Logic Help

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pu_golf88
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Logic Help

Postby pu_golf88 » Fri Aug 20, 2010 3:42 pm

I've been going through a book, Elements of Logic, to try and get a stronger grasp of logic. I'm having trouble with the following trying to decide if they are an argument or not. The book doesn't seen to give many examples or deep explanations or help with any of these would be appreciated.

1. The weather is going to change, because the barometer has fallen.
2. The car stopped running because the gas line was clogged.
3. You'd do well to put aluminum siding on that old house of yours. It's not too expensive and never needs repainting.
4. That woman was always complaining, so I packed up and left her.
5. Since inflation is accelerating, the price of gold will increase.

There's a couple more, but you get the idea. I initially thought all of these were arguments, but now I'm feeling somewhat confident that they are NOT arguments.

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Cromartie
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Re: Logic Help

Postby Cromartie » Fri Aug 20, 2010 4:39 pm

pu_golf88 wrote:I've been going through a book, Elements of Logic, to try and get a stronger grasp of logic. I'm having trouble with the following trying to decide if they are an argument or not. The book doesn't seen to give many examples or deep explanations or help with any of these would be appreciated.

1. The weather is going to change, because the barometer has fallen.
2. The car stopped running because the gas line was clogged.
3. You'd do well to put aluminum siding on that old house of yours. It's not too expensive and never needs repainting.
4. That woman was always complaining, so I packed up and left her.
5. Since inflation is accelerating, the price of gold will increase.

There's a couple more, but you get the idea. I initially thought all of these were arguments, but now I'm feeling somewhat confident that they are NOT arguments.


Only no. 4 is not an argument. In 1, 2, 3 and 5, the person making the statement is trying to justify a conclusion based on a set of stated and unstated premises.

For no. 1: Conclusion: The weather is going to change.
Premise 1 (stated): The barometer has fallen.
Premise 2 (unstated): Whenever the barometer falls, the weather always changes.

Same principle applies in 2, 3 and 5.

For no. 4, the person making the statement is only stating a fact and not trying to justify a conclusion.

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pu_golf88
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Re: Logic Help

Postby pu_golf88 » Fri Aug 20, 2010 5:32 pm

Thanks, I think I was getting confused because the conclusions didn't follow from the premises.

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dub
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Re: Logic Help

Postby dub » Fri Aug 20, 2010 5:48 pm

4 is an argument.

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Cromartie
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Re: Logic Help

Postby Cromartie » Fri Aug 20, 2010 6:10 pm

dub wrote:4 is an argument.


How is it an argument? The fact that the woman is always complaining does not necessarily lead to the person leaving her. In this case, it is the reason he left her, but he could just as well have stayed notwithstanding her frequent complaining. In other words, it does not automatically follow that if the woman always complains, he would leave her. He is simply saying "I left her, and this is the reason". Statement of fact.

Now if it was worded "Because the woman was always complaining, I had to leave her", that would be an argument.

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dub
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Re: Logic Help

Postby dub » Fri Aug 20, 2010 6:45 pm

Cromartie wrote:
dub wrote:4 is an argument.


How is it an argument? The fact that the woman is always complaining does not necessarily lead to the person leaving her. In this case, it is the reason he left her, but he could just as well have stayed notwithstanding her frequent complaining. In other words, it does not automatically follow that if the woman always complains, he would leave her. He is simply saying "I left her, and this is the reason". Statement of fact.

Now if it was worded "Because the woman was always complaining, I had to leave her", that would be an argument.


An argument needs a premise and a conclusion; it does not require that the conclusion necessarily follows from the premises.

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Cromartie
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Re: Logic Help

Postby Cromartie » Fri Aug 20, 2010 8:54 pm

dub wrote:
Cromartie wrote:
dub wrote:4 is an argument.


How is it an argument? The fact that the woman is always complaining does not necessarily lead to the person leaving her. In this case, it is the reason he left her, but he could just as well have stayed notwithstanding her frequent complaining. In other words, it does not automatically follow that if the woman always complains, he would leave her. He is simply saying "I left her, and this is the reason". Statement of fact.

Now if it was worded "Because the woman was always complaining, I had to leave her", that would be an argument.


An argument needs a premise and a conclusion; it does not require that the conclusion necessarily follows from the premises.


I disagree. An argument by definition is a set of statements with a conclusion that either necessarily follows from the premises (deductive), or is supported by the premises (inductive). The statement "That woman was always complaining, so I packed up and left her" does not fall into either of the two.

