In this paper I raise a difficulty for Joseph LaPorte's account of chemical kind terms. LaPorte has argued against Putnam that H₂O content is neither necessary nor sufficient to fix the reference of the kind term 'water' and that we did not discover that water is H₂O. To this purpose, he revisits Putnam's Twin Earth story with the fictional scenario of Deuterium Earth, whose ocean consists of 'dwater', to conclude that we did not discover that deuterium oxide is (a kind (...) of) water (usually called 'heavy water'). Instead, according to LaPorte, by including deuterium oxide in the extension of the term 'water', we simply refined our vague use of the term 'water'. But we could have decided to exclude deuterium oxide from the extension of the term 'water'. Let us call this the thesis of semantic stipulation. I raise two problems for LaPorte's Deuterium Earth story. First, I show that 'dwater' (i.e. deuterium oxide not as a kind of water) does not have the same scientific credibility of 'heavy water' (i.e. deuterium oxide as a kind of water). Second, I argue that for the thesis of semantic stipulation to go through one would need to show that 'dwater' is semantically on a par with 'heavy water'. Namely, one would need to show that 'dwater' is a projectible kind term, capable of supporting inductive inferences. But, in fact, it is not, because the term is vulnerable to an unwelcome Goodmanian scenario, unless one surreptitiously reintroduces some Putnamian assumptions about D₂O content being necessary and sufficient to fix the reference of the term. (shrink)

In recent years attacks on the Kripke-Putnam approach to natural kinds and natural kind terms have proliferated. In a recent paper, Häggqvist and Wikforss (The British Journal for the Philosophy of Science, 1–23, 2017) attack the once-dominant essentialist account of natural kinds. Häggqvist & Wikforss also suggest that it is time to return to some sort of cluster-based descriptivist semantics for natural kind terms, thus targeting both the metaphysical and semantic tenets that underpin the Kripke-Putnam approach. In our paper we (...) want to challenge both parts of Häggqvist and Wikforss’ project. We will argue that the anti-essentialist considerations and arguments they raise against the Kripke-Putnam view are far from compelling in some cases, and certainly not decisive against a reasonable form of the view. On the semantic side, although Häggqvist and Wikforss give few details about what a viable cluster-based descriptivist theory should look like, we will argue that one can already see the approach to be a non-starter. Ignorance and error arguments of the kinds provided by Kripke and Putnam continue to be decisive objections. The only way we can see to save the cluster descriptivist approach is to make the essential properties postulated by Kripke and Putnam become essential features of the descriptive cluster. But this makes the success of the approach parasitic on the correctness of the Kripke-Putnam view. (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)

If natural kinds have microstructural essences they have them independently of rules for the application of kind terms. This suggests that what those rules are should make no difference to the essences being discoverable. I present two thought-experiments that suggest otherwise, however. Each shows an authority’s application of rules creates the appearance of there being kind essences; absent those rules, the appearance vanishes. This suggests natural kind essences are not independent of authority-sanctioned rules.

The A-theory and the B-theory advance competing claims about how time is grounded. The A-theory says that A-facts are more fundamental in grounding time than are B-facts, and the B-theory says the reverse. We argue that whichever theory is true of the actual world is also true of all possible worlds containing time. We do this by arguing that time is uniquely groundable: however time is actually grounded, it is necessarily grounded in that way. It follows that if either the (...) A-theory or the B-theory is actually false, then it is necessarily false. (shrink)

The A-theory and the B-theory advance competing claims about how time is grounded. The A-theory says that A-facts are more fundamental in grounding time than are B-facts, and the B-theory says the reverse. We argue that whichever theory is true of the actual world is also true of all possible worlds containing time. We do this by arguing that time is uniquely groundable: however time is actually grounded, it is necessarily grounded in that way. It follows that if either the (...) A-theory or the B-theory is actually false, then it is necessarily false. (shrink)

Philosophical treatments of natural kinds are embedded in two distinct projects. I call these the philosophy of science approach and the philosophy of language approach. Each is characterized by its own set of philosophical questions, concerns, and assumptions. The kinds studied in the philosophy of science approach are projectible categories that can ground inductive inferences and scientific explanation. The kinds studied in the philosophy of language approach are the referential objects of a special linguistic category—natural kind terms—thought to refer directly. (...) Philosophers may hope for a unified account addresses both sets of concerns. This paper argues that this cannot be done successfully. No single account can satisfy both the semantic objectives of the philosophy of language approach and the explanatory projects of the philosophy of science approach. After analyzing where the tensions arise, I make recommendations about assumptions and projects that are best abandoned, those that should be retained, and those that should go their separate ways. I also recommend adopting the disambiguating terminology of “scientific kinds” and “natural kinds” for the different notions of kinds developed in these different approaches. (shrink)

Some explanations in social science, psychology and biology belong to a higher level than other explanations. And higher explanations possess the virtue of abstracting away from the details of lower explanations, many philosophers argue. As a result, these higher explanations are irreplaceable. And this suggests that there are genuine higher laws or patterns involving social, psychological and biological states. I show that this ‘abstractness argument’ is really an argument schema, not a single argument. This is because the argument uses the (...) ‘is lower than’ relation, and this relation admits of different readings. I then suggest four rigorous definitions of the ‘is lower than’ relation, and show that the abstractness argument’s prospects are much brighter for some of these definitions than for others. To show this, I evaluate the so-called ‘disjunctive threat’ to the abstractness argument. (shrink)

The paper considers whether psychiatric kinds can be natural kinds and concludes that they can. This depends, however, on a particular conception of ‘natural kind’. We briefly describe and reject two standard accounts – what we call the ‘stipulative account’ (according to which apparently a priori criteria, such as the possession of intrinsic essences, are laid down for natural kindhood) and the ‘Kripkean account’ (according to which the natural kinds are just those kinds that obey Kripkean semantics). We then rehearse (...) a more permissive account: Richard Boyd’s ‘homeostatic property cluster’ (HPC) account. We argue that psychiatric kinds can in principle count as natural kinds on the HPC account. Moreover, specific psychiatric kinds (Tourette’s, schizophrenia, etc.) can be natural kinds even if the category psychiatric disorder is not itself a natural kind. (shrink)