
Fallacies - bildung
http://www.nizkor.org/features/fallacies/
======
mbateman
(I'm a philosophy professor.)

Some training in logic -- reflecting on what make good reasons and justified
conclusions -- does have value. It has the same sort of value that learning
grammar does. It enables you to make certain things explicit, to put them
under conscious scrutiny and control, when needed.

But I think this sort of enumeration of logical fallacies is of very limited
value. In the abstract there are only a few ways that arguments fail, and
informal fallacies are all iterations on an extremely similar theme.

Moreover, the kind of argument for which it is easiest to characterize
fallacies is deductive, and many instances of reasoning that appear deductive
are in fact statistical, inductive, inferences to the best explanation, or
some combination thereof. Even for deductive arguments, what if any fallacies
are being committed will depend upon how one interprets suppressed premises.

The best thing is to learn about different sorts of reasoning and how they
work in good cases, and pick up a feel for some fallacies along the way. At
the end of the day, reasoning is an art.

~~~
dragonwriter
> But I think this sort of enumeration of logical fallacies is of very limited
> value. In the abstract there are only a few ways that arguments fail, and
> informal fallacies are all iterations on an extremely similar theme.

I think the value of enumerations -- in addition to creating a vocabulary
which is often useful in discussing problems with an argument, even if, as you
correctly note, exactly which fallacy is most applicable is a subject of
interpretation -- is that it helps recognize instances of potentially
problematic arguments. Even if, on a certain level of abstraction, a lot of
the named fallacies are just different views of a smaller number of real
problems, understanding the different manifestations of those common problems
helps to recognize them in practice.

~~~
syntaxfree
The limit case of this is lesswrong.com, which is a kind of cultish/Vulcan
purge of all fallacies. (Ask around about Roko's basilisk)

~~~
mchusma
I read both HN and LW, and enjoy both. I've noticed people on HN describing LW
as "cultish" a couple of times now, and am constantly suprised by this. Can
you shed any light on why you feel this way?

~~~
gjm11
I think there are two main things about LW that strike some people as cultish.
(There are others, less important.) Both are less true than they were, say, a
year ago.

1\. Its distinctive brand of rationalism grew out of this huge long series of
blog posts by Eliezer Yudkowsky, conventionally referred to on LW as "The
Sequences". So: we have a group of people united by their adherence to a set
of writings by a single person -- a mixture of generally uncontroversial
principles and more unusual ideas. It's not a big surprise if this reminds
some people of religious scriptures and the prophets who write them.

2\. The LW culture takes seriously some ideas that (a) aren't commonly taken
very seriously in the world at large, and (b) share some features with some
cults' doctrines. Most notably, following Yudkowsky, a lot of LW people think
it very likely that in the not too distant future the following will happen:
someone will make an AI that's a little bit smarter than us and able to
improve itself (or make new AIs); being smarter than us, it can make the next
generation better still; this iteration may continue faster and faster as the
AIs get smarter; and, perhaps on a timescale of days or less, this process
will produce something as much smarter than us as we are smarter than
bacteria, which will rapidly take over the world. If we are not careful and
lucky, there are many ways in which this might wipe out humanity or replace us
with something we would prefer not to be replaced by. -- So we have a near-
omnipotent, incomprehensible-to-us Intelligence, not so far from the gods of
various religions, and we have The End Of The World (at least as we know it),
not so far from the doomsdays of various religions.

Oh, and LW is somewhat associated with Yudkowsky's outfit, MIRI (formerly the
Singularity Institute), and Yudkowsky is on record as saying that the Right
Thing to do is to give every cent one can afford to them in order to reduce
the probability of a disastrous AI explosion. Again, kinda reminiscent of
(e.g.) a televangelist telling you to send him all your money because God is
going to wrap things up soon. On the other hand, I do not believe that's his
current position.

For the avoidance of doubt, I do not myself think LW is very cult-like.

------
coldtea
Logical fallacy #1: that actual argumentation in real life can be reduced to
some axiomatic system where you can just discard arguments as logical
fallacies.

It's easy as a nerd to fell into that trap, but real life has much more
nuances than those fallacy lists capture.

Case in point: "the no true scotchman fallacy". In real life groups CAN be
argued to have certain characteristics to recongnise members from non-members,
hypocritical members, non-practicing members, posers and "fakes". So the "no
true scotchman" fallacy breaks down when you're dealing with such nuances.

Or take "appeal to tradition": 1) X is old or traditional 2) Therefore X is
correct or better.

Well, it depends on how you define correct or better. If you value tradition
and see conformance to it as the most important metric, then X is indeed
better for you.

