Logical Fallacies

Accent

Accent is a fallacy of pragmatics (the study of how speech is used),

not of semantics (the study of meaning) like equivocation,

and not of syntax (the study of structure) like amphiboly.

It takes place when a shift of meaning arises (or could arise) as a consequence

of changes in the vocal emphasis and tone given to its words or parts.

As with the previous examples, when reading an instance of this fallacy,

the meaning of the phrase may seem ambiguous, and the ambiguity disappears only once you say it out loud.

The problem, however, consists in figuring out HOW to read the phrase out loud.

On what non-arbitrary basis can we make such a determination, especially in cases when we don't have the proper context to understand the intended meaning of a phrase?

Keep in mind that how you say something out loud can be determined by how the phrase in question is punctuated.

The fallacy of accent, therefore, can often be a consequence

of improper punctuation, which may itself be a function of context.

An English Professor wrote

the following sentence on the board:

"A woman without her man is nothing."

He then asked his students to punctuate it correctly.

All the males in the class wrote:

"A woman, without her man, is nothing."

All the females in the class wrote:

"A woman: without her, man is nothing."

Punctuation is more powerful

than you may normally realize...

Equivocation

Equivocation is a semantic fallacy.

It occurs when the meaning of the same word or phrase

changes between different parts of the same argument,

or when different speakers use the same word in a discussion without realizing that each of them mean something different by the same word.

Amphiboly

Amphiboly is a fallacy of syntax

(that is to say, one based on grammatical structure).

It occurs when a bad argument trades upon

grammatical ambiguity to create an illusion of cogency:

Instead of using the same word with multiple meanings

(as with equivocation), amphiboly involves the use of sentences

which can be interpreted in multiple ways

with equal justification.

An amphiboly is an ambiguity which results from

ambiguous grammar and awkward phrasing.

Composition

Division

Begging the question

This fallacy is committed

when one assumes in the premises

of an argument

the very point that the argument

is supposed to prove.

In other words,

begging the question is

CIRCULAR REASONING!

Note: You should be aware that

in ordinary language,

many people misuse the phrase

" that begs the question."

What they actually mean is

"that raises the question"

(as in "that raises the question of

why we should adopt that policy").

In most cases, the meaning intended can be easily inferred from the context of the discussion, but you should be aware of the distinction.

Bifurcation

(also known as

False dilemma,

or the

Either/Or fallacy)

This black-and-white fallacy is committed

when one omits consideration

of all reasonable alternatives,

and creates what superficially looks

like a dilemma with mutually exclusive options.

In order to prove the fallacy,

one need only point to

some other reasonable alternative

not already considered.

http://thecolbertreport.cc.com/videos/d0x6zg/better-know-a-district---massachusetts--4th---barney-frank-update

"Teach the Controversy"

Faulty analogy

The problem with this analogy is that it's mistakenly comparing

a descriptive law (one that tells us how something does behave)

with a prescriptive or normative law (one that tells us how we ought to behave),

but these are two very different things.

Notice also that the faulty analogy

also produces a fallacy of equivocation,

since there are two different meanings

of the word "law" being used.

Sweeping

generalization

This fallacy occurs

when one applies a general rule

to those exceptional cases

in which the rule does/should apply.

The problem with a sweeping generalization

is that we move too quickly

from a generalization

to a particular claim.

This fallacy can also occur

when one over-emphasizes evidence

supporting a particular belief, stereotype or prejudice,

while ignoring evidence contradicting it

(this second condition is usually the result of a cognitive bias known as selection or confirmation bias).

Hasty

generalization

Questionable cause

Post hoc

ergo propter hoc

This fallacy is committed whenever one reasons

to a causal conclusion based solely

on one event preceding another in time,

arguing that the first event

must have been the cause of the second.

While it is a necessary condition of causal relations that the cause precede the effect,

this is not a sufficient condition.

Post hoc evidence may suggest

the hypothesis of a causal relation,

but such a hypothesis must then be tested

to find if there is indeed such a connection.

Slippery slope

Fallacies of relevance

are instances of reasoning in which

an argument relies on premises

that are not relevant to the conclusion,

and therefore cannot establish its truth.

In the case of red herrings, an irrelevant topic

is presented in order to divert attention

from the original issue.

Sometimes the term non-sequitur is applied

to fallacies of relevance and red herrings.

This simply refers to an argument in which

the conclusion does not follow from its premises,

but the expression is primarily used when the gap between premises and conclusion is particularly wide.

Abusive ad hominem

This fallacy occurs whenever a person

has given up attempting to persuade an audience

about the truth or reasonableness of a position

with arguments and evidence,

and resorts instead to mere personal attacks

in an attempt to discredit the opposition.

Circumstantial

ad hominem

This form of ad hominem fallacy is indirectly used against

some person or group of persons, suggesting that they hold their views mainly because of their special circumstances, vested interests, or some particular motivation.

While this may or may not be true, such circumstances and vested interests are to

the truth or the reasonableness

of a particular position,

which ought to be judged

on its own merits.

Tu quoque

An argument in which one attempts

to defend oneself or another from criticism

by turning the critique back against

the accuser or some other party

(the classic children's response: "but she started it!"),

or

by arguing that a proposition must be false

because the behavior of the person proposing it

is inconsistent with her proposition

(the other classic response: "look who's talking").

A person's lack of personal credibility does not automatically invalidate the truth of her claims

or the merits of her arguments.

Poisoning the well

To poison the well is to commit a pre-emptive ad hominem strike

against an argumentative opponent,

usually formulating the attack in such a way that,

whatever the opponent says, it will somehow 'confirm' the pre-emptive strike.

If the well of discourse is poisoned from the outset

(even without the introduction of an ad hominem),

any water drunk from it will taint the audience's conclusions.

