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All the cool kids know their logical fallacies!
April 19, 2012 9:01 AM   Subscribe

Your Logical Fallacy Is... complete with free downloadable infographic poster.
posted by Miko (41 comments total) 65 users marked this as a favorite

 
from the explanation of begging the question on their page:
"circular reasoning is bad mostly because it's not very good"

that had to be intentional - how many other fallacies are used in defining the fallacies?
posted by idiopath at 9:12 AM on April 19, 2012


tu quoque
posted by infini at 9:16 AM on April 19, 2012


Pretty similar to two weeks ago; everyone seems to be doing these things these days. (Not a double, though.)
posted by Admiral Haddock at 9:23 AM on April 19, 2012


I like it, but... I'm not sure I understand the poster thing, or why this meme deserves it's own page with links to different poster sizes, explaining the process of taking it to a print shop to print it out, why anybody would want to do that, or even what the author gains out of jumping through these particular hoops.

Is this, too, a thing now?
posted by Blue_Villain at 9:23 AM on April 19, 2012


Logical fallacy exist, yes, but they are no more useful than any other aspect of predicate logic. In my years of study of philosophy, the only thing I have learned that is actually useful and applicable is "Make sure both sides agree on common definitions before you start to argue."
posted by rebent at 9:28 AM on April 19, 2012 [6 favorites]


Blue_Villain: " Is this, too, a thing now?"

If I were to answer "why not?", which logical fallacy would that be?

Personally I found that extra link interesting because I assumed they'd be "here -- pay me for a poster of this" and they were instead -- "hey, here's how to take this work that I think is important and get it for free (or for payment to somebody else)"; no offense to designers to try to monetize their interesting work, but I thought that was pretty neat.

(Yes, I now realize I should have figured that out by the use of "free" in the post.)
posted by MCMikeNamara at 9:34 AM on April 19, 2012 [2 favorites]


Logical fallacy exist, yes, but they are no more useful than any other aspect of predicate logic.

These are all informal fallacies, and they have nothing to do with predicate logic.
posted by thelonius at 9:35 AM on April 19, 2012 [7 favorites]


why this meme deserves it's own page

Grocer's Fallacy: If an item can be pluralized, it must therefore be proprietary to itself.
posted by Smart Dalek at 9:39 AM on April 19, 2012 [10 favorites]


This is the third post about logical fallacies in a little over a month. Both of the previous threads inspired a lot of discussion about how poor these lists tend to be. A lot of the criticisms will carry over to this one.

I'm a little bothered by the way that some of the fallacies have headings that are names and others have headings that are adjectives. Why have both 'ambiguity' and 'anecdotal'? Why not 'ambiguous' and 'anecdotal', or 'ambiguity' and 'anecdote'?
posted by painquale at 9:40 AM on April 19, 2012 [1 favorite]


...what the author gains out of jumping through these particular hoops...

From the link to donate via Paypal: "Give us money for beer and/or future educational projects." Sounds like a worthy goal to me!
posted by TreeRooster at 9:40 AM on April 19, 2012


thelonius is right.

To choose a particularly clear illustration, begging the question is formally deductively valid.
posted by Fists O'Fury at 9:40 AM on April 19, 2012 [1 favorite]


I think the idea is that the more you educate people around you about common fallacies in succinct, easily recognizable ways, the more adept they'll become at cutting through invalid arguments, and the harder it will be for others to take refuge in them.

However it could be argued that a certain innate unreasonableness is present in people who rely on fallacies, to a degree that can amount to a perfect blind spot. I'm reminded of the (highly argumentative) commenter on, um, a certain forum, who complained about what he saw as overuse of the term "straw man". But he didn't suggest it was used wrongly or anything. He was just tired of seeing it used, with the strong implication that it was with specific respect to his own comments. That perhaps the it wasn't the term that was overused did not seem to occur to him, or at least he didn't let on.