Who is to say what metric you should use for "correct", in issues like ethical
ones, that are not clear cut and measurable as things are in the hard sciences
and mathematics?

~~~
baddox
You're completely misrepresenting what the No True Scotsman fallacy is. The
key characteristic of a No True Scotsman fallacy is that the arguers original
claim is revised to handle a counterexample. In the titular example, the
arguer originally says "no Scotsman does x," and the obvious implied
definition of "Scotsman" is simply a man from Scotland. But when faced with a
counterexample (a man from Scotland who _does_ do x), the arguer revises the
original claim by adding the word "true." Under this revelation, the arguer's
original claim is not an actual claim about what men from Scotland do, but
rather a _proposed definition_ for the term "true Scotsman."

~~~
coldtea
> _You 're completely misrepresenting what the No True Scotsman fallacy is.
> The key characteristic of a No True Scotsman fallacy is that the arguers
> original claim is revised to handle a counterexample._

Yes. I don't think I'm misrepresenting it. Revising an original claim to
handle a counterexample is something that is essential in actual
conversations. It can just mean you forgot an important distinction in your
original claim.

> _Under this revelation, the arguer 's original claim is not an actual claim
> about what men from Scotland do, but rather a proposed definition for the
> term "true Scotsman."_

That's beside the point. In real life conversations, we often use the term X
to mean the essense of X (the true X) and not just the bare notion of X. That
is, there's nothing fallacious about the following exchange:

\- A metal fan would never listen to Bieber.

\- Well, I'm a metal fan and I listen to Bieber.

\- Well, you're not a true metal fan then.

~~~
baddox
The example you give about metal fans and Bieber is a _perfect_ example of No
True Scotsman. The term "metal fan" will be widely understood to mean "someone
who likes metal music," not "someone who never listens to anything other than
metal music." The initial claim is clearly false, so the person revises the
claim to contain the word "true," which reduces the argument to nothing more
than "well I refuse to consider you a metal fan if you listen to Bieber."

------
rayiner
Fallacies are invoked too often in internet arguments. Take ad hominem, for
example. People invoke ad hominem as a counter to people who attack the
credentials/funding sources of scientists who have an interest in promulgating
a particular point of view. However, it is totally valid to argue that the
minority of scientific studies that find, say, chemical X not to be harmful
were funded by chemical companies. It's not a valid counter for a purely
logical argument, but debates on the internet are rarely based on pure logic.
Rather, they are usually based on evaluating the credibility of experts,
evaluating the relevance of evidence, and distinguishing what kind of
conclusions can and cannot be determined by particular evidence.

To me, a better source for internet debate is the Federal Rules of Evidence:
[http://www.law.cornell.edu/rules/fre](http://www.law.cornell.edu/rules/fre).
Particularly the modern statistical approach to evaluating the relevancy of
evidence based on Bayes' rule:
[http://en.wikipedia.org/wiki/Evidence_under_Bayes_theorem](http://en.wikipedia.org/wiki/Evidence_under_Bayes_theorem).

~~~
dragonwriter
Attacks against credentials are valid against an argument to authority (in
which case they are, in fact, pointing out a fallacy), but you only have an
argument to authority when a conclusion is offered on the sole basis that the
conclusion was offered by an authority. When the actual argument by the
alleged authority is presented (including by reference), an attack against
credentials is not a valid rebuttal, because the credentials are not the
support offered for the conclusion. It is appropriate and correct to label
such an attack, offered as a rebuttal, as invalid by way of the ad hominem
fallacy.

~~~
rayiner
Your point is correct, but irrelevant. Almost any internet debate that you an
imagine is ultimately rooted in arguments to authority. It's simply not useful
to look at internet arguments as logical ones. It's the wrong level of
abstraction. They involve some basic logical reasoning, but generally, they
are all about weighing conflicting evidence and expert opinions. Should we
regulate fracking? It all depends on what the evidence is, and which evidence
we believe and which evidence we don't believe. Each of those expert opinions
might be characterized as logical arguments themselves (generalizing from
particular empirical observations to conclusions), and could possible be
tackled at that level (well you can't reach this particular inference from
that particular data point), but that would make internet arguments completely
intractable and not very illuminating.

~~~
dragonwriter
Weighing conflicting evidence and expert opinions is a domain in which correct
understanding of fallacies -- particularly those of argument to authority and
ad hominem -- is critical. In fact, it is a domain I which it is critically
important, because it is intimately tied to the vital distinction between
_expert opinion_ , on the one hand, and _reference to evidence which happens
to have been previously presented by an expert_ , on the other.

