Quine's paradox is a paradox concerning truth values, attributed to W. V. O. Quine. It is a related problem to the liar paradox and uses indirect self-reference.
- “Yields falsehood when preceded by its quotation” yields falsehood when preceded by its quotation.
What is the sentence talking about?
Let's take the step that the sentence implies.
- 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.”
We now have returned to the original case. So this sentence asserts:
- “The sentence ““yields falsehood when preceded by its quotation” yields falsehood when preceded by its quotation.” is false.”
In other words, the sentence says that it is false. This is a paradox: If it's true, it's false, and if it's false, it's true.
See also