Logical Fallacies: a Study

[Banquo's Ghost]

You forgot one:

Argumentam ad Tribesman:

Bollox.

[al Roumi]

Do the esteemed Mods agree that this should be stikied? It might provide useful guidance/reference...

[Sigurd]

I for one will compliment your list of fallacies. Great job!!

But if I should add some constructive criticism I would want you to clarify the Non Sequitur section of your post. The randomness is less common. The more common fallacy of this type is the use of false conclusions to valid premises.
Also if you are going to expand your list I would have added these fallacies:

Red Herring
Petitio principii(Begging the question)
Ad hominem Tu quoque (you too)
Argumentum ad antiquitatem (appeal to tradition)
Argumentum ad numerum (Appeal to numbers)

A while ago I tried to introduce formal debates to the orgahs. We had a few articles in the gahzette about this and we tried to organize a few real formal debates with referees, where the best one was published in the gahzette. Sadly it was only a brief spark before it died.
Link to the first gahzette article (It is the Backroom article).

[Ariovistus Maximus]

Thanks everyone for the compliments!

You forgot one:

Argumentam ad Tribesman:

Bollox.

You're right; he deserves special mention.

I for one will compliment your list of fallacies. Great job!!

But if I should add some constructive criticism I would want you to clarify the Non Sequitur section of your post. The randomness is less common. The more common fallacy of this type is the use of false conclusions to valid premises.

Thanks! Good clarification.

Also, yes there are an ABUNDANCE of fallacies, and still a good many that are commonly used in internet debate! I will probably start in on some more (and some fixes) later this afternoon.

You know, I've had a similar idea myself. To have a sort of courtroom-style debate. There is little to no closure in debate as it is, and as I'm sure you know, people just come away irritated at their opponent and don't even CONSIDER the possibility that their opponent is right, even if they "won" the argument.

So people continue to post the same old thing because they don't feel that they've been disproven.

If it were feasible, it would be cool to have a couple of members who act as a panel of judges, and then at the end of the debate, they could rule as to which case was best presented.

Of course, there are many flaws with that idea, and I'm told that it's not feasible. It is asking quite a lot.

[Beskar]

Argumentum ad antiquitatem

:wave: Hello Evil Men from Mars.

[Sasaki Kojiro]

Now we just need an "argumentum ad pretending to have a phd in economics when they don't really"

Normally, the backroom is made of informal arguments and discussion. And it's easy to point out the logical fallacies in someone elses casual argument while leaving your own statement as "In my opinion this is a bad idea".

[Lemur]

You missed one of the most common:

13. Tu quoque

Or, you too, nanny-nanny-boo-boo!

[A] Latin term that describes a kind of logical fallacy. A tu quoque argument attempts to discredit the opponent's position by asserting his failure to act consistently in accordance with that position; it attempts to show that a criticism or objection applies equally to the person making it. It is considered an ad hominem argument, since it focuses on the party itself, rather than its positions. [...]

You-too version

This form of the argument is as follows:

A makes criticism P.
A is also guilty of P.
Therefore, P is dismissed.

This is an instance of the two wrongs make a right fallacy. [...]

Inconsistency version

This form of the argument is as follows:

A makes claim P.
A has also made past claims which are inconsistent with P.
Therefore, P is false.

This is a logical fallacy because the conclusion that P is false does not follow from the premises; even if A has made past claims which are inconsistent with P, it does not necessarily prove that P is either true or false.

Example:

"You say aircraft are able to fly because of the laws of physics, but this is false because twenty years ago you also said aircraft fly because of magic."

-edit-

And how could I forget one of my all-time favorites:

14. No true Scotsman

Or, moving the goalposts.

No true Scotsman is a logical fallacy where the meaning of a term is ad hoc redefined to make a desired assertion about it true. It is a type of self-sealing argument. [...]

When faced with a counterexample to a universal claim, rather than denying the counterexample or rejecting the original universal claim, this fallacy is employed to shift the definition of the original class to tautologically exclude the specific case or others like it.

A universal claim is of the form "All x are y" or "No x are y." In the example above, the universal claim is "No Scotsmen are brutal maniacal rapists." (No S are BMR.) The counterexample is given by the Aberdonian, who, it is implied, is a brutal maniacal rapist. The response relies on a continued insistence that No Scots are brutal maniacal rapists, and to thus conclude that the brutal maniacal and rapacious Aberdonian is no true Scot. Such a conclusion requires shifting the presumed definition of "Scotsman" to exclude all brutal maniacal rapists.

