Well, if you always lied, you could still say that you never lie, you'd only be lying

If you never lie, on the other hand, you couldn't say that you always lie, because then you'd be lying. But of course someone who never lies can sincerely say that he never lies, so you really couldn't tell if someone is a liar or not, even if he'd 'truthfully'* say that (s)he never lies.


* By truthfully I here mean something like 'being consistent with one's values', or something like that.

More on it can be found on the Wikipedia page of the 'liar paradox': Liar paradox - Wikipedia, the free encyclopedia

By the way: I surely consider things like this to be logical 'problems', and I surely consider logic to be a branch of philosophy; so I don't think this thread is out of place here.