The Twin Earth thought experiment invites us to consider a liquid that has all of the superficial properties associated with water (clear, potable, etc.) but has entirely different deeper causal properties (composed of “XYZ” rather than of H2O). Although this thought experiment was originally introduced to illuminate questions in the theory of reference, it has also played a crucial role in empirically informed debates within the philosophy of psychology about people’s ordinary natural kind concepts. Those debates have sought to accommodate (...) an apparent fact about ordinary people’s judgments: Intuitively, the Twin Earth liquid is not water. We present results from four experiments showing that people do not, in fact, have this intuition. Instead, people tend to have the intuition that there is a sense in which the liquid is not water but also a sense in which it is water. We explore the implications of this finding for debates about theories of natural kind concepts, arguing that it supports views positing two distinct criteria for membership in natural kind categories – one based on deeper causal properties, the other based on superficial, observable properties. (shrink)

The Twin Earth thought experiment invites us to consider a liquid that has all of the superficial properties associated with water (clear, potable, etc.) but has entirely different deeper causal properties (composed of “XYZ” rather than of H2O). Debates about natural kind concepts have sought to accommodate an apparent fact about ordinary people's judgments: Intuitively, the Twin Earth liquid is not water. We present results showing that people do not have this intuition. Instead, people tend to judge that there is (...) a sense in which the liquid is not water but also a sense in which it is water. (shrink)

In a number of influential papers, Machery, Mallon, Nichols and Stich have presented a powerful critique of so-called arguments from reference, arguments that assume that a particular theory of reference is correct in order to establish a substantive conclusion. The critique is that, due to cross-cultural variation in semantic intuitions supposedly undermining the standard methodology for theorising about reference, the assumption that a theory of reference is correct is unjustified. I argue that the many extant responses to Machery et al.’s (...) critique do little for the proponent of an argument from reference, as they do not show how to justify the problematic assumption. I then argue that it can in principle be justified by an appeal to Carnapian explication. I show how to apply the explication defence to arguments from reference given by Andreasen and by Churchland. (shrink)

One of the central debates in the philosophy of language is that between defenders of the causal-historical and descriptivist theories of reference. Most philosophers involved in the debate support one or the other of the theories. Building on recent experimental work in semantics, we argue that there is a sense in which both theories are correct. In particular, we defend the view that natural kind terms can sometimes take on a causal-historical reading and at other times take on a descriptivist (...) reading. The meaning will shift depending on the conversational setting. The theoretical view has roots in work by Kitcher. We present some original experiments that support the thesis. (shrink)

The present research examines whether identity essentialism, an important component of psychological essentialism, is a fundamental feature of human cognition. Across three studies (Ntotal = 1723), we report evidence that essentialist intuitions about the identity of kinds are culturally dependent, demographically variable, and easily malleable. The first study considered essentialist intuitions in 10 different countries spread across four continents. Participants were presented with two scenarios meant to elicit essentialist intuitions. Their answers suggest that essentialist intuitions vary dramatically across cultures. Furthermore, (...) these intuitions were found to vary with gender, education, and across eliciting stimuli. The second study further examined whether essentialist intuitions are stable across different kinds of eliciting stimuli. Participants were presented with two different scenarios meant to elicit essentialist intuitions—the “discovery” and “transformation” scenarios. Their answers suggest that the nature of the eliciting stimuli influences whether or not people report essentialist intuitions. Finally, the third study demonstrates that essentialist intuitions are susceptible to framing effects. Keeping the eliciting stimulus (i.e., the scenario) constant, we show that the formulation of the question eliciting a judgment influences whether or not people have essentialist intuitions. Implications of these findings for identity essentialism and psychological essentialism, in general, are discussed. (shrink)

Two important thought-experiments are associated with the work of Hilary Putnam, one designed to establish multiple realizability for mental kinds, the other designed to establish essentialism for natural kinds. Comparing the thought-experiments with each other reveals that the scenarios in both are structurally analogous to each other, though his intuitions in both are greatly at variance, intuitions that have been simultaneously well received. The intuition in the former implies a thesis that prioritizes pre-scientific over scientific indicators for identifying mental kinds (...) in certain circumstances, while his intuition in the latter implies a converse thesis, prioritizing scientific over pre-scientific indicators for identifying natural kinds in analogous circumstances. In this paper I question whether we can consistently endorse both of these intuitions. A consideration is presented to attempt to justify the common intuition found in the multiple realization thought-experiment. Then it is argued that this same consideration has application in the structurally analogous Twin-Earth thought-experiment. This recommends a kind of multiple realization thesis for natural kinds, in opposition to a scientific essentialist approach. The various respects in which mental kinds like pain and natural kinds like water are similar to each other, such that similar philosophical treatments are warranted for both, are enumerated. (shrink)

This paper presents an extension of Putnam's account of how substance terms such as ‘water’ and ‘gold’ function and of how a posteriori necessary truths concerning the underlying microstructures of such kinds may be derived. The paper has three aims. I aim to refute a familiar criticism of Putnam's account: that it presupposes what Salmon calls an ‘irredeemably metaphysical, and philosophically controversial, theory of essentialism’. I show how all of the details of Putnam's account—including those that Salmon believes smuggle in (...) such essentialist commitments—can be squared with a rejection of any such essentialist metaphysics. I aim to reveal why Steward is wrong to suppose that, by helping himself to the claim that ‘H2O’ is a rigid designator of a substance, Kripke, too, presupposes something controversially ‘metaphysical’. I aim to show how my proposed account also sidesteps a variety of objections raised by Needham and others who argue that Kripke's and Putnam's accounts of how ‘water’ and.. (shrink)