It's sort of like the way I'm sick and tired of the way people around me are wearing out the phrase "holy god almighty, don't you ever take a bath?" in my presence. I wish they'd just stop beating that catchphrase to death. I mean, is that a thing?
posted by George_Spiggott at 9:50 AM on April 19, 2012 [5 favorites]


It's always ad hominem. And if you disagree, it's probably because you're stupid and/or a jerk.
posted by LordSludge at 10:12 AM on April 19, 2012


from the explanation of begging the question on their page:
"circular reasoning is bad mostly because it's not very good"

that had to be intentional - how many other fallacies are used in defining the fallacies?
posted by idiopath at 5:12 PM on April 19


I'm sure they did the same thing for "Poisoning the well". Only a fool would think otherwise.
posted by Decani at 10:27 AM on April 19, 2012


I thought the link was going to point to the comments section of a Facebook post about how Obama plans to take away all our guns. Instead, it is merely a reference guide for the entire thread.
posted by Chuffy at 10:50 AM on April 19, 2012


All propositions of Logic are generalizations of tautologies --Wittgenstein.

If I understand correctly, according ot Wittgenstein logic can only say that a thing is the same as itself, or that two things that are different are not the same. But perhaps this is making a 'no true scottsman' logical fallacy truism.
posted by Golden Eternity at 10:52 AM on April 19, 2012


Logical fallacy exist, yes, but they are no more useful than any other aspect of predicate logic. In my years of study of philosophy, the only thing I have learned that is actually useful and applicable is "Make sure both sides agree on common definitions before you start to argue."
Yeah, The whole problem with promoting the idea of "Logical falacies" without even bothering to tell people what logic even is just ends up with people finding a new way to bitch about people who disagree with them.
I think the idea is that the more you educate people around you about common fallacies in succinct, easily recognizable ways, the more adept they'll become at cutting through invalid arguments, and the harder it will be for others to take refuge in them.
Well, maybe. But I think the vast majority of invalid arguments simply derive from false premises. The actual logic may be perfectly sound. You rarely ever see truly faulty thinking, it's just that people are arguing from premises that differ, and people don't actually think about what their premises are. (In some sense this could be considered "begging the question", I suppose)

For example, the logical fallacy that gets complained about the most is "Ad Hominem" But in order to be a true Ad-Hominem it has to be in the form of something like "Your argument is wrong because you are fat". Something like "you're fat and therefore more likely to be biased on the issue of eating this cake"

The other problem though is trying to look for "Logical fallacies" in ordinary every day discussion, because technically people almost never try to define their terms, and therefore they are almost never truly logically consistent. You could find a logical problem in almost any statement.

Let's take a look at the first sentence of this website, for example:
A logical fallacy is usually what has happened when someone is wrong about something. It's a flaw in reasoning. They're like tricks or illusions of thought, and they're often very sneakily used by politicians and the media to fool people.
So, we all obviously know what he means there - but it begs the question: Can be people be wrong about things? Is there really an external world about which we can form incorrect ideas? If someone has a logically incorrect thought, is it true that they have tricked, or does reality itself change? It's easy to say no, but if you think about it - the person fooled has no way of knowing that they were fooled, and as best as they can discern reality, reality does in fact match what they think.

Of course, these questions aren't actually germane to whether or not the statement is actually correct or not. But they still pose a logical flaw, because not all the premises are defined.

I do actually happen to think it's wrong, in an empirical sense. and I think most people are wrong because they are working form incorrect premises.
If I understand correctly, according ot Wittgenstein logic can only say that a thing is the same as itself, or that two things that are different are not the same. But perhaps this is making a 'no true scottsman' logical fallacy truism.
Well, in a sense that's true. Logic can really only be used fully to examine logical objects, like mathematics or something. You can define math from a logical foundation and then go off and do various proofs. But you can't sit in a room and use "logic" to determine if water is made from hydrogen and oxygen, or whether or not Obama is a secret Muslim who wants to make everyone gay.

I do think it would be good if people learned out to make logical arguments, rather then simply look for holes in them.

But carping about logical fallacies does not help people do that.
posted by delmoi at 11:02 AM on April 19, 2012 [3 favorites]


Knowing about logical fallacies only gives us the tools to dismiss other people's arguments as being poorly constructed.

