How do I learn to detect logical fallacies in a conversation?

It is difficult for me to ascertain when the person I am communicating is using a logical fallacy to trick me into believing him or doubting my judgement, even when I realise it hours after the argument.

I have seen countless arguments in Reddit threads and I couldn’t figure out who was in the right or wrong unless I looked at the upvote counts. Even if the person is uttering a blatant lie, they somehow make it sound in a way that is completely believable to me. If it weren’t for those people that could exactly point out the irrationality behind these arguments, my mind would have been lobotomised long ago.

I do want to learn these critical thinking skills but I don’t know where to begin from. I could have all these tips and strategies memorised in theory, but they would be essentially useless if I am not able to think properly or remember them at the heat of the moment.

There could be many situations I could be unprepared for, like when the other person brings up a fact or statistic to support their claim and I have no way to verify it at the moment, or when someone I know personally to be wise or well-informed bring up about such fallacies, perhaps about a topic they are not well-versed with or misinformed of by some other unreliable source, and I don’t know whether to believe them or myself.

Could someone help me in this? I find this skill of distinguishing fallacies from facts to be an extremely important thing to have in this age of misinformation and would really wish to learn it well if possible. Maybe I could take inspiration from how you came about learning these critical thinking skills by your own.

Edit: I do not blindly trust the upvote count in a comment thread to determine who is right or wrong. It just helps me inform that the original opinion is not inherently acceptable by everyone. It is up to me decide who is actually correct or not, which I can do at my leisure unlike in a live conversation with someone where I don’t get the time to think rationally about what the other person is saying.

lvxferre,
@lvxferre@lemmy.ml avatar

Note that a fallacy is a reasoning flaw; sometimes the goal might be to trick you, indeed. But sometimes it’s just a brainfart… or you might be dealing with something worse, like sheer irrationality. That said:

  • look for the conclusion. What is the point that the writer is delivering? (Note: you might find multiple conclusions. That’s OK.)
  • look at what’s being used to support that conclusion. What is the core argument?
  • look for the arguments used to feed premises into the core argument. Which are they?

Then try to formalise the arguments that you found into “premise 1, premise 2, conclusion” in your head or in a text editor. Are the premises solid? Do you actually agree with them? And do they actually lead into the conclusion? If something smells fishy, you probably got a fallacy.

Get used to at least a few “big” types of fallacies. There are lists across the internet, do read a few of them; you don’t need to memorise names, just to understand what is wrong with that fallacious reasoning. This pic has a few of them, I think that it’s good reference material, specially at the start:

https://www.pesec.no/content/images/size/w1460/2020/03/School-Of-Thought---Fallacies-Poster.png

In special I’ve noticed that a few types of fallacy are really common on the internet:

  • genetic fallacy - claiming that an argument is true or false because of its origin. Includes ad hominem, appeal to nature, appeal to authority, ad populum, etc.
  • red herring - bringing irrelevant shit up as if it supported the conclusion, when it doesn’t matter. In special, I see appeal to emotion (claiming that something is false/true because it makes you feel really bad/good) all the time.
  • oversimplification - disregarding key details that either stain the premises or show that they don’t necessarily lead to conclusion. False dichotomy (“if X is true, Y is false” in situations where both can be true or false) is a specially common type of oversimplification.
  • strawman - distortion of an opposing argument into a way that is easier to beat. Again, notice that “intention” doesn’t matter; only that the opposing argument isn’t being addressed.
  • moving goalposts - when you counter an argument, the person plops another in its place, without acknowledging that it’s a new argument. Often relies heavily on ad hoc (making stuff up on the spot to shield an argument)
  • four terms - exploiting multiple meanings associated with the same word to create an argument like “A is B¹, B² is C, thus A is C”.

