Last week I asked a question about a barber? Does he shave himself? He shaves only the men who do no shave themselves, and nobody else.
Let’s look at the possible answers, which would appear to be ‘Yes’ or ‘No’
If the answer is ‘Yes’ then that means he does shave himself. But he only shaves men who don’t shave themselves. That breaks the rules
If the answer is ‘No’ then he is one of the men who doesn’t shave himself, so by the rules, he should shave… himself!
Since Russell proposed this paradox a few people have been less than impressed, writing it off as ‘wordplay’, but that seems to me like a rather killjoy approach to an interesting situation.
About the time I learnt about the barber – when I was about 15 – I read about another ‘logical story’… the story then referred to a ‘Hangman’; but given my total opposition to capital punishment, let’s talk about a surprise test at school. That’s puzzle will be posted tomorrow.