Thou shalt not commit logical fallacies

Cheetah

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I came across this page recently, and considering the debates going on at CFC, I think it deserves a small thread. :)

poster.jpg


Huge poster-size pdfs available here

As for a discussion:

Which logical fallacies annoys you the most? Are there certain topics where some fallacies are especially popular? Do you find it easy to recognize logical fallacies, especially in real life?
 
My favorites are slippery slope and black-or-white (which I prefer to call false dichotomy because it sounds smarter).
I dislike strawmen because a strawman in an internet argument is such a trite cliche and and so insultingly obvious that it cheapens the whole discussion.
 
Oh, strawmen can be constructed very beautifully and smoothly. It's almost an art form sometimes.

I agree that false dichotomies are very powerful and thus very annoying. It's not that hard to get someone else to become trapped in a false dichotomy.
 
I love the slippery slope one. If interracial couples were to get married, what's to stop someone from marrying a turtle or for dogs to have sex with cats?!
 
Oh, strawmen can be constructed very beautifully and smoothly. It's almost an art form sometimes.

The majority of strawmen seem to arise accidentally though. As the user has genuinely misunderstood the position he or she argues against.


Slippery Slope arguments are a bit weird. I don't think slippery slopes are inherently fallacious, though they are most of the time. Whenever a slippery slope is fallacious it is usually due to some attendant intellectual dishonesty.

The good old example slippery slope: Tolerance of gays lead to tolerance of pedophilia/bestiality:

Actually this has historically been right once, during the madness of the free love movement back in the early 70's. A lot of child abuse (and other kinds of sexual abuse) went on in that period because no one really had an idea of consent.
(This was primarily due to dogmatic insistence on an extremely blue eyed version of Rosseauism where all bad human behaviour were due to societal constraints and when these were overcome people would just be naturally good).
Luckily people sobered up and realised that there seemed to be a very important component on good sexual relations: Consent. This led to the "consent doctrine" that is still prevalent today where a lot of sexual abnormalities are tolerated and legally protected as long as they involve consenting adults but bestiality and pedophilia are specifically criminalised as children and animals cannot give legal consent.

Most people who still stick with that specific slippery slope now, seem to use to other tactics when the whole consent thing is mentioned. Either they shout as loud as they can to drown out the objection (what's the name of that specific rhetorical tactic), they try do deem the consent objection irrelevant for the argument in the name of "simpliciity" (what's the name of that logical fallacy) or they simply try to define the consent term in a way that exclude anything but their preferred sexualities.

Let's posit another sexual tolerance related slippery slope: If we give official recognition to homosexuality/homosexual couple, we'll eventually have to give recognition to transsexuals and then the intersexed will want recognition too and then i'll have to accept and respect all sorts of double-gendered weirdoes.

This is a far more plausible slippery slope. There's a clear thematic similarity between those groups. Non-standard sexuality that has been given some legitimacy by the psychiatric/medical community. And the consent issue doesn't really factor in here.

We could take that argument to the absurd conclusion and argue that if we grant legitimacy to the transgendered/intersexed we'll eventually end up giving legal recognition to the "fursonas" of furries/otherkin. But such an argument would probably run into trouble with the psychiatric/medical community.
 
The fallacy fallacy.
 
I love the slippery slope one. If interracial couples were to get married, what's to stop someone from marrying a turtle or for dogs to have sex with cats?!

I like that one too. The people committing that fallacy are usually oblivious to the fact that it works both ways--if the government tells same sex couples they can't get married, why can't they do the same to interracial couples or interfaith couples or divorcees?
 
I rarely encounter logical fallacies; an incomplete understanding of the relevant facts tends to be more relevant in my experience.

One can, after all, construct a logically airtight argument from a factual basis that is effectively imaginary.
 
My sig has some more logical fallacies. A lot of them are the same as in op's link, but in a little bit less obnoxious form (no PDF).

The one logical fallacy I hate the most is argument from personal incredulity. For example, "I don't understand how life could have evolved from nothing so it didn't" is an example of argument from personal incredulity. Do these people ever stop to think that maybe they're just not very bright?

Another one that annoys me is confusing correlation with causality, mostly because it's so common. For example, the Finnish police claims that 99% of heroin users started by smoking cannabis. While that may be true, the claim in itself doesn't mean much. Only around 1% of cannabis users become heroin users.
 
I love the slippery slope one. If interracial couples were to get married, what's to stop someone from marrying a turtle or for dogs to have sex with cats?!

Well, once negroes were allowed to marry whites it was only a matter of decades until men started marrying men, so there you go. :mischief:
 
If arguments are about convincing people, logically fallacious arguments often beat the logical coherent ones. The general public generally likes (over)simplicity and the debater who can hold out the longest with the easiest understandable arguments (whether they are valid are not) is usually considered the winner.
 
Well, once negroes were allowed to marry whites it was only a matter of decades until men started marrying men, so there you go. :mischief:

:eek: You're right! What have we done! If we let Catholics marry Protestants, what's to stop an African and European couple from marrying?!
 
Well, once negroes were allowed to marry whites it was only a matter of decades until men started marrying men, so there you go. :mischief:

I hope you're not implying that the former led to the latter :crazyeye:

from my link said:
Post-hoc ergo propter hoc
This fallacy follows the basic format of: A preceded B, therefore A caused B, and therefore assumes cause and effect for two events just because they are temporally related (the latin translates to "after this, therefore because of this").
 
Honestly, I think it's FAR more conducive to good argumentation to follow normative guidelines on how arguments OUGHT to be made, rather than telling people what NOT to do.

