The Original Liar Paradox from Antiquity

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Dan Christensen

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Jan 27, 2019, 2:09:01 PM1/27/19

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The Cretan poet, Epimenides (circa 600 BC), famously wrote that Cretans are “always liars.” Paradoxically, it would seem that if he was telling the truth, then he was lying. And if he was lying, he only confirmed that he was telling the truth! An impossible situation? Well, not exactly.

It turns out that there are many possible narratives that would be logically consistent with the original scenario. Epimenides’ famous rant could, for example, have been the only lie ever told by a Cretan. All that is required is that Epimenides’ statement be a lie and that at least one Cretan once told the truth.