Page "Liar paradox" Paragraph 11

However, that the liar sentence can be shown to be true if it is false and false if it is true has led some to conclude that it is " neither true nor false ".

This response to the paradox is, in effect, the rejection of the claim that every statement has to be either true or false, also known as the principle of bivalence, a concept related to the law of the excluded middle.