I don't know how useful this is. Firstly, they may be right but have a bad argument. Secondly, they may be wrong, but their argument stems from a problem that really should be addressed. I mean, yes, Obama is not a secret Muslim. But there's real sense of disenfranchisement at the source of this complaint (as well as a mountain of privilege.) Telling people they are wrong because their arguments don't follow good rhetoric does nothing to address their disenfranchisement nor educate them as to their privilege.

There's a reason brilliant men, such as Bill Clinton, sound like old farmers when they address people. Because most people understand the world anecdotally, frame that understanding in the form of homilies, and want their feelings about the world to at least be acknowledged, instead of dismissed.

Not that I don't suck at all of this myself. God, I love me some logical fallacies, and knowing when somebody else is spouting nonsense, and my usual approach to world change is to try to shame people into being different. Hasn't worked so far, but I keep at it. There's probably a logical fallacy behind this, but, man, I would not appreciate it were you to point it out to me.
posted by Bunny Ultramod at 11:11 AM on April 19, 2012 [2 favorites]


begging the question is formally deductively valid.
Although "p ⇒ p" is always true, that's why begging the question is invalid: "(p ⇒ p) ⇒ p" isn't a tautology at all.
posted by roystgnr at 11:17 AM on April 19, 2012


Firstly, they may be right but have a bad argument.

This is actually addressed in the list, that the presence of a fallacy in an argument doesn't necessarily make the conclusion wrong. Anyway, I love stuff like this, not because I like pointing out other people's mistakes (though I do!) but because I like catching myself making them, as well as just playing around with them in writing.
posted by Navelgazer at 11:18 AM on April 19, 2012


Yes. I feel like its like "first-world problems." If you apply the phrase to your own experiences, it can be useful in helping give yourself some perspective. If you apply it to other people's experiences, you may be an asshole.
posted by Bunny Ultramod at 11:35 AM on April 19, 2012 [4 favorites]


begging the question is formally deductively valid.

Although "p ⇒ p" is always true, that's why begging the question is invalid: "(p ⇒ p) ⇒ p" isn't a tautology at all.


No, begging the question isn't invalid. 'p therefore p' is valid, and deductively so. Necessarily, if p is true, then p is true. '(p --> p) --> p' doesn't entail that p, so it isn't really relevant, though I think I see what you're thinking.

BtQ is defective for reasons unrelated to its validity. I guess the standard line is something like this: it's a pragmatic defect. BtQ can never be used to prove anything, that is, to show that something is so not already known to be so. If I argue that p therefore p, then, though my argument is valid, it can't establish the truth of p. If I don't already know that p, then I don't know whether the inference is sound, b/c I don't know whether the premise is true. And if I do know that the premise is true, then I already know that the conclusion is true. So such an argument is useless. But, again, deductively valid.

This all presupposes the classical conception of logical consequence, which isn't quite the same as the informal notion of consequence.
posted by Fists O'Fury at 12:08 PM on April 19, 2012


And slippery slope even got its own post a couple weeks ago. In reality, most slopes are slippery, especially when coated in the baby oil of freedom.
posted by RobotVoodooPower at 12:43 PM on April 19, 2012


It seems surprising that "(p ⇒ p) ⇒ p" is not a tautology, but sure enough, it isn't. When p is false, that sentence becomes (F⇒F)⇒F, which is equivalent to T⇒F, which is false! I loved logic class so much....
posted by thelonius at 12:57 PM on April 19, 2012


This is the third post about logical fallacies in a little over a month.

Unfortunately for the desire to avoid a situation in which popular topics get a lot of attention in a short time window, the tag search only revealed "poster" as a tag appearing within the last few months (I forget the time window) despite my inclusion of the tags "logic," "logical," "fallacy," and "fallacies." Short of reading the whole blue every day, which I can't afford to do, and having a perfect memory for content that's been posted, I don't know what a person could do.

