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

First off, Reddit (and Lemmy) is not a good place to learn about logical arguments and debate. The whole voting system is designed to filter popular opinions to the top and bury things that people dont like. If you sound authoritative and match your argument to the tone and biases of the community, your statements go to the top. If you get defensive or your answer doesn't match the subreddit you get dog piled with down votes. If there are any topics you are genuinely an expert in just go hang out in the appropriate subreddit and watch all the complete bullshit, half truths and personal opinions that get recycled over and over as gospel truth.

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:

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.

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.

Generally a good approach is to try learning the rules of logic. Logic is all about proving things to be true using only facts. It can also be helpful to try some logic puzzles or riddles which can only be solved using hard logic. Note that this won't automatically make you a better critical thinker, but it will help you exercise that muscle.

Also, it's helpful to play devil's advocate. If you hear someone making an argument, try to imagine how you would dispute that argument if you disagreed with it. It doesn't matter if you actually agree or not, just imagine you did and think about what your counter argument would be. This is what high school debate teams have to do; they are given a topic and a position and have to defend their position.

It always helps to be aware of the facts, or at least of how to find facts. If you see a debate happening where you can't tell who is right, do your own research on a site like Wikipedia and try to see what the truth is for yourself. Not every argument has a correct answer, but you will at least be able to see where each side is coming from.

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.

You just have to read them like flash cards. Careful not to get caught in the fallacy fallacy though. A fallacious argument doesn't mean someone is wrong, it just means they suck at arguing.

Logical fallacies and calling them out are just a tool in the tool box. They're really only useful though when someone is being maliciously fallicious or their entire evidence base hangs on a fallacy. But even then, they may still be correct.

A good example is "the standard model is true because the pope said so." This is an appeal to authority fallacy, but the stance that "the standard model is true" is correct anyway.

So I'm not sure how applicable this is - I'm a programmer, and I'm not neurotypical - but here's how it works for me

If this, then that. When a certain trigger happens, I've conditioned myself to stop my train of thought and reevaluate

When I realize I'm uncomfortable or agitated, I first ask myself "am I dehydrated? Am I overheated?". If not, I look at the situation... If I'm talking to someone and feel agitated, is it because of something that happened earlier today, is it because I'm just in a mood, or is there any other reason this is a me thing, and snapping at them would be unfair.

It's a lot of introspection, and I'm not sure it applies to someone who doesn't need coping mechanisms like this... But here's how it applies to logical fallacies:

If someone says something I feel is wrong, first I ask myself, why do I think that?

Maybe I've been taught wrong. I first heard the vaccines cause autism from a parent who said "I think he was susceptible, and the shock to his system from the vaccines triggered his autism". On it's face, that made sense - it wasn't until a coworker sighed and walked away after a comment I made that I googled it, and there was evidence against it and none for it, so I changed my mind immediately. I had no facts, one opinion by someone with a personal stake in it, and so I was wrong.

So if I only "know" a thing because I was told or because I assumed it, I immediately pull out my phone and look for evidence. You can do it very quick with practice, and people generally respond well when you take them seriously - either you go "huh, I guess you're right" and they're all smiles, or you show them what you found and go into the conversation with sources - either they can refute the source or you know they're ignoring the numbers

So now, let's say you're arguing something not so clear-cut, I have a reason to believe what I do based on facts, but the answer isn't obvious.

So first off, I don't care if you're the surgeon general or an anonymous Lemmy poster - ideas matter, people don't. The only time you trust authority is when you aren't able to understand the issue - and that comes up plenty, but it has no place in a conversation about the issue - you should be trying to understand ideas if you're talking about it. If they bring up a person, that's not an actual argument... Just ignore the names and the titles.

