| User | Comment |
|---|
| serendipity | | posted 24-Dec-2001 2:55am |
Screw this. I failed my first year psychology mainly on formal logic.
|
| Dino | | posted 24-Dec-2001 3:59am |
If B then not A.
Although I'd still like to think about it incase its more than one. But deffo on the first one. |
dab   | | posted 24-Dec-2001 9:25am |
I'm surprised you didn't include the commonly and erroneously believed answer of 'if not C then not A'. |
heyzeus1  | | posted 24-Dec-2001 9:57am |
if a then c
now yesterday, when i looked at this i found a few ways to defeat the logic of this, but right now my head is fuzzy and i havent had my coffee yet |
| heyzeus1 | | posted 24-Dec-2001 10:04am |
if i eat too many eggs then my farts become offensive
if my farts become offensive people look at me funny
therefore if i eat too many eggs people look at me funny. |
| juliw | | posted 24-Dec-2001 10:44am |
if A then C DUH |
| juliw | | (reply to heyzeus1) posted 24-Dec-2001 10:46am |
lol |
| Biggles | | posted 24-Dec-2001 10:54am |
It depends what "then" is used to mean in this statement. |
| kaleb777 | | (reply to heyzeus1) posted 24-Dec-2001 11:04am |
That was my point in qual. Try some of the options with A = lives in Sacramento, B = lives in California and C = Lives in the USA then try the same ones with your example. There is no way of knowing which are logical because in depends entirely on what A,B and C stand for. |
| heyzeus1 | | (reply to kaleb777) posted 24-Dec-2001 11:08am |
what? that works.
with your a b and c it still only holds up with the answer if a then c |
| kaleb777 | | (reply to heyzeus1) posted 24-Dec-2001 11:59am |
My point was that my example and yours cannot both work for all of them so answering this survey depends on what A, B and C are. |
| Jemmy | | posted 24-Dec-2001 12:28pm |
What? |
| phi | | (reply to dab) posted 24-Dec-2001 12:35pm |
uh, ~C => ~A is in fact true. If no one looks at heyzeus funny, he must hot have had too many eggs. |
| phi | | (reply to kaleb777) posted 24-Dec-2001 12:36pm |
I'm not even going to bother explaining why you're wrong; you've demonstrated elsewhere that you're not interested in knowing. |
| heyzeus1 | | (reply to kaleb777) posted 24-Dec-2001 12:43pm |
actualy it doesn't matter |
| kaleb777 | | (reply to phi) posted 24-Dec-2001 12:58pm |
Oh pull ya head in you condescending craphead! Look at my example where "A then C" is true, then look at heyzeus's where "A then C" is false. Don't talk down to me. |
| confetti | | posted 24-Dec-2001 1:00pm |
None of them are logical. I'm probably wrong though. This is the part of iq tests that I usually score the highest on--I love math--but my brains turn to mush on vacation. |
| kaleb777 | | (reply to heyzeus1) posted 24-Dec-2001 1:00pm |
Why did you mention that you had found a few ways to defeat the logic of this if it doesn't matter? |
| heyzeus1 | | (reply to kaleb777) posted 24-Dec-2001 1:26pm |
i dont know what i was thinking then, cause i cant find any way to defeat it now. with your options and mine, the results are exactly the same. a then c is not false in my example |
| jkiehart | | posted 24-Dec-2001 1:26pm |
wees |
| jkiehart | | posted 24-Dec-2001 1:26pm |
Oh God I love the new w*e*e*s feature |
| heyzeus1 | | (reply to jkiehart) posted 24-Dec-2001 1:27pm |
wees
wees
wees
me too!
i am going to use it every time now
saves some typing time |
| kaleb777 | | (reply to heyzeus1) posted 24-Dec-2001 1:45pm |
You eat eaggs and people look at you funny? Yeah OK. How do you eat them, with a pitchfork? |
| heyzeus1 | | (reply to kaleb777) posted 24-Dec-2001 1:52pm |
see step b |
| kaleb777 | | (reply to heyzeus1) posted 24-Dec-2001 1:55pm |
With "A then C", step B is not considered. |
| heyzeus1 | | (reply to kaleb777) posted 24-Dec-2001 1:58pm |
?
