What Happens After Philosophy Eats its Tail?
The Liar Paradox and peak subversion in philosophy
If I were to tell you that I always lie, should you believe me then or not?
This is the liar paradox which goes back to ancient Greek philosophy. If I’m lying when I say I’m always lying, as I should be if I’m a liar, then I’m not a liar after all because in that case, at least, I’m telling the truth about myself.
And if I’m telling the truth about myself when I say I always lie, then that generalization about me must be true, which means I’m a liar so you shouldn’t believe anything I say, including that generalization.
Thus, my statement that I’m always lying seems both true and false, which is impossible.
The paradox is that in attempting to undermine my credibility, or in explaining why I shouldn’t be believed because I’m a liar, I seem to re-establish that credibility. How, then, can an unremittingly negative viewpoint be expressed without presupposing its positivity? How can an extreme skeptic or pessimist repudiate all knowledge without building back up at least some knowledge, namely the negative or subversive kind?
Isn’t the liar or the skeptic somewhat like the morose person who claims to be sad all the time, but who finds that she’s suddenly happy…
