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Single Idea 21597

[filed under theme 5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives ]

Full Idea

Russell says the best chance of avoiding vagueness are the logical connectives. ...But the vagueness of 'true' and 'false' infects the logical connectives too. All words are vague. Russell concludes that all language is vague.

Gist of Idea

Logical connectives have the highest precision, yet are infected by the vagueness of true and false

Source

report of Bertrand Russell (Vagueness [1923]) by Timothy Williamson - Vagueness 2.4

Book Ref

Williamson,Timothy: 'Vagueness' [Routledge 1996], p.54


A Reaction

This relies on the logical connectives being defined semantically, in terms of T and F, but that is standard. Presumably the formal uninterpreted syntax is not vague.

Related Idea

Idea 21596 Vagueness undermines the stable references needed by logic [Williamson]


The 31 ideas with the same theme [general role and status of logical connectives]:

The logical connectives are not objects, but are formal, and need a context [Russell]
Logical constants seem to be entities in propositions, but are actually pure form [Russell]
We use logical notions, so they must be objects - but I don't know what they really are [Russell]
Logical connectives have the highest precision, yet are infected by the vagueness of true and false [Russell, by Williamson]
'And' and 'not' are non-referring terms, which do not represent anything [Wittgenstein, by Fogelin]
My fundamental idea is that the 'logical constants' do not represent [Wittgenstein]
The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna]
The logical connectives are 'defined' by their introduction rules [Gentzen]
Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen]
If logical truths essentially depend on logical constants, we had better define the latter [Hacking on Quine]
Prior rejected accounts of logical connectives by inference pattern, with 'tonk' his absurd example [Prior,AN, by Read]
We need to know the meaning of 'and', prior to its role in reasoning [Prior,AN, by Belnap]
Prior's 'tonk' is inconsistent, since it allows the non-conservative inference A |- B [Belnap on Prior,AN]
Maybe introducing or defining logical connectives by rules of inference leads to absurdity [Prior,AN, by Hacking]
'¬', '&', and 'v' are truth functions: the truth of the compound is fixed by the truth of the components [Jackson]
With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
Truth-functors are usually held to be defined by their truth-tables [Bostock]
Natural deduction introduction rules may represent 'definitions' of logical connectives [Prawitz]
Logical concepts rest on certain inferences, not on facts about implications [Fine,K]
Classical connectives differ from their ordinary language counterparts; '∧' is timeless, unlike 'and' [Shapiro]
Formalising arguments favours lots of connectives; proving things favours having very few [Burgess]
The nature of each logical concept is given by a collection of inference rules [Correia]
Logical connectives contain no information, but just record combination relations between facts [Read]
The connectives are studied either through model theory or through proof theory [Mares]
Define logical constants by role in proofs, or as fixed in meaning, or as topic-neutral [Sider]
Wittgenstein reduced Russell's five primitive logical symbols to a mere one [O'Grady]
Connectives link sentences without linking their meanings [MacBride]
Natural language includes connectives like 'because' which are not truth-functional [McGee]
Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]
The sense of a connective comes from primitively obvious rules of inference [Rumfitt]
In specifying a logical constant, use of that constant is quite unavoidable [Rumfitt]