I reconsider the monism/pluralism debate about natural kinds. Monism claims that there is a privileged division of reality into natural kinds, while pluralism states that there are many ways of classifying objects according to different purposes. I compare three different monistic accounts of natural kinds with the pluralism advocated by promiscuous realism. The analysis of some examples of the classification of celestial objects suggest that there are indeed different legitimate ways of classifying things according to different purposes; contrary to monism, (...) the boundaries between kinds are not fixed. These results show that promiscuous realism is a better account of natural kind. (shrink)

In cognitive psychology, concepts are those data structures that are stored in long-term memory and are used by default in human beings.

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)

Scientific essentialism aims to account for the natural laws' special capacity to support counterfactuals. I argue that scientific essentialism can do so only by resorting to devices that are just as ad hoc as those that essentialists accuse Humean regularity theories of employing. I conclude by offering an account of the laws' distinctive relation to counterfactuals that portrays laws as contingent but nevertheless distinct from accidents by virtue of possessing a genuine variety of necessity.

In this paper, I focus on life-threatening medical conditions and argue that from the point of view of natural properties, induction(s), and participation in laws, at least some of the ill organisms dealt with in somatic medicine form natural kinds in the same sense in which the kinds in the exact sciences are thought of as natural. By way of comparing two ‘divisions of nature’, viz., a ‘classical’ exact science kind (gold) and a kind of disease (Graves disease), I show (...) that there is no justifiable ‘ontological gap’ between disease kinds and exact sciences kinds. We have instead a difference of degree. (shrink)

Predictive approaches to the mind claim that perception, cognition, and action can be understood in terms of a single framework: a hierarchy of Bayesian models employing the computational strategy of predictive coding. Proponents of this view disagree, however, over the extent to which perception is direct on the predictive approach. I argue that we can resolve these disagreements by identifying three distinct notions of perceptual directness: psychological, metaphysical, and epistemological. I propose that perception is plausibly construed as psychologically indirect on (...) the predictive approach, in the sense of being constructivist or inferential. It would be wrong to conclude from this, however, that perception is therefore indirect in a metaphysical or epistemological sense on the predictive approach. In the metaphysical case, claims about the inferential properties of constructivist perceptual mechanisms are consistent with both direct and indirect solutions to the metaphysical problem of perception (e.g. naïve realism, representationalism, sense datum theory). In the epistemological case, claims about the inferential properties of constructivist perceptual mechanisms are consistent with both direct and indirect approaches to the justification of perceptual belief. In this paper, I demonstrate how proponents of the predictive approach have conflated these distinct notions of perceptual directness and indirectness, and I propose alternative strategies for developing the philosophical consequences of the approach. (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)

The need for an explicit and exact definition of a planet has arise out of the growing rate of discovery of Trans-Neptunian Objects (TNOs) with physical and orbital properties comparable with those of Pluto, the smallest planet of the solar system. On July 29, 2005, the IAU Circular 8577 has announced the discovery of a TNO, named 2003UB313, bigger than Pluto; its discoverers have asserted that 2003UB313 must be regarded as the tenth planet of the solar system. Lacking of a (...) definition of a planet, the International Astronomical Union has been unable to decide whether 2003UB313 should be classified as a planet, and no official name has been given to 2003UB313. Eventually, astronomers gathered at the 26th General Assembly of International Astronomical Union agreed on a definition of a planet, and Pluto was demoted from the role of planet. This situation is very interesting for the philosopher of science who can be an eyewitness of a real process of explication of a scientific concept. In this paper I examine various proposals for defining the concept of a planet and put them into a philosophical context. The principal philosophical results is that planet, as defined by the new official definition, is not a natural kind. (shrink)