(throwing arms up in exasperation) |
| kaleb777 | | (reply to heyzeus1) posted 24-Dec-2001 2:20pm |
If A then B then C is the entire expression, so A then C excludes B. |
LindaH  | | (reply to kaleb777) posted 24-Dec-2001 2:33pm |
But it still exists. If I have the TV and stereo off, then I'm concentrating, if I'm concentrating, it means I'm writing stories. Therefore, if I have the TV and stereo off, then I am writing stories. |
| heyzeus1 | | (reply to kaleb777) posted 24-Dec-2001 3:12pm |
it doesnt matter though |
| dab | | (reply to phi) posted 24-Dec-2001 4:33pm |
Foo! I meant if not A then not C. That's the common logical error, unless I had another brain fart. |
| Zang | | posted 24-Dec-2001 6:32pm |
Only one: "If A then C".
|
| Zang | | (reply to kaleb777) posted 24-Dec-2001 6:38pm |
I didn't bother trying to argue this with you in qualification. You are misunderstanding the question, and the essence of logic. Just because something is true, it is not necessarily logical. |
| Zang | | (reply to LindaH) posted 24-Dec-2001 6:40pm |
That isn't a very good example. None of those statements ring true. |
| LindaH | | (reply to Zang) posted 24-Dec-2001 8:55pm |
None of which statements ring true? How about this one:
If I am sitting in my "Don't bug me" chair (A), I want to be left alone (B). If I want to be left alone, then I'm in a bad mood(C).
Sitting in my "Do not bug me" chair (A) = I am in a bad mood(C) |
| icurok | | posted 25-Dec-2001 6:49am |
If A then C. 'If A then B' suggest that A is a subset of B, and 'If B then C' suggest that B is a subset of C. If that is the case then A must be a subset of C, therefore 'If A then C'. |
| icurok | | (reply to LindaH) posted 25-Dec-2001 7:05am |
In both your statements to kaleb and Zang you've substituted the word 'then' for '=' which actually changes the meaning of the phrase.
If I have my TV and stereo off (A), then I'm concentrating (B)
Is this always the case? If not, then its not a logical statement. I could have my TV and stereo off for another reason. In which case, (A )is not a full subset of (B) but merely overlaps, and therefore I cannot state that if (A) then (B).
If I'm concentrating (B), then I'm writing stories (C)
That doesn't sound very logical. Am I always writing stories when I'm concentrating? If so, then it is logical. If not, then its not a logical statement. If there exists any other reason as to why I might be concentrating (other than writing stories), then I cannot state that if (B) then (C).
If I have my TV and stereo off (A), then I'm writing stories (C)
If both the previous statements are logical, then this statement will be logical.
However, 'If (A) then (C)' is not the same as '(A)=(C)'.
|
| LindaH | | (reply to icurok) posted 25-Dec-2001 12:52pm |
"then" can be the same thing as '=' if it's always true. If I always have either the radio or TV on all day, unless I'm concentrating, and the only time I really concentrate is when I'm writing stores, then TV and stereo off = I am writing stories.
I think my second example is a better one, about the chair. |
| kaleb777 | | (reply to Zang) posted 25-Dec-2001 1:11pm |
I don't want to say my IQ but I'm not ashamed of it. I simply don't see what's happening here. I admit it's probably a flaw in my mentality. Am I reading too much into it? Anyway, I see so much wrong with this that I'm not going to bother to argue anymore. I am a logical butt-hole with no lateral thinking ability. It's not the first time I've been told that.  |
| kaleb777 | | (reply to heyzeus1) posted 25-Dec-2001 1:12pm |
Well nothing really matter does it, so eat chicken and be happy! |
| kaleb777 | | (reply to LindaH) posted 25-Dec-2001 1:15pm |
Huh? Maybe I'm too dunk to get what you're saying. But HUH?????????? |
| Biggles | | (reply to kaleb777) posted 25-Dec-2001 1:20pm |
I don't get it either.......  I think I'm trying to make the word "then" mean something different to the SC. Or maybe I'm just being dim! lol |
| kaleb777 | | (reply to Biggles) posted 25-Dec-2001 1:36pm |
Yay Biggles. I knew I wasn't the only one to have problems with this. You rule! |
| lion | | posted 25-Dec-2001 5:32pm |
There is no "C", therefor there is no spoon! |
| icurok | | (reply to LindaH) posted 25-Dec-2001 6:30pm |
No it can't. If something equals something then it doesn't matter which side of the equals sign you put it
'2+2=4' is the same as '4=2+2'
'A=B' is the same as 'B=A'
But 'If A then B' is NOT the same as 'If B then A'. If A is a subset of B, then if A is true you can logically assume B is also true, but not the other way around because they don't equal each other.
