1. General Remarks and Historical Context

In its simplest form, the Liar is a puzzle generated when someone says, “This is false”. If true, this is false, and if false, true. Either way leads to contradiction.

Early texts in the tradition instead present the paradox as a puzzle about someone who says, “I am a liar ( kādhib )”. Or rather—since the Arabic word ‘ kādhib ’ need not imply any intention to deceive—“I am a false-teller”, that is, someone who says false things. Unfortunately, this is ambiguous: it could mean that they always say false things; or it could mean that they sometimes say false things. Careful authors clarify what it means, or avoid this problem entirely, instead presenting the paradox as a puzzle about someone who says, “All my sayings are false”. [ 1 ]

In ordinary circumstances, “All my sayings are false” is self-refuting, but it is not a paradox.…