Despite many attempts to achieve an adequate definition of living systems by means of a set of necessary and sufficient conditions, the opinion that such an enterprise is inexorably destined to fail is increasingly gaining support. However, we believe options do not just come down to either having faith in a future success or endorsing skepticism. In this paper, we aim to redirect the discussion of the problem by shifting the focus of attention from strict definitions towards a philosophical framework (...) that allows conceiving of living systems as a natural kind, but whereby natural kinds are not to be defined by fixed necessary and sufficient conditions. We argue for a property-cluster kind approach according to which living systems constitute a natural kind with vague boundaries, capable of changing, and whose members do not need to instantiate every property. We draw from Boyd’s homeostatic property-cluster theory and introduce two modifications, one regarding homeostatic mechanisms and another related to the scientific role of kinds. Thus, our view overcomes some difficulties of Boyd’s theory and we are able to account for the natural kindhood of living things. We also emphasize the most appealing features of our approach for specific research fields and address three objections to this sort of approach. (shrink)

In this article I examine some of the issues involved in taking psychiatric disorders as natural kinds. I begin by introducing a permissive model of natural kind-hood that at least prima facie seems to allow psychiatric disorders to be natural kinds. The model, however, hinges on there in principle being some grounding that is shared by all members of a kind, which explain all or most of the additional shared projectible properties. This leads us to the following question: what grounding (...) do psychiatric disorders qua natural kinds have? My principal method for examining the issue is a case study of a particular psychiatric disorder: the so-called “apathetic children.” I argue that there appear to be at least two competing models that both appeal to non-organic a grounding of the disorder. However, for other psychiatric disorders, such as Alzheimer’s disease, the evidence points toward an organic explanation of the disorder. I contend that what unites psychiatric disorders is not a distinctive type of grounding that all psychiatric disorders share, but the distinctive set of determinable properties that is shared by all psychiatric disorders. (shrink)

It has recently been argued that the concept of natural kinds should be eliminated because it does not play a productive theoretical role and even harms philosophical research on scientific classification. We argue that this justification for eliminativism fails because the notion of ‘natural kinds’ plays another epistemic role in philosophical research, namely, it enables fruitful investigation into non-arbitrary classification. It does this in two ways: first, by providing a fruitful investigative entry into scientific classification; and second—as is supported by (...) bibliometric evidence—by tying together a research community devoted to non-arbitrary classification. The question of eliminativism then requires weighing off the benefits of retaining the concept against its harms. We argue that the progressive state of philosophical work on natural kinds tips this balance in favour of retaining the concept. (shrink)