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5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence

[propositions can only be true or false]

13 ideas
Bivalence is a regulative assumption of enquiry - not a law of logic [Misak on Peirce]
Bivalence implies not just to sentences, but that general terms are true or false of each object [Quine]
Language can violate bivalence because of non-referring terms or ill-defined predicates [Dummett]
Undecidable statements result from quantifying over infinites, subjunctive conditionals, and the past tense [Dummett]
Vagueness seems to be inconsistent with the view that every proposition is true or false [Mautner]
Standard disjunction and negation force us to accept the principle of bivalence [Mares]
Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares]
A third value for truth might be "indeterminate", or a point on a scale between 'true' and 'false' [O'Grady]
Deflationism must reduce bivalence ('p is true or false') to excluded middle ('p or not-p') [Engel]
No attempt to deny bivalence has ever been accepted [Sorensen]
If bivalence is rejected, then excluded middle must also be rejected [Rowlands]
The principle of bivalence distorts reality, as when claiming that a person is or is not 'thin' [Baggini /Fosl]
When faced with vague statements, Bivalence is not a compelling principle [Rumfitt]