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Barber Paradox (Russell's Paradox)


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142 replies to this topic

#11 stupiditysniper

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Posted 08 July 2007 - 10:43 PM

ok, it actually can be solved. i see the paradox that he cant/wont shave anyone who shaves themselves, so if he goes to shave himself... he would break his creed. but anyone else can shave him. you see, anybody can shave the barber regardless if they shave themselves or not.
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#12 jkirby1988

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Posted 17 July 2007 - 12:53 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.
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#13 montybd

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Posted 06 August 2007 - 12:53 PM

i agree wid "jkirby1988".
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#14 retskcah .eht

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Posted 08 August 2007 - 09:52 AM

It is possible...
If and only if the barber is a girl or the barber is a young boy below age of 13 so his beard does not grow jet.
This is not a paradox but an puzzle or ridle if u wish...


"Dont try to seek the answer unles you fully understand the question."
retskcah eht 8.8.2007
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#15 reaper69

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Posted 12 August 2007 - 07:05 AM

Technically, if the barber was to shave someone including himself, they were unshaven and in need of a shave. So at the moment prior to shaving himself he had not shaved himself; therefore making him eligible to be shaved by himself. It is a matter of timing.
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#16 lex talionis

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Posted 23 August 2007 - 08:07 PM

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 metiond promise.
______
I am suprised this is written by a logician and a mathematician.
with this wording the answer to this question is he could never keep his promise. Based on the rules of logic and the fact that this cannot be considered a parodox if it is based on assumption.

1) he did not specify if by everybody he meant everyone in the village. (he could not possibly shave everybody).

2) if he did mean the everyone in the village then all he would have to do to keep his promise is shave out side of the village. It would need to be worded like this:---There was a barber in a village, who promised to shave everybody in his village that does not shave him or herself.---

3) the best wording for this scenario is:---There was a barber in a village, who promised to shave everybody that is a resident of his village and does not shave himself (or herself).
With this wording logically all he would have to do to keep his promise and be able to shave himself would be to move out of his village and come to the village to shave everyone.

The reason this has been so hard to figure out is that it was written ignorantly.
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#17 craizee

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Posted 31 August 2007 - 09:41 PM

I bring to the table (as mentioned in earlier posts) that this is a matter of grammar.

The paradox reads:
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?

With the placement of the commas after "a village" and also after "shave everybody", the sentence can be reordered to read:
There was a barber in a village who does not shave himself (or herself) who promised to shave everybody.
Can the barber shave himself and keep the mentioned promise?

The first red herring is the question of the barber's gender. It is ambiguous in the statement. However, it is clearly revealed in the proposed question that this barber is clearly a man.

The second red herring that everyone gets stuck on is that the order of the wording (with the strategically placed commas) makes you believe that there is a condition to the rule where the barber can only shave those who don't shave themselves. This is not the case. Simply put- the barber does not shave himself. He promised to shave everybody. If the barber shaves himself, then the barber is in compliance with the promise to shave everyone. Therefore, the answer is yes.

The fact that the promise to shave everybody has absolutely no bearing on the fact that the barber does not shave himself. But by shaving himself would close the loophole of including the barber within the terms of "everyone".

The statement that he does not shave himself only indicates that this was fact when he made the promise. The act of him shaving himself would occur after the promise was made, so that would verify that statement in terms of a time line.
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#18 slw27

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Posted 02 September 2007 - 12:10 AM

1. the promise only applies to people who live in the village, the barber doesn't live there

2. the promise doesn't specify whether the promise is aimed at man or animal. if the promise is meant for animals the barber can shave himself/herself and not break the promise

3. there is no time parameter set for the promise. the promise may only apply between certain times, eg during his/her normal working hours, after which the barber can shave himself/herself.
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#19 slw27

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Posted 02 September 2007 - 12:48 PM

in order to make sure the barber only shaves people who don't shave themselves the barber must base his/her decision of who to shave on whether or not the person looks like they need to shave.
for this solution the barber is female, in order to look like she doesn't need to shave she removes hair by using wax; in doing this she hasn't broken her promise.
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#20 quzz008

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Posted 22 September 2007 - 06:30 AM

Well, he can.
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