Teaching & Learning Guide for: Vagueness: Supervaluationism

• Published in: Philosophy compass 2010-02, Vol.5 (2), p.213-215
• Main Author: Keefe, Rosanna
• Format: Article
• Language: English
• ISSN: 1747-9991; 1747-9991
• DOI: 10.1111/j.1747-9991.2009.00272.x

This guide accompanies the following article(s): Rosanna Keefe, ‘Vagueness: Supervaluationism.’Philosophy Compass 3.2 (2008): 315–24, 10.1111/j.1747‐9991.2008.00124.x Author’s Introduction Vagueness is an extremely widespread feature of language, famously associated with the sorites paradox. One instance of this paradox concludes that a single grain of sand is a heap of sand, by starting with a large heap of sand and invoking the plausible premise that if you take one grain of sand away from a heap of sand, then you still have a heap. The supervaluationist theory of vagueness states that a sentence is true if and only if it is true on all ways of making it precise. This yields borderline case predications that are neither true nor false, but yet classical logic is preserved almost entirely. The sorites paradox is solved because the main premise comes out false – on each way of making ‘heap’ precise, there is some first grain that turns a heap into a non‐heap – but there is no sharp boundary to ‘heap’ because it is a different grain on different ways of making ‘heap’ precise; so, there is no grain of which it is true to say it is that first grain. The theory has a range of merits in comparison with rival theories, such as the epistemic view or degree theories of vagueness. Objections have been made (and answers offered) in relation to its treatment of higher‐order vagueness and what it says about truth and validity. Author Recommends Fine, Kit. ‘Vagueness, Truth and Logic.’Synthese 30 (1975). 265–300. Reprinted in Keefe and Smith 1997. This is the classic text introducing supervaluationism as a treatment of vagueness. It provides both philosophical discussion and formal modelling, demonstrating the adherence to classical logic that the theory yields. Keefe, Rosanna and Peter Smith, eds. Vagueness: A Reader. Cambridge, MA: MIT Press. This collection includes many classic papers on vagueness, including Fine’s paper, cited above, a paper by Dummett that offers (but rejects) a precursor of the supervaluationist view, another less well‐known early presentation of the view by Henyrk Mehlberg and discussion and defences of the main rival theories of vagueness. Keefe, Rosanna. Theories of Vagueness. Cambridge: Cambridge University Press, 2000. This book defends a supervaluationist theory of vagueness. It discusses the phenomena of vagueness and what is required of a theory of vagueness, before considering and rejecting the major alternatives in turn. Williamson, Ti