Do you think this question is logical ? - Physics Forums: Physics, Astronomy, Math, & Philosophy Forums!

 Physics Forums: Physics, Astronomy, Math, & Philosophy Forums! Do you think this question is logical ?
 Register FAQ Members List Calendar Search Today's Posts Mark Forums Read
#1
03-13-2006, 08:44 AM
 abcde Junior Member Join Date: Mar 2006 Posts: 3
Do you think this question is logical ?

Hi all, this is my first post here ...

and I have a question in my mind that I want to share with you ...

in my last exam I had a question, which was like this :

in the following all these scentences are true, except :

1- true
2- true
3- not true
4-all of the above

what do you think the answer is? and is it logical?

thanks for the chance ...
#2
03-14-2006, 03:30 AM
 physicsmathsman Junior Member Join Date: Mar 2006 Posts: 2

Quote:
 Originally Posted by abcde Hi all, this is my first post here ... and I have a question in my mind that I want to share with you ... in my last exam I had a question, which was like this : in the following all these scentences are true, except : 1- true 2- true 3- not true 4-all of the above what do you think the answer is? and is it logical? thanks for the chance ...
if the question is which from the four sentences is not true.
i would have to say 4.
because 3 is obviously the liar paradox, and four declares that all of the above is either not true or true, when obviously 3 isn't considered true/false so 4 is the problematic one.
#3
03-15-2006, 08:55 AM
 abcde Junior Member Join Date: Mar 2006 Posts: 3

but I have some questions regarding your choice :

1- why did you say :
Quote:
 when obviously 3 isn't considered true/false so 4 is the problematic one
while its obvious that its "not true" so it is false?

2- you also said :
Quote:
 four declares that all of the above is either not true or true
while it cannot be the same (hence their difference), so if we say that (1&2) are true, (3) must be false and it should be the answer. However the presence of (4) Indicate that their is a paradox (as you said), and there are two sentences which are false; so there are two answers for this question while we can only choose one, which makes it illogical...

thats my opinion, but what do you think? am I right or wrong?

thanks again...
#4
03-16-2006, 11:57 AM
 physicsmathsman Junior Member Join Date: Mar 2006 Posts: 2

look, as i see it 3 is the liar paradox (i'm guessing you're familiar with already), therefore it has no one value (true/not true) therefore it cannot be either false/true.
4 says about all of the above that they clearly one of the values true/not true, but because one of them, 3 isn't equivalent to the others (it doesn't even have one of the values) therefore the statemnt '4' is not true.
3 isn't false but it isn't true either.
#5
03-16-2006, 06:51 PM
 abcde Junior Member Join Date: Mar 2006 Posts: 3

Im sorry, but Im not getting your idea : why (3) can't have a value?

isn't it false already? I mean : not true = false

and without the presence of (4) it will be the true answer, because its an exception ...

isnt that right?
#6
10-18-2006, 03:24 PM
 HallsofIvy Senior Member Join Date: Oct 2006 Posts: 464

Quote:
 Originally Posted by abcde Im sorry, but Im not getting your idea : why (3) can't have a value? isn't it false already? I mean : not true = false and without the presence of (4) it will be the true answer, because its an exception ... isnt that right?
(3) asserts that it is false. If you agree that it is false, then what it says is ... TRUE! That is, assuming that it is false, leads to the conclusion that it is true. On the other hand, if you assume that what it is saying is true, then you must conclude, because this is what it says, that it is FALSE!

My original though was that these are possible answers to some true or false statement that we were not told. In that case, if there is one single correct answer, it can't be (1) or (2) because they say the same thing- if one is correct, so is the other. (d) can't be the correct answer because either (a) or (b) contradicts (c). The only possible single correct answer is (c).
But that's clearly not what the other posters are thinking. Since we were not given any other statement, they are assuming that each answer is to be considered a complete statement itself- as in (a) This statement is true, (b) This statement is true, (c) This statement is false, (d) all of the above statements are true.

