Live data from Hacker News

Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

plover.net

111–120 of 134 posts

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#111
post #26
post #23

Am I the only one troubled by the last example? And then suppose you encounter a woman who tells you that because of the insults she has received from guys in the skeptic community, she has decided that the skeptic movement is fundamentally sexist. Receiving insults from men that identify as skeptics does not mean that the skeptic movement is fundamentally sexist. Telling her she just committed a fallacy doesn't seem…

She may have just committed a fallacy in truth. That doesn't mean telling her so is the right choice. If you don't address her experience, you're missing the point. You can "believe" all kinds of things without feeling them and living them out. In her case, skeptics may believe they are not fundamentally sexist. But her observation would then be that this belief is only skin deep. It should trouble the skeptic that a…

In that example, the author makes his own fallacy. Apparently the speaker's experiences are the only valid ones, and the responder has no right to share his experience - which some of his "I hope it should be clear that none of these are appropriate responses" are doing.

Some of his examples are condescending, which is the basis of what he's trying to get at, others are only condescending if you wilfully choose to take them that way. The problem isn't in pointing out the fallacy, it's with the tone of the commentary. The simple fact that you name a fallacy while exposing it does not mean you're a lazy debater.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#113
post #80

Earlier quoted context omitted.

>In the context of deductive, rather than inductive, argument. The very context that you should never use, in other words, which was exactly my point! If you're going to require all evidence deductively imply a conclusion (i.e. have an infinite likelihood ratio), then you're excluding all real-world evidence, and making the very fallacy I described (which I didn't realize was claimed for something else). So it seems…

> The very context that you should never use, in other words No, that's not other words for what I said. > which was exactly my point! Yes, that you should never use deductive reasoning was one of your points (and a ludicrous one). No, that point isn't an "in other words" of anything in my response. > If you're going to require all evidence deductively imply a conclusion Having some contexts within which deductive re…

>Having some contexts within which deductive reasoning is used ...

Okay, you object to my claim that there are no contexts in which to use deductive reasoning. Point taken, I wasn't entirely clear about that. I was speaking in the context of the discussion, which was about the set of exchanges in which fallacies are brought up. This is basically the realm of policy debate and empirical claims.

It is there that I claim you shouldn't be invoking fallacies only applicable to deductive reasoning, because there are almost never situations where the crucial issue hinges on a disagreement about a deduction.

>Deductive implication isn't equivalent to having an "infinite likelihood ratio". ...

It's not clear you are using the term correctly. I mean this value:

http://en.wikipedia.org/wiki/Bayes_factor

Saying that a piece of evidence necessarily entails a conclusion is indeed equivalent to an infinite (as much as the term is meaningful) likelihood ratio, as that is what is necessary to make your confidence in the conclusion equal to 100% and thus reduce to the case of Aristotelian deductive logic. (Probabilistic inference is such logic generalized to the cover uncertainty.)

>Well, yeah, real world evidence is prior to a deductive argument, not part of it; insofar as it contributes to a deductive argument, it does so as part of an inductive justification for the premises of a deductive argument.

As above, that "deductive argument" generally is not going to be a deduction. Your induction-based premise is only going to get you e.g. "this policy probably will save money in the long run", which means your supposedly deductive continuation is tainted with the same uncertainty.

To the extent that there is a pure syllogism in there ("we should do that that will probably save money; this will probably save money; therefore we should do that") the debate is rarely about its validity, but rather, about the degree to which those things really all probable. And in that case, the fact that experts are sometimes wrong is not a reason to reject the evidential value of their opinions. (Like I said the first time around.)

>You didn't warn against using the appeal to authority fallacy, you endorsed (not "warned against) using something you called the "the appeal to authority fallacy",

I most certainly did warn against using "appeal to authority is a fallacy" to ignore the evidential value of exper opinions; read the comment again. That is how fallacy invokers use it in practice, and why it is, well, bad reasoning.

>and then defined that as something that is not what the "appeal to authority fallacy" actually refers to.

Not if your own words are to be believed: you said the real "appeal to authority fallacy" was an OR of three situations, the last of which was exactly what I said it was: the notion that authorities are only probabilistic evidence. My point is that it's called a fallacy despite the authority only being used as probabilistic evidence in the first place!

>> And that you generally endorse (the genuine fallacy of) rejecting evidence simply because it doesn't guarantee a conclusion.

>No, I don't, and nothing in my post stated that, or supports your claim that I endorse that. That's just something you invented.

