http://www.yourlogicalfallacyis.com

Just printed an A3 of this.

 

See now http://lesswrong.com/lw/c9u/logical_fallacies_poster_a_lesswrong_adaptation/

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I think depicting ancient philosophers seated on a throne in heaven and the large caption "thou shalt not" sends a... somewhat mixed message about appeal to authority.

"Appeal to authority" doesn't even seem like much of a fallacy to me... If I'm an argument with a non-physicist on whether faster than light travel is possible, and I'm a non-physicist myself, am I better off explaining some elementary understanding of physics I happen to have or quoting a famous physicist?

I would think that a summary of the understanding of a famous physicist would be much stronger Bayesian evidence than some elementary secondhand physics explanation from me.

Of course, an entire physics textbook, complete with citations of key physics papers and findings, is probably stronger Bayesian evidence still.

Edit: Looks as though the poster addresses my point:

It is important to note with this fallacy that authorities in given fields may very well have valid arguments, and that one should not dismiss another's experience and expertise. To form an argument, however, one must defend it on its merits i.e. know why the person in authority holds the particular position that they do. It is, of course, entirely possible that the opinion of a person or institution of authority is wrong; therefore the authority that such a person or institution holds does not have any intrinsic bearing upon whether their claims are true or not.

It sounds as though they're saying it's okay to borrow arguments from people in authority, but they're unclear on whether just taking their opinion at face value is okay.

To make your own personal estimate as accurate as possible, it seems like you'd want to average together independent estimates from many people that were familiar with the relevant arguments and evidence, weighting folks according to their expertise/prediction track record. It seems silly to privilege your own estimate. So I'm definitely in favor of relying on this sort of authority for making your own personal estimate, but you might not want to share them to prevent information cascades. See also.

My understanding is that the "appeal to authority fallacy" is specifically about appealing to irrelevant authorities. Quoting a physicist on their opinion about a physics question within their area of expertise would make an excellent non-fallacious argument. On the other hand, appealing to the opinion of say, a politician or CEO about a physics question would be a classic example of the appeal to authority fallacy. Such people's opinions would represent expert evidence in their fields of expertise, but not outside them.

I don't think the poster's description makes this clear and it really does suggest that any appeal to authority at all is a logical fallacy.

I agree the poster is wrong. Appeals to authority can also be non-fallacious but of very weak inductive strength: for example, when the authority holds the minority opinion for her field. They are also fallacious as deductive arguments.

Quoting a physicist on their opinion about a physics question within their area of expertise would make an excellent non-fallacious argument.

"Science is the belief in the ignorance of experts."

so the poster provides an immediate pop quiz. feature not a bug?

Isn't that what posters are (usually) supposed to be?

If so then don't have posters.

Why do you hate warm-fuzzies?

I don't. I just try to get them separately from rationality info (so that both can be separately optimised).

This precludes the possibility that both warm fuzzies and rationality info are optimized by having overlap between them.

What exactly is an applause light? Based on Eliezer's post, I see it as a description of a goal, without any specifics on how to achieve that goal. I'm not sure I see that in this poster; the poster presents an implied suggestion on how to reason better (look for fallacies like these in the speech of yourself and others).

If you're suggesting that being able to avoid these logical fallacies falls out of reading Less Wrong automatically, and the poster is therefore preaching to the choir here, that's a different allegation.

Applause lights are when you say a meaningless or almost meaningless phrase meant to evoke good feelings about your position. "Freedom" "America" "Democracy" "The greater good" etc. The poster is really more to make you feel good about yourself and your knowledge of biases than for anything useful.

I see, and math textbooks are to make people feel good about their knowledge of math? How did you determine this?

Contrast a math textbook to a poster that just has Euler's Identity. One is useful for teaching you about math, the other is just to show off that you're a fan of math to other people in your in-group. This poster is for people that want to point to a box during an argument and feel smug. There's nothing terribly wrong with that, but it's still basically just saying "yay math".

I have friends who admit they fill their shelves with math textbooks partially to signal that they're intellectual. It's possible to have both an educational payload and a signaling payload.

I like it. Are their definitions all perfect and complete? Certainly not. But, at least in my own experience, the sanity waterline of (say) an undergraduate dorm is typically so low that hanging something like this on the wall for communal reference might tend to improve the level of conversation. Anyway, it looks like it's under a creative commons license which allows remixing.

Come to think of it, it could be reformatted to make a series of cards to play Newspaper Editorial Page Logical Fallacy Bingo.

But, at least in my own experience, the sanity waterline of (say) an undergraduate dorm is typically so low that hanging something like this on the wall for communal reference might tend to improve the level of conversation.

Indeed. It's easy to fall into the Nirvana Fallacy and forget just how stupid humans are by nature and how just considering these points would lead to a significant rise in the waterline.

Slippery slope

You made out like if we allow A to happen, then Z will eventually happen too, therefore A should not happen.

The problem with this reasoning is that it avoids engaging with the issue at hand, and instead shifts attention to extreme hypotheticals. Because no proof is presented to show that such extreme hypotheticals will in fact occur, this fallacy has the form of an appeal to emotion fallacy by leveraging fear. In effect the argument at hand is unfairly tainted by unsubstantiated conjecture.

Example: Colin Closet asserts that if we allow same-sex couples to marry, then the next thing we know we'll be allowing people to marry their parents, their cars and Bonobo monkeys.

It's a nice graphic, but it makes the same mistakes as all the other lists written by those who believe in mere classical rationality.

It's not obvious to me that Bayesian reasoning implies that slippery slopes always happen. In short, I don't understand your assertion.

Too strong; one does not need for them to always happen.

In response to the question you meant to ask, Yvain said it well

Too strong; one does not need for them to always happen.

One does if one presents the reasoning as an unqualified logical deduction. That is the realm where most of these 'logical fallacies' apply.

But that's an unreasonable standard to hold people to. If the argument can be made sound by adding a load of "will probably tend to..." operators, you should do so, not nitpick.

Yvain said there are slippery slopes and identified Schelling points as a natural stopping point of them. Nonetheless, I think we should be suspicious of the slippery-slop argument because it can easily be a fully general counter argument unless it resorts to specific evidence in support.

Edit: My question is more directed at the divide you asserted between "classical rationality" and whatever alternative you think is better.

it can easily be a fully general counter argument unless it resorts to specific evidence in support.

Right. So

  • If we eat ice-cream on tuesdays now, soon the earth will be attacked by killer neopods!

is a poor slippery slope, whereas

  • If we eat ice-cream on tuesdays now, we'll soon eat it every day

is not.

I like, but I think that all fallacy lists really need to come with a qualifier, lest they be misunderstood.

To all those who complained about the sarcastic illustration, the lack of references, the weird categorization that should rather fit a bayseian framework, the simplific or even wrong definitions, this poster has ONE key difference with the ideal poster, it exists.

If it sparks criticisms that lead to a new, LessWrong compatible poster, then it is well worth the critics.

Anybody with proposals for a structure e.g. a hierarchy of fallacies and a design theme?

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It occurred to me that many of these might be manifestations of the affect heuristic:

  • genetic
  • ad hominem
  • appeal to nature
  • appeal to emotion?
  • composition/division?
  • slippery slope?
  • appeal to authority?
  • bandwagon?