Vagueness, Logic and Use: Four Experimental Studies on Vagueness


  • This work was partially funded by an NSERC USRA. Thanks to Diana Raffman, Phil Kremer, Jeremy Fantl, Penny Pexman, the referees for Mind & Language, and audiences at the University of Toronto Grad Forum and the Paris ‘Vagueness and Language Use' conference for helpful comments.

Phil Serchuk, Department of Philosophy, University of Toronto, 170 St. George St., Toronto, Ontario, M5R 2M8, Canada.


Although arguments for and against competing theories of vagueness often appeal to claims about the use of vague predicates by ordinary speakers, such claims are rarely tested. An exception is Bonini et al. (1999), who report empirical results on the use of vague predicates by Italian speakers, and take the results to count in favor of epistemicism. Yet several methodological difficulties mar their experiments; we outline these problems and devise revised experiments that do not show the same results. We then describe three additional empirical studies that investigate further claims in the literature on vagueness: the hypothesis that speakers confuse ‘P’ with ‘definitely P’, the relative persuasiveness of different formulations of the inductive premise of the Sorites, and the interaction of vague predicates with three different forms of negation.