Yes you did: you claimed that the debates we're referring to crucially involve deductive rather than inductive logic. You claimed that the appeal to authority fallacy is relevant. But it's only relelvant to deductive claims thereon, which means that all of its invocations in this context are invalid arguments -- nobody is trying to claim that the authorities' endorsement guarantees the conclusion.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#114
post #83

This is wrong on so many levels that it's difficult to keep track of them all. Let's start with the introduction: Why did people who deployed these [critical thinking] terms always look so rigid, so predictable, so feeble? Why did people who avoided them look so confident in comparison, so much more in command of their resources, so much more mature? Their arguments seemed to possess an inner strength; the baloney de…

I suggest you go and re-read TFA. All your points showcase extreme naivety and prejudice. Just two examples upon many: > Translation: Some people never shut up after they have been proven wrong, and the author values this assertiveness over whether their arguments are logically sound . He concludes that the most assertive arguer is automatically correct . He calls for the total abandonment of logic and reason and to…

Reread it yourself. He does in fact uphold forcefulness ("confidence", "command", "outmaneuver", not "feeble") and rhetoric ("inner strength", "emotion") as superior to logical thought ("predictable", "rigid"). It's like he just discovered that street-level debates don't follow Oxford rules, that some people cannot be persuaded by logic, and that other people can be persuaded by illogical means, so he denounces the use of logic and stands by the illogical means as the path to deducing correctness. He views rhetoric as persuasiveness as correctness. His examples all reinforce this analysis.

And let's consider that "inner strength". It is not the actual strength of the argument since that is what the logic-users would see and support. If the argument had outer strength, the baloney detectors would not have called it out in the first place. This "inner strength" is a feeling he gets from the argument. It is an emotional uplift. It is irrelevant to the actual strength of the argument.

When the baloney detectors are correct, they very well ought to be assertive, stubborn, and convinced of their own correctness. Why should they accept their opponent's views as fact after they have proved it insufficiently justified or logically false?

And yes, conversations can be multifaceted. I'm sorry to have to inform you that serious logical flaws and mistakes of fact in one facet of a multifaceted conversation do in fact invalidate that one facet of the conversation.

And please refrain from the insults, although it was nice to learn that I am both young and old at the same time, and also a racist.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#115
The only point I get from this post is that too much self-congratulatory navel-gazing harms one's ability to engage in any sort of discussion. This goes for both the logic-in-all-things capital-S Skepticism the post argues against and the post itself.

What we've got here is...failure to communicate.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#116
post #89

I don't care if it falls under a logical fallacy or not. If you insult me, the conversation is over.

Try saying that on any of the "freethought" or skeptic blogs and you will be mocked, banned, comments deleted, in that order as a "tone troll." On the other hand, if you insult (or insult back!) one of them, you are deemed a regular "troll". Leave without further comment and you are a "drive-by troll."

If he gets banned, the conversation is indeed over so his point stands, eh?

A funny thing about this "tone troll" business is that PZ bans people for asking for more civility in discussions, and he banned Thunderf00t for being incivil. Go figure.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#117
post #113

Earlier quoted context omitted.

> The very context that you should never use, in other words No, that's not other words for what I said. > which was exactly my point! Yes, that you should never use deductive reasoning was one of your points (and a ludicrous one). No, that point isn't an "in other words" of anything in my response. > If you're going to require all evidence deductively imply a conclusion Having some contexts within which deductive re…

>Having some contexts within which deductive reasoning is used ... Okay, you object to my claim that there are no contexts in which to use deductive reasoning. Point taken, I wasn't entirely clear about that. I was speaking in the context of the discussion, which was about the set of exchanges in which fallacies are brought up. This is basically the realm of policy debate and empirical claims. It is there that I clai…

> Okay, you object to my claim that there are no contexts in which to use deductive reasoning. Point taken, I wasn't entirely clear about that. I was speaking in the context of the discussion, which was about the set of exchanges in which fallacies are brought up. This is basically the realm of policy debate and empirical claims.

First, deductive reasoning has a role there, though obviously it is combined with inductive reasoning. I've directly addressed how the two interact in my prior post, so I don't feel the need to repeat it.

Second, while there are a class of fallacies that are relevant only to deductive arguments, and certain named fallacies that have different applications in deductive contexts, many named fallacies are specific to inductive arguments, or have specific application to them. Including, as it is actually defined (versus how you have mispresented it) the fallacy of appeal to authority. > As above, that "deductive argument" generally is not going to be a deduction.

Yes, it will.

> Your induction-based premise is only going to get you e.g. "this policy probably will save money in the long run",

The following is a valid syllogism where the major premise states a decision rule, the minor premise states a probabilistic characterization on an issue of fact of the type that would be an natural conclusion of inductive reasoning, and the conclusion follows of necessity from the premises and is not, itself, probabilistic: P1. If more probable than not that a person has committed a tort against another, they should be pay damages P2. It is more probable than not X commit the tort of trespass to chattels against Y, C. Therefore, X should pay damages to Y.

