Assume that everyone was lying. Then this statement is true, but as a lie it must be false. Contradiction. So this case is not possible.
Asumme that not everyone was lying. E.g. some other post is false. Then this statement is false. This fits together if you have another post that is false.
This is why I can't take philosophy serious anymore.
Examples like the "this statement is false" thing are just rife with equivocations and other blatant nonsense. Yes, there is such a thing as "neither true nor false", but every example for "both true and false" I've seen is based on lousy thinking and semantic games.
Also, as a JS programmer, the distinction between true/false/neither/ineffable is very familiar (i.e.: true/false/null/undefined, null denoting the absence of a value and undefined denoting the absence of a definition -- though of course in practice the distinction is rarely necessary resulting in a lot of confusion and unnecessary double checks).
It's got nothing to do with "mysticism". It's just arm chair linguistics.
