The present thesis explores some metaphysical issues concerning biochemical kinds and the relations between chemical and biological properties and phenomena. The main result of this thesis is that there is something sui generis about biochemical kinds. This result is motivated by two theoretical steps. The first is characterising biochemical functions as weakly emergent from the chemical structure [Chapter 3, Chapter 6]. The second is via an account for which biochemical kinds are natural categories [Chapter 4, Chapter 7]. The thesis comprises (...) four parts. Part I [Chapter 1, Chapter 2] aims to offer the methodological and conceptual tools that underpin this research. Chapter 1 presents the debate on the unity of science and the motivation of the research. Chapter 2 presents the account of natural kinds that will be used throughout the thesis. Part II [Chapter 3, Chapter 4] offers a detailed metaphysical analysis of the molecular gene. Chapter 3 argues that molecular genes are weakly emergent from nucleic acids. Chapter 4 argues that the category "molecular gene" can be deemed a natural kind, following the account presented in Chapter 2. Part III [Chapter 5, Chapter 6, Chapter 7] explores some of the themes related to biochemical kinds and generalises some of the results from Part II. Chapter 5 considers biochemical functions and how functional attribution should be interpreted for biochemical molecules. Chapter 6 considers the relation between biochemical functions and structure, spelt in terms of weak emergence and explores unity in biochemistry. Chapter 7 considers the topic of biochemical kinds per se and argues that biochemical kinds are natural categories. Part IV [Chapter 8] elucidates the main outcome and the implications that this research can have for future discussion in the philosophy and metaphysics of biochemistry and the unity of science. (shrink)

A central question for philosophical psychology is which mental faculties form natural kinds. There is hot debate over the kind status of faculties as diverse as consciousness, seeing, concepts, emotions, constancy and the senses. In this paper, I take emotions and concepts as my main focus, and argue that questions over the kind status of these faculties are complicated by the undeservedly overlooked fact that natural kinds are indeterminate in certain ways. I will show that indeterminacy issues have led to (...) an impasse in the debates over emotions and concepts. I first consider and reject one way of resolving this impasse. I then suggest a different method, which places more emphasis on a close analysis of predictive and explanatory practices in psychology. I argue that when we apply this method, a new position emerges: that it is indeterminate whether concepts or emotions are natural kinds. They are neither determinately natural kinds, nor determinately not natural kinds. Along the way, we will see that natural kinds have been put to two completely different theoretical uses, which are often been blurred together, and that they are ill-suited to fulfil one of them. (shrink)

Standard arguments for essentialism with respect to natural kinds such as gold, star, water or tiger enlist essentialist principles or essentialist intuitions. I argue that we need neither. All it takes to establish essentialism for the kinds in question are insights from science and semantics. Semantics establishes that natural kind predicates such as “is gold” or “is a star” are paradigm terms whose application conditions are relationally determined, object involving, and actuality dependent. Science assures us that a posteriori hypotheses such (...) as “∀x” are deeply explanatory, as well as true. Taken together, these results establish essentialism for kinds such as gold, star, water or tiger. I consider this a deflationary result. When it comes to natural kind essentialism, there is no need for substantial metaphysics, be it essentialist or otherwise. (shrink)

Some philosophers understand natural kinds to be the categories which are constraints on enquiry. In order to elaborate the metaphysics appropriate to such an account, I consider the complicated history of scurvy, citrus, and vitamin C. It may be tempting to understand these categories in a shallow way (as mere property clusters) or in a deep way (as fundamental properties). Neither approach is adequate, and the case instead calls for middle-range ontology: starting from categories which we identify in the world (...) and elaborating their structure, but not pretending to jump ahead to a complete story about fundamental being. (shrink)

Part of a book symposium on Anjan Chakravartty's Scientific ontology: integrating naturalized metaphysics and voluntarist epistemology (Oxford University Press, 2017).

This article uses the case study of ethnobiological classification to develop a positive and a negative thesis about the state of natural kind debates. On the one hand, I argue that current accounts of natural kinds can be integrated in a multidimensional framework that advances understanding of classificatory practices in ethnobiology. On the other hand, I argue that such a multidimensional framework does not leave any substantial work for the notion “natural kind” and that attempts to formulate a general account (...) of naturalness have become an obstacle to understanding classificatory practices. (shrink)

Several philosophers have recently tried to define natural kinds in epistemic terms only. Given the persistent problems with finding a successful metaphysical theory, these philosophers argue that we would do better to describe natural kinds solely in terms of their epistemic usefulness, such as their role in supporting inductive inferences. In this paper, I argue against these epistemology-only theories of natural kinds and in favor of, at least partly, metaphysical theories. I do so in three steps. In the first section (...) of the paper, I propose two desiderata for a theory of natural kinds. In the second section, I discuss one example of a ‘general’ epistemology-only theory, proposed by Marc Ereshefsky and Thomas Reydon, and argue that theories like theirs fail to provide adequate criteria of natural kinds. In the third section, I focus on one example of a ‘specific’ epistemology-only theory, proposed by P. D. Magnus, and use it to show why such theories cannot justify the claim that the proposed epistemic criteria account for the naturalness of kinds. (shrink)

The account of natural kinds as stable property clusters is premised on the possibility of separating the epistemic value of natural kinds from their underlying metaphysics. On that account, the co-instantiation of any sub-cluster of the properties associated with a given natural kind raises the probability of the co-instantiation of the rest, and this clustering of property instantiation is invariant under all relevant counterfactual perturbations. We argue that it is not possible to evaluate the stability of a cluster of properties (...) without taking stock of the metaphysical picture used to account for that stability. Thus, even on the stable property cluster account, the epistemic value of natural kinds remains partly grounded in their metaphysical status. (shrink)

There is a perennial philosophical dream of a certain natural order for the natural kinds. The name of this dream is ‘the hierarchy requirement’. According to this postulate, proper natural kinds form a taxonomy which is both unique and traditional. Here I demonstrate that complex scientific objects exist: objects which generate different systems of scientific classification, produce myriad legitimate alternatives amongst the nonetheless still natural kinds, and make the hierarchical dream impossible to realize, except at absurdly great cost. Philosophical hopes (...) for a certain order in nature cannot be fulfilled. Natural kinds crosscut one another, ubiquitously so, and this crosscutting spells the end of the hierarchical dream. (shrink)

In this paper, I outline a theory of social kinds. A general theory of social kinds has to set out at least three conditions: existence conditions, persistence conditions, and identity conditions. For the sake of expediency, I focus on the existence and persistence conditions. The paper is organized just as life: first with existence, then persistence. I argue that anti-realism is more attractive than realism as an account of the existence conditions, despite the fact that realism has been under-appreciated. Then (...) I argue for a particular theory of the persistence conditions, which I call the basic overlapping traits theory (BOTT), based on an analogy to an approach to personal identity. The upshot of the argument is that from an anti-realist metaphysics we have the capacity to discuss a wider diversity of social phenomena. (shrink)