Emma Tobin

Microstructuralism in the philosophy of chemistry is the thesis that chemical kinds can be individuated in terms of their microstructural properties (Hendry in Philos Sci 73:864–875, 2006 ). Elements provide paradigmatic examples, since the atomic number should suffice to individuate the kind. In theory, Microstructuralism should also characterise higher-level chemical kinds such as molecules, compounds, and macromolecules based on their constituent atomic properties. In this paper, several microstructural theses are distinguished. An analysis of macromolecules such as moonlighting proteins suggests that all the forms of microstructuralism cannot accommodate them.

This chapter discusses the distinction between natural kinds and natural properties. Some theorists deny the distinction, and claim that natural kinds can be identified with properties. For example, natural kinds might be understood as the perfectly natural properties, reducible to properties or the extensions of properties. Alternatively, one might argue that natural kinds and natural properties are distinct and that natural kinds could be considered as a sui generis type of entity. For example, one might hold that natural kinds require a distinct kind of universal, substantival universal, or sortal. Alternatively, one might claim that properties themselves form natural kind groupings, in virtue of causal mechanisms. This chapter argues that classification into natural kinds can reflect real differences between natural groups, without the supplementary ontological distinction between properties and kinds.

This paper examines whether structural realism entails an anti-realist thesis about natural kinds. Structural Realism is the view that the scientific realist can only support a realist claim about the structure of reality rather than its objects. Ladyman (1998) (2002) & French & Ladyman (2003) motivate the claim that ontic structural realism eliminates ‘objects’ as a distinct ontological category, thereby eliminating any possibility of a metaphysical account of individual objects. This is empirically motivated by fundamental physics. Those inclined towards realism about the rest of the sciences (chemistry, biology, the medical sciences, economics and so on) might think the appeal of structural realism as a general metaphysics for all of the sciences limited. Nevertheless, recent literature argues that mature special sciences e.g. economics, can be equally described by mathematical/syntactic models making the appeal of structural realism a more general one for the metaphysics of all of the sciences. {Ross (2006)}. Given a commitment to ontic structural realism, if natural kinds are kinds of “object”, then anti-realism about natural kinds should follow. However, I examine two realist theses about natural kinds and argue that a commitment to structural realism is not straightforwardly inconsistent with either

Realist accounts of natural kinds rely on an account of causation where the relata of causal relations are real and discrete. These views about natural kinds entail very different accounts of causation. In particular, the necessity of the causal relation given the instantiation of the properties of natural kinds is more robust in the fundamental sciences (e.g. physics and chemistry) than it is in the life sciences (e.g. biology and the medical sciences). In this paper, I wish to argue that there is a difference in kind between the putative natural kinds of the fundamental sciences and those of the life sciences, such that a uniform account of causation cannot capture both. The upshot is that we must either reject the claim that the kinds of the life sciences are genuine natural kinds, or accept that there are different kinds of causal relations involving the relata of natural kinds. I accept the latter. I reject the objection that the true causal relations that relate macro-level kinds are to be found by “going down a level” to causal relation at the fundamental kind, because the relevant causal mechanisms are not at the fundamental level. Since, autonomous mechanistic accounts of causal relations at the macro-level can be provided (e.g. in Biology and medicine), I argue that realism about the natural kinds of the life sciences is justified. I address the problem of negative causation as a counterexample to the positive account of causation that is entailed by realism about natural kinds in the life sciences. I argue that an acceptance of realist accounts of two different kinds of natural kind makes a uniform analysis of causation look unpromising. (277 words)

Biological species are often taken as counterexamples to essentialist accounts of natural kinds. Essentialists like Ellis (2001) agree with nominalists that because biological kinds evolve, any distinctions between kinds of biological kind must ultimately be arbitrary. The resulting vagueness in the extension of natural kind predicates in the case of species has led to the claim that species ought to be construed as individuals rather than kinds (Ghiselin 1974, 1987; Hull 1976, 1978). I examine the possibility that causal features extrinsic to the properties of natural kinds are responsible for establishing the unity of the properties of a natural kind. I reject the intuitive idea that laws of nature might act as such an external mechanism because this would entail an account of ceteris paribus biological laws, where there are no plausible truthmakers in terms of kinds or properties. I suggest instead that symbiosis is a plausible external causal mechanism, which explains the evolution of homeostasis in natural kind clusters. This involves the acceptance of an expanded account of evolutionary development as cooperative symbiosis