To wit, if we were to try to "force" this statement into an argument:

Conclusion: I packed up and left the woman.
Premise: The woman was always complaining.

We cannot deduce from the premise that the conclusion automatically follows, and there does not appear to be any unstated premise (assumption) that would, in conjunction with the stated premise, lead to the conclusion. Further, the premise regarding the woman's incessant complaining does not support the statement that I packed up and left the woman.

On the other hand, consider this slightly modified version: "The woman was always complaining, so I had to leave her."

Conclusion: I had to leave the woman.
Premise: The woman was always complaining.
Unstated premise (assumption): I cannot/can never be with a woman who is always complaining.

What you might be referring to in your post above is the distinction between a valid and invalid and/or sound and unsound argument.

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dub
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Re: Logic Help

Postby dub » Fri Aug 20, 2010 10:18 pm

Right, obviously a deductive argument has a conclusion necessitated by its premises.

However, an invalid argument, unsound, weak argument (etc) is an argument nevertheless. Especially in LSAT world where you have questions like:

"The reasoning in the argument is flawed because the argument" (PT21, S3, #5) when it's explicit that the argument is flawed and the test makers call it an argument nonetheless.

Also, an unstated assumption in the #4 could very well be the conditional statement: "If a woman complains, I will pack up and leave." Your example is no stronger than #4's.

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Re: Logic Help

Postby Adjudicator » Fri Aug 20, 2010 10:22 pm

dub is correct; any time premises are offered in support of a conclusion, it is an argument, regardless of validity or invalidity. The form of an argument is purely structural and meaning is irrelevant at that stage, until you evaluate for validity.

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Re: Logic Help

Postby Cromartie » Fri Aug 20, 2010 11:36 pm

Adjudicator wrote:dub is correct; any time premises are offered in support of a conclusion, it is an argument, regardless of validity or invalidity. The form of an argument is purely structural and meaning is irrelevant at that stage, until you evaluate for validity.


I agree that any time premises are offered in support of a conclusion, the statement constitutes an argument, regardless of validity or invalidity. I apologize if my post was confusing and led you to understand otherwise. However, I also think that a statement can only be an argument if it contains premises that are offered in support of a conclusion. By conclusion, I mean something that the speaker/writer is trying to prove. Arguments by their very nature require that the "arguer" is attempting to prove the truth or falsity of something, and he attempts to accomplish this by offering premises that either logically lead to or support the conclusion.

My contention is that statement no. 4, as written, does not constitute the writer trying to prove anything/proffer premises in support of a conclusion. The writer is simply stating a fact.

If you disagree with this assertion, what is the writer trying to prove then?

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Re: Logic Help

Postby AverageTutoring » Fri Aug 20, 2010 11:59 pm

Cromartie wrote:
Adjudicator wrote:dub is correct; any time premises are offered in support of a conclusion, it is an argument, regardless of validity or invalidity. The form of an argument is purely structural and meaning is irrelevant at that stage, until you evaluate for validity.


I agree that any time premises are offered in support of a conclusion, the statement constitutes an argument, regardless of validity or invalidity. I apologize if my post was confusing and led you to understand otherwise. However, I also think that a statement can only be an argument if it contains premises that are offered in support of a conclusion. By conclusion, I mean something that the speaker/writer is trying to prove. Arguments by their very nature require that the "arguer" is attempting to prove the truth or falsity of something, and he attempts to accomplish this by offering premises that either logically lead to or support the conclusion.

My contention is that statement no. 4, as written, does not constitute the writer trying to prove anything/proffer premises in support of a conclusion. The writer is simply stating a fact.

If you disagree with this assertion, what is the writer trying to prove then?


I agree with you.

If we re-write number 4 to include the unstated premis: I left my wife because she was always complaining. This is a statement. I do not consider a statement to be an argument.

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Re: Logic Help

Postby Justiceinbrothel » Sat Aug 21, 2010 1:18 am

I think powerscore LR Practice guide has done such a phenomenal jobs in terms of teaching ninjas how to draw correct setup?

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Cromartie
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Re: Logic Help

Postby Cromartie » Sat Aug 21, 2010 7:50 am

dub wrote:Right, obviously a deductive argument has a conclusion necessitated by its premises.

However, an invalid argument, unsound, weak argument (etc) is an argument nevertheless. Especially in LSAT world where you have questions like:

"The reasoning in the argument is flawed because the argument" (PT21, S3, #5) when it's explicit that the argument is flawed and the test makers call it an argument nonetheless.