So, no, the distinction between the valid use of attack against credential to
rebut expert opinion, and the fallacious, ad hominem, nature of such an attack
when used to “rebut” evidence that happens to have been previously presented
by an alleged expert is not, at all, irrelevant to internet debate.

------
reqres
I'm trying to find the name of a suspected logical fallacy that I think some
founders make... wonder if anyone can spot it?

It goes something like: 1\. Established product A has traits X,Y and Z and is
a billion dollar business 2\. Our new Product B also has traits X,Y and Z and
so it will be a billion dollar business

Example I saw the other week from "Why Bitcoin Matters"

> A mysterious new technology emerges, seemingly out of nowhere, but actually
> the result of two decades of intense research and development by nearly
> anonymous researchers. Political idealists project visions of liberation and
> revolution onto it; establishment elites heap contempt and scorn on it. On
> the other hand, technologists – nerds – are transfixed by it. They see
> within it enormous potential and spend their nights and weekends tinkering
> with it. What technology am I talking about? Personal computers in 1975, the
> Internet in 1993, and – I believe – Bitcoin in 2014.

Please note, I'm _not_ knocking bitcoin here. I'm just wondering if this is
indeed a fallacy and has a name.

~~~
bladedtoys
"Fallacy of the undistributed middle"

all A are X

this B is X

therefore this B is A

then: for A: successful business. for X: has certain traits. for B: our new
product.

~~~
spenuke
Not really. The case is not being made that "all successful businesses have
this specific trait".

I think the most relevant fallacy here is "post hoc ergo propter hoc", which
says that if A came before B, then A must have caused B.

I.e., this business had traits A, and then they went on to become successful,
so it must have been these traits, since they were there first.

~~~
bladedtoys
True, there isn't even a claim of "all" (which makes it even weaker of
course).

But there is likely a plausible explanation why some property of the product
improves its sales. And indeed, that property may really be necessary for a
product's success. But it may be an insufficient cause.

e.g. facebook started among college kids so my product focused college kids
will success.

So I'm thinking it's a flavor of over generalization or selection bias and I
opine that you can most easily show how ridiculous that kind of reasoning is
with the "A is X, B is X therefore B is A" fallacy.

------
tokenizer
It's always nice to see the fallacies of debate promoted so we can hopefully
all improve in our exchanging of ideas.

Ones to really watch out for IMO are Appeal to Emotion and Ad Hominem. These
two are the most used fallacies in internet debates IMO. The more you
familiarize yourself with these, the better you may become in recognizing a
poor argument.

~~~
pgsandstrom
Personally I would guess that biases such as confirmation bias interferes with
or reasoning much more than any fallacies. Also, they are harder to get rid
of.

~~~
tokenizer
Agreed. The fallacies are simply a toolset for confirmation bias IMO.

Personally, I think cognitive dissonance is a major problem. People in general
have opinion set A at any given moment, and when a direct contradiction to one
opinion in set A occurs, they either fight it, or flee.

There's a lot of science behind the idea that most people use their reptilian
brain in arguments, emotionally defend their already engrained views, and then
try to logically defend it after the fact.

The real challenge is while defending your own views, to try and attempt at
discerning whether or not you are simply emotionally responding to a cognitive
dissonance, or whether you are rationally defending a built up worldview with
foundations in knowledge and insight.

I'd like to say I do the latter, but I'm sure everybody would like to agree
with that...

------
sz4kerto
That's good as well:
[https://yourlogicalfallacyis.com/](https://yourlogicalfallacyis.com/)

~~~
Aoyagi
Agreed. I also use
[http://www.fallacyfiles.org/taxonomy.html](http://www.fallacyfiles.org/taxonomy.html)

------
frobozz
Sadly missing is the "Fallacy Fallacy", which seems to crop up in internet
discussions rather frequently.

~~~
spenuke
Good point. Though the fallacy fallacy is just a special case of Denying the
Antecedent:

    
    
      1. If [argument is sound], then [conclusion is true].
      2. [argument] is not sound.
      3. Therefore, [conclusion] is not true.
    

Similar to:

    
    
      1. If it has rained, then the street is wet.
      2. It hasn't rained.
      3. Therefore, the street isn't wet.

------
felideon
Interesting. Just keep in mind that pointing fallacies out in friendly
conversation is very annoying.

Relevant previous discussion on "YOUR BALONEY DETECTION KIT SUCKS":
[https://news.ycombinator.com/item?id=5832320](https://news.ycombinator.com/item?id=5832320)

------
iopq
"For example, a moderate amount of exercise is better than too much exercise
or too little exercise."

Of course, "too much" and "too little" already implies a negative. "Too much"
of anything is bad, that's why it's called "too much".

------
grandalf
I'd love to see all the fallacies reframed as "persuasion tactics".

