Locke is often cited as a precursor to contemporary natural kind realism. However, careful attention to Locke’s arguments show that he was unequivocally a conventionalist about natural kinds. To the extent that contemporary natural kind realists see themselves as following Locke, they misunderstand what he was trying to do. Locke argues that natural kinds require either dubious metaphysical commitments (e.g., to substantial forms or universals), or a question-begging version of essentialism. Contemporary natural kind realists face a similar dilemma, and should (...) not appeal to Locke in their defense. (shrink)

Kripke has argued that definitions of units of measurements provide examples of statements that are both contingent and a priori. In this paper I argue that definitions of units of measurement are intended to be stipulations of what Kripke calls "theoretical identities": a stipulation that two terms will have the same rigid designation. Hence such a definition is both a priori and necessary. The necessity arises because such definitions appeal to natural kind properties only, which on Kripke's account are necessary.

In this encyclopedia entry I canvass the current interpretations of John Locke's concept of Real Essence and the role it plays in his philosophy.

I question here the differentiation of kinds as substantive universals in Lowe and Ellis’ metaphysics, by taking up, for the argument’s sake, two extreme approaches on kind differentiation and kind change, a Heraclitan and a Spinozan approach. I show that, as things currently stand, Heraclitanism or Spinozism about kinds is consistent with the broad tenets of Lowe and Ellis’ metaphysics of kinds.

In this paper I discuss a central objection against diseases being natural kinds—namely, that diseases are processes or transitions and hence they should not be conceptualized in the ‘substantish’ framework of natural kinds. I indicate that the objection hinges on conceiving disease kinds as phase kinds, in contrast to the non-phase, natural kinds of the exact sciences. I focus on somatic diseases and argue, via a representative comparison, that if disease kinds are phase kinds, then exact science kinds are phase (...) kinds as well. On the other hand, if exact science kinds are non-phase kinds, then disease kinds are non-phase kinds as well. This objection should thus be rejected, under a certain caveat, though. If natural kind membership has an influence over the diachronic identity of kind members, then it is possible, in principle, to draw the phase/non-phase distinction such that an ‘ontological gap’ lies between medical kinds and exact science kinds. I show further that this caveat is unavoidable even in relation to substantive universals and ‘essential’ properties—two controversial, strong features that were traditionally associated to natural kinds. (shrink)

My starting point is that discussions in philosophy about the ontology of technical artifacts ought to be informed by classificatory practices in engineering. Hence, the heuristic value of the natural-artificial distinction in engineering counts against arguments which favour abandoning the distinction in metaphysics. In this chapter, I present the philosophical equipment needed to analyse classificatory practices and then present a case study of engineering practice using these theoretical tools. More in particular, I make use of the Collectivist Account of Technical (...) Artifacts (CAT) according to which there are different classificatory practices for natural, artificial, and social objects. I demonstrate that in the community studied, artificial kinds are marked by distinctive classificatory practices. The presence of these distinctive classificatory practices in engineering with regard to artificial kinds should inform discussions about the ontology of technical artifacts just as the distinctive classificatory practices in natural science inform discussions about natural kinds. (shrink)

The theory of concepts advanced in the dissertation aims at accounting for a) how a concept makes successful practice possible, and b) how a scientific concept can be subject to rational change in the course of history. Traditional accounts in the philosophy of science have usually studied concepts in terms only of their reference; their concern is to establish a stability of reference in order to address the incommensurability problem. My discussion, in contrast, suggests that each scientific concept consists of (...) three components of content: 1) reference, 2) inferential role, and 3) the epistemic goal pursued with the concept's use. I argue that in the course of history a concept can change in any of these three components, and that change in one component—including change of reference—can be accounted for as being rational relative to other components, in particular a concept's epistemic goal.This semantic framework is applied to two cases from the history of biology: the homology concept as used in 19th and 20th century biology, and the gene concept as used in different parts of the 20th century. The homology case study argues that the advent of Darwinian evolutionary theory, despite introducing a new definition of homology, did not bring about a new homology concept (distinct from the pre-Darwinian concept) in the 19th century. Nowadays, however, distinct homology concepts are used in systematics/evolutionary biology, in evolutionary developmental biology, and in molecular biology. The emergence of these different homology concepts is explained as occurring in a rational fashion. The gene case study argues that conceptual progress occurred with the transition from the classical to the molecular gene concept, despite a change in reference. In the last two decades, change occurred internal to the molecular gene concept, so that nowadays this concept's usage and reference varies from context to context. I argue that this situation emerged rationally and that the current variation in usage and reference is conducive to biological practice.The dissertation uses ideas and methodological tools from the philosophy of mind and language, the philosophy of science, the history of science, and the psychology of concepts. (shrink)