# Socratic Paradox/Paradox 2

< Socratic Paradox(Redirected from Liar Paradox)

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## Paradox

Socrates is supposed to have raised the question:

Is the following statement in italics true or false?

Suppose the statement in italics is true.

Then it is false.

That is, what it says is different from the way things actually are.

So, the sentence is not false.

Therefore it is true.

But it cannot be both.

### Resolution

The sentence is meaningless.

## Also known as

This paradox is often seen referred to as the **liar paradox** or **liar's paradox**.

## Also see

## Source of Name

This entry was named for Socrates.

## Sources

- 1918: Bertrand Russell:
*The Philosophy of Logical Atomism*: 7. The Theory of Types and Symbolism: Classes - 1964: Donald Kalish and Richard Montague:
*Logic: Techniques of Formal Reasoning*... (previous) ... (next): $\text{I}$: 'NOT' and 'IF': $(3)$ - 1979: Douglas R. Hofstadter:
*Gödel, Escher, Bach: an Eternal Golden Braid* - 1993: M. Ben-Ari:
*Mathematical Logic for Computer Science*... (previous) ... (next): Chapter $1$: Introduction: $\S 1.1$: The origins of mathematical logic - 1998: David Nelson:
*The Penguin Dictionary of Mathematics*(2nd ed.) ... (previous) ... (next): Entry:**liar paradox** - 2008: David Nelson:
*The Penguin Dictionary of Mathematics*(4th ed.) ... (previous) ... (next): Entry:**liar paradox** - 2014: Christopher Clapham and James Nicholson:
*The Concise Oxford Dictionary of Mathematics*(5th ed.) ... (previous) ... (next): Entry:**liar paradox**