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Single Idea 8173

[filed under theme 5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence ]

Full Idea

Two features of natural languages cause them to violate bivalence: singular terms (or proper names) which have a sense but fail to denote an object ('the centre of the universe'); and predicates which are not well defined for every object.

Clarification

Bivalence says sentences can only be 'true' or 'false'

Gist of Idea

Language can violate bivalence because of non-referring terms or ill-defined predicates

Source

Michael Dummett (Thought and Reality [1997], 4)

Book Ref

Dummett,Michael: 'Thought and Reality (Gifford Lectures)' [OUP 2006], p.47

A Reaction

If we switch from sentences to propositions these problems might be avoided. If there is no reference, or a vague predicate, then there is (maybe) just no proposition being expressed which could be evaluated for truth.

The 21 ideas from 'Thought and Reality'

8163 Since 'no bird here' and 'no squirrel here' seem the same, we must talk of 'atomic' facts [Dummett]
8161 We know we can state facts, with true statements [Dummett]
8165 To 'abstract from' is a logical process, as opposed to the old mental view [Dummett]
8166 Truth is part of semantics, since valid inference preserves truth [Dummett]
8167 If Presentism is correct, we cannot even say that the present changes [Dummett]
8168 To know the truth-conditions of a sentence, you must already know the meaning [Dummett]
8170 Sentences are the primary semantic units, because they can say something [Dummett]
8169 We can't distinguish a proposition from its content [Dummett]
8175 A theory of thought will include propositional attitudes as well as propositions [Dummett]
8174 The theories of meaning and understanding are the only routes to an account of thought [Dummett]
8173 Language can violate bivalence because of non-referring terms or ill-defined predicates [Dummett]
8176 We could only guess the meanings of 'true' and 'false' when sentences were used [Dummett]
8179 The law of excluded middle is the logical reflection of the principle of bivalence [Dummett]
8180 'That is red or orange' might be considered true, even though 'that is red' and 'that is orange' were not [Dummett]
8178 Empirical and a priori knowledge are not distinct, but are extremes of a sliding scale [Dummett]
8181 A justificationist theory of meaning leads to the rejection of classical logic [Dummett]
8182 Verificationism could be realist, if we imagined the verification by a superhuman power [Dummett]
8183 If truths about the past depend on memories and current evidence, the past will change [Dummett]
8184 Philosophers should not presume reality, but only invoke it when language requires it [Dummett]
8185 We can't make sense of a world not apprehended by a mind [Dummett]
8186 Time is the measure of change, so we can't speak of time before all change [Dummett]