[Reenk Roink]

Here's the thing though with these fallacies, some of them are just absolutely essential in discussion or debate to get things going (and others like ad Tribesman and ad hominem at times are just entertaining). Take appeals to authority, very important in all kinds of matters. Appeals to popularity and tradition also can sway my opinion a lot.

These so called logical fallacies (most of the ones listed) actually have very little to do with logic formally (they should actually be called "what some consider to be bad forms of reasoning"). For example, Sigurd brought up begging the question as an example of a fallacy. Actually, in purely logical terms (again logic is concerned with syntactical form of statements), circular reasoning is deductively valid - the epitome of "logic"). The only reason we don't like that type of argument is because:

1) it seems cheap (it probably is cheap - but it's logical )
2) Aristotle was playing some game and didn't want people to beg the question and so we use one of his crappy game rules to this day as one of the no-no's for discussion/debate (why does this guy have so much continued influence? )

And nothing makes me facepalm more when some guy comes in and says "OH argumentum ad ............... you're wrong lol!" Because (and I believe this also gets included in those lists of logical fallacies) just because someone makes a fallacious argument does not mean his point or his conclusion is false or wrong. On the flip side, anyone can support a false/wrong point or conclusion using an argument with a perfectly logical form. Already too much emphasis is put on the argument and not on the conclusion/point being made.

I like (some of) the org debates because aside from calling out strawmen (which should be done definitely kills discussion) these debates aren't usually flooded with people making laundry lists of the above mentioned fallacies. Which is good.

[Sigurd]

Here's the thing though with these fallacies, some of them are just absolutely essential in discussion or debate to get things going ... Take appeals to authority, very important in all kinds of matters.

It only becomes a fallacy when used wrong.
Argumentum ad verecundiam only becomes a fallacy when using authority figures that aren't really authority figures, or using radical authority figures which is removed from the mainstream i.e goes against other qualified authority figures.

A great example is quoting Albert Einstein in matters of politics or religion. Now Einstein was a clever guy, but his field of expertise was physics not politics or religion.

[Sasaki Kojiro]

And nothing makes me facepalm more when some guy comes in and says "OH argumentum ad ............... you're wrong lol!" Because (and I believe this also gets included in those lists of logical fallacies) just because someone makes a fallacious argument does not mean his point or his conclusion is false or wrong. On the flip side, anyone can support a false/wrong point or conclusion using an argument with a perfectly logical form. Already too much emphasis is put on the argument and not on the conclusion/point being made.

I like (some of) the org debates because aside from calling out strawmen (which should be done definitely kills discussion) these debates aren't usually flooded with people making laundry lists of the above mentioned fallacies. Which is good.

I agree. And even with the strawman fallacy, there's strawmanning someone and then there's reading between the lines and following things to a possible conclusion (which might not be what the person intended).

Also, sometimes people only talk about two option because they don't feel like exploring every option. False dichotomy

It only becomes a fallacy when used wrong.
Argumentum ad verecundiam only becomes a fallacy when using authority figures that aren't really authority figures, or using radical authority figures which is removed from the mainstream i.e goes against other qualified authority figures.

A great example is quoting Albert Einstein in matters of politics or religion. Now Einstein is a clever guy, but his field of expertise was physics not politics or religion.

But even so, it's absolutely silly to call "logical fallacy" on a post like:

We should keep the 2nd amendment like we always have, after all, thomas jefferson said that we had the right to self defense

since the gun control argument boils down to "under what circumstances do individual rights trump collective well being". You can't use really logic to decide that. Additionally, the evidence used (crime statistics etc) always has confounding variables and can be argued to be biased one way or the other. An actual argument against gun control would take into account the trade off between individualism vs collectivism, use empirical data involving many different studies, and in short would require many hours of work and extensive resources--not "argumentum ad tradition and argumentum ad authority!"

What we generally do in the backroom is chip away at it. Logically valid arguments and cited sources are nice and all, but it's kind of like having an umpire for a backyard baseball game.

