Single Idea 13693

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

Full Idea

In a 'supervaluation' we take a trivalent interpretation, and assign to each wff T (or F) if it is T (or F) in every precisification, leaving the third truth-value in any other cases. The wffs are then 'supertrue' or 'superfalse' in the interpretation.

Clarification

See Idea 13692 for 'precisification'

Gist of Idea

A 'supervaluation' assigns further Ts and Fs, if they have been assigned in every precisification

Source

Theodore Sider (Logic for Philosophy [2010], 3.4.5)

Book Reference

Sider,Theodore: 'Logic for Philosophy' [OUP 2010], p.83


A Reaction

[my non-symbolic summary] Sider says the Ts and Fs in the precisifications are assigned 'in any way you like', so supervaluation is a purely formal idea, not a technique for eliminating vagueness.

Related Idea

Idea 13692 A 'precisification' of a trivalent interpretation reduces it to a bivalent interpretation [Sider]