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Single Idea 21604

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

Full Idea

'Admissible' interpretations respect all the theoretical and ostensive connections. ...'Supervaluation' is the assignment of truth to the statements true on all admissible valuations, falsity to the false one, and neither to the rest.

Gist of Idea

Supervaluation assigns truth when all the facts are respected

Source

Timothy Williamson (Vagueness [1994], 5.2)

Book Ref

Williamson,Timothy: 'Vagueness' [Routledge 1996], p.144


A Reaction

So 'he is bald' is true if when faced with all observations and definitions it is acceptable. Prima facie, that doesn't sound like a solution to the problem. Supervaluation started in philosophy of science. [p.156 'Admissible seems vague']

Related Idea

Idea 21607 Supervaluation has excluded middle but not bivalence; 'A or not-A' is true, even when A is undecided [Williamson]


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]
A 'supervaluation' assigns further Ts and Fs, if they have been assigned in every precisification [Sider]
Supervaluational logic is classical, except when it adds the 'Definitely' operator [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]