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Single Idea 21567

[filed under theme 5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox ]

Full Idea

Such a proposition as 'all the judgements made by Epimenedes are true' will only be prima facie capable of truth if all his judgements are of the same order.

Gist of Idea

'All judgements made by Epimenedes are true' needs the judgements to be of the same type

Source

Bertrand Russell (The Theory of Logical Types [1910], p.227)

Book Ref

Russell,Bertrand: 'Essays in Analysis', ed/tr. Lackey,Douglas [George Braziller 1973], p.227


A Reaction

This is an attempt to use his theory of types to solve the Liar. Tarski's invocation of a meta-language is clearly in the same territory.


The 19 ideas with the same theme [problem when liars refer to themselves]:

If you say truly that you are lying, you are lying [Eubulides, by Dancy,R]
One of their own prophets said that Cretans are always liars [Anon (Titus)]
Vicious Circle: what involves ALL must not be one of those ALL [Russell]
'All judgements made by Epimenedes are true' needs the judgements to be of the same type [Russell]
The Liar makes us assert a false sentence, so it must be taken seriously [Tarski]
Tarski avoids the Liar Paradox, because truth cannot be asserted within the object language [Tarski, by Fisher]
'This sentence is false' sends us in a looping search for its proposition [Wittgenstein, by Fogelin]
If we write it as '"this sentence is false" is false', there is no paradox [Quine]
The Liar reappears, even if one insists on propositions instead of sentences [Gupta]
Strengthened Liar: either this sentence is neither-true-nor-false, or it is not true [Gupta]
The machinery used to solve the Liar can be rejigged to produce a new Liar [Hart,WD]
An infinite series of sentences asserting falsehood produces the paradox without self-reference [Yablo, by Sorensen]
The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess]
If you know that a sentence is not one of the known sentences, you know its truth [Priest,G]
There are Liar Pairs, and Liar Chains, which fit the same pattern as the basic Liar [Priest,G]
Self-reference paradoxes seem to arise only when falsity is involved [Read]
Banning self-reference would outlaw 'This very sentence is in English' [Sorensen]
Strengthened Liar: 'this sentence is not true in any context' - in no context can this be evaluated [Horsten]
The liar paradox applies truth to a negated truth (but the conditional will serve equally) [Halbach]