But then again the:

*posts crappy source article*
argumentum ad authority! My opinion is correct!
Citation, Please!
*posts crappy source article*

exchange is part of the backroom charm

I don't know, some threads I feel like people should put more effort into thinking their arguments through, others I feel like doing so is an exercise is naivety given the scope of the argument.

[Ariovistus Maximus]

Here's the thing though with these fallacies, some of them are just absolutely essential in discussion or debate to get things going (and others like ad Tribesman and ad hominem at times are just entertaining).

I would hardly call them essential.

I could start a debate entitled:

"Banquo's Ghost is an evil, amoral censor," and that would definitely get discussion going.

But that hardly means that would be productive, relevant, or helpful. And it seems to me that this sort of thing occurs often enough to warrant greater attention to the intricacies of logic in debate.

Take appeals to authority, very important in all kinds of matters. Appeals to popularity and tradition also can sway my opinion a lot.

Well that's the very nature of fallacy; it's a good thought/method that is slightly warped somewhere along the line.

Thus, there is indeed a fine line in many cases between a fallacy and a valid argument.

For instance, in court, you could say that a witness' testimony is an 'appeal to authority' of sorts, if for instance that individual was the sole witness. But it isn't considered fallacious for obvious reasons.

These so called logical fallacies (most of the ones listed) actually have very little to do with logic formally (they should actually be called "what some consider to be bad forms of reasoning").

Most of them are informal fallacies, yes. The point is that people, in an attempt to employ "logical" arguments, commit fallacies.

Because (and I believe this also gets included in those lists of logical fallacies) just because someone makes a fallacious argument does not mean his point or his conclusion is false or wrong.

Of course not. Ironically, you are making the strong implication that the notion of fallacy is false because it has not been proven true. This is, of course, a fallacy. However, I will not simply call out the fallacy, but explain why I think it is so.

Are you familiar with truth tables?

When is the only time that a statement is considered valid in a truth table? When it is a tautology.

For instance, the fallacy of the converse.

If I am human, I can speak.

Therefore, if I can speak, I am human.

Well, of course not. Parrots can speak. (And of course handicapped humans cannot sometimes speak due to the handicap, but for sake of example.)

So, I could use that argument, and most of the time I would be correct. Usually, if I pointed to a thing that could speak, it would be human.

But occasionally I would point at a parrot or parakeet.

Thus, an argument may be TRUE, but that does NOT necessarily make it VALID.

And we are discussing the validity, not the truth, of arguments.

On the flip side, anyone can support a false/wrong point or conclusion using an argument with a perfectly logical form. Already too much emphasis is put on the argument and not on the conclusion/point being made.

So, in summary, you are throwing the proverbial baby out with the bathwater.

Yes, debate is still not cut and dried. Discretion is required.

But it's still a good idea to avoid invalid arguments, and there's certainly no reason to legitimize invalid arguments just because they are correct upon occasion.

The truth of an argument is different from case to case; obviously you can't come up with a set of rules.

However, if you try to avoid methods of argument that more often than not tend to false conclusions, you will be more productive.

I like (some of) the org debates because aside from calling out strawmen (which should be done definitely kills discussion) these debates aren't usually flooded with people making laundry lists of the above mentioned fallacies.

Agreed. And really, I'd also agree that fallacious statements aren't the end of the world in a relaxed discussion.

As I said, if you've read the essay, this was written for the TWC. The D&D there is structured differently than the backroom here at the .Org.

The D&D is more toned for debate, and the backroom has a little more of a friendly discussion atmosphere IMO.

So, it may not be as applicable, but I would say that it's a good thing to keep in mind.

And yes, the flip side of the coin is that you can't just scream "FALLACY!" and leave it at that, either.

[Sigurd]

You know, I've had a similar idea myself.

If it were feasible, it would be cool to have a couple of members who act as a panel of judges, and then at the end of the debate, they could rule as to which case was best presented.

Of course, there are many flaws with that idea, and I'm told that it's not feasible. It is asking quite a lot.

Just to let you get an idea of how we did it back then.
This is the only debate we finished : Crazed Rabbit vs. Waldinger (now woad&fangs)
The ruling was not posted in the thread, but in the December number of the gahzette also in the Backroom section.

You can find other debates by clicking on the Debate prefix to the thread names (Backroom). It was originally meant for formal debates, but have later been used indiscriminately to any whim of the thread starter. You will find the oldest threads with the prefix: Debate to be the true debate threads.