There are also some “markers” that smell fallacy for me from a distance. You should not trust them (as they might be present where there’s no fallacy, or they might be absent even when the associated fallacy pops up); however, if you find those you should look for the associated fallacy:

  • “As a” at the start of a text - genetic fallacy, specially appeal to authority
  • "Trust me" - red herring, specially appeal to emotion (once you contradict the argument there’s a good chance that the other will create drama because you didn’t blindly trust them, so the whole thing boils down to “accept this as true otherwise you’ll hear my meltdown”).
  • “I don’t understand” followed by a counter-argument - strawman. Specially common in Reddit.
  • “Actually” - red herring through trivia that is completely irrelevant in the context.
anotherlemmyuser,

I’m genuinely curious here, why is learning to identify logical fallacy at the point of conversation that important to you? Just research yourself afterwards, otherwise how would you know what is wrong unless you have already decided or learnt it is wrong to begin with. In my opinion, it is not that important unless you are engaged in professional persuasion or your opinion at the very moment holds a lot of weight. You could maybe identify inconsistency or twist their words until they contradict themselves? Otherwise, the best approach if you are not sure is to find out later. At the end of the day what matters to me most is my opinion, I do not care if I disagree with the person I am interacting with, or if the person disagrees with me. Maybe cause I’m not a politician. ;-)

HelixDab,

That seems like a dangerous approach to not care if you disagree with people. Shouldn't you know if your disagreement with them is based on sound reasoning?

anotherlemmyuser,

Oh, what I meant is that I wouldn’t care to argue for long if I disagree with the person I am interacting with. I did not mean being stubborn and sticking with the same opinion. I just take into consideration what the person has said, and think or research about it afterwards. Apologies for my unnatural English.

anotherlemmyuser,

Oops, I have no idea why the comment is reposted many times. I shall try to delete.

nonstopshirtflutter,

Logical fallacies don’t necessarily disagree with facts. While the most common examples are simply unsupported statements that sound supported, very often we don’t have the luxury of working with clearly factual statements as a basis.

All rhetoric is at the end of the day a fallacy, as the truth of the matter is independent on how it is argued. Yet we don’t consider all rhetoric invalid, because we can’t just chain factual statements in real debates. Leaps of logic are universally accepted, common knowledge is shared without any proof, and reasonable assumptions made left and right.

In fact one persons valid rhetoric is another persons fallacy. If the common knowledge was infact not shared, or an assumption not accepted, the leap in logic is a fallacy.

I would try to focus less on lists of fallacies or cognitive biases and more on natural logic. Learn how to make idealised proofs, and through that learn to identify what is constantly assumed in everyday discussions. The fallacies itself don’t matter, what matters is spotting leaps in logic and why it feels like a leap in logic to you.

After all, very often authoritive figures do tell the truth, and both sides of the debate agree on general values without stating them. If someone starts questioning NASA or declares they actually want more people to live in poverty, they did infact spot very real logical fallacies in the debate, but at the same time those fallacies only exist from their point of view, and others might not care to argue without such unstated common ground.

buckybeaky,

Reddit’s obsession with logical fallacies is one of the things I was hoping we could get rid of moving here

nromdotcom,

Agreed. OP should be working on critical thinking skills in general and not specifically focusing on logical fallacies.

Logical fallacies and argumentation theory in general certainly have their place. But unless you’re taking part in a debate club or otherwise getting really really deep into these topics, they may do you more harm than good in thinking critically and having productive discussions.

The reddit (and, previously, slashdot) obsession with logical fallacies has been almost entirely as a way to prevent critical thinking and end discussion rather than promoting either.

min0nim,
@min0nim@aussie.zone avatar

The old Slashdot obsession of calling out logical fallacies lead to the hyper normalisation of climate change denial. We had a whole load of really smart people who were very quick to call out any appeal to authority (of, you know, actual climate scientists), but a bit too lazy to read the source material themselves.

Fun times.

flamingarms,

Rather than not encouraging focusing and learning fallacies, maybe we are simply saying that they need to also learn to use them appropriately? Fallacies are not just the informal ones that everyone is referencing here in this thread, but also the formal ones which are very much required for logical argument structure. So even in learning about fallacies, there will be opportunities to understand the difference between informal and formal, why they are different, and how that applies to discourse. Knowledge is power; it just needs to be balanced with understanding on how to use and I think a deep dive into fallacies could actually assist in that regard.

nromdotcom,

I dunno. For someone just starting to want to think critically during discussions of when reading things, asking them to get serious in the academic pursuit of logic and argument theory might not be the way. For one, it’s probably just asking for them to get stalled in the sort of dunning kruger zone of identifying fallacies and stopping there.

Especially when such behavior is already endemic to the internet and many platforms have feedback loops designed to reward this behavior. Just dunk on 'em and move on - watch the upvotes and retweets roll in.