Obviously, there are syllogisms where one of the premises is inductively defined where the conclusions would involve a probabilistic statement, but this is not necessary.

> To the extent that there is a pure syllogism in there ("we should do that that will probably save money; this will probably save money; therefore we should do that") the debate is rarely about its validity

When the syllogism is explicitly stated and structured as a syllogism, there is rarely a debate about its validity, because people rarely explicitly lay out invalid syllogisms. OTOH, in practice, the elements that are presented are only those of an invalid syllogism and that is challenged.

> I most certainly did warn against using "appeal to authority is a fallacy" to ignore the evidential value of exper opinions

Which, is a reference to the fallacy, not a use of the fallacy, first, and second, not something I endorsed, so the fact that you warned against that does not support your claim that I endorsed the use to the fallacy that you warned against, and, finally, the thing you described actually wasn't the fallacy by that name.

OTOH, you endorsed the use of (not reference to) what you explicitly (and inaccurately) described as the fallacy of appeal to authority to support claims.

> That is how fallacy invokers use it in practice

To the extent that thing that you mistakenly describe as the fallacy of appeal to authority is something people reference as the fallacy of appeal to authority for the purpose you suggest, it is an inaccurate and, as such, inappropriate reference to the fallacy. Its also not exclusively how it is invoked in practice, though certainly for every fallacy there is some set of the actual references to it which are incorrect in this way.

> you said the real "appeal to authority fallacy" was an OR of three situations, the last of which was exactly what I said it was: the notion that authorities are only probabilistic evidence.

Actually, no, the last was that the appeal was made in a deductive context, not "the notion that authorities are only probabilistic evidence".

> My point is that it's called a fallacy despite the authority only being used as probabilistic evidence in the first place!

And my point is that (in addition to misusing language in attempting to say this) you are fabricating things when you claim that I have endorsed this.

> Yes you did: you claimed that the debates we're referring to crucially involve deductive rather than inductive logic.

No, I didn't. I said that appeals to authority in a deductive context are fallacious. I did not make the generalization you make here about "the debates we're referring to", nor do I even have any idea what specific debates you think we are referring to.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#118

Earlier quoted context omitted.

So wait, thinking "guys, elevator come-ons are not such a good idea" is "Fair enough" is radical, post-modern feminism?

I firmly feel there's nothing wrong with asking someone in an elevator whether they'd like to get coffee. That said, to answer your question, my answer is no. Someone responding to "guys, elevator come-ons are not such a good idea" with "fair enough" doesn't remotely make someone a radical, post-modern feminist. Why do you ask?

> I firmly feel there's nothing wrong with asking someone in an elevator whether they'd like to get coffee.

Please ask a psychologist to be screened for Antisocial Personality Disorder and/or Autism.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#119
post #14

Earlier quoted context omitted.

I totally agree with his assessment of the misuse of the term ad-hominem too. An ad-hom fallacy is "your argument is wrong because you're an immoral moron", not "your argument is wrong for these reasons, you immoral moron". The latter is not very nice and probably shouldn't be encouraged, but it's not an ad-hominem because the insult is not part of the argument, just an unpleasant aside.

Also, there is nothing illogical about saying "this person or source of information has a reputation for being wrong or deceitful, therefore I will not be spending my time examining their claims." This is not really an ad hominem, just saying that due to the unlikelihood of an individual having anything to contribute, you are choosing to not engage their argument. I suppose this falls under "running away from the arg…

Exactly. Which is why it would be an ad hominem (or really, ad feminum) to say "How can we possibly trust you as our CFO? You're a woman!" since there is no pertinent relationship between gender and the job's requirements. However, there's nothing illogical about saying "How can we possibly trust you as our CFO? You're a convicted embezzler!"

Indeed, if the personal considerations are this relevant, it would quite illogical not to consider them. Likewise, I someone has established a general reputation for idiocy, slop, and other crimes against lucidity, it's perfectly reasonable to flag their remarks as dubious until proven otherwise. It's actually a perfectly rational conservation of time and energy.

Re: Logical Fallacies Are Usually Irrelevant or Cited Incorrectly

#120

Earlier quoted context omitted.

I firmly feel there's nothing wrong with asking someone in an elevator whether they'd like to get coffee. That said, to answer your question, my answer is no. Someone responding to "guys, elevator come-ons are not such a good idea" with "fair enough" doesn't remotely make someone a radical, post-modern feminist. Why do you ask?

> I firmly feel there's nothing wrong with asking someone in an elevator whether they'd like to get coffee. Please ask a psychologist to be screened for Antisocial Personality Disorder and/or Autism.

Nice. Feminist bullies use the same tactics and insults that kids use in middle school.

What's so wrong with asking someone in an elevator? I'm all ears. Is it because you think women will cower in terror because they're an enclosed box with a man?

Post reply on HN