In any case, I don't think it's really a problem. Logical fallacies, as a subject, seem to come up here every day in comments. It doesn't surprise me all that much that some graphic designers have finally gotten around to working with them, or that people who are interested in argument in rhetoric have a good appetite for them. I saw this one when three different friends from three different places posted it in their Facebook feeds.
posted by Miko at 12:58 PM on April 19, 2012


In any case, I don't think it's really a problem. Logical fallacies, as a subject, seem to come up here every day in comments. It doesn't surprise me all that much that some graphic designers have finally gotten around to working with them, or that people who are interested in argument in rhetoric have a good appetite for them.

They come up here every day but as many in this thread and the (many) others about this topic point out, this constant discussion of them is kind of a bad thing. The sort of people who have an appetite for this stuff seem to be the ones who are looking for weapons that they can hurl at others to show what logical geniuses they are, when in fact knowing these fallacies really isn't all that practically useful in most arguments or in general.

It's just another form of the Grammar Nazi tendency: you can wrap yourself in the guise of being correct and proper and just trying to maintain good discourse when it's really just mental masturbation and a desperate attempt to get everyone to see how smart you think you are.
posted by Sangermaine at 1:14 PM on April 19, 2012 [1 favorite]


However it could be argued that a certain innate unreasonableness is present in people who rely on fallacies, to a degree that can amount to a perfect blind spot.

When I was a young philosophy major my logic professor constructed a major exam entirely from Ronald Reagan quotes. My logic professor also being the chair of the Peace Studies Institute and all of us in the room being good little lefties (save one), this struck everybody in the room as both entertaining and educational.

The one who disagreed was a young conservative type. He failed the exam then spent the time devoted to reviewing the answers exclaiming, "but it's TRUE."
posted by mph at 1:17 PM on April 19, 2012


Oh! A presidential debate BINGO board! How lovely.
posted by JimmyJames at 1:20 PM on April 19, 2012 [1 favorite]


tu quoque

What did you call me? That's an ad hominem
posted by Hoopo at 1:24 PM on April 19, 2012


tu quoque

What did you call me? That's an ad hominem


Took you long enough to parse it
posted by infini at 1:29 PM on April 19, 2012


BtQ can never be used to prove anything, that is, to show that something is so not already known to be so. If I argue that p therefore p, then, though my argument is valid, it can't establish the truth of p.

That's pretty much a prose explanation of what it means to say '(p --> p) --> p' is false.
posted by straight at 1:42 PM on April 19, 2012


Knowing about logical fallacies only gives us the tools to dismiss other people's arguments as being poorly constructed.

I don't know how useful this is.


It can be useful if the person being introduced to the concepts really understands them and uses that understanding when constructing their own arguments--hopefully to avoid using them, but either way really. While I totally sucked at symbolic logic, learning about truth values etc was fascinating and I found I couldn't help but try to apply it in my political science and philosophy classes afterwards. It wouldn't surprise me if being introduced to fallacies in logic commonly employed in rhetoric could lead to something similar.
posted by Hoopo at 1:45 PM on April 19, 2012


'p therefore p' is valid, and deductively so.
Right, but that's not begging the question. If I tell you "p implies p" (or some longer circular argument that boils down to the same thing), then I'm not arguing that you should believe in p, and I'm not begging the question. If I am arguing that you should believe in p, then I'm arguing "p implies p, therefore p", which is deductively invalid.
posted by roystgnr at 3:07 PM on April 19, 2012 [1 favorite]


Unfortunately for the desire to avoid a situation in which popular topics get a lot of attention in a short time window, the tag search only revealed "poster" as a tag appearing within the last few months (I forget the time window) despite my inclusion of the tags "logic," "logical," "fallacy," and "fallacies." Short of reading the whole blue every day, which I can't afford to do, and having a perfect memory for content that's been posted, I don't know what a person could do.

Sorry, I didn't mention it in order to criticize the post. I just wanted to point people back to the previous threads.

So, we all obviously know what he means there - but it begs the question: Can be people be wrong about things?

Of all the threads in which to use 'begs the question' in that way....
posted by painquale at 3:39 PM on April 19, 2012 [2 favorites]


Of all the threads in which to use 'begs the question' in that way....
I'm not really sure what you mean. The point I'm making isn't that we don't know whether or not people can be wrong. It's that it hasn't been stipulated as a logical premise, which means that a statement that relies on it being true is technically logically invalid.