If I'm eating McDonalds (A), I'm eating fast food (B).
If I'm eating fast food (B), I'm not necessarily eating McDonalds (A).
|
| cody | | (reply to Biggles) posted 25-Dec-2001 9:13pm |
It means "Therefore". |
| heyzeus1 | | (reply to kaleb777) posted 25-Dec-2001 10:35pm |
if a=it doesn't matter then b - it doesnt matter. if b it doesnt matter then c - it doesnt matter. therefore if a - it doesnt matter then c- it doesnt matter.  |
| Zang | | (reply to LindaH) posted 26-Dec-2001 1:05am |
That's better. |
| Zang | | (reply to kaleb777) posted 26-Dec-2001 1:09am |
Please! I wasn't casting aspersions on your intelligence. You may have a fine and logical mind, but not be familiar with the mechanisms of logic. You said that the example heyzeus1 used, didn't work. I thought it did. I suspect that if it didn't work for you, the fault lies not in the logic, but in the premise. In order to test the validity of a propositional construction, it is preferable to use a premise which is irrefutable. Your geographical one is superior. |
| Zang | | (reply to icurok) posted 26-Dec-2001 1:32am |
This is what I was trying to point out in qualification. Good example. One of the essential rules of logic is: "Universal affirmatives can only be partially converted." For example: (A)"All halibut are fish."(B)"All fish live underwater." You can conclude that (C) "All halibut live underwater." You cannot conclude that "Everything that lives underwater is a halibut." |
| Oscar | | posted 26-Dec-2001 9:02am |
If A then C.
I love logical games like this. I used to be really good at them. |
| Oscar | | (reply to Dino) posted 26-Dec-2001 9:09am |
I think you're wrong.
Check this geometrical situation:
If A = B
and B = C
Then A = ?
Get it?
I could be wrong. I just don't get your answer. |
| Oscar | | (reply to jkiehart) posted 26-Dec-2001 9:09am |
lol
Isn't that the best?! |
| jkiehart | | (reply to Oscar) posted 26-Dec-2001 9:30am |
Yes! |
| LindaH | | (reply to icurok) posted 26-Dec-2001 1:46pm |
OK, I worded it wrong then. I should have stuck with If/Then and not mentioned the equals. |
| LindaH | | (reply to kaleb777) posted 26-Dec-2001 2:00pm |
If I am in McDonalds, then I am eating a burger. If I am eating a burger, then I am happy. Therefore, if I am in McDonalds, I am happy. |
| autumnlight | | posted 27-Dec-2001 9:55am |
All the ones with 'not' in are the logical ones. |
| ASexyBabe | | posted 27-Dec-2001 10:42am |
D!!!!! |
| kaleb777 | | (reply to LindaH) posted 27-Dec-2001 11:01am |
Doesn't that disprove it? You are saying that everytime you are in McDonalds you are happy. If you're in there during a hold up you won't be. |
| LindaH | | posted 27-Dec-2001 11:26am |
I would be if I was eating a hamburger! (Just kidding)
Darn it, I can never think of good examples. My chair one would work though. Here:
If I am sitting in my "Don't bug me" chair (A), I want to be left alone (B). If I want to be left alone, then I'm in a bad mood(C).
So if I'm sitting in my "Don't bug me" chair (A) then I am in a bad mood(C)
If I eat too much sugar, I get hyper and silly. If I get hyper and silly, people think I'm weird. So if I eat too much sugar, people think I'm weird. |
| LindaH | | (reply to kaleb777) posted 27-Dec-2001 1:56pm |
I think I can explain it best without using examples.
If A *ALWAYS* leads to B, and B *ALWAYS* leads to C, then A will *ALWAYS* lead to C. |
| mandy | | posted 27-Dec-2001 10:05pm |
D) Jar of Almonds! |
| kaleb777 | | (reply to LindaH) posted 28-Dec-2001 10:47am |
So "then" means 'always'? |
| Dino | | (reply to Oscar) posted 28-Dec-2001 11:28am |
Back to this logical thingummy. Okay I get it now A=C. I imagined it as roads leading to a place.