You were the one who posted the original question! How did you intend it?
#7
01-06-2007, 09:31 PM
 Pachomius Junior Member Join Date: Jan 2007 Posts: 9

Quote:
 Originally Posted by abcde Hi all, this is my first post here ... and I have a question in my mind that I want to share with you ... in my last exam I had a question, which was like this : in the following all these scentences are true, except : 1- true 2- true 3- not true 4-all of the above what do you think the answer is? and is it logical? thanks for the chance ...
Please write four sentences of the subject and predicate type and then ask which sentence you want us to tell you to be the exception to all being true.

Like this maybe?

Quote:
 The following sentences are all true except one, point out the exception. 1. The sun exists. 2. The moon exists. 3. The earth exists. 4. The self exists for Buddhists.
In which case I will choose 4 to be the exception at least for Buddhists, because they literally maintain that the self does not exist.

But I guess I really don't know the deep and acronymic logic you guys are into. Sorry for the interruption.

Pachomius
#8
01-10-2008, 09:49 PM
 chrisforbes Member Join Date: Jan 2008 Location: London Posts: 94

I would regard this as a trick question.

In logic you are supposed to debate the pros and cons of all the statements by quoting other philsophers views, this means the market can check you have done you reading.

You could answer any out of the 4 and still get a top mark provided you backed it up with quotations of logic from other philosophers before coming to your own conclusion.

If you get really good you can play other philosophers off against each other, but this is very subjective. Good fun nonetheless.

Bertrand Russell a History of Western Philosophy will give you all the basics to nail these types of debates and impress your tutors.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts vB code is On Smilies are On [IMG] code is On HTML code is Off
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Physics Forums Dr. Elliot McGucken's Announcements Physics & Math in Video Games Rebel Scientists : A Renaissance in Physics Physics, Philosophy, and Math General Physics General Philosophy General Math General Physics, Math, & Philosophy Homework Physics Classical Physics Quantum Physics Condensed Matter / Solid State Physics Special & General Relativity String Theory, LQG, Branes Nuclear & Particle Physics Experimental Physics Techniques Physics Fraud: Physics Crackpots: Physics Hoaxes Cutting Edge Physics Research Pulsoid Theory Physics Pub: Brain Teasers/Puzzles/Paradoxes Time Vector / Relativity / Moving Dimensions     Time Vector Theory (http://members.triton.net/daveb)     Moving Dimensions Theory     Reality Physics (www.realityphysics.com)     Structured Time Theories Astronomy & Astrophysics Astronomy & Cosmology Stellar Astrophysics: Stars, The Sun The Planets, Planetary Motion, Newton, Kepler Large Scale Structure of The Universe Mathematics General Math Calculus Differential Equations Linear Algebra, Advanced Algebra Differential Geometry & Topology Probability, Statistsics Set Theories, Infinities, Number Theory Engineering & Applied Science Architectural Engineering Automotive Engineering, NASCAR Mechanical Engineering Electrical Engineering Materials & Chemical Engineering Systems, Design, and Industrial Engineering Technology / Information Technology Computers Internet & Information Technologies Search & Indexing Technologies Philosophy General Philosophy Metaphysics and Epistemology Ethics, Morality, Moral Theories, Religion Logic Philosophy of Religion Philosophy of Language * Linguistics Philosophy of Politics & Law Human Philosophy: Anthropology, Sociology and Psychology Philosophy of the Arts Famous Books & Famous Physicists The Written Word Books & Literature Science & Religion Poetry for Physicists Famous Books & Famous Physicists Relativity: The Special and the General Theory by Albert Einstein The Feynman Lectures on Physics: The Definitive and Extended Edition by Richard Feynman The Trouble With Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next by L Not Even Wrong: The Failure of String Theory And the Search for Unity in Physical Law by Peter Woit

All times are GMT. The time now is 06:07 AM.