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Barber Paradox (Russell's Paradox)


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142 replies to this topic

#41 Jasonatron

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Posted 30 January 2008 - 02:00 PM

Barber Paradox (Russell's Paradox) - Back to the Paradoxes

Analogue paradox to the paradox of liar formulated English logician, philosopher and mathematician Bertrand Russell.
There was a barber in a village, who promised to shave everybody, who does not shave himself (or herself).
Can the barber shave himself and keep the mentioned promise?


Yes, if the barber shaves himself, then the barber has shaved himself, and the barber does not then need to shave him. Conversely, if the barber has not shaven, then the barber will take the liberty of shaving himself for himself. Then, the barber will have shaved himself, and the barber need not then to shave him.

Edited (better wording?):
In a village, the barber shaves everyone who does not shave himself/herself, but no one else.
Who shaves the barber?


Nobody shaves the barber. This is why you should read carefully before you enter into contract. Lesson learned.
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#42 mudkip201

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Posted 03 February 2008 - 01:53 AM

Saying that anyone can shave the barber would break the barber's promise because the barber promises to shave everyone who doesn't shave themselves. If someone shaved the barber he would have to shave himself because the barber didn't shave themselves, if that makes sense. My solution is that the barber is a woman who doesn't grow facial hair so there needn't be any shaving.


If the barber was a woman, she probably wouldn't have facial hair, although she might. Then there would have to be at least 2 barbers.
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#43 mudkip201

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Posted 03 February 2008 - 01:56 AM

Barber Paradox (Russell's Paradox) - Back to the Paradoxes

Analogue paradox to the paradox of liar formulated English logician, philosopher and mathematician Bertrand Russell.
There was a barber in a village, who promised to shave everybody, who does not shave himself (or herself).
Can the barber shave himself and keep the mentioned promise?

Edited (better wording?):
In a village, the barber shaves everyone who does not shave himself/herself, but no one else.
Who shaves the barber?


Maybe the barber has his or her slave shave him/herself and the barber as well.

Edited by mudkip201, 03 February 2008 - 01:56 AM.

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#44 riddle_me_this

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Posted 04 February 2008 - 04:56 AM

In a village, the barber shaves everyone who does not shave himself/herself, but no one else.
Who shaves the barber?


In this, no gender is given for the barber.
Thus, the barber is female and has no facial hair. She does not shave herself, but shaves everyone else.
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#45 vime

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Posted 04 February 2008 - 10:09 AM

Barber Paradox (Russell's Paradox) - Back to the Paradoxes

Analogue paradox to the paradox of liar formulated English logician, philosopher and mathematician Bertrand Russell.
There was a barber in a village, who promised to shave everybody, who does not shave himself (or herself).
Can the barber shave himself and keep the mentioned promise?

Edited (better wording?):
In a village, the barber shaves everyone who does not shave himself/herself, but no one else.
Who shaves the barber?


Why the hell do people keep such stupid promises. I mean look at the mess... he kept the promise n we are figuring out the solution so that he dosen't have to break his promise.
The barber promised to shave everybody who does not shave themselve. This means that being a barber its his job to shave people ... specially those who dont shave themselves(he's not doing this for free). The barber has not specified any clauses that [ONLY] who do not shave himself will be shaved by me. People who have shaved themselves obviously wont go to the barber n waste their money. Therefore his customers are the unshaven people. So as a good barber he promised to shave everybody, who does not shave himself (or herself). Therefore the barber can shave himself as he hasn't been selective about his customers.
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#46 9gradebrainiac

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Posted 09 February 2008 - 05:16 AM

I understand that this is supose to tease saying that if he shaves everyone that doesnt shave and he doesnt shave he must shave himself but then if he continues to shave himself he must stop because he now does not not shave himself. Yet nowhere in the riddle does it say he is incapable of shaving someone who already shaves =] just saying.... and it is worded rather oddly like sharknateher said, so I'm not sure if I have this down right.







i'm not much of the nerd or "educationally challenged" if i may (no offense to everybody) but if i'm correct when you said "because he does not not shave himself" in my opinion it either: 1. sounds like your trying to make yourself sound more intelligent because of that statement... or 2.that statement just goes with the whole deal.
1. but wat im trying to say is if you do want to make yourself sound smarter then wouldn't it be more logical to just say simply: because he shaves himself
2. or by you saying that do you think it just fits better with that first sentence.. like i said "it just goes with the whole deal"?

i was just reading through these because i happen to be interested in these logical puzzles.. i came across some great points, i saw yours, and i questioned it... i thought what the heck why not just say wat i'm thinking right?... wrong because right now i'm sure i'm being laughed at because here i am a 9th grader correcting someone who is obviously much older than i am... trying to make myself sound smart.. hmm
oh well...i tend to point out the obvious alot :D

but.. if you think the first "paragraph" i just wrote had a point to it.. then let me know i wanna know whether i can be smart or am smart either/or..
preciate it!
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#47 9gradebrainiac

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Posted 10 February 2008 - 02:46 AM

maybe the barbers beard doesn't grow it is possible (I've met people who do not need to shave) he keeps his promise and everybody is happy it does not say that his beard grows



true but who says he only shaves beards and mabey he is really a she and shaves her legs therefor shaving herself and breking that promise... :)
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#48 bnetter

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Posted 15 February 2008 - 11:54 PM

He can do it he did not say that he would only shave those who didn't shave themselves so he could.
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#49 cm0265880

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Posted 27 February 2008 - 08:10 AM

The answer is simple and uncomplex. Its yes. No more no less. This "paradox" seems to me, to be a middle school logic puzzle. It almost mindless, but to each his own I guess.
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#50 cm0265880

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Posted 27 February 2008 - 08:26 AM

All females have facal hair even if its undectable it still there
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