PRAGMATISM AND VAGUENESS: THE VENETIAN LECTURES BY CLAUDINE TIERCELIN (EDITED BY GIOVANNI TUZET)

Abstract

Reviewed by: Pragmatism and Vagueness: The Venetian Lectures; Edited by Giovanni Tuzet by Claudine Tiercelin David W. Agler Claudine Tiercelin Pragmatism and Vagueness: The Venetian Lectures; Edited by Giovanni Tuzet Mimesis International, 2019, 84 pages, no index. Take a hypothetical sequence of human beings ordered by height from tallest to shortest. Make sure there is no more than a difference of a millimeter between each person and make sure the tallest person is clearly tall and the shortest person is clearly not tall. Now consider the following argument: P1 A person of height n is tall (where n is some arbitrarily large value); P2 For any height n, if n is tall, then n–1mm is tall (if you think a millimeter makes a difference as to whether someone is tall or not, then use a smaller unit of measurement); C Therefore, a person of height n = 1mm is tall. P1 and P2 are intuitively true, C is intuitively false, yet the argument is deductively valid (the conclusion follows by repeated uses of universal elimination and modus ponens). Rejecting P1 seemingly commits one to saying very tall people are not tall (which is absurd) while rejecting P2 seemingly commits one to saying that the predicate "is tall" picks out some precise height n such that an individual of height n is tall while an individual one millimeter shorter is not tall (also absurd). This is the sorites paradox. The paradox is thought to emerge because of the vagueness of predicates like "is tall" and given the ubiquity of vague terms in some of our best theories, vagueness poses a threat to logic and metaphysics. Tiercelin's book analyzes vagueness from a pragmatic perspective. More precisely, this book explains why pragmatists (particularly of the Peircean stripe) ought to take vagueness as a perfection of language, rather than defect, and why taking such a stance requires a commitment to ontological vagueness (vagueness in the world). The book is divided into three lectures corresponding to talks delivered by Tiercelin on 7–9 March 2018 at Ca' Foscari University in Venice. In what follows, I give the reader a sense of each of these lectures and then conclude with a brief critical assessment. Lecture 1 concerns three topics: (i) the unity of pragmatism, (ii) that pragmatists ought to reject the reduction of the vague to the precise, and (iii) that vagueness is a perfection of language since the world itself is vague. Concerning (i), Tiercelin argues that while commentators [End Page 458] have stressed the differences between pragmatists (e.g. James's nominalism vs. Peirce's realism), these differences are overblown. For Tiercelin, there is a common core of positions held by classical pragmatists and many of the commonly cited differences between said pragmatists are illusory. Rather than being divided, pragmatists are united in their commitment to the need for general rules, a non-reductive and non-passive form of empiricism, a stress on the role of practice and action, and a commitment to fallibilism (pp.20–23). With respect to (ii), Tiercelin takes one of the central features of pragmatism to be its opposition to nominalism construed as reductionism (p.15). For Tiercelin, the impetus to reduce is largely due to a lack of attention to some real feature in language, ontology, or knowledge. Anti-reductionists are thus realists insofar as they attend to some reality that has been ignored. Regarding the reduction of the vague to the precise, pragmatists are thus said to be realists about vagueness as they attend to the real features of the world that are vague. Consequently, they ought to reject the view that at least some vague terms can be reduced to precise terms. With respect to (iii), Tiercelin contends that since the source of vagueness is ontological, vagueness in language is a representational perfection of language. This claim is distinctive since vagueness is usually regarded as a defect of some sort. Take the epistemic theory of vagueness (e.g. Williamson 1994). This theory contends that vagueness is due to an epistemic deficiency: we fail to know the precise cut-off of vague terms. With respect to the sorites paradox, the major/quantified...