Hitler was right about some things, George Washington was wrong about some things - pretending otherwise is dumb. I'm on Hitler's side about interior design... Nazi stuff looks imposing and regal. I'm also Jewish, so I'm not exactly a fan of the guy. Ideas matter, where they come from has nothing to do with anything

Next, is "if I can't understand why someone would do/think this, I'm missing facts". If you can't give me a solid argument for the other side, I take everything you say about the topic with a grain of salt. No one is evil in their own story, no one takes a hilariously bad stance just because they're dumb... They have a reason to think that way, and if I can't understand why, then I'm missing something.

And if I'm missing something, it's foolish to make up my mind before I hear what that is.

Then you get to the actual arguments. I lay it out in my head. I break down the individual statements - do they make sense individually? Are they actually related to each other?

Most of all, it's important to see the difference between winning the argument and making a point. I'm not a great speaker - i don't remember specifics well, I remember my conclusions. I lose arguments all the time, and I pride myself on the fact that if I realize I'm wrong, I'll turn on a dime and own up to it.

But winning an argument and being right are almost unrelated things.

Finally, go back and fact check. The argument might be long over, but the goal should always be to understand better and gain a deeper perspective - follow up for your own sake

So my advice is: stop, reevaluate, and refocus. Every time something doesn't sound right to you, take a minute. Take a breath, remember your goal, and decide if what you've just been told changes that.

It's easy to get buried in details or lost in the heat of the moment, so make a habit of taking yourself out of it

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.

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.

What helped me: "Rationality Rules" on youtube had a video series (and even a tabletop game) about types of logical fallacies with the focus on religious apologetics.

And as you said: Upvotecount show whose opinion/argument is popular with the viewership. There can be a correlation with how sound the argument is logically.

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

My recommendation is to take a Critical Thinking and/or other philosophy classes at your local community college (granted one exists near you).

This is a great (free) illustrated book about logical fallacies:

https://bookofbadarguments.com/

The Demon Haunted World by Carl Sagan. Any other advice I might have given has already been said. There's also the audio book version read by Sagan.

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.

https://youtu.be/Qf03U04rqGQ

In my sophomore year at college I needed to add a "filler" class to have something to do in campus between my two "real" classes. I chose to take Logic and it was one of the best decisions I ever made. Not only was it interesting, it helped me think and analyze arguments. I am pretty sure there are universities that give you free access to the course but it wouldn't surprise me if you can find logic courses for free on YouTube as well.

Probably learn first order logic (aka boolean algebra). But something important to keep in mind is: just because an argument contains a fallacy doesn't mean the conclusion is wrong. There might be another logical argument that proves the same conclusion without using a fallacy. So it's actually a fallacy to assume Fallacy -> Falsehood.

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.

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...

Posts like this have me longing for a Save feature...

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 🙂

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. ;-)

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

We learned to recognize a lot of them in college Philosophy 101.

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

https://en.wikipedia.org/wiki/List_of_fallacies

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

The very first step is to know the fallacies. Find a list.

The second step is to familiarise yourself with them. Learn the fallacies. It can also be called sophism in some languages. Familiarising yourself with them will allow you to recognise them.

Third is to be vigilant during a conversation to detect them. Sometimes you will be the one to use them.

The easiest, and amont the most common, are fallacies tied to reputation: when you consider something right or wrong because of who made the statement. It's sketchy because it can be used as a shortcut in conversation, but by itself the truth or wrongness of the argument doesn't depend on who said it, never. But some people have demonstrated expertise or they habit of lying or manipulating. Other fallacies usually involve the language or the logic, so it's harder to detect, but it's a great mental exercise.

I know it sounds dismissive, but I would get an Introduction to Logic and Reasoning textbook, and read it and attempt the problems. The internet is great, and you can get a lot from wikis, but you're not going to beat the amount of useful info condensed into a book like that. The problems will also help you apply the knowledge. Also, since logic doesn't generally change much over time, you don't need to worry about getting the most up to date edition.

The only way to really get good at detecting fallacious arguments is practice.

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.

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.

lesswrong.com/rationality is good to help you to think more rationally

Taking a logic course at a university would help.

Probably not entirely related but I like Judge Judy's comment: If something doesn't make sense, it probably isn't true.