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)

Ellis argues that certain essential properties of objects in the world not only determine the nature of these objects but also how they will behave in any situation. In this paper I will critique Ellis's essentialism from the perspective of the philosophy of chemistry, arguing that our current knowledge of chemistry in fact does not lend itself to essentialist interpretations and that this seriously undercuts Ellis's project. In particular I will criticize two key distinctions Ellis draws between internal vs. external (...) properties and essential vs. accidental properties, showing that at the chemical level such distinctions are insupportable. If essential properties only exist at the level of sub-atomic physics, then Ellis's hopes that essentialism will provide a theoretical basis for a philosophy of chemistry are at best hopes for a very distant future, since the argument that chemical structure and dynamics can be explained at the quantum level derived is purely from analogy to much simpler systems than those chemists actually study. This suggests that we have very little scientific evidence that scientific essentialism is a viable ontology. †To contact the author, please write to: Department of Philosophy, University of Notre Dame, Notre Dame, IN 46556; e-mail: [email protected]. (shrink)

The classical model of the molecule assumes that it has a definite shape and structure like a mechanical object in the world of possible experience. This study deals with this assumption so as to shed some light on the foundations of the model. Arguments based on Kant’s theory of transcendental idealism suggest that neither shape nor structure are attributes of the molecule, but are rather contributions of the subject. This claim has great relevance to the questions of whether or not (...) a quantum treatment of the molecule can derive structure without recourse to any approximation, and the possible existence of emergence and downward causation. The answer to the first question is in the negative, and to the second is that agnosticism is the only possible attitude to have toward this problem. We are creatures who can only imagine what is going on by observing phenomena. All that is accessible to us is the modal structure of the model. The causal structure of the real system is not. From the same point of view and taking the concept of the affordance into account, the adequacy of the concept of molecular structure will be argued. The point is to specify what objects the concept can legitimately be applied to. Also briefly discussed in relation to shape and structure is the idea that molecular chirality might be a probe to reveal the nature of space. (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)

I review a widely accepted argument to the conclusion that the contents of our beliefs, desires and other mental states cannot be causally efficacious in a classical computational model of the mind. I reply that this argument rests essentially on an assumption about the nature of neural structure that we have no good scientific reason to accept. I conclude that computationalism is compatible with wide semantic causal efficacy, and suggest how the computational model might be modified to accommodate this possibility.