Some people are always critical of vague statements. I tend rather to be critical of precise statements; they are the only ones which can correctly be labeled 'wrong'.

This is based on a story of two doors and two guards one who lies and one who doesn't. And mutatis mutandis for humans. One way to do this is to ask "Which door would the other guard say leads to hell?".

He then earned a BSc from the University of Chicago in 1955 and his Ph. Raymond Merrill Smullyan (born May 25 1919) is an American mathematician concert pianist logician Taoist philosopher and magician. from Princeton University in 1959.