I definitely don’t want discourage OP from learning anything, but I do want to be careful in what direction we point a beginner.

I think maybe learning to find good sources of information and verify claims might be a better first step. That doesn’t give OP any shortcuts I’m discussions, which is good. Then they may begin to notice different patterns or forms of discussion and at that point they can start to classify them and learn about them if they see fit.

flamingarms,

Such good points; I’m convinced. To continue on your line of thinking, after learning some media literacy and starting to notice different patterns and forms of discussion, I wonder if learning Aristotelian syllogisms would be a good next step. So we still aren’t jumping right into fallacies per se, but we start to understand logic structure and what is formally valid/invalid. So now it’s got them thinking about how to structure and challenge their own beliefs and arguments. And while we are now potentially hitting formal fallacies, I think this would not give any immediate tools for dunking on anyone either because, in my experience, converting a real-time argument to a syllogism is very very difficult without a ton of experience and practice breaking arguments down into simpler ideas. What do you think?

nromdotcom,

Yeah, I like that. After being able to recognize and validate claims, being able to verify the validity (at least logically if not factually) of any conclusions drawn from those claims seems like a good next step.

flamingarms,

Should we go ahead and put a curriculum together and start shipping it to universities, or…?

HelixDab,

"Truth" is a matter of conclusions and meaning, not of facts. Factual information would be something like--and this is an intentionally racist argument--53% of the murder arrests in the US come from a racial group that makes up 14% of the population. This is a fact, and it can be clearly seen in FBI statistics. But your conclusions from that fact--what that fact means--that's the point of rhetoric and logic. Faulty logic would make multiple leaps and say, well, obvs. this means that black people are more prone to commit murder. A more logically sound approach would look at things like whether there where different patterns in law enforcement based on racial groups, what factors were leading to murder rates in racial groups and whether those factors were present across all demographics, and so on.

Nonameuser678,
@Nonameuser678@kbin.social avatar

There's this app called cranky uncle and it goes through things like this and then helps to you learn how to identify them. It was developed by a university researchers in Australia with the aim of improving people's ability to recognise misinformation

cinaed666,
@cinaed666@kbin.social avatar

It doesn't look like it has been mentioned here yet: https://www.amazon.com/Skeptics-Guide-Universe-Really-Increasingly/dp/1538760533
This book goes really deep into every different kind of logical fallacy.

XiELEd,

Mostly Informal fallacies, but I liked that book too!

Clipper152, (edited )

It helps to remember that the mind is not a truth machine, but a survival machine.

I recommend learning some psychology. The more you know about how the mind works, the easier it is to understand and spot logical fallacies, both in yourself and others.

Edit: also, you should practice those critical thinking skills instead of just keeping them in theory. You could apply them to past situations, for example.

XiELEd,

I’m a bit new to self-studying logic (and rhetoric) but I think you should learn about “Formal fallacies” and “Informal fallacies”. Formal fallacies are those that arguments that are systematically false, like all A is B, some C is A, some C is not B, therefore all C is A. But in real arguments you have to convert those organic arguments into these terms (which could be the hardest part), and then you find out if it is a fallacy… I remember there was a way to find out if arguments are valid based on adding stars, I’ll probably send it later… But be warned, an argument can be “valid”, but still have the wrong premises! You can say, All cats are on fire, therefore some things on fire are cats… and the argument would still be valid, but rest on false premises… Informal fallacies, I think, are somewhat out of the scope of formal logic, but they are still considered faulty arguments, like Strawman…

Parsnip8904,
@Parsnip8904@beehaw.org avatar

I would suggest getting a book called Thinking Fast and Slow, and reading it slowly and deliberately, less than 5-10 pages a day. It not only tells you how to find these kind of fallacies but also why you’re likely to fall for them and how.

Moghul, (edited )

I have seen countless arguments in Reddit threads and I couldn’t figure out who was in the right or wrong unless I looked at the upvote counts. Even if the person is uttering a blatant lie, they somehow make it sound in a way that is completely believable to me. If it weren’t for those people that could exactly point out the irrationality behind these arguments, my mind would have been lobotomised long ago.

