There is a classic logic problem known as the Barber paradox (itself a variant of Russell's paradox): in a town where the barber shaves every man who doesn't shave himself, who shaves the barber? If ...
No less a mind than Bertrand Russell, of Principia Mathematica fame, was responsible for this paradox, which opened a hole in math. It’s those barbers. The Barber Paradox shows that barbers are not to ...