E.g. http://www.limbicnutrition.com/blog/resources/a-code-of-conduct-for-effective-rational-discussion/

A Code of Conduct for Effective Rational Discussion

The Fallibility Principle
When alternative positions on any disputed issue are under review, each participant in the discussion should acknowledge that possibly none of the positions presented is deserving of acceptance and that, at best, only one of them is true or the most defensible position. Therefore, it is possible that thorough examination of the issue will reveal that one’s own initial position is a false or indefensible one.

The Truth-Seeking Principle
Each participant should be committed to the task of earnestly searching for the truth or at least the most defensible position on the issue at stake. Therefore, one should be willing to examine alternative positions seriously, look for insights in the positions of others, and allow other participants to present arguments for or raise objections to any position held with regard to any disputed issue.

The Clarity Principle
The formulations of all positions, defences, and attacks should be free of any kind of linguistic confusion and clearly separated from other positions and issues.

The Burden of Proof Principle
The burden of proof for any position usually rests on the participant who sets forth the position. If and when an opponent asks, the proponent should provide an argument for that position.

The Principle of Charity
If a participant’s argument is reformulated by an opponent, it should be expressed in the strongest possible version that is consistent with the original intention of the arguer. If there is any question about that intention or about implicit parts of the argument, the arguer should be given the benefit of any doubt in the reformulation.

The Relevance Principle
One who presents an argument for or against a position should attempt to set forth only reasons that are directly related to the merit of the position at issue.

The Acceptability Principle
One who presents an argument for or against a position should attempt to use reasons that are mutually acceptable to the participants and that meet standard criteria of acceptability.

The Sufficiency Principle
One who presents an argument for or against a position should attempt to provide reasons that are sufficient in number, kind, and weight to support the acceptance of the conclusion

The Rebuttal Principle
One who presents an argument for or against a position should attempt to provide an effective rebuttal to all serious challenges to the argument or the position it supports and to the strongest argument on the other side of the issue.

The Resolution Principle
An issue should be considered resolved if the proponent for one of the alternative positions successfully defends that position by presenting an argument that uses relevant and acceptable premises that together provide sufficient grounds to support the conclusion and provides an effective rebuttal to all serious challenges to the argument or position at issue. Unless one can demonstrate that these conditions have not been met, one should accept the conclusion of the successful argument and consider the issue, for all practical purposes, to be settled. In the absence of a successful argument for any of the alternative positions, one is obligated to accept the position that is supported by the best of the good arguments presented.

The Suspension of Judgement Principle
If no position comes close to being successfully defended, or if two or more positions seem to be defended with equal strength, one should, in most cases, suspend judgment about the issue. If practical considerations seem to require an immediate decision, one should weigh the relative risks of gain or loss connected with the consequences of suspending judgment and decide the issue on those grounds.

The Reconsideration Principle
If a successful or at least good argument for a position is subsequently found by any participant to be flawed in a way that raises new doubts about the merit of that position, one is obligated to reopen the issue for further consideration and resolution.

From: “Attacking Faulty Reasoning: A Practical Guide to Fallacy-Free Arguments” by T. Edward Damer (Amazon .co.uk/ .com )

Lovett is excellent at following these guidelines, FYI. If anyone wants an example of how to argue, look at Lovett's posts.
 
Excellent poster! Here are my thoughts on a few:

Strawman: I don't like it because I feel that it's just plain wrong. The person said what they said. Don't go changing or quote hunting to come up with something that is totally not what they said.

Ad Hominem: This too, I think is morally wrong.You shouldn't care who the person is, what their beliefs are, what they had for breakfast, what they're wearing, what deodorant they use (or not) and if they have a weird medical condition that makes them crave goat cheese once a week on Saturdays at 7:32 pm. Go to their argument, find what you disagree with, and present why you disagree with it.

Loaded Question: I don't dislike this as much. I love using it! I hate having it be used on me. It always feels very successful using it to close a conversation, because no one can come up with a good rebuttal. And then it sucks to have it used against you. So it's a double-edged sword.

Bandwagon: It's just stupid. I feel like too many evolutionists believe in this. "It's being taught in schools! Science has accepted it! So WHY AREN'T YOU GETTING WITH THE TIMES?!" ....because I'm just not?

No True Scotsman: I confess to using this. Of course, I believe in a higher set of morals, so perhaps some grace can be given here, hmm?

The Fallacy Fallacy: Interesting. It's a good point. Just because something is difficult to defend, does not necessarily mean it is automatically wrong. It's a good thing to remember for all of us.

and those were the ones that most grabbed my attention.
 
No True Scotsman: I confess to using this. Of course, I believe in a higher set of morals, so perhaps some grace can be given here, hmm?

I'm frequently accused of making this fallacy, but in most cases, I'm pretty sure I'm only pointing out how the one that accuses me of such doesn't seem to get the concept he or she is arguing against. It's like being accused of making a NTSF when I'm saying that a true vegetarian doesn't eat meat, because not eating meat is what makes a vegetarian.
 
I want to use that poster as the basis for a Rush Limbaugh drinking game.
 
I want to use that poster as the basis for a Rush Limbaugh drinking game.

Finally somebody has a post worth quoting in this circle jerk of a thread. :goodjob:
 
Well you have to understand that "slippery slope" is indeed a logical fallacy while also frequently a human truth. Using logic to evaluate the actions and needs of humans is helpful but often overrated.
 
As I understand it, 'no true Scotsman' is more about moving the goalposts rather than actually making claims about groups of people.
 
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