Talk:Logical fallacy

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Main article on a wider subject. Better organisation of the list required.

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Better organization of the list[edit]

Informal Fallacies part 1 - Math 101, Spring 2007 handout, Department of Mathematical Sciences, Northern Illinois University
Informal Fallacies part 2 - Math 101, Spring 2007 handout, Department of Mathematical Sciences, Northern Illinois University

also form a far tighter list:

Informal Fallacies[edit]

Appeal to Force: using force or the threat of force to gain acceptance to his or her conclusion.
Abusive (Ad hominem): instead of trying to disprove the truth of what is asserted, one attacks the person who made the assertion
Circumstantial: An attempt to prove an opponent ought to accept an argument because of the special beliefs and circumstances of your opponent.
Argument from Ignorance: Assertion that a statement is true because it has not been proven false.
Appeal to Pity: pity is appealed to for the sake of getting a conclusion accepted.
Appeal to the People: Attempt to win popular assent by arousing the feelings and enthusiasm of the multitudes.
False Authority: Use of the feeling of respect or admiration people have for a popular person to win assent to a conclusion, especially for matters outside the province of their special fields of authority.
Accident: Attempt to discredit a general rule by taking a particular exception to that rule. What is true “in general” might not be universally true without qualification, because circumstances alter cases
Hasty Generalization: Converse of the fallacy of accident, hasty generalization is when you make a conclusion based on atypical cases
False Cause: Mistaking what is not the cause for a certain phenomenon for the real cause. Sometimes this fallacy occurs when one event precedes a second, and is therefore falsely claimed to be the cause of the second event.
Begging the Question: Assume as a premise for your argument the very conclusion you want to prove.
Complex Question: presume a definite answer to a prior, unasked question

Ambiguity Fallacies[edit]

Irrelevant Conclusion: Argument purporting to establish a particular conclusion is directed to prove a different conclusion
Equivocation: Use of expressions of double meaning in order to mislead.
Grammatical Construction: Unclear statement because of the loose or awkward way its words are combined
Composition: Applying properties of parts of a whole to the whole itself
Division: reverse of composition; What is true for the whole is true of its parts--BruceGrubb (talk) 18:59, 20 August 2021 (UTC)

Carl Sagan’s Baloney Detection Kit[edit]

Ad hominem — Latin for “to the man,” attacking the arguer and not the argument
Argument from authority
Argument from adverse consequences
Appeal to ignorance
Special pleading
Begging the question, also called assuming the answer
Observational selection, also called the enumeration of favorable circumstances, or as the philosopher Francis Bacon described it, counting the hits and forgetting the misses
Statistics of small numbers
Misunderstanding of the nature of statistics
Inconsistency
non sequitur — Latin for “It doesn’t follow”
post hoc, ergo propter hoc — Latin for “It happened after, so it was caused by”
Meaningless question
Excluded middle, or false dichotomy — considering only the two extremes in a continuum of intermediate possibilities
Short-term vs. long-term — a subset of the excluded middle, but so important I’ve pulled it out for special attention
Slippery slope, related to excluded middle
Confusion of correlation and causation
Straw man — caricaturing a position to make it easier to attack
Suppressed evidence, or half-truths
Weasel words

That should help--BruceGrubb (talk) 19:36, 20 August 2021 (UTC)

The subtypes of the 'fallacy fallacy' seem wrong[edit]

First time using a wiki, apologies if i'm doing it wrong

There are 4 subtypes listed for the fallacy fallacy:

Forward: Argument A for the conclusion B is fallacious. Therefore, B is false.
Converse: The conclusion B is false. Therefore, Argument A for B is fallacious.
Converse of Inverse: Argument A for the conclusion B is not fallacious. Therefore, B is true.
Inverse: The conclusion B is true. Therefore, Argument A for B is not fallacious.

I see 2 problems here:

#1: The words 'converse' and 'inverse' are used incorrectly[edit]

In propositional logic, these terms are used like this:

original: P -> Q
converse: Q -> P
inverse: !P -> !Q
contrapositive: !Q -> !P

In this case:

P = Argument A is fallacious
Q = Conclusion B is wrong

What this article describes as converse of inverse is actually just the inverse, and vice versa.

#2: Not all variants are fallacious[edit]

The inverse of the converse(a.k.a. the contrapositive) of a conditional statement shares the same truth value as the original, by definition. This however doesn't apply to converse and inverse. While being logically equivalent to each other, they can differ from the original, and I'd argue that they actually do in this case. E.g. The following sentence

> The conclusion turns out to be wrong, therefore the argument supporting that conclusion must in some way be flawed

sounds like perfectly valid reasoning to me, but according to this article, it is a 'converse fallacy fallacy'

If I'm wrong, I'd appreciate a counterexample

LastExceed (talk) 13:59, 8 March 2022 (UTC)

You seem to be right regarding the use of inverse. And while it is true that if some conclusion is wrong, then an argument for that conclusion must in some way be flawed, it isn't necessarily true that the argument involves a fallacy; there are non-fallacious argumentative errors that can be made. 𝒮𝑒𝓇𝑒𝓃𝑒 ^talk 16:09, 8 March 2022 (UTC)

can you give an example of a non-fallacious argumentative error?

