Are acids natural kinds? Or are they merely relevant kinds? Although acidity has been one of the oldest and most important concepts in chemistry, surprisingly little ink has been spilled on the natural kind question. I approach the question from the perspective of microstructural essentialism. After explaining why both Brønsted acids and Lewis acids are considered functional kinds, I address the challenges of multiple realization and multiple determination. Contra Manafu and Hendry, I argue that the stereotypical properties of acids are (...) not multiply realized. Instead, given the equivalence between the proton-donating and electron-accepting mechanisms of Brønsted and Lewis, respectively, I show that acidity as a property type can be identified with a unique microstructural property, namely the presence of a LUMO or other low energy empty orbital. In doing so, I defend the view that the Lewis theory encompasses Brønsted–Lowry, and that all Brønsted acids are also Lewis acids. Contra Hacking and Chang, I thus maintain that the different concepts of acidity do not crosscut, and that the hierarchy requirement is met. Finally, by characterizing natural kinds as powerful objects and by adopting a dispositional view of functions, I illustrate how the microessentialist can make sense of the latent and relational character of most acids. In sum, I contend that acids are genuine natural kinds, even for the microstructural essentialist. (shrink)

I modify and generalize Carnap’s notion of frameworks as a way of unpacking Goodman’s metaphor of “making worlds with symbols”. My frameworks provide, metaphorically, a way of making worlds out of symbols in as much as all our framework-bound access to the world is through frameworks that always stand to be improved in accuracy, precision, and usually both. Such improvement is characterized in pragmatist terms.

Recent work on Natural Kind Essentialism has taken a deflationary turn. The assumptions about the grounds of essentialist truths concerning natural kinds familiar from the Kripke-Putnam framework are now considered questionable. The source of the problem, however, has not been sufficiently explicated. The paper focuses on the Twin Earth scenario, and it will be demonstrated that the essentialist principle at its core (which I call IDENT)—that necessarily, a sample of a chemical substance, A, is of the same kind as another (...) sample, B, if and only if A and B have the same microstructure—must be re-evaluated. The Twin Earth scenario also assumes the falsity of another essentialist principle (which I call INST): necessarily, there is a 1:1 correlation between (all of ) the chemical properties of a chemical substance and the microstructure of that substance. This assumption will be questioned, and it will be argued that, in fact, the best strategy for defending IDENT is to establish INST. The prospects for Natural Kind Essentialism and microstructural essentialism regarding chemical substances will be assessed with reference to recent work in the philosophy of chemistry. Finally, a weakened form of INST will be presented. (shrink)

A critique of LaPorte's views on chemical kinds, like jade and ruby, is presented. More positively, a new slant is provided on the question of whether elements are natural kinds. This is carried out by appeal to the dual nature of elements, a topic that has been debated in the philosophy of chemistry but not in the natural kinds literature. It is claimed that the abstract notion of elements, as opposed to their being simple substances, is relevant to the Kripke–Putnam (...) approach to natural kinds and to some criticisms that have been raised against it, although I do not support the K–P account. The proposed view avoids the traditional microstructuralist approach to natural kinds. The article also addresses the question of whether natural kinds concern metaphysical or epistemological considerations. Recent attempts by chemists to modify the periodic table are brought to bear on the question of classification and consequently on whether the identification of elements is interest dependent. (shrink)

It is widely held by philosophers not only that there is a causal condition on perception but also that the causal condition is a conceptual truth about perception. One influential line of argument for this claim is based on intuitive responses to a style of thought experiment popularized by Grice. Given the significance of these thought experiments to the literature, it is important to see whether the folk in fact respond to these cases in the way that philosophers assume they (...) should. We test folk intuitions regarding the causal theory of perception by asking our participants to what extent they agree that they would ‘see’ an object in various Gricean scenarios. We find that the intuitions of the folk do not strongly support the causal condition; they at most strongly support a ‘no blocker’ condition. We argue that this is problematic for the claim that the causal condition is a conceptual truth. (shrink)