Also, an unstated assumption in the #4 could very well be the conditional statement: "If a woman complains, I will pack up and leave." Your example is no stronger than #4's.


So, if no. 4 is an argument the way it is currently written, what is the conclusion and what is/are the premise(s)?

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Re: Logic Help

Postby justtotalk » Sat Aug 21, 2010 12:51 pm

Arguments by their very nature require that the "arguer" is attempting to prove the truth or falsity of something, and he attempts to accomplish this by offering premises that either logically lead to or support the conclusion.
?


Then why would #2 be an argument? Since it's past tense, there's no assumption that all clogged gas lines cause cars to stop. From the author's POV, this is simply a fact about a specific car. There's no attempt to prove any conclusion.

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Re: Logic Help

Postby Anaconda » Sat Aug 21, 2010 2:59 pm

justtotalk wrote:
Arguments by their very nature require that the "arguer" is attempting to prove the truth or falsity of something, and he attempts to accomplish this by offering premises that either logically lead to or support the conclusion.
?


Then why would #2 be an argument? Since it's past tense, there's no assumption that all clogged gas lines cause cars to stop. From the author's POV, this is simply a fact about a specific car. There's no attempt to prove any conclusion.


The conclusion is "the car stopped". Its a basic cause and effect.

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Re: Logic Help

Postby justtotalk » Sat Aug 21, 2010 10:51 pm

The car definitely stopped. That's not a conclusion--it's just a statement of fact.

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Re: Logic Help

Postby Anaconda » Sat Aug 21, 2010 11:11 pm

justtotalk wrote:The car definitely stopped. That's not a conclusion--it's just a statement of fact.


It's an argument. Just because it's written like that doesn't mean it's not. The way you're arguing would mean that none of these 5 examples could be arguments, since they all contain facts.


I really don't understand your logic at all. Since when can conclusions not be facts? Since when are facts and parts of an argument mutually exclusive?


PS: I'm with dub on this one - they're all arguments. Even if it's invalid, it can still be an argument as long as the conclusion correctly or incorrectly follows from the premises. There are valid arguments and there are invalid arguments. However validity isn't a concern in #4, it's an implied cause and effect relationship.
Last edited by Anaconda on Sat Aug 21, 2010 11:36 pm, edited 1 time in total.

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Re: Logic Help

Postby Anaconda » Sat Aug 21, 2010 11:34 pm

Last point:

Premise and/or conclusion indicators are present in 4/5 examples (the one without is obviously an argument). Something to consider. I think some of you guys are simply overanalyzing them.

1. The weather is going to change, because the barometer has fallen.
2. The car stopped running because the gas line was clogged.
3. You'd do well to put aluminum siding on that old house of yours. It's not too expensive and never needs repainting.
4. That woman was always complaining, so I packed up and left her.
5. Since inflation is accelerating, the price of gold will increase.

Also, why would a book explaining logic mixup arguments and non-arguments? These types of books are not textbooks - there's no drills or anything to test your knowledge of the material. I think the OP had his own personal doubts, but he never said this was an exercise to identify arguments vs. non-arguments. There's enough in each example to be classified as arguments. There's a premise and conclusion in each, however ambiguous they may be.

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Cromartie
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Re: Logic Help

Postby Cromartie » Sun Aug 22, 2010 12:29 am

Anaconda wrote:Last point:

Premise and/or conclusion indicators are present in 4/5 examples (the one without is obviously an argument). Something to consider. I think some of you guys are simply overanalyzing them.

1. The weather is going to change, because the barometer has fallen.
2. The car stopped running because the gas line was clogged.
3. You'd do well to put aluminum siding on that old house of yours. It's not too expensive and never needs repainting.
4. That woman was always complaining, so I packed up and left her.
5. Since inflation is accelerating, the price of gold will increase.

Also, why would a book explaining logic mixup arguments and non-arguments? These types of books are not textbooks - there's no drills or anything to test your knowledge of the material. I think the OP had his own personal doubts, but he never said this was an exercise to identify arguments vs. non-arguments. There's enough in each example to be classified as arguments. There's a premise and conclusion in each, however ambiguous they may be.


Well, only the OP can answer this definitively, but it would appear based on his question that he is going through a drill or an end-of-the-chapter thing in the book that asks him to identify if each of the statements is an argument or not. If the book already said they all are arguments, why would the OP have to decide whether or not they are arguments, as indicated in his post?

