s. (...) In its more modern form, natural kind essentialism was popularised in the 1970s mainly by Saul Kripke and Hilary Putnam. Traditionally, natural kind essentialism has been associated with intrinsic and microstructural properties, but contemporary work has made it clear that more refined versions of natural kind essentialism may have to accept extrinsic or relational essences. (shrink)

In this paper, I present, generalize and develop the extensionalist theory of rigidity for general terms in light of criteria commonly applied to theories of general term rigidity. According to the theory, a general term is rigid if its extension is constant across all possible worlds. This position has been widely dismissed because it conflicts with the seemingly straightforward idea that natural kind terms have varying extensions from world to world. This criticism holds only to the extent that natural kind (...) terms are indeed rigid. If it turns out that we need not view them as rigid, then the extensionalist theory fares well when compared with other theoretical requirements. (shrink)

The notion of rigidity looms large in philosophy of language, but is beset by difficulties. This paper proposes a simple theory of rigidity, according to which an expression has a world-relative semantic property rigidly when it has that property at, or with respect to, all worlds. Just as names, and certain descriptions like The square root of 4, rigidly designate their referents, so too are necessary truths rigidly true, and so too does cat rigidly have only animals in its extension. (...) After spelling out the theory, I argue that it enables us to avoid the headaches that attend the misbegotten desire to have a simple rigid/non-rigid distinction that applies to expressions, giving us a simple solution to the problem of generalizing the notion of rigidity beyond singular terms. (shrink)

The principal question addressed is whether there is a division among common nouns which is similar to a familiar division among noun phrases that designate particular-level individuals: the one which is captured in the relevant literature as the difference between de jure rigid and not de jure rigid singular terms. In relation with the previous philosophical literature relevant to noun rigidity it is argued that the extant positions on the matter are not defended on the basis of well-founded syntactic categories (...) and proper semantic arguments. Proper ways to argue for rigidity ascriptions to nouns are described. Then, such arguments are sought for the case of rigid/non-rigid division among count common nouns. It is shown that there are plausible, albeit inconclusive, reasons to hold that among common nouns (N-bar expressions) only simple common nouns are kind designators, and that if that is the case these simple common nouns will have to be reckoned as de jure rigid designators. (shrink)

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. (shrink)

Though it is often claimed that some general terms are rigid designators, it has turned out to be difficult to give a satisfying definition that avoids making all general terms rigid, and even if a non-rigid reading is available, makes that non-rigid reading matter. Several authors have attempted to develop examples that meet the trivialization challenge, with Martí and Martínez-Fernández providing what is, perhaps, the most convincing strategy. I show that the type of example Martí and Martínez-Fernández offer nevertheless fails (...) to meet the trivialization challenge and, accordingly, that we should still have serious doubts about whether continuing the search for a non-trivial definition of general term rigidity would be fruitful. (shrink)

Although it is common to claim that certain general terms or kind terms are rigid designators and that their rigidity helps explain their behavior in modal contexts, it has turned out to be surprisingly difficult to define an adequate notion of rigidity for general terms. Such definitions tend, as argued in particular by Scott Soames, to lead to a type of overgeneralization that leaves the purported rigidity of general terms explanatorily inert. In recent years, several attempts have been made to (...) circumvent the problem, and the present article focuses on a particular and potentially powerful strategy developed by Joseph LaPorte in his recent book Rigid Designation and Theoretical Identities for blocking one of the core inferences in Soames’s case against general term rigidity. I argue that the type of response LaPorte promotes is bound to fail; though it might initially appear to circumvent the threat of trivialization described by Soames, it is susceptible to a different and arguably even worse kind of trivialization challenge. In conclusion, Soames’s arguments remain a significant obstacle to identifying a non-trivializing definition of kind term rigidity, and we have good reasons to think that an explanation for the modal status of theoretical identity statements must be sought elsewhere. (shrink)

The question whether the notion of rigidity can be extended in a fruitful way beyond singular terms has received a standard answer in the literature, according to which non-singular terms designate kinds, properties or other abstract singular objects and generalized rigidity is the same thing as singular term rigidity, but for terms designating such objects. I offer some new criticisms of this view and go on to defend an alternative view, on which non-singular terms designate extensions in general, and generalized (...) rigidity is identity of extension across possible worlds. I develop some fundamental positive considerations that make this view virtually inevitable as a view of generalized rigidity, emphasizing its exclusive ability to offer a purely logical justification of the necessity of several kinds of statements that go beyond true identity statements between rigid singular terms. (shrink)

Natural kind terms have exercised philosophical fancy ever since Kripke, in Naming and Necessity, claimed them to be rigid designators. He there drew attention to the peculiar, name-like behavior of a family of prima facie loosely related general terms of ordinary English: terms such as ‘water’, ‘tiger’, ‘heat’, and ‘red’. Just as for ordinary proper names, Kripke argued that such terms cannot be synonymous with any of the definite descriptions ordinary speakers associate with them. Rather, the name-like behavior of these (...) so-called natural kind terms is to be explained, just as in in the case of proper names, by the doctrine of rigid designation. And as a consequence of thus extending the notion of rigid designation to general terms, he famously endorsed the claim that so-called ‘theoretical identifications’, i.e. statements like (1) Water is H2O, are necessary, if true. (shrink)

