A man walks up to you and says:
"
Everything I say to you is a lie."
Is he telling you the truth or is he lying?
this is one of the oldest paradoxes known to man. it's even in the Bible, though written slightly differently. another example of the same question is "i am a liar, so it is just for me to say that all liars are liars" but by saying this you must have lied about being a liar as the text states... but then you must be telling the truth as you are not a liar and it is not just for you to say you are a liar, so you are lying - therefore you are a liar...etc.