LastExceed (talk) 19:39, 8 March 2022 (UTC)

To take a silly example, if I argue (P1) The Moon is made of cheese, and (P2) All cheese is edible, so (C) the Moon is edible, I have made an error (the Moon isn't made of cheese), but I would not ordinarily be said to have committed a fallacy. The argument is valid, it just isn't sound. 𝒮𝑒𝓇𝑒𝓃𝑒 ^talk 01:43, 9 March 2022 (UTC)

Indeed, one of the most common problems with an argument are premises not being true. This isn't a flaw in the reasoning or way of thinking meaning it isn't a fallacy. It is however a stumbling block to making a sound argument. People tend to overlook that in order to have a sound argument, not only must the conclusion follow (and lack flaws in reasoning) but ALSO the premises be actually true. Phenomenally easy to forget and since people focus so much on fallacies and that a false premise doesn't have a convenient "fallacy label"...it even gets over looked by people versed in critical thinking. Very good catch though LastExceed on inverse/converse! ShabiDOO 17:53, 9 March 2022 (UTC)

"Offensive = True" fallacy[edit]

Any word on the fallacy that if truth is offensive, anything offensive is true?

E.g:

Person 1: Homosexuals are wicked and want to rape you.

Person 2: gets offended

Person 1: It's the truth, because it's offensive.

A Serb (Talk) 19:51, 11 April 2023 (UTC)

Not a listed fallacy fallacy[edit]

It seems as though people keep coming up with or 'discovering' new fallacies and so it just occurs to me : what if there is an infinite number of fallacies and we only ever know of a small finite number of them? So what if it is a fallacy to assume that only because you checked all possible lists of fallacies extremely thoroughly (and let's assume you actually did and that you ended up with a correct understanding of each fallacy) and your argument didn't match any fallacy that therefore your argument is correct?Fisherman75 (talk) 08:11, 23 July 2023 (UTC)Fisherman75

There probably does exist an infinite number of potential informal fallacies of pretty simple form; they get named and described in relation to the potentially infinite ways and styles of human discussion and argument over the ages, when someone cares to (and it may or may not catch on). I think droves of them are sure to come into and go out of fashion in the times ahead (though there will be many duplicates and reinventions).

As for strictly formal fallacies, while there's an infinite number of possible wrong forms of logical arguments, arguments can be (re)structured so that they're broken down into smaller pieces, and then there's only a finite number of ways that the small pieces of logic can be wrong. But strictly formal errors don't capture all error.

Your scenario reminds of how software and debugging works. Most software is written without any proof of correctness, just like most arguments people make are formulated without a logical proof. For software, however, usually testing is done to find bugs, just like people usually satisfy themselves with spotting "obvious" flaws in arguments rather than showing with finality that it's all in order. For software, long series of automated tests are sometimes used to exclude bugs -- but it is obvious that except in very special cases, such testing does not rule out the possibility that still more bugs exist, and the tests are developed with the rest.

Actually, people very often go (both in argumentation and in software development): 1. "I haven't found an error in it, so there isn't any." 2. "Look, here's an error." 3. "Damn, it actually doesn't work." And sometimes also, 4. "There, I fixed it / here's an alternative." The first part seems like a special case of argument by assertion. --ApooftGnegiol (talk) 10:19, 23 July 2023 (UTC)

Now I thought of it. "Absence of evidence is not evidence of absence", or argument from ignorance, describes it. --ApooftGnegiol (talk) 10:56, 23 July 2023 (UTC)

I'm not sure that I agree that there could be an infinite number of (somehow defensible) informal fallacies. Because "infinity" is way beyond "an imaginably big number". But it may depend on how finely you want to cut the cake. Nevertheless it would be interesting to see a calculation which demonstrated that the number of informal fallacies was infinite.

Getting back to the point of the question - I don't think that anyone has made the assertion that we have discovered all formal or informal fallacies; so I doubt that anyone is making the argument that, if something didn't match a pre-existing fallacy, then it must be correct. Furthermore you can simply be wrong. The Moon is not, in fact, made of cheese - and claiming that it is is just "being wrong".Bob ^{"Life is short and (insert adjective)"} 15:12, 23 July 2023 (UTC)

It's probably large but not actually infinite, yes. How many social categories and contexts could people potentially come up with, with which it would be possible to identify distinct nuances and subtle differences in the use of fallacies worth giving different descriptions? If, hypothetically, people were to compare and identify which were "the same" and which weren't, probably the number wouldn't grow forever, because people don't process things in infinity fine-grained ways. --ApooftGnegiol (talk) 15:23, 23 July 2023 (UTC)

Sure. That's what I meant when I wrote: "But it may depend on how finely you want to cut the cake." You can slip an infinite number of divisions between the numbers "1" and "2" (maths nerds are welcome to jump in); though I'm not really convinced you can do this with ideas.

Appeal to the Individual[edit]

When discussing social justice issues hyper-individualists will often entirely reject a notion of privilege or injustice as applying to them in any way because they are "individuals" implying that even if they share an attribute with someone else it's somehow different because it's their attribute and so they remain 100% different than everyone else. It reminds me of a kind of magical thinking or cop out when it comes to their notion of the individual. Even if many of the categories are just formalized constructs used initially by 'the oppressors' to continue dividing people as the status quo already was it's still relevant because the point is to reverse that invented or happenstance discrimination even the forms that weren't really formalized initially by the oppressors but instead identified and studied by social justice scholars later on. There's a lot of this stuff I disagree with and I do feel there is a bit too much collectivism in a lot of the arguments we're seeing these days and there is a lot of triggerhappy underestimation of the sheer complexity of society, but some people also take individualism way too far on the other side and I think this is one aspect of it. Is there such a thing as "Appeal to the Individual", or is that already a clear example of one fallacy?Fisherman75 (talk) 16:19, 26 July 2023 (UTC)

Huh?[edit]

The example given in https://rationalwiki.org/wiki/Logical_fallacy#Fallacy_of_modal_logic is just deductive logic. Accumulator (talk) 08:30, 10 September 2024 (UTC)