Upvotes on a comment or thread are absolutely not the way to determine which person is right, and it’s not even the way to determine which point of view is more popular. All those numbers give you is how many upvotes the comment got. In two separate communities, you’ll see completely contradictory statements be most popular because the people who feel a certain way tend to congregate.

If you want to become a more discerning information consumer, you can look up the common logical fallacies and keep them in mind, but nothing beats actually being informed, and forming your own opinion. Now, this is pretty hard because all news media is inherently biased, and so many things happen all the time that it’s hard to keep up.

What I’ve found helpful, is when it comes to things I don’t know about, I read the discussion as “this person says this, and that person says that”, rather than “this person is saying the truth, and that person is lying”. If it’s a subject that matters to me, I’ll have a look at some news, see where the general consensus is, analyze it from my own point of view, and form my opinion like that. If it doesn’t really matter to me, I don’t really do that, and just relay information as “I heard it might be either X or Y, but I don’t know for sure”, “I heard from Z that something or other”.

Edit: Of course, it’s not like I’m some paragon of unbiased information crunching. I have my own biases that I’m aware of, but naturally I think I’m right, so I think they’re not a problem, which is probably a problem. Everything you experience is relative.

Viking_Hippie,

I recommend using your fallacy is as both a handy reference and a shortcut for explaining it to the person committing one of the most common fallacies as well as anyone else reading.

By using that, you’ll be able to spot a lot of bullshit you might otherwise miss and eventually get to the point where you’re able to spot the ones you come across most often without looking it up 🙂

OsakaWilson,

I taught my daughters the usual logical fallacies from a young age. While doing that I learned that while occasionally, they appear in pristine form (looking at you, Slippery Slope and No True Scotsman), usually, they come rather nuanced, often clustered together, and difficult to identify.

A great way to get good at them is watch Fox News and identify them as they come. You can watch other networks and find them, but for a constant stream, Fox is a goldmine.

AnalogyAddict,

All news is a goldmine, you just find them easier to identify on Fox because you disagree with them, which sets off your alarm bells. It’s A LOT harder to identify fallacies that support your own biases.

OsakaWilson,

Your final statement is very true, however there is a reason that Fox News had to defend themselves by claiming they are entertainment. Anyone who believes that Fox News does not have more logical fallacies than most other news really needs to assess their own cognitive biases. I can see logical fallacies on topics I agree with and they piss me off more because I believe that they throw discredit on the perspective that can be argued on it’s own merits.

Little_mouse,

The trouble with ‘Slippery Slope’ and ‘No True Scotsman’ is that they themselves are not fallacies. Invoking them without proper justification is the fallacy. The same sort of thing happens all the time with ‘Appeal to Authority’, you can probably trust a scientific consensus about a subject in which they are all experts, but you probably shouldn’t trust an individual expert on a topic for which they are not recognized as an expert.

For an example of Slippery Slope: Fascists will absolutely try to demonize the most available target, and then because they always need an out-group, they continue cutting at what they consider the ‘degenerates’ of society until they are all that remain. (And then they find some new definition of degenerate)

“No True Scotsman” is valid in that there is at some point by definition after which you are no longer talking about something. “No true vegetarian eats meat” is valid, as this is definitional. “No true member of Vegetarians United eats meat” lacks proper justification, and refers to an organization, not a proper definition. This gets really messy when people conflate what group people are in with what they ‘are’ or what makes them a good example of a group. Especially when religion is involved.

Fried_out_Kombi,
@Fried_out_Kombi@lemmy.world avatar

I think part of it is they’re logical fallacies. For instance, the scientific consensus on climate change is not technically proof of climate change; rather, it’s all the observations, statistics, etc. that are the evidence for climate change. Thus, it is true that claiming an argument is true solely because of scientific consensus is indeed a logical fallacy, as logical fallacies are relating to, well, logic.

For all practical purposes, however, we live in a complex world with lots of uncertainty, and we can generally trust expert consensus if for no other reason than they’re more likely to understand the facts of a certain technical matter better than us, and thus more likely to be able to ascertain the truth. And when discussing complex, technical concepts, I’m generally going to trust expert consensus so long as I am reasonably assured that they are indeed experts and that they have no systemic conflict of interest.

Rodeo,

‘Appeal to Authority’, you can probably trust a scientific consensus about a subject in which they are all experts, but you probably shouldn’t trust an individual expert on a topic for which they are not recognized as an expert.

