Alexander James Bird

In this paper I draw a connection between Kuhn and the empiricist legacy, specifically between his thesis of incommensurability, in particular in its later taxonomic form, and van Fraassen's constructive empiricism. I show that if it is the case the empirically equivalent but genuinely distinct theories do exist, then we can expect such theories to be taxonomically incommensurable. I link this to Hacking's claim that Kuhn was a nominalist. I also argue that Kuhn and van Fraassen do not differ as much as might be thought as regards the claim that observation is theory laden.

1.Following Kripke, many philosophers have accepted the existence of propositions concerning essences, and, more generally, propositions asserting necessities, that are knowable only a posteriori. Such an acceptance is consistent with the claim that ultimately all knowledge of necessity is a priori. A posteriori knowledge of necessity may be held to be a consequence of the combination of a priori knowledge of a proposition asserting essence or necessity with a posteriori knowledge of a non-modal proposition. E. J. Lowe (2007: 287–88) denies even this kind of derived a posteriori knowledge of essence or necessity. He reconstructs the form of an argument that is intended to lead to a proposition concerning essence but which is known a posteriori: This schema may be exemplified thus: As this example illustrates, instances of (1) are a priori propositions concerning essence, while instances of (2) are a posteriori propositions; instances of the conclusion are propositions asserting particular essences, and are, it is claimed, knowable only a posteriori.1.

Rae Langton and Jennifer Hornsby have argued that pornography might create a climate whereby a woman’s ability to refuse sex is literally silenced or removed. Their central argument is that a failure of ‘uptake’ of the woman’s intention means that the illocutionary speech act of refusal has not taken place. In this paper, I challenge the claims from the Austinian philosophy of language which feature in this argument. I argue that uptake is not in general required for illocution, nor is it required for refusal in particular. I conclude with remarks on the relationship between illocutionary and perlocutionary speech-acts.

Let us call a property that is essentially dispositional a potency.1 David Armstrong thinks that potencies do not exist. All sparse properties are essentially categorical, where sparse properties are the explanatory properties of the type science seeks to discover. An alternative view, but not the only one, is that all sparse properties are potencies or supervene upon them. In this paper I shall consider the differences between these views, in particular the objections Armstrong raises against potencies.

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.

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)..