this sentence is false

in a village there lives a barber who shaves all and only the people who do not shave themselves.

so, who shaves the barber?

if he shaves himself, he does not; if he does not shave himself, he does.

["the point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it," bertrand russell, 1918.]