Practical Application of the "Liar's Paradox"

The Liar Paradox. "Truth" for English sentences is not
definable in English.
Proof. Suppose it is. Then so is its complement
"False".
Let s be the sentence "This sentence is false" .
Since the phrase "This sentence" refers to s, we
have
s iff "This sentence is false" iff "s is
false" iff not s.
A contradiction.


This concept, presented as a formal logical
presentation of the traditional liar's paradox "if the
liar says he is a liar, then he is telling the truth,"
can be applied directly to counselling psychology and
conflict resolution.

One of the biggest "relationship breakers" is the
statement "I know I'm right!". There is no effective
response, it cuts off all argument or discussion. An
informal presentation of the liar's paradox
effectively proves that there is no absolute truth:

"So, you know you're right?"
"Certainly."
"Then, you know when you're wrong?"
"Of course."
"Then, when you're wrong, you're wrong about it?
"What? No, when I'm wrong I'm right!"
"That doesn't make any sense."

.

Relevant Pages

  • Practical Application of the "Liars Paradox"
    ... The Liar Paradox. ... "Truth" for English sentences is not ...
    (sci.math)
  • Re: Why Regularity?
    ... that no language can define its own truth predicate. ... There's a more recent treatment of the paradox in "The Liar", ... Is my analogy between the liar paradox and ZFC consistent? ...
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  • Re: Solution to Liar Paradox
    ... English sentences must have truth assignments that satisfy them. ... Having an allowable truth assignment does not by itself solve the Liar ... For example, consider Curry's paradox; ...
    (sci.logic)
  • Re: Why Regularity?
    ... that no language can define its own truth predicate. ... There's a more recent treatment of the paradox in "The Liar", ... according to Tarski the content of that statement is ...
    (sci.math)
  • Re: Solution to Liar Paradox
    ... It is like Russell's paradox: ... why is the Liar not such sentence in spite of all appearances? ... self-reference, negation, substitution and consistency. ... is not a sentence because then English sentences are not complete, ...
    (sci.logic)