Difference between revisions
liar-paradox
Status and infobox
- status:
—→ partial - kind:
—→ problem - year:
—→ -350 - statement:
—→ Is the sentence 'This sentence is false' true or false?
Relations
- + related to hilbert-second: The original curation links this problem to Hilbert's second problem: consistency of arithmetic; the argument for the link has not been written yet.
Source +22 −0
+---
+title: The liar paradox
+kind: problem
+status: partial
+year: -350
+authors: attributed to Eubulides
+statement: Is the sentence 'This sentence is false' true or false?
+space: value
+---
+Tarski showed in 1933 that a sufficiently strong language cannot define its own truth predicate, which blocks the paradox by moving truth to a metalanguage. Kripke's 1975 theory of truth allows gaps instead. Gödel used a relative of the paradox to prove incompleteness. Formal fixes exist; whether any captures ordinary truth is debated.
+
+Posed c. 4th century BCE, attributed to Eubulides.
+
+## Related problems
+
+- The original curation links this problem to [[related::Problem:hilbert-second|Hilbert's second problem: consistency of arithmetic]]; the argument for the link has not been written yet.
+
+## Sources
+
+- [Wikipedia: Liar paradox](https://en.wikipedia.org/wiki/Liar_paradox)
+
+[[Space:value|Value and reason]] · [[Continent:philosophy|Philosophy]]
Revision 233 as rendered
Tarski showed in 1933 that a sufficiently strong language cannot define its own truth predicate, which blocks the paradox by moving truth to a metalanguage. Kripke's 1975 theory of truth allows gaps instead. Gödel used a relative of the paradox to prove incompleteness. Formal fixes exist; whether any captures ordinary truth is debated.
Posed c. 4th century BCE, attributed to Eubulides.
Related problems
- The original curation links this problem to Hilbert's second problem: consistency of arithmetic; the argument for the link has not been written yet.