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Fallacies: which do you see the most?

  1. Apr 21, 2009 #1
    I couldn't think of a better place to put this thread, so sorry if it's out of place.

    I am just wondering what fallacies you see most often. This could be in real life or even on the forums. Personally I see the Straw-man and argumentum ad hominem the most, but the Bandwagon fallacy and Ipse Dixit (appeal to authority) also seem to appear frequently.

    For a list of fallacies and meanings, see: http://changingminds.org/disciplines/argument/fallacies/fallacies_alpha.htm or even wikipedia seems to be reliable for this one: http://en.wikipedia.org/wiki/List_of_fallacies
  2. jcsd
  3. Apr 21, 2009 #2
    Mixing correlation and causation is probably the one that I have to fight the most. I'm not sure if I run into it more often, but it really sticks out to me, and people tend to be more aggressive about using it.

    I've actually had this conversation with somebody to no avail. "Look, even if you DON'T put a penny on your eye, the stye would go away on its own in a day or two. Just because your mom put a penny on her eye and the stye went away doesn't mean the penny cured the stye."

    Nope... she's convinced that putting a penny over your eye can cure a stye.
  4. Apr 21, 2009 #3
    I see "appeal to common belief" once in a while, especially when discussing religion or politics.
  5. Apr 21, 2009 #4
    Red Herring definitely. Switching of topics seems an incredibly common method of attempting to win an arguement.
  6. Apr 21, 2009 #5


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    Switching from a rigorous, verifiable line of argumentation to a fallacious "correlation = causation" argument is a favorite tactic of some people with a political axe to grind. For examples, look at "George Bush kept us safe after 9/11" or "torture prevented further attacks in the US". There are many more examples, but you get the idea.

    The same people seem to buy into the idea that teaching sexual abstinence reduces teen pregnancies, abortions, and STDs, in the face of evidence that proper education in the prevention of disease and pregnancies is far more effective.
  7. Apr 21, 2009 #6
    people will never admit to it or argue it as such, but the tendency to let ones beliefs follow their party affiliation is painfully obvious. so i guess appeal to authority is primary failure mode.
  8. Apr 21, 2009 #7

    Chi Meson

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    "straw man," tautologies, non-sequitors, and stupidity. I see these a lot.
  9. Apr 21, 2009 #8


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    Some people don't have a party affiliation. Can you wrap your mind around that? There is very little substantive difference between Democrats and Republicans and there is plenty of corruption to go around, thank you. Pointing fingers at one party or another is great fun for those with nothing else to do, and it is highly recommended by the party brass. It does not benefit US citizens or voters at all, and I heartily recommend that a few citizens think about the "value" of such a "dichotomy" and consider alternatives.
  10. Apr 21, 2009 #9

    I forgot about that! I find red herring to be the most bothersome with non-sequitors as a close second.
  11. Apr 21, 2009 #10
    yeah, i can wrap my mind around it. i have no affiliation, either. straddling the fence, so to speak.
  12. Apr 21, 2009 #11
    Yeah, when you fall for it you wind up argueing on multiple fronts and not seeming to get anywhere. Quite annoying.
  13. Apr 21, 2009 #12

    Ivan Seeking

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    I find that the appeal to amateurs where authority is required is a far more common mistake - one of the great failings of the internet and the local bar.

    The other one seen fairly frequently here [esp in the past] is the appeal to Occam's Razor, as if it were a physical law.
  14. Apr 21, 2009 #13

    Ivan Seeking

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    Yes, I was more than sick of being labeled a liberal just because I think Bush was a disaster in more ways that I care to count.

    Ironically, I now find myself supporting a massive government spending program. The reason I originally became a Republican was my objection to liberal spending policies!