It has been argued that prototypes cannot compose, and that for this reason concepts cannot be prototypes (Osherson and Smith in Cognition 9:35–58, 1981; Fodor and Lepore in Cognition 58:253–270, 1996; Connolly et al. in Cognition 103:1–22, 2007). In this paper I examine the intensional and extensional approaches to prototype compositionality, arguing that neither succeeds in their present formulations. I then propose a hybrid extensional theory of prototype compositionality, according to which the extension of a complex concept is determined as (...) a function of what triggers its constituent prototypes. I argue that the theory escapes the problems traditionally raised against extensional theories of compositionality. (shrink)

Fodor’s theory of concepts holds that the psychological capacities, beliefs or intentions which determine how we use concepts do not determine reference. Instead, causal relations of a specific kind between properties and our dispositions to token a concept are claimed to do so. Fodor does admit that there needs to be some psychological mechanisms mediating the property–concept tokening relations, but argues that they are purely accidental for reference. In contrast, I argue that the actual mechanisms that sustain the reference determining (...) concept tokening relations are necessary for reference. Fodor’s atomism is thus undermined, since in order to refer with a concept it is necessary to possess some specific psychological capacities. (shrink)

Recent experimental studies have claimed to find evidence for the view that natural kind terms such as “water” are ambiguous: that they have two extensions, one determined by superficial properties, the other by underlying essence. In an online experiment, we presented to 600 participants scenarios describing discoveries of novel samples that differ in deep structure from samples of a familiar kind but are superficially identical, such as a water-like substance that is not composed of H2O. We used three different types (...) of question sets to probe whether the participants considered the sample as a member of the kind or not. Our results did not confirm the predictions of the ambiguity view. They were, rather, consistent with views that take underlying essences to be the sole criterion for membership in a natural kind. (shrink)

Following the influential thought experiments by Hilary Putnam and others, philosophers of language have for the most part adopted semantic externalism concerning natural kind terms. In this article, we present results from three experiments on the reference of natural kind terms. Our results confirm some standard externalist assumptions, but are in conflict with others: Ordinary speakers take both appearance and underlying nature to be central in their categorization judgments. Moreover, our results indicate that speakers’ categorization judgments are gradual, and proportional (...) to the degree of similarity between new samples and familiar, “standard” samples. These findings pose problems for traditional theories, both externalist and internalist. (shrink)

Causal theories of reference for natural kind terms are widely agreed to play a central role in arguments for the claim that theoretical identity statements such as “Water is H2O” are necessary, if true. However, there is also fairly wide-spread agreement, due to the arguments of Nathan Salmon, that causal theories of reference do not alone establish such essentialism about natural kinds: an independent, non-trivial essentialist premise is also needed. In this paper I will question this latter agreement. I will (...) argue that there is an independently attractive explanation of why such identity statements are metaphysically necessary, if true: an explanation which relies on assumptions about the semantics of natural kind terms, general philosophical assumptions about reference, and straightforward empirical assumptions, but presupposes no non-trivial essentialist premises. (shrink)

This paper excavates a debate concerning the claims of ordinary language philosophers that took place during the middle of the last century. The debate centers on the status of statements about ‘what we say’. On one side of the debate, critics of ordinary language philosophy argued that statements about ‘what we say’ should be evaluated as empirical observations about how people do in fact speak, on a par with claims made in the language sciences. By that standard, ordinary language philosophers (...) were not entitled to the claims that they made about what we would say about various topics. On the other side of the debate, defenders of the methods of ordinary language philosophy sought to explain how philosophers can be entitled to statements about what we would say without engaging in extensive observations of how people do in fact use language. In this paper, I defend the idea that entitlement to claims about what we say can be had in a way that doesn’t require empirical observation, and I argue that ordinary language philosophers are engaged in a different project than linguists or empirically minded philosophers of language, which is subject to different conditions of success. (shrink)

Recent experimental work on “natural” kind terms has shown evidence of both descriptive and nondescriptive reference determination. This has led some to propose ambiguity or hybrid theories, as opposed to traditional description and causal‐historical theories of reference. Many of those experiments tested theories against referential intuitions. We reject this method, urging that reference should be tested against usage, preferably by elicited production. Our tests of the usage of a biological kind term confirm that there are indeed both descriptive and causal‐historical (...) elements to the reference determination of some natural kind terms. We argue that to accommodate our results and earlier ones, we should abandon the common assumption that any one theory of reference fits all natural kind terms. Rather, it is likely that some terms are descriptive, some causal‐historical, some ambiguous, and some hybrid. This substantive conclusion is accompanied by a methodological one. Our experiments, like some earlier ones, found participants contradicting both each other and themselves. We argue that these contradictions indicate a lack of linguistic competence with the term. We conclude that these experiments have been faulty, because they test terms that are novel to participants and/or use fantastical vignettes. We provide some suggestions for future research. (shrink)

Kripke-Putnam argument for natural kind essentialism can be said to depend on placeholder essentialist intuitions. But some argue that such philosophical intuitions are merely preschooler cognitive biases which are not supported by scientific knowledge of natural kinds. Chemical substances, for instance, whether elements or compounds do not have such privileged set of underlying properties (‘same substance’ relation) which are present in all members of the kind and which provide necessary and sufficient condition for kind membership. In this paper, I argue (...) that placeholder essentialism works for at least some of the scientific natural kinds especially for the basic chemical natural kind, i.e., element. I argue that the dual sense of the element (the basic substance and the simple substance) along with microstructuralism helps explain the essence of an element not only at the abstract level but also at the more concrete level. Based on this essentialist account of element, I conclude that placeholder essentialism is not completely without merit, and it fits nicely with at least some of our scientific natural kinds. (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)