Online research in philosophy

Some experimental studies have recently claimed to undermine semantic externalism about natural kind terms. However, it is unclear how philosophical accounts of reference can be experimentally tested. We present two externalistic adaptations of psychological placeholder essentialism, a strict externalist and a hybrid externalist view, which are experimentally testable. We examine Braisby's et al. (1996) study which claims to undermine externalism, and argue that the study fails in its aims. We conducted two experiments, the results of which undermine internalism and the hybrid theory, and support strict externalism. Our conclusion is that lay speakers' natural kind concepts involve a belief in an external category essence, which determines reference.

This paper discusses whether it can be known a priori that a particular term, such as water, is a natural kind term, and how this problem relates to Putnams claim that natural kind terms require an externalist semantics. Two conceptions of natural kind terms are contrasted: The first holds that whether water is a natural kind term depends on its a priori knowable semantic features. The second.

A great deal of discussion in the recent literature has been devoted to the so-called 'McKinsey' paradox which purports to show that semantic externalism is incompatible with the sort of authoritative knowledge that we take ourselves to have of our own thought contents. In this paper I examine one influential epistemological response to this paradox which is due to Crispin Wright and Martin Davies. I argue that it fails to meet the challenge posed by McKinsey but that, if it is set within an externalist epistemology, it may have application to a related paradox that concerns the problem of radical scepticism.

Controversy continues to attach to the question whether an externalism about mental content is compatible with a traditional doctrine of privileged self-knowledge. By an externalism about mental content, I mean the view that what concepts our thoughts involve may depend not only on facts that are internal to us, but on facts about our environment. It is worth emphasizing, if only because it is still occasionally misperceived, that this thesis is supposed to apply at the level of sense and not merely at that of reference: what concepts we think in terms of -- and not just what they happen to pick out -- is said by the externalist to depend upon environmental facts. By a traditional doctrine of privileged self-knowledge, I mean the view that we are able to know, without the benefit of empirical investigation, what our thoughts are in our own case. Suppose I entertain a thought that I would express with the sentence `Water is wet'. According to the traditional doctrine, I can know without empirical investigation (a) that I am entertaining a thought; (b) that it has a particular conceptual content, and (c) that its content is that water is wet.

Semantic externalism about a class of expressions is often thought to make conceptual analysis about members of that class impossible. In particular, since externalism about natural kind terms makes the essences of natural kinds empirically discoverable, it seems that mere reflection on one's natural kind concept will not be able to tell one anything substantial about what it is for something to fall under one's natural kind concepts. Many hold the further view that one cannot even know anything substantial about the reference-fixers of one's natural kind concepts by armchair reflection. In this paper I want to question this latter view and claim that, because of the way our standard methodology of doing theories of reference relies on semantic intuitions, typical externalists in fact presuppose that one can know the reference-fixers of one's natural kind concepts by mere armchair reflection. The more interesting question is how substantial such knowledge can be. I also take some steps toward answering this question.

Paul Boghossian has argued that Externalism is incompatible with privileged self-knowledge because (i) the Externalist can cite no property to be the reference of an empty natural kind concept such as the ether; (ii) without reference there is no content; hence (iii) either we do know on the basis of introspection alone whether an apparent natural kind thought has content or not, in which case we can infer from self-knowledge and a priori knowledge of Externalism alone to the existence in our environment of water, gold etc.; (iv) or we do not know, without empirical investigation, whether an apparent natural kind thought has content. An Externalist not wanting to accept either (iii) or (iv) can deny (i). All empty natural kind concepts refer to the necessarily uninstantiated property of being identical to nothing. Since they have different senses and self-knowledge is only held to extend to the existence and identity of sense, this is compatible with privileged self-knowledge, and Externalism is still true of the concepts.

Several authors have argued that, assuming we have a priori knowledge of our own thought-contents, semantic externalism implies that we can know a priori contingent facts about the empirical world. After presenting the argument, I shall respond by resisting the premise that an externalist can know a priori: If s/he has the concept water, then water exists. In particular, I think Boghossian’s own Dry Earth example suggests that such thought-experiments do not provide such a priori knowledge. Boghossian himself rejects the Dry Earth experiment, however, since it would imply that externalism is true of empty concepts as well as non-empty concepts. Yet in this paper I respond by defending empty-concept externalism, from criticisms deriving from Boghossian as well as from Jessica Brown. Specifically, I argue that such a view does not preclude an empty concept from having the appropriate form or structure—nor would it reveal a priori that a linguistic community is necessary for an empty concept to have a content.