logical fallacies

[lilbrattyteen]

In Philosophy 101, we are told about the different logical fallacies - i.e., the slippery slope fallacy, the appeal to authority, the ad hominem argument, etc. All (or most) are listed at http://www.fallacyfiles.orgRead more... )

Comments

[lilbrattyteen]

Brilliant. I'm not brown-nosing; this is just purely brilliant.
But now I'm not sure I made that very clear, judging by your response to number 1.
Better question: who decides that the ad hominem isn't relevant? I often judge opinions by who posesses them. It's an appeal to ethos. I'd trust a computer geek more than my grandma when it comes to tech questions.

Logic and reason being different? Being a mere high school student, I know nothing of the formal accepted terms and definitions in the academic field of philosophy. But this sounds very fascinating. What if we found intelligent life in the universe and their brains were put together so that their forms of logic were very different? Even wierder, what if we bioengineered a new intelligent life form here on earth, and it had a different logical thinking method? That would have such interesting ramifications for human thought....but that's neither here nor there.

Your journal facinates me. Friend back? All I really want to do is read it, it's just...wow...

[rogerdr]

Trusting the speaker by vocation or reputation is more of an appeal to authority, which is closely tied to ad hominem. Either way, an argument, properly posed, should show no respect for the person giving it; it stands upon its own stated assumptions-or doesn't.

[lilbrattyteen]

In English class we learned that ethos is an appeal to authority. Teacher said that ethos was an accepted form of appeal to be used in persuasive essay. Was my teacher really telling us to be illogical?

Because this community has some damned cool people and I need some friends, is it ok if I friend you? Your friends list looks very small - but maybe that's intentional.

[catachrestic]

1) What are the logical underpinnings of these logical fallacies?

There aren't any. That's what makes them logical fallacies.

[lilbrattyteen]

No, but how does one logically prove that they are logical fallacies?

[catachrestic]

Either by showing that the argument made is invalid or that the premises are untrue.

[solid_silence]

Easily - if you can find even one example where the conclusion to a given chain of logic doesn't follow -

e.g. Appeal to authority.

Bill is an expert on apples.
Bill asserts that the unmarked box marked simply 'apples' in front of us are Granny Smith apples.

Following the logic of the general form of an 'appeal to authority', we MUST conclude that because Bill says so, the box MUST contain Granny Smiths.

But if we open the box and find inside it a mix of Golden Delicious and Pink Lady apples, then we MUST conclude that the logic of the appeal to authority is fallible (although not necessarily always wrong) and cannot be relied upon.

Hence the appeal to authority is established as an informal fallacy.

[bullet__theory]

1) The logical underpinnings? Um, truth isn't necessarily preserved from premises to conclusion. The only reason we even pay attention to common fallacies is because, at first glance, they may appear to be valid. That is why we give them labels, e.g. fallacy of affirming the consequent; so that it can be driven into our head that those patterns of inference do not guarantee truth.

2) I can't remember exactly what context it was mentioned, but I remember by Epistemology professor mentioning something about it being debated in some circles whether or not modus ponens is actually a valid inference pattern? I know it seems crazy, which is probably why I dismissed it from my memory completely. I wish I could remember now, since it might have had non-western origins.

[bullet__theory]

Please excuse the infinite typos, also.

[lilbrattyteen]

Aaaah this makes my head hurt. Had to look up modus ponens on wikipedia.
I can see why someone would debate modus ponens on this ground:
Just because P implies Q does not mean that P implies Q every single time P occurs.

I googled "modus ponens fallacy" and found nothing. It must be very obscure to begin with.

[chamcha]

I don't see why someone would. If P did not imply Q sometime that P were true, then it would be false to say that P implies Q.

[danman3459]

Hey there. If you're interested in this type of stuff, it is very well-developed in formal logic. I would highly recommend a formal logic class from a university. While many informal fallacies cannot be formed into classical logic, many can and you'll probably enjoy it

[hollowuvula]

I mean, it isn't like there is a way to empirically determine what is a fallacy and what is valid logic.
Your compulsive need to confirm all of your beliefs empirically is proof that you have been brainwashed by "Western culture." The true philosopher has faith in the dictates of reason.

But seriously, though, asking for empirical proof of the validity of an argument is a category mistake, just like it would be to ask for empirical proof that 2+2=4.

What one can do is show (logically!) that a fallacy is bad reasoning, via a reductio ad absurdum, for instance. No real philosopher would just accept that something was a fallacy because someone told him or her so. I recommend you start with the ad hominem fallacy, since it's pretty easy to show why that one's no good.

[lilbrattyteen]

Your compulsive need to confirm all of your beliefs empirically is proof that you have been brainwashed by "Western culture." The true philosopher has faith in the dictates of reason.

Was that a joke? You said "but seriously" afterwards. I didn't get it! :-P

But couldn't there possibly be forms of reasoning that are fallacious some of time and not other parts of the time? I'll have to cogitate on that.

[chamcha]

But couldn't there possibly be forms of reasoning that are fallacious some of time and not other parts of the time? I'll have to cogitate on that.

That makes no sense. If they aren't valid 'sometimes' (on Thursdays???), then we don't really have any reason for saying that they're ever valid.

Yes. Please go "cogitate" on that for a while.

[lilbrattyteen]

Not "sometimes" as in Thursdays, but "sometimes" as in some situations.
I'm sure there are examples of logical fallacies being used to get conclusions that are empirically correct, but the real reason for the conclusion being correct does not involve the fallacy.