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message 1: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
We have to discuss logic when we come back from the long weekend. I want to talk about inductive and deductive arguments first, a few fallacies, and then introduce ethos, pathos and logos.

What I want to know is: how do you know the difference between inductive and deductive reasoning?
I'm pretty good at deductive. I feel like I have it down. A = B and B = C, therefore A = C.
But I get confusticated with the formula for inductive:
A = x
and
B = x
therefore
A = B ??


message 2: by RandomAnthony (new)

RandomAnthony | 14536 comments Holy bejesus hell. I need coffee.

Actually, I really like this type of material. I always get inductive and deductive confused, though. This reminds me somewhat of stats. Every time I need to learn T-scores, Z-scores, etc. I have to relearn them, but I usually find that thing kind of interesting...I just don't use the concepts very often.


message 3: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
So, let me elaborate. I'm team teaching with my mentor teacher and we're using the example of Arizona's immigration law and/or the "ground zero mosque." We can find the fallacy in the inductive reasoning of the anti-mosque peeps:
Muslim-Americans are Islamic
Terrorists are Islamic
therefore
Muslim Americans must be terrorists.


message 4: by Phil (new)

Phil | 11605 comments First you must consider that it's not a mosque, and it's not at ground zero.

Second, your statement "Terrorists are Islamic" is not fact, it is a generalization. Therefore, a conclusion based on it is invalid.


message 5: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
Yeah, I know. I'm trying to show examples of faulty logic.


message 6: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
That's why I said "we can find the fallacy" in that example.


message 7: by Phil (new)

Phil | 11605 comments Did I find it? :)


message 8: by Félix (new)

Félix (habitseven) Bingo.


message 9: by [deleted user] (new)

Larry wrote: "Bingo."

I didn't even know any spaces had been called yet, I need to pay closer attention :(


message 10: by Félix (new)

Félix (habitseven) Indeed you should, Jim. It's all about paying attention.


message 11: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
Ok, so now. That reasoning doesn't work, but it is what some are relying on to oppose the cultural center in NYC.
We were also using this to explain the (faulty) support for Arizona's law:
Mexican are Illegal Immigrants.
Illegal Immigrants are Drug Traffickers.
therefore all Mexicans are Drug Trafficers.

I know this isn't right. But isn't it what they're saying is the logic that passing a law stating that catching more of "them" will help stop the drug problem at the border?

Anyway, these are just the examples we're going to show the studnents are INCORRECT.
Other than the famous:
Socrates is human.
Humans are mortal.
therefore
Socrates is a mortal,
can we figure out a good example of correct logic?

And why?


message 12: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
Oh, and kudos to Phil for figuring out the fallacies.


message 13: by Phil (new)

Phil | 11605 comments Sally wrote: "can we figure out a good example of correct logic?

And why?
"


I would say that IF each premise is universally TRUE, THEN the conclusion follows.

In your latest example, the statement "Illegal Immigrants are Drug Traffickers" is NOT universally true.

If you can disprove any of the premises, you have disproved the conclusion.


message 14: by RandomAnthony (new)

RandomAnthony | 14536 comments Are you using this to teach writing, Sallers, like persuasive essays or something? I'm trying to establish context here...


message 15: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
Yes, yes!
But isn't that the thing about logic, that the premises can be TRUE and the conclusion False?

Isn't one beginning with the conclusion and finding premises to support it?


message 16: by Phil (last edited Sep 04, 2010 08:37AM) (new)

Phil | 11605 comments Sally wrote: "But isn't that the thing about logic, that the premises can be TRUE and the conclusion False?"

Example, please?

My first thought is, "only if you've reached the wrong conclusion." And that would be faulty logic, not a flaw in logic itself.


message 17: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
A deductive argument must be water tight, true. But inductive reasoning can use true premises to reach an incorrect conclusion.


message 18: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
Using the inductive formula again,
A = x
B = x
(both of which are not incorrect)
therefore
A must equal B

Mary is Mexican.
Drug Trafficers crossing into Arizona are Mexican.
therefore,
Mary must be a Drug Trafficker.


message 19: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
The premises are true, but the conclusion is false.


message 20: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
ooooo, BUN!


message 21: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
So, what we can say is that inductive REASONING is testing a hypothesis, while deductive ARGUING is attempting to prove something is either true or false?


message 22: by Rebecca (new)

Rebecca White (rebecca_white) | 1028 comments Good subject, and it makes me happy that it's being taught! When I did my student teaching, I saw two teachers try to give a talk on them, but they were working from notes written by somebody else, hadn't prepared very well, and didn't really know what they were talking about. Sigh.
When I took philosophy in college, there seemed to be a very specific, rather short list of fallacies, but now I've done some googling and it seems there have been a whole lot of fallacies added! I guess that isn't surprising. But I thought this was pretty good and specific, and lists the fallacies as I understand them (which the others probably relate to, one way or another): http://www.logicalfallacies.info/

One that you seem to be looking for ("Isn't one beginning with the conclusion and finding premises to support it?" is similar to "begging the question" or a circular argument. (Isn't there a thread about pet peeves? One of mine is when professional word-people use "begging the question" when they mean "raising the question.")


message 23: by RandomAnthony (new)

RandomAnthony | 14536 comments Ok, I'm going to skip to the pedagogical. I like the idea of giving the kids arguments and points like you did above and asking them to explain why they're valid or not valid and using their thinking as the springboard to conversation/instruction. Are you comfortable with them working in groups yet, Sallers? The Mexican one is good, I think. I also like the idea of using Venn Diagrams to analyze the similarities and differences between good and bad reasoning. What do you think?


message 24: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
We were trying to figure a way to use venn diagrams for this. I like the idea of introducing images and graphic organizers.

And RA, thank you. I was presenting faulty arguments because my point is to have them show why they are incorrect. They're not examples of MY reasoning, but they're what I believe to be the heart of the debates in our country currently under the umbrella topic of racial intolerance.


message 25: by RandomAnthony (last edited Sep 04, 2010 09:44AM) (new)

RandomAnthony | 14536 comments Oh, you could use Venns to compare/contrast inductive/deductive, too, but you probably figured that out already...I agree, it's easier to use negative, faulty examples at first.

Cookies in the oven.


message 26: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
When do we ever have all of the facts?


message 27: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
Thanks, Bun! I needed a correct way to do that with the example we have so that I don't confuse them.


message 28: by Félix (new)

Félix (habitseven) Illegals are Mexican
Illegals don't speak English
Mexicans have dark skin
Mary has dark skin
Mary doesn't speak English
Therefore Mary is a Mexican illegal
What part of "illegal" doesn't Mary understand?

Sorry, Sally. I got carried away.


message 29: by Kevin (new)

Kevin  (ksprink) | 11469 comments shoot, i thought this thread was about Leonard Nimoy and jackie would be saying nice things


message 30: by janine (new)

janine | 7715 comments i accidentally stumbled into this thread. in school our philosophy teacher tried to teach us logic, but our questions confused him so much he didn't understand logic anymore. that was one less test we had to take. we also drove our english teacher crazy by refusing to believe romeo and juliet is a tragic story.


message 31: by Sally, la reina (new)

Sally (mrsnolte) | 17320 comments Mod
When you come back from sabbatical, dutch friend, you wll see how much I appreciated this.


message 32: by Félix (new)

Félix (habitseven) Ah, Janine.


message 33: by janine (new)

janine | 7715 comments Sally wrote: "When you come back from sabbatical, dutch friend, you wll see how much I appreciated this."

:)


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