In philosophy and logic there is something know as the liar's paradox. Consider the following statement:
"This statement is false."
If "This statement is false" is true, then it is false, which in turn would mean that it is actually true, but this would mean it is false … and so on ad infinitum.
If "This statement is false" is false, then it is true, which in turn would mean it is actually false, but this would mean it is true … and so on ad infinitum.
Sometimes the truth is both true and false at the same time — just like the picture to the right. (Don't believe me? Try flipping it upside down.)