That in itself is the ad hominem fallacy: you need to judge the claim based on its merits, not the merits of the person making the claim.

For example when David Suzuki talks about climate change and people say “well he’s just a biologist, he’s not qualified!” That may be true but it doesn’t invalidate his statements.

lvxferre,
@lvxferre@lemmy.ml avatar

No true Scotsman is a fallacy, more specifically ad hoc while defending a generalisation about a group defined by another criterion. Easier shown with an example:

  • [Alice] Vegetarians don’t eat cheese.
  • [Bob] I know plenty vegetarians who eat cheese. They just don’t eat meat.
  • [Alice] Those who eat cheese are not true vegetarians.

If we accept the definition of vegetarian that you implied (someone who doesn’t eat meat), “not eating cheese” is at most a generalisation. As such, when Alice says “Those who eat cheese are not true vegetarians”, she is incurring in the fallacy.

The slippery slope is an interesting case, because it’s both a fallacy and a social phenomenon. And evoking the social phenomenon doesn’t automatically mean that you’re using the fallacy.

As a fallacy, it’s failure to acknowledge that the confidence in the conclusion is smaller than the confidence in the premises - so if you’re chaining lots of premises, your trust in the conclusion will degrade to nothing. Here’s a simple example of that:

  • if A happens, then B will happen 90% of the time. if A doesn’t happen, B never happens.
  • if B happens, then C will happen 90% of the time. if B doesn’t happen, C never happens.
  • […C then D, D then E, E then F, in the same fashion as above]
  • if F happens, then G will happen 90% of the time. if F doesn’t happen, G never happens.

So if A happens, what’s the likelihood of G also happening? It is not 90%, but (90%)⁶ = 53%. Even with rather good confidence in the premises, the conclusion is a coin flip. (Incidentally, a similar reasoning can be used to back up Ockham’s Razor.)

As a social phenomenon, however, the slippery slope is simply an observed pattern: if a group, entity or individual does something, it’s/they’re likely to do something similar but not necessarily identical in the future. That covers your example with fascists.

The same sort of thing happens all the time with ‘Appeal to Authority’, you can probably trust a scientific consensus about a subject in which they are all experts, but you probably shouldn’t trust an individual expert on a topic for which they are not recognized as an expert.

The reason why appeal to authority is a fallacy (more specifically, a genetic fallacy) is because the truth value of a proposition does not depend on who proposes it. If an expert said that 2+2=5 (NB: natural numbers), it would be still false; and if the village idiot said that 2+2=4, it would be still true.

We can still use authority however, but that requires inductive reasoning (like the one I did for the slippery slope), that is considerably weaker than deductive reasoning. And it can be still contradicted if you manage to back up an opposing claim with either 1) deductive logic, or 2) inductive logic with more trustable premises.

masterspace,

A great way to get good at them is watch Fox News and identify them as they come. You can watch other networks and find them, but for a constant stream, Fox is a goldmine.

Honestly a great way to learn them is to argue with people online in places like Lemmy / Kbin. When people argue against you on something you know to be right, it forces you to either a) reconsider your own stance or b) think about why they’re wrong or why their argument is invalid and how to point that out, either way it often leads to logical fallacies, and the more you intentionally try to identify examples of them, the easier they are to intuitively recognize.

foosel,
@foosel@feddit.de avatar

Maybe this helps, it has some good examples on what the various fallacies look like, and combining that knowledge with a hunch of “something here sounds fishy” is basically what I do I think.

youtu.be/Qf03U04rqGQ

C4d,

There used to be poster you could buy / wallpaper you could download that essentially summarised this Wikipedia page:

en.wikipedia.org/wiki/List_of_fallacies

Otherwise it’s practice (eg critical appraisal training).

NeoLikesLemmy,

Read some of the old “Miss Marple” Stories, then some “Hercule Poirot” Stories.

C4d,

Ah yes. The little grey cells.

PatFussy,

Sometimes a strawman gets more upvotes/reception than a well thought out argument. Its difficult to win over people when their minds are made up in the first sentence. It only gets harder if you are doing this irl so your best bet is to gaslight them before they gaslight you. Its the American way.

Viking_Hippie,

You had me until “to hunt the monster you must become the monster” 😄

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