If Road A leads to Bloggsville
and Bloggsville leads to the road to Crapsville
then Road A leads (eventually) to Crapsville. |
| LindaH | | (reply to kaleb777) posted 28-Dec-2001 1:26pm |
To me it does. If someone said If (insert anything here) then (insert anything else here) I would take that to mean always, or one particular situation. |
| kaleb777 | | (reply to LindaH) posted 28-Dec-2001 1:34pm |
'If oranges are orange then all fruit is orange' - sort of like that? |
| LindaH | | (reply to kaleb777) posted 28-Dec-2001 2:34pm |
No, not like that. If I am eating an orange fruit, then it is an orange. (Because I never eat any other orange fruit, that will always be true.)
...or If I am sitting in my "Do not bug me" then I want to be left alone. (That's always true, if I never sit in it for any other reason) |
| Oscar | | (reply to Dino) posted 28-Dec-2001 3:13pm |
yep yep yep I think you got it. |
| kaleb777 | | (reply to LindaH) posted 29-Dec-2001 11:12am |
You are placing conditions on the statements using the words 'if' or 'because'. That was my initial point. The word 'then' is so ambiguous, especially when discussing logic, that it is impossible to know which statements are logical because as you have just shown, there needs to be conditions placed on the statements. |
| LindaH | | (reply to kaleb777) posted 29-Dec-2001 12:34pm |
But no matter what they are, if the A,B, and C are false, the equation is still a logical equation. Because the premise is that they are true. |
| kaleb777 | | (reply to LindaH) posted 29-Dec-2001 12:38pm |
But in some cases A then C could be false, in others A then C could be true, depending on what A, B and C stand for. I've already said that and I can't see the point in going around in circles any more. |
| LindaH | | (reply to kaleb777) posted 29-Dec-2001 12:53pm |
If A, B, and C are true, then "If A then C" will most definitely absolutely positively without a doubt be true, and couldn't be anything but true. Because even though B isn't expressed in the last equation, it is implied. |
| kaleb777 | | (reply to LindaH) posted 29-Dec-2001 12:59pm |
Oh, we're implying things now are we? I don't know how well assumption and implication go with logic. Read what you said. If A,B and C are true then "If A then C" must be true. Isn't it possible for 'If A then B' and 'B then C' to be true but NOT 'A then C'? |
| Biggles | | (reply to kaleb777) posted 29-Dec-2001 4:16pm |
I agree that "then" is really ambiguous I'm good at logic - I'm very logical and methodical but I'm uneasy about the phrasing of this one. |
| LindaH | | (reply to kaleb777) posted 29-Dec-2001 7:09pm |
What I meant by implied is that it is still in there. B still exists. No, I don't think it's possible. I don't understand how it could be. I'd like to see an example of A, B, and C all being true in that equation, but not "If A then C" |
| LindaH | | (reply to kaleb777) posted 29-Dec-2001 7:16pm |
If we know that A being true means B being true, and B being true means C is true, then you can guarantee that A being true means that C is true. I don't understand how it couldn't be. |
| LindaH | | (reply to kaleb777) posted 29-Dec-2001 7:48pm |
|
| Lahdee | | posted 29-Dec-2001 9:05pm |
My brain hurts. |
| kaleb777 | | (reply to LindaH) posted 30-Dec-2001 10:26am |
I can't think right now. There has to be an example. |
| LindaH | | posted 30-Dec-2001 10:47am |
Well, no matter what A, B, and C are the whole equation is still logical. Even if A or B is false, it's still a valid argument, just with false premises.
If All vegetables are green, and corn is a vegetable, then corn is green. (Valid argument, false premise) I think cody's question means "Which conclusion makes a valid argument" |
| Dino | | (reply to Oscar) posted 31-Dec-2001 3:44am |
*runs naked through the town yelling 'Eureka'* |
| Oscar | | (reply to Dino) posted 31-Dec-2001 12:30pm |
lol |
| skylark |
If A then C. |
| Wookiewoman | | posted 5-Jan-2002 10:24pm |
more then one is not logical |
