The Psychology of Vagueness: Borderline Cases and Contradictions


  • We gratefully acknowledge the help of two anonymous referees on an earlier version of this paper. As well, we have had very useful discussions with Paul Egré, Nancy Hedberg, Hotze Rullman and James Hampton. An earlier version of some parts of the present paper was presented at ESSLLI 2009 and is printed in the Proceedings of that meeting. We thank the organizers and audience at the ESSLLI meeting for their comments also. The collection of data concerning the acceptance of (what seem to be) classical contradictions when it comes to judgments concerning borderline cases was motivated by some more ‘informal experiments' done by Pelletier and Len Schubert in the mid-1980s. This work is reported in Pelletier, 1988, but unfortunately(?) only in Hungarian in a journal that has ceased publication many years ago. The website contains both the Hungarian version and an English version. (Scroll to #24 on the list of ‘Refereed Journal Articles'.) This earlier experimental work of Schubert and Pelletier is also mentioned in Kyburg, 2000, who proposes a rather different pragmatic analysis of the data than the one presented in Pelletier, 1988 and also different from the one presented in the current paper.

F. J. Pelletier, Department of Philosophy, University of Alberta, Edmonton, AB, Canada T6G 2E7.


In an interesting experimental study, Bonini et al. (1999) present partial support for truth-gap theories of vagueness. We say this despite their claim to find theoretical and empirical reasons to dismiss gap theories and despite the fact that they favor an alternative, epistemic account, which they call ‘vagueness as ignorance’. We present yet more experimental evidence that supports gap theories, and argue for a semantic/pragmatic alternative that unifies the gappy supervaluationary approach together with its glutty relative, the subvaluationary approach.