    I noticed tonight on PBS, one guest stated that Obama is getting pressure from the liberals to prosecute those who authorized the use of torture. This struck me as yet another fallacy suggesting that anyone who doesn't support the current Republican position is liberal. Or do we conclude that only Republicans and moderates torture people or condone as much?
    Last edited: Apr 21, 2009
  15. Apr 21, 2009 #14
    What would frequently steering a conversation toward one's own topic of interest be called? I believe there is such a term in law. That I am guilty of.
  16. Apr 22, 2009 #15


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    Red Herring covers the vast majority of what I encounter.
  17. Apr 22, 2009 #16


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    I see a lot of slippery slope arguments, often countered by appeal to common practice.

    Correlation = causation is one that bugs me the most, but I'm not sure if it's the one I see most often.

    And one other that I don't see often, but am rather touchy about because I have to deal with a small group of people who resort to it often and give me blank stares when I challenge their arguments is the Appeal to Novelty. They're always trying to justify spending on projects that are the newest, latest and greatest thing in their mind, but when I ask for any sort of evidence that it works, or that the thing they want to do will accomplish what they need it to do before spending money on it, they just resort to telling me "Well, it's the newest thing, and we couldn't accomplish this with cheaper methods so we have to use this expensive way, and we have to move toward the future." And then I ask them why they tried the cheaper ways and were they so convinced those would work when they spent the money on those first...and they just get quiet and change the topic.
  18. Apr 22, 2009 #17


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    From the webs best science comic xkcd.org
  19. Apr 22, 2009 #18
    I hear a lot of ad hominem arguments at work, but these guys are not logicians, so what do you expect? And of course, Ad hominem leads naturally to non-sequiturs. They say that we should avoid straw man arguments. Yeah, like the only falacious argument is a straw man argument. And there's the constant stream of red herrings, in view of which we really should provide them with copies of my new book "Logical Falacies and You."
  20. Apr 22, 2009 #19
    No doubt that the ad hominem is the most common fallacy ever. Maybe a logical consequence of the tendency to moral panic, which also impies a "begging the question" or the circular argument fallacy in the form:

    1: He disagrees with us about our most basic beliefs, so he is a threat to societal values and interests, in other words a Folk devil.

    2: Folks devils are crooks and hence he is wrong (ad hominem).

    3: He is wrong, so we are right -> consensus! Hence goto 1: (begging the question)

    No way to ever break through this, so the witch hunts and wars will just continue.
  21. Apr 22, 2009 #20


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    Straw-men, ah hominem

    (I think 'correlation versus causation' is more formally the fallacy of 'hasty conclusion'.)
  22. Apr 23, 2009 #21
    In such circumstances you are not actually performing an appeal to authority, but postulating that it is reasonable for this authority to be correct.

    Indeed, Occam's Razor is not a physical law -- in fact, it is more certain than a physical law. Naturally, using this razor is not a fallacy by definition.
  23. Apr 23, 2009 #22
    I will start with a disclaimer that I am capable of falling foul of fallacies! I try to avoid it, but am no perfect being, :smile:.


    I'd have to go for ad hominem and non sequitur. It seems to me that the rest flow from these two (are different forms, or special types, of them could be another way of putting it). I see it being that ad hominem is the non sequitur of people without the ability/inclination to even attempt to form a logical structure, whilst a non sequiter is the delightfully more benign failed attempt at creating said logical structure.

    I don't get inherently annoyed by non sequitur (unless it is part of a knowingly subversive strategy), for it is just a flawed attempt (although it can get tiring on occasions); nobody can get through life without ever falling foul of the non sequitur trap, and it is something that can certainly be with improved with effort.

    People can live their lives, and form their arguments, in a riotously non sequitur manner, but remain wonderfully fine people. I really don't think the same can be said for those who live by ad hominem principles.

    I just find ad hominen thoroughly abhorrent (it just represents an ugly part of humanity, IMO). It is quite simply unjustifiable in any scenario, as well as being potentially quite dangerous. A particular person can be guilty of the occasional ad hominem argument in particularly stressful situations without it being a reflection on the person, but those who seem to form their whole world view and actions on a backbone of ad hominem thinking, well, they stand a tremendous chance of being a person I am not going to be a great fan of.
    Last edited: Apr 23, 2009
  24. Apr 23, 2009 #23
    Brilliant. I laughed at this.
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