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Single Idea 9049
[filed under theme 7. Existence / D. Theories of Reality / 10. Vagueness / f. Supervaluation for vagueness
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Full Idea
The supervaluationist view of vagueness is that 'tall' comes out true or false on all the ways in which we can make 'tall' precise. There is a gap for borderline cases, but 'tall or not-tall' is still true wherever you draw a boundary.
Gist of Idea
Supervaluationism keeps true-or-false where precision can be produced, but not otherwise
Source
R Keefe / P Smith (Intro: Theories of Vagueness [1997], §1)
Book Ref
'Vagueness: a Reader', ed/tr. Keefe,R /Smith,P [MIT 1999], p.7
A Reaction
[Kit Fine is the spokesperson for this; it preserves classical logic, but not semantics] This doesn't seem to solve the problem of vagueness, but it does (sort of) save the principle of excluded middle.
The
17 ideas
from R Keefe / P Smith
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9044
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If someone is borderline tall, no further information is likely to resolve the question
[Keefe/Smith]
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9048
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The simplest approach, that vagueness is just ignorance, retains classical logic and semantics
[Keefe/Smith]
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9049
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Supervaluationism keeps true-or-false where precision can be produced, but not otherwise
[Keefe/Smith]
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9050
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A third truth-value at borderlines might be 'indeterminate', or a value somewhere between 0 and 1
[Keefe/Smith]
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9045
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Vague predicates involve uncertain properties, uncertain objects, and paradoxes of gradual change
[Keefe/Smith]
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9047
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Many vague predicates are multi-dimensional; 'big' involves height and volume; heaps include arrangement
[Keefe/Smith]
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9053
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If there is a precise borderline area, that is not a case of vagueness
[Keefe/Smith]
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9055
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The epistemic view of vagueness must explain why we don't know the predicate boundary
[Keefe/Smith]
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9056
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Vague statements lack truth value if attempts to make them precise fail
[Keefe/Smith]
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9058
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Some of the principles of classical logic still fail with supervaluationism
[Keefe/Smith]
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9059
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The semantics of supervaluation (e.g. disjunction and quantification) is not classical
[Keefe/Smith]
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9060
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Supervaluation misunderstands vagueness, treating it as a failure to make things precise
[Keefe/Smith]
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9061
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People can't be placed in a precise order according to how 'nice' they are
[Keefe/Smith]
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9062
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If truth-values for vagueness range from 0 to 1, there must be someone who is 'completely tall'
[Keefe/Smith]
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9063
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How do we decide if my coat is red to degree 0.322 or 0.321?
[Keefe/Smith]
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9065
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S5 collapses iterated modalities (◊□P→□P, and ◊◊P→◊P)
[Keefe/Smith]
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9064
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Objects such as a cloud or Mount Everest seem to have fuzzy boundaries in nature
[Keefe/Smith]
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