This essay critically considers the issue of natural kind essentialism. More specifically, the essay critically probes the philosophical use of chemical examples to support realism about natural kinds. My simple contention is that the natural kind debate can be understood in terms of two different cultures of academic production. These two cultures will be conceptualized using Thomas Kasulis’s distinction between intimacy and integrity as cultural orientations. Acknowledging Kasulis’s contention that, “What is foreground in one culture may be background in another”, (...) it may very well be the case that philosophers writing about chemistry place chemical practice in the background, thereby adopting the orientation of integrity. Chemists and philosophers of chemistry, on the other hand, place chemical practice at the foreground of their work, thereby adopting the orientation of intimacy. Because the intimacy orientation is grounded in chemical practice, it is preferable to the integrity orientation. Understanding the natural kinds debate from this perspective highlights the fact that the misuse of chemical examples by certain philosophers is informed by an orientation of detachment from actual chemical practice. This underscores the importance of an intimate understanding of chemical practice when deploying chemical examples in the context of philosophical discussions about ontology and metaphysics. (shrink)

Many philosophers attribute extraordinary importance to the idea of natural kinds seemingly intimating that the very possibility of certain kinds of activity are ontologically beholden to the existence of kinds. Specifically, regarding chemistry, Brian Ellis intimated that the success of any plausible metaphysical essentialism depends upon its “reliance on examples from chemistry.” Ellis’s view is representative of a tradition in analytic philosophy that has utilized chemical examples as paradigmatic natural kinds. In this regard, Kripke and Putnam emerge as the architects (...) of an entrenched research program dedicated to the chemical tradition of natural kinds in analytic philosophy. The emergence of a critical body of literature by philosophers of chemistry and others has shattered the complacent reliance upon chemical examples as exemplary kinds. On the basis of this emerging critical literature, I will critically explore the way in which chemical practice and inquiry affects the natural kind debate. So, instead of the pretense that we simply carve nature at its joints, we need to become better grounded in the practice of science, and especially with regard to the debate about natural kinds in chemical practice. Consistent with this orientation, we need to make the practice turn, that is, eradicate the fantasy of logical reconstruction and become involved with the interpretative and historical challenges of understanding the nuances of practice. The point here is quite clear, metaphysical questions regarding natural kind should be imminent to scientific practice. Indeed, any legitimate metaphysics of natural kinds should be appropriately informed and grounded in practice and not operate on the basis of a priori sovereignty. I will insert this critical discussion within the analytical context of the notion of interpretive communities and make the case that philosophers should not assume that appeals to the purity of philosophy can substitute for the complexity and practical orientation of chemical practice. (shrink)

ABSTRACT I propose a division of the literature on natural kinds into metaphysical worries, semantic worries, and methodological worries. I argue that the latter set of worries, which concern how classification influences scientific practices, should occupy centre stage in philosophy of science discussions about natural kinds. I apply this methodological framework to the problems of classifying chemical species and nanomaterials. I show that classification in nanoscience differs from classification in chemistry because the latter relies heavily on compositional identity, whereas the (...) former must consider additional properties, namely, size, shape, and surface chemistry. I use this difference to argue for a scale-dependent theory of scientific classification. _1_ Introduction _2_ The Methodological Problem of Kinds _3_ Chemical Kindhood: Reactivity, Microstructure, and the Structure–Property Paradigm _4_ Scale-Dependence and Nanoscale Kinds _5_ Conclusion. (shrink)

Recently, macroscopic accounts of chemical kind individuation have been proposed as alternatives to the microstructural essentialist account advocated by Kripke, Putnam, and others. These accounts argue that individuation of chemical kinds is based on macroscopic criteria such as reactivity or thermodynamics, and they challenge the essentialism that grounds the Kripke-Putnam view. Using a variety of chemical examples, I argue that microstructure grounds these macroscopic accounts, but that this grounding need not imply essentialism. Instead, kinds are individuated on the basis of (...) similarity of reactivity between substances, and microstructure explains similarity of reactivity. (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)