I see your point about cause and effect (if...then) though, and that's why I thought that 2 was an argument. The writer is arguing that the clogged gas line, and not any other factor, caused the car stoppage. There could be a number of possible reasons the car stopped, but the writer is arguing that the stoppage is due to the clogged gas line.

4, although similar to 2, contains a fundamental difference in that the writer is simply stating his reason for leaving (The woman always complains, so I left). It's just like if I say "I like ice cream because it's delicious". I'm not really arguing or trying to prove a conclusion. I'm just saying I like it because it's delicious. You can't really say there are a number or reasons for me to like ice cream but I'm arguing that of all the possible reasons, the flavor is what makes me like ice cream. For this to be viable, you would have to assume that I'm lying.

On the other hand, if I say "You like ice cream because it's delicious", my statement would be an argument.

But then again, maybe I am just overanalyzing things... wouldn't exactly be out of the norm for me to do so...

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Anaconda
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Re: Logic Help

Postby Anaconda » Sun Aug 22, 2010 1:09 am

No, no, no.

"I like ice cream because it is delicious" IS an argument.

Of course you're arguing for something - you're saying that you like ice cream!

Premise: Ice cream is delicious
Conclusion: I like ice cream

This argument is basically: Ice cream is delicious. Therefore, I like ice cream OR Since I think ice cream is delicious, I like ice cream.

Why wouldn't it be an argument? You're missing some fundamentals here. Once again, "because" is a premise indicator. You don't need both conclusion and premise indicators, you can have only one or neither. This one has a premise indicator, the condition before it is the conclusion.

"I like ice cream" on the other hand IS NOT an argument because there are no premises, it's just a statement where no reasoning is added to make a conclusion. This is where I think you're getting confused.

I think you might be so used to seeing such complex arguments that such simple sentences may not appear to be arguments to you when if fact they are! Your definition of an argument is really constricted and is way off base. The subject (you, I, third person) is completely irrelevant.


Consider, if any of these 5 examples were just facts, it would be obvious:

1. The weather is going to change.
2. The car stopped running.
3. You'd do well to put aluminum siding on that old house of yours.
4. That woman was always complaining.
5. Inflation is rising.

None of those have premises to lead us to the conclusion, they're just statements or facts. Once we add the missing part, the nature completely changes and we have an argument. You've got to distinguish between facts/statements and parts of an argument.

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pu_golf88
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Re: Logic Help

Postby pu_golf88 » Sun Aug 22, 2010 1:55 am

Cromartie wrote:
Anaconda wrote:Last point:

Premise and/or conclusion indicators are present in 4/5 examples (the one without is obviously an argument). Something to consider. I think some of you guys are simply overanalyzing them.

1. The weather is going to change, because the barometer has fallen.
2. The car stopped running because the gas line was clogged.
3. You'd do well to put aluminum siding on that old house of yours. It's not too expensive and never needs repainting.
4. That woman was always complaining, so I packed up and left her.
5. Since inflation is accelerating, the price of gold will increase.

Also, why would a book explaining logic mixup arguments and non-arguments? These types of books are not textbooks - there's no drills or anything to test your knowledge of the material. I think the OP had his own personal doubts, but he never said this was an exercise to identify arguments vs. non-arguments. There's enough in each example to be classified as arguments. There's a premise and conclusion in each, however ambiguous they may be.


Well, only the OP can answer this definitively, but it would appear based on his question that he is going through a drill or an end-of-the-chapter thing in the book that asks him to identify if each of the statements is an argument or not. If the book already said they all are arguments, why would the OP have to decide whether or not they are arguments, as indicated in his post?

I see your point about cause and effect (if...then) though, and that's why I thought that 2 was an argument. The writer is arguing that the clogged gas line, and not any other factor, caused the car stoppage. There could be a number of possible reasons the car stopped, but the writer is arguing that the stoppage is due to the clogged gas line.

4, although similar to 2, contains a fundamental difference in that the writer is simply stating his reason for leaving (The woman always complains, so I left). It's just like if I say "I like ice cream because it's delicious". I'm not really arguing or trying to prove a conclusion. I'm just saying I like it because it's delicious. You can't really say there are a number or reasons for me to like ice cream but I'm arguing that of all the possible reasons, the flavor is what makes me like ice cream. For this to be viable, you would have to assume that I'm lying.

On the other hand, if I say "You like ice cream because it's delicious", my statement would be an argument.

But then again, maybe I am just overanalyzing things... wouldn't exactly be out of the norm for me to do so...


It is a exercise in the book on identifying arguments (and their premises and conclusions) or non arguments. I personally think the book does a poor job of describing this so far.




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