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Single Idea 21610

[filed under theme 7. Existence / D. Theories of Reality / 10. Vagueness / f. Supervaluation for vagueness ]

Full Idea

Supervaluation seems to inherit the power of classical logic, ...but also enables it to be extended. It makes room for a new operator 'definitely' to express supertruth in the object-language.

Gist of Idea

Supervaluation adds a 'definitely' operator to classical logic

Source

Timothy Williamson (Vagueness [1994], 5.3)

Book Ref

Williamson,Timothy: 'Vagueness' [Routledge 1996], p.149


A Reaction

Once you mention higher-order vagueness you can see a regress looming over the horizon. 'He is definitely definitely definitely bald'. [p.164 he says 'definitely' has no analysis, and is an uninteresting primitive]


The 30 ideas with the same theme [narrowing down the vagueness]:

Supervaluation can give no answer to 'who is the last bald man' [Fine,K]
A vague sentence is only true for all ways of making it completely precise [Fine,K]
Logical connectives cease to be truth-functional if vagueness is treated with three values [Fine,K]
Meaning is both actual (determining instances) and potential (possibility of greater precision) [Fine,K]
With the super-truth approach, the classical connectives continue to work [Fine,K]
Borderline cases must be under our control, as capable of greater precision [Fine,K]
Supervaluationism keeps true-or-false where precision can be produced, but not otherwise [Keefe/Smith]
Vague statements lack truth value if attempts to make them precise fail [Keefe/Smith]
Some of the principles of classical logic still fail with supervaluationism [Keefe/Smith]
The semantics of supervaluation (e.g. disjunction and quantification) is not classical [Keefe/Smith]
Supervaluation misunderstands vagueness, treating it as a failure to make things precise [Keefe/Smith]
Supervaluation keeps classical logic, but changes the truth in classical semantics [Williamson]
You can't give a precise description of a language which is intrinsically vague [Williamson]
Supervaluation assigns truth when all the facts are respected [Williamson]
Supervaluation has excluded middle but not bivalence; 'A or not-A' is true, even when A is undecided [Williamson]
Truth-functionality for compound statements fails in supervaluation [Williamson]
Supervaluationism defines 'supertruth', but neglects it when defining 'valid' [Williamson]
Supervaluation adds a 'definitely' operator to classical logic [Williamson]
Supervaluationism cannot eliminate higher-order vagueness [Williamson]
Supervaluation refers to one vaguely specified thing, through satisfaction by everything in some range [Hawley]
Supervaluationism takes what the truth-value would have been if indecision was resolved [Hawley]
A 'precisification' of a trivalent interpretation reduces it to a bivalent interpretation [Sider]
Supervaluational logic is classical, except when it adds the 'Definitely' operator [Sider]
A 'supervaluation' assigns further Ts and Fs, if they have been assigned in every precisification [Sider]
We can 'sharpen' vague terms, and then define truth as true-on-all-sharpenings [Sider]
A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read]
Identities and the Indiscernibility of Identicals don't work with supervaluations [Read]
Supervaluations say there is a cut-off somewhere, but at no particular place [Read]
In the supervaluationist account, disjunctions are not determined by their disjuncts [Horsten]
If 'Italy is large' lacks truth, so must 'Italy is not large'; but classical logic says it's large or it isn't [Horsten]