It may seem silly but philosophers actually spent a lot of time thinking about how to define thought itself in a logical way. If you look at the famous phrase "I think, therefore I am", by Descartes, the whole idea was to try to figure out what "true" statements he could actually make, given the fact that all senses could in theory be mistaken.

From Wikipedia:
The phrase became a fundamental element of Western philosophy, as it was perceived to form a foundation for all knowledge. While other knowledge could be a figment of imagination, deception or mistake, the very act of doubting one's own existence serves to some people as proof of the reality of one's own existence, or at least that of one's thought.

The statement is sometimes given as Dubito, ergo cogito, ergo sum (English: "I doubt, therefore I think, therefore I am").[2] A common mistake is that people take the statement as proof that they, as a human person, exist. However, it is a severely limited conclusion that does nothing to prove that one's own body exists, let alone anything else that is perceived in the physical universe. It only proves that one's mind exists (that part of an individual that observes oneself doing the doubting). It does not rule out other possibilities, such as waking up to find oneself to be a butterfly who had dreamed of having lived a human life.
Again, if you're not even "logically allowed" to assume that the external universe you experience exists, then how can you say that someone is "logically wrong" about something that you can't even claim exists.

Of course, starting from this premise Descartes was able to "prove" that god exists.

You can make a claim like "Assuming my perception of reality is correct - then this person is wrong", but that's a much weaker claim, because as we all know everyone's perception of reality must be somewhat incorrect.

Anyway, like I said it's not really a problem, it's just an example of why trying to find "Logical fallacies" in people's statements is a waste of time. Unless they are talking about math or some other formal system, it's something that will always succeed if you include missing premises as one of the logical fallacies. If you exclude that one, then I actually don't think logical fallacies are all that common, rather people are argue based on incorrect premises. Sometimes those premises have not been thought through.

Lets take the following "Logical" statement
Premise 1: If someone's father was a Muslim, they are a Muslim
Premise 2: Obama's father is a Muslim.
Conclusion: Obama is a muslim
We know the conclusion is wrong but there isn't actually any logical fallacy in play here, given the two logical premises. If you look at the Birthers a lot of their statements are very "logical" they just have totally whack premises.

If you want to convince someone that it's wrong, you can't just say "Logical fallacy" because there isn't one. But you can point out that if those premises are true, it means no one can convert from Islam to Christianity. And, you can point out that because Obama's Grandfather was a christian who converted to Islam, if Obama's father was truly Muslim, it must be possible to convert from Christianity to Islam. So if those premises are true, the ratio of Muslims to Christians can only increase (not counting differing birth rates, or genocide)

On the other hand, if you just say "He says he's a Christian, he went to a Christian church" etc. then they can accuse you of using a "logical fallacy" because you are assuming that if he says he's a Christian he must be one. (And they probably will if they're smart enough to figure that out)

Anyway, the point is not that trying to reason about things logically is bad, but rather 1) You can easily be wrong without making any logically incorrect steps and 2) Rather then trying to point out "logical fallacies" it would be better to teach people how to use logic correctly in the first place, which will let them see if arguments aren't logically sound without memorizing a long list of "logical fallacies".

In fact, it's actually easier to learn the basic rules of logic then it is to memorize a list of logical fallacies anyway. So it isn't even like this is a simpler or less error-prone way to go about teaching how to evaluate arguments.
posted by delmoi at 6:21 PM on April 19, 2012