~~~
abvdasker
Yeah, I'm not crazy about the overly simplistic way some of these "fallacies"
are constructed. I've always thought people who go on about fallacies in
argument are incredibly smug, and the fallacies themselves are just names
given to things we already recognized and understood.

In the "Appeal to Pity" fallacy the example given is:

Jill: "He'd be a terrible coach for the team." Bill: "He had his heart set on
the job, and it would break if he didn't get it." Jill: "I guess he'll do an
adequate job."

The argument that Bill cares immensely about the job IS evidence that he would
likely do it well. A coach who cares is more likely to work hard, be more
invested in the outcomes of games, etc.

But the real problem, as you mention, is that people don't argue to logically
prove something. People argue to convince someone else (often not even the
person they're arguing with). If you can convince people you won the argument,
you won the argument. It doesn't matter whether you appealed to base human
emotion or made a logically/factually empty argument.

------
dharmach
"Science fallacy": Anything coming from a scientist or a science/research
group/organization becomes "scientifically proven" and therefore "the truth".

~~~
asgard1024
Sounds like "appeal to authority" to me, but the way you stated it, it looks
more like a straw man.

The reason to trust scientists is their method, which gives a good
approximation to truth. If you are capable of evaluating their results
yourself, then you don't need to trust them, but if you aren't, you have a
good reason to trust them, even if technically committing the fallacy, because
what else are you gonna do?

------
anywherenotes
Actually I think "Ad Hominem" is a rather good filter. Although it's not a
proof of statement being true or false, it's still good to ask your self a
question "why is this person saying this?"

For example: A stranger rolls up in a truck up to a kid on their walk from
school and says "get in my truck, your parents were in an accident, and I need
to drive you to hospital". Now all the person said could be true - but I would
strongly advise from getting into the truck.

~~~
alextingle
_Ad hominem_ is when you dismiss what someone says because of who they are,
not what they say.

There's no fallacy with simply not bothering to listen to them in the first
place, if they have a history of spouting bullshit.

------
Dylan16807
What's wrong with example one, the fact that it doesn't explicitly say
'probably'? Just because something is a conclusion doesn't mean it's an
absolute. When talking about real-life situations, there are no absolutes.
Your premises can change behind your back.

Sometimes you have to go with the most likely option to not get stuck in a
quagmire. Being imprecise for the purposes of focus is not an _error_.

------
alextingle
The Adventures of Fallacy Man (Comic):

[http://existentialcomics.com/comic/9](http://existentialcomics.com/comic/9)

------
jheriko
interesting, but i want to nitpick on the appeal to authority:

> This fallacy is committed when the person in question is not a legitimate
> authority on the subject. More formally, if person A is not qualified to
> make reliable claims in subject S, then the argument will be fallacious.

Such arguments are fallacious even when person A is a well informed individual
who is sufficiently well qualified to understand the subject. Not recognising
this misses the spirit of the fallacy - that all claims must be substantiated
and that prior performance is /completely/ irrelevant as to whether any
individual claim is valid - even when that experience makes it the case that
person A is the foremost expert in the field.

~~~
tquishinisti
Yes, and it's amazing and ironic how many otherwise authoritative sources
(i.e. sources worth reading and listening to) get this totally wrong -- they
_still_ think that the source of an idea can have a bearing on whether it is
true. I think they are variously conflating three issues: (1) whether an idea
is true, (2) whether one can (rationally) rely upon it in some way, (3)
whether one understands it.

------
omegamu
It's always interesting to see these (in)formal fallacies on the internet.
They're really only fallacies if they're wrong.

Usually I just want to say "fallacy of not knowing mathematical logic."

------
snowwrestler
Fallacies are favorites of Internet forums because you don't need a bit of
domain knowledge to attack any argument. They're sort of like grammar or
spelling corrections.

------
squirejons
the biggest logical fallacy is not realizing that homo sapiens is evolved to
NOT use logic in certain areas: tribal allegiances, bonding and politics. You
can see this play out in the GOP/conservative vs Dem/liberal farces in various
forums and on TV every day. Same thing goes for what passes for the term
'political correctness.'

Also, religion--logic does not come into play there.

Also, death and the afterlife--logic is precluded there as well.

Homo sapiens is evolved to use logic in certain limited areas only.

