Psychological essentialism and semantic externalism: Evidence for externalism in lay speakers’ language use

Abstract

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, Franks, and Hampton's (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.

Keywords:

• Natural Kind Concepts
• Psychological Essentialism
• Reference
• Semantic Externalism
• Semantic Internalism

Acknowledgments

We would like to thank (in alphabetical order) Nick Braisby, Daniel Cohnitz, Antti Kauppinen, Joseph LaPorte, Edouard Machery, Panu Raatikainen, Michael Strevens, and two anonymous referees for helpful comments and discussions, and Henri Pettersson for help in conducting the experiments. This work has been financially supported by the Academy of Finland (project 214088).

Notes

Notes

[1] As an anonymous referee pointed out, some philosophers may share the externalistic intuitions without being ‘externalists’ in every meaning of the term; for instance, a descriptivist can claim that a natural kind term t refers not to anything that fits the identifying description D, but only to what actually fits the identifying description (e.g., ‘water’ applies solely to the actual watery substance). However, we are here concerned solely with reference, not meaning in general (whatever that precisely amounts to), and even the causal descriptivists are externalists in the referential sense: for instance, the description actual watery substance does not alone suffice to determine the reference of ‘water’, but only together with the actual, possibly unknown, nature of water. (This kind of Jacksonian descriptivism is, however, implausible for other reasons: see Jylkkä, 2008.) Moreover, the recent studies attacking externalism do so by challenging Putnamian intuitions about natural kinds; if they were successful, they would equally challenge internalist theories which accept these intuitions, if such theories can be formulated.

[2] It is quite explicit in the essentialist literature that the essence beliefs are a necessary criterion in categorization, but whether they are sufficient is more implicit. However, such a view is presupposed at least in transformation (e.g., Hampton, Estes, & Simmons, 2007; Rips 1989) and discovery studies (e.g., Keil, 1989), where essentialism is taken to imply that an object with non-typical appearance but typical deep structure should be categorized in the extension of the concept (in other words, possessing the relevant essence is taken to be sufficient for category membership).

[3] What determines which objects are ordinarily called t is arguably determined by some recognitional capacity separate from the essence beliefs (see Jylkkä, 2008; also Brown, 1998).

[4] Putnam's scenario about the robot cats can be considered somewhat underspecified. For instance, if the robot cats had recently invaded the Earth and replaced all the ordinary, mammalian cats, probably no one would believe that the cat-essence is to be a robot. In the scenario it is supposed that the creatures called ‘cats’ have all along been robots, and that there are no mammalian cat-like creatures around at all.

[5] ‘You have a female pet cat named Tibby who has been rather unwell of late. Although cats are known to be mammals, the vet, on examining Tibby carefully, finds that she is, in fact, a robot controlled from Mars’ (Braisby et al, 1996, p. 256).

[6] Arguably, philosophers have become quite adept at imagining hugely improbable courses of events in their thought experiments. It would be quite difficult for a philosopher to prompt subjects to imagine such scenarios, using familiar natural kinds, while remaining completely neutral and letting the subjects freely make up their minds about the proper way of using natural kind terms. Using fictitious natural kinds is a simple way of bypassing this difficulty.

[7] The test was conducted using non-weighted values, on which mean answer to the negative scenarios was 1.3 (‘yes’) and to the positive -1.4 (‘no’).

[8] We would like to thank an anonymous referee for pressing this point.