Standard Kripke-Putnam semantics is widely taken to entail that theoretical identifications like ‘Brontosauruses are Apatosauruses’ or ‘Gold is 79Au’ are necessary, if true. I offer a new diagnosis as to why this modal consequence ensues. Central to my diagnosis is the concept of a paradigm term. I argue that modal and epistemic peculiarities that are commonly considered as distinctive of natural kind expressions are in fact traits that are shared by paradigm terms in general. Philosophical semantics should broaden its focus (...) from natural kind expressions to paradigm terms. (shrink)

Since Hilary Putnam and Saul Kripke's first attacks on traditional, descriptivist theories of natural kind terms, it has become customary to speak of the ‘Putnam-Kripke’ view of meaning and reference. This article argues that this is a mistake, and that Putnam's account of natural kind terms is importantly different from that of Kripke. In particular, Putnam has from the very start been sceptical of Kripke's modal claims, and in later papers he explicitly rejects the proposal that theoretical identity statements are (...) metaphysically necessary (if true). I suggest that this is wholly in line with Putnam's earlier, Quine-inspired writings on general terms, and his preoccupation with the philosophy of science. Moreover, I argue that the picture of general terms that emerges from Putnam's writings is more plausible than that suggested by Kripke. However, contrary to Putnam, I also suggest that Putnam's later views on natural kinds and natural kind terms do not support standard Twin Earth externalism. (shrink)

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)

The paper argues that the assumption that there are property designators, together with two theoretically innocent claims, leads to a puzzle, whose solution requires us to reject the position that all (canonical) property designators are rigid. But if we deny that all (canonical) property designators are rigid, then the natural next step is to reject an abundant conception of properties and with it the suggestion that properties are the semantic values of predicates.

There is a considerable sub-literature, stretching back over 35 years, addressed to the question: Precisely which general terms ought to be classified as rigid designators? More fundamentally: What should we take the criterion for rigidity to be, for general terms? The aim of this paper is to give new grounds for the old view that if a general term designates the same kind in all possible worlds, then it should be classified as a rigid designator. The new grounds in question (...) have to do with excavating the connection between rigid designation and semantic structure. Other original contributions of the present work consist in developing responses to some objections to this approach to rigid designation. (shrink)

Rigid expressionism is the view that all natural kind terms and many other kind terms are rigid designators. Rigid expressionists embrace the ‘overgeneralization’ of rigidity, since they hold that not just natural kind terms but all unstructured kind terms are rigid designators. Unfortunately overgeneralization remains a defeating problem for rigid expressionism. It runs together natural kind terms and nominal kind terms in a way that enforces a false semantic uniformity. The Kripke/putnam view of natural kind terms minus the claim of (...) rigidity is correct, but a traditional descriptivist theory is appropriate for nominal kind terms. None of them should be thought of as either rigid or non-rigid, however. (shrink)

The classification-cum-explanation Kripke assigns to rigidity requires the notion to apply to singular and general terms alike. But Kripke's own notion of rigidity is tailor-made for singular terms, and an extensive debate has not secured a general notion of rigidity apt to provide the classification-cum-explanation Kripke aims for. I propose that we look for a Kripkean alternative to generalized rigidity. I argue that on Kripkean premises, natural kind terms and proper names belong to the meta-semantic category of paradigm terms. I (...) also argue that the property of being a paradigm term effects precisely the classification-cum-explanation Kripke attributes to rigidity. I conclude that Kripkeans should acknowledge that being a paradigm term, rather than designating rigidly, plays the role Kripke delineates, and that we can stop worrying about generalizing rigidity. Kripke's notion works fine for singular terms. And there is no need for rigidity to apply beyond these. (shrink)

En este trabajo, critico una estrategia argumental que ha sido utilizada para defender la concepción de la rigidez para expresiones predicativas entendida como identidad de lo designado en los distintos mundos posibles. Se trata de una estrategia basada en la suposición de que las descripciones tendrían la capacidad de designar individuos inusuales en la misma medida en que ciertas expresiones predicativas descriptivas serían capaces de designar propiedades inusuales. Señalo que esta suposición no es compatible con ciertos principios que gobiernan el (...) funcionamiento semántico de las descripciones y con la verdad intuitiva de ciertas predicaciones que las incluyen.In this paper, I criticize an argumentative strategy that has been used in the literature to defend the view according to which rigidity for predicative expressions should be understood as identity of designation across possible worlds. It is a strategy that is based on the supposition that definite descriptions could designateunusual individuals just as well as some descriptive predicative expressions are able to designate unusual properties. I point out that this presupposition is at odds with some principles governing the semantic behaviour of definite descriptions and with the intuitive truth of some predications that include them. (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)