Quine's Paradox

Quine's paradox is a paradox concerning truth values, attributed to Willard Van Orman Quine. It is related to the liar paradox as a problem, and it purports to show that a sentence can be paradoxical even if it is not self-referring and does not use demonstratives or indexicals (i.e. it does not explicitly refer to itself). The paradox can be expressed as follows:

"Yields falsehood when preceded by its quotation" yields falsehood when preceded by its quotation.

If the paradox is not clear, consider each part of the above description of the paradox incrementally:

it = yields falsehood when preceded by its quotation
its quotation = "yields falsehood when preceded by its quotation"
it preceded by its quotation = "yields falsehood when preceded by its quotation" yields falsehood when preceded by its quotation.

With these tools, we may now reconsider the description of the paradox. It can be seen to assert the following:

The statement "'yields falsehood when preceded by its quotation' yields falsehood when preceded by its quotation" is false.

In other words, the sentence implies that it is false, which is paradoxical—for if it is false, what it states is in fact true.

Read more about Quine's Paradox:  Motivation, Application

Famous quotes containing the words quine and/or paradox:

    Some have said that the thesis [of indeterminacy] is a consequence of my behaviorism. Some have said that it is a reductio ad absurdum of my behaviorism. I disagree with this second point, but I agree with the first. I hold further that the behaviorism approach is mandatory. In psychology one may or may not be a behaviorist, but in linguistics one has no choice.
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