Alexander James Bird

La thèse kuhnienne de l’incommensurabilité semble mettre en cause le réalisme scientifique. Une réponse à cette mise en cause consiste à se focaliser sur la continuité de la référence. La théorie causale de la référence, en particulier, semble offrir la possibilité d’une continuité de la référence susceptible de fournir une base pour l’espèce de comparabilité entre théories que requiert le réaliste. Dans « baptiser et rebaptiser : la vulnérabilité des désignations rigides », Kuhn attaque la théorie causale et l’essentialisme auquel cette théorie est liée. La position de Kuhn est défendue par Rupert Read et Wes Sharrok [Read & Sharrok 2002b]. Dans cet article, j’examine les arguments présentés par Kuhn, Read et Sharrok, et je montre qu’ils ne fournissent aucune raison de douter ni de la théorie causale, ni de l’essentialisme.

Int his article, I argue that Kuhn was a historicist in two respects. First, he was a conservative in Mannheim’s sense—tradition is important for understanding scientific change, and the evaluation of a scientific idea is relative to historical context. Secondly, Kuhn embraced determinism—there is a pattern to scientific change, akin to laws of scientific development. I show that Kuhn’s determinism requires that he is an internalist about the causes of scientific change; Kuhn’s internal- ism contrasts with the externalism that characterises much post-Kuhnian science studies. I conclude by considering how Kuhn’s historicism relates to the philosophical purposes of Kuhn’s history of science.

Thomas Kuhn was undoubtedly the strongest influence on the philosophy of science in the last third of the twentieth century. Yet today, at the beginning of the twenty-first century it is unclear what his legacy really is. In the philosophy of science there is no characteristically Kuhnian school. This could be because we are all Kuhnians now. But it might also be because Kuhn’s thought, although revolutionary in its time, has since been superseded. In a sense both may be true. We are all Copernicans—yet almost everything Copernicus believed we now disbelieve. In this paper I shall examine the development of Kuhn’s thought in connection with changes in the philosophy of science during the second half of the twentieth century. Now that philosophy in general, philosophy of science in particular, is in a post-positivist era, we all share Kuhn’s rejection of positivism. But we do not, for the most part, share Kuhn’s belief in incommensurability, or his scepticism about truth and objective knowledge. Just as in Copernicus’ case, Kuhn initiated a revolution that went far beyond what he himself envisaged or even properly understood.

Many authors have argued in favour of an ontology of properties as powers, and it has been widely argued that this ontology allows us to address certain philosophical problems in novel and illuminating ways, for example, causation, representation, intentionality, free will and liberty. I argue that the ontology of powers, even if successful as an account of fundamental natural properties, does not provide the insight claimed as regards the aforementioned non-fundamental phenomena. I illustrate this argument by criticizing the powers theory of causation presented by Mumford and Anjum and showing that related criticisms can be directed at other abuses of powers.

Essentialism as applied to individuals is the claim that for at least some individuals there are properties that those individuals possess essentially. What it is to possess a property essentially is a matter of debate. To possess a property essentially is often taken to be akin to possessing a property necessarily, but stronger, although this is not a feature of Aristotle’s essentialism, according to which essential properties are those thing could not lose without ceasing to exist. Kit Fine (1994) takes essential properties to be those that an object has in virtue of its identity, while other essentialists refer (as Fine also does) to the nature of an object as the source of its essential properties. It is sometimes important to distinguish the essential properties of a thing and the ‘full’ essence of a thing. The latter is the set of the essential properties of a thing, when that set necessarily suffices to determine the thing’s identity. One might hold that something has essential properties without agreeing that it has an identity-determining essence. Essentialism was largely in abeyance during the first two thirds of the twentieth century thanks to the domination of analytic philosophy by anti-metaphysical logical empiricism and the linguistic turn. The rehabilitation of essentialism owes much to the development of a formal apparatus for the understanding of modality more generally, thanks to C. I. Lewis, Ruth Barcan Marcus, and Saul Kripke. Kripke’s discussion of essentialism both about individuals and also about about natural kinds brought essentialism to wider philosophical prominence. Natural kind essentialism, which finds its modern genesis also in the work of Hilary Putnam, claims that natural kinds have essential properties: to say that possession of property P is is part of the essence of the kind K implies that, necessarily, every member or sample of the kind K possesses P. Essentialism about individuals has been linked to thinking about natural kinds by the contentious claim that one of the essential properties of any entity is that it belongs to the natural kind (or kinds) it actually belongs to. In this chapter I shall first outline certain claims and arguments concerning essentialism concerning individuals (Section 2)..