Of all the threads in which to use 'begs the question' in that way....
Wait, I think I just figured out what you meant. Did you think I was using the term "begs the question" in the common incorrect way? I thought I was using it correctly.
The fallacy of petitio principii, or "begging the question", is committed "when a proposition which requires proof is assumed without proof", or more generally denotes when an assumption is used, "in some form of the very proposition to be proved, as a premise from which to deduce it".[2] Thus, insofar as petitio principii refers to arguing for a conclusion that has already been assumed in the premise, this fallacy consists of "begging" the listener to accept the "question" (proposition) before the labor of logic is undertaken. The fallacy may be committed in various ways.
What I meant was, In order to make a statement about what usually happens when people are wrong, you need to first assume people can be wrong. You're assuming people can be wrong without evidence. Now reading that again though it may only qualify as begging the question if the statement you were trying to prove was the one you assumed, in which case I guess it would have been an incorrect usage. I was under the impression that you were begging the question any time you used an assumption implicitly without stating it, because if the conclusion was correct, you could could then go back and prove the origional premise, like so:
A) Proven conclusion: People are often wrong because they have used a logical fallacy
B) Therefore people are sometimes wrong.
Clearly A implies B, so how is that not begging the question?
posted by delmoi at 6:46 PM on April 19, 2012


Yeah, it was just a jab at your use of the phrase. Begging the question is a property of arguments (or presenters of arguments). You can say "this argument begs the question," but you can't say "this statement begs the question," and the bit you were responding to was just a statement. You were using the phrase to mean "this quoted bit raises the question..." which is the "incorrect" way. (If you use a question mark, you're probably using the phrase incorrectly.)

It's a bit tricky because you were talking about arguments that beg the question while using the phrase "beg the question" in the other way.

If I'm reading you right, you think that an argument begs the question if the premises are not explicitly argued for. But that's not begging the question. And making assertions that could not be true without other unstated assumptions being true isn't begging the question either. (If you thought this, you'd collapse the incorrect and correct uses of the phrase... if an assertion raised a question about the truth of something the speaker assumed, then you'd think it "begged the question" in both senses. So maybe that's what was going on.)
posted by painquale at 7:48 PM on April 19, 2012


you were using the phrase to mean "this quoted bit raises the question..." which is the "incorrect" way. (If you use a question mark, you're probably using the phrase incorrectly.)
Yeah, except as I explained, that's not what I meant - I meant that the statement, by itself implied it's own premise, which is the definition of begging the question, at least my understanding of the definition. I didn't simply mean it 'raised' the question.
posted by delmoi at 7:57 PM on April 19, 2012


the statement, by itself implied it's own premise

Statements don't have premises; arguments do. There wasn't an argument in what you were quoting. So it was hard to see how you meant it other than in the question-raising sense.
posted by painquale at 12:29 AM on April 20, 2012


delmoi: even if I take you at your word, it is your responsibility as a writer to know the most frequent kinds of misunderstandings and mistakes, and to avoid engaging in or encouraging them.

As to the possibility that they are begging the question that someone can be wrong, argument is meaningless without the possibility that someone can be wrong. Assuming that someone can be wrong is to argument as the possibility of communication is to speech. Also, I find it hard to believe that anyone above the bottom 2nd percentile of cognative development has failed to ever observe someone being demonstrably wrong ("I don't know where the toy is", said by the child holding the toy behind her back, for example).
posted by idiopath at 8:51 AM on April 21, 2012


I'm late to this party, I only saw it because of the mention in this now-closed MeTa.

I'll say this about logic and logical fallacies... as useful as the concepts are, they are often misused as badly as anything else.

You don't like someone's views? You nitpick their argument, find some fallacy or error, then act like that invalidates the entirety of everything they have to say.

Most of the time if you were actually interested in getting at the truth of the matter under discussion you'd do well to instead ask yourself:

- Why would a sane, intelligent, decent person have thought that?
- Is there some frame of reference from which it looks like that?
- Is there some merit there that I'm missing?
- Even if flawed, what is there of value in what they're saying?

Most of the time when you're bothering to talk about logical fallacies outside of academia, it's not because you are so interested in the truth, or so committed to careful reasoning. It's just another way to dismiss stuff you want to dismiss, just another way confirm your confirmation bias.

Plenty of the time in the very instance you are pointing out a logical fallacy, you are at the same time committing one yourself.

Quite often it's some version of this:

Newton believes in Alchemy
Alchemy is nonsense
Therefore everything Newton has to say is nonsense
posted by philipy at 10:34 AM on April 24, 2012


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