If a case is so stated that contrary evidence is automatically precluded

(thus rendering it as an untestable or unfalsifiable claim),

no argument against it can be offered,

not because the charge is necessarily true

but because it's ultimately meaningless.

An easy way to spot this kind of fallacy is to notice that

any evidence one could potentially present against the original charge

can always be re-interpreted to be consistent with the original claim.

Philosophers sometimes argue that such claims

are so bad that they are "not even wrong."

Straw Man

Special pleading

This fallacy occurs when a person or group makes itself a special exception

(without any rational justification)

to the reasonable application of standards, principles, or expectations that normally apply

to everyone else,

or, conversely, when a person or group argues (again, without any rational justification)

that the same standards, principles, or expectations that normally apply to everyone, should not apply to a particular person or group.

The problem with this way of thinking is the introduction of an unjustified double standard.

Bandwagon

(appeal to popularity)

Did you also catch the instances (used or mentioned) of

• abusive ad hominem
• composition
• equivocation
• faulty analogy
• amphiboly
• circumstantial ad hominem
• appeal to inappropriate authority
• appeal to emotion
• questionable cause
• "teach the controversy"?

Or did you only see the fallacy you were originally looking for?

Remember, critical thinking requires permanent vigilance.

Appeal to

ignorance

When it is argued that a proposition is true

simply on the basis that is has not been proved false,

(or that it is false because it has not been proved true).

In other words, this type of fallacious argument uses

an admitted ABSENCE of evidence to pass off as ACTUAL evidence.

This fallacy also occurs when the party making a claim

asks his/her opponent to disprove the conclusion.

If the conclusion is not disproved,

the claim is then mistakenly asserted to be true on that basis.

In reality, however, the person making the affirmative claim

is the one who has the burden of proof, not the skeptic.

If a claim does not satisfy your standards of evidence,

you have every right not to accept it.

Argument from

personal incredulity

In this type of argument, it is fallaciously argued that

one's own inability to solve a mystery,

understand a phenomenon or process,

or figure out the solution to a problem,

somehow warrants said person in drawing an answer

out of thin air without any rational justification or supporting evidence.

Remember:

Just because can't figure out the answer to some mystery

doesn't mean that there isn't a perfectly normal, natural explanation for it.

An absence of knowledge or understanding

gives us NO justification in reaching a conclusion,

especially one that's to everyday experience.

The God

of the Gaps

This fallacy refers to the misguided attempt to "explain"

some currently unknown process by simply assuming

that the explanation is ultimately God.

The problem with this fallacy is not with the truth of its claim

(that may or may not be the case),

but with the fact that retreating to God

doesn't actually provide an EXPLANATION

of the nature of the phenomenon in question.

Here is a funny example:

http://berto-meister.blogspot.com/2011/01/bill-oreilly-proves-gods-existence.html

And here is an interesting illustration of this phenomenon:

http://berto-meister.blogspot.com/2011/07/neil-degrasse-tyson-god-of-gaps.html

.

Appeal to tradition

Before you argue that a belief or practice

should be continued or respected

merely because it's a tradition,

ask yourself a few questions:

• What is the justification for the tradition?

• What exactly constitutes the tradition?

• Does the tradition entail consequences that go beyond the point you're trying to make?

Appeal to

inappropriate

authority

Appeal to emotion

Appeal to

consequences

Naturalistic Fallacy

(aka the appeal to nature,

or the is/ought fallacy).

This type of argument mistakenly equates

natural with good and unnatural with bad.

In this sort of argument,

nature is taken to be an ideal

or desired state of being,

not simply explaining how things are

but how they should be.

The main problem with this fallacy

is that one cannot logically derive

a prescriptive value judgment (an ought),

from a descriptive empirical fact (an is).

Another problem is that it is easy

to find plenty of counterexamples

to the natural/good, unnatural/bad equation.

Did you notice that while this argument refutes the naturalistic fallacy,

it ends up committing the fallacy

of hasty generalization?

But correct spelling, while obviously important, is not enough to guarantee your work is up to par.

Consider the following examples:

Fallacies of Relevance

And remember, punctuation matters too!

Dear Jack,

I want a man who knows what love is all about. You are generous, kind, thoughtful. People who are not like you admit to being useless and inferior. You have ruined me for other men... I yearn for you! I have no feelings whatsoever when we’re apart. I can be forever happy – will you let me be yours?

Jill

Dear Jack,

I want a man who knows what love is. All about you are generous, kind, thoughtful people, who are not like you. Admit to being useless and inferior! You have ruined me. For other men I yearn! For you I have no feelings whatsoever. When we’re apart I can be forever happy. Will you let me be?

Yours,

Jill

Always remember

to proofread your work!

Refutation

[Joe McCarthy] announced that he had penetrated "Truman's iron curtain of secrecy" and that he proposed forthwith to present 81 cases... Cases of exactly what?

"I am only giving the Senate," he said, "cases in which it is clear there is a definite Communist connection… persons whom I consider to be Communists in the State Department."

…Of Case 40, he said, "I do not have much information on this except the general statement of the agency… that there is nothing in the files to disprove his Communist connections."

James Randi on investigating the "paranormal"

YOU

Warning:

This video contains profane language, as well as multiple logical fallacies.

Your moral and/or intellectual sensibilities might be offended.

CONTRARY

Of course, when you say things like that, someone is bound to make fun of you...

http://www.hulu.com/watch/143249/saturday-night-live-outrageous-clown-squad-kickspit-dirt-festival?c=43:162

What does this mean?

If there's no reason for it, it's probably nonsense...

Refutation

Remember:

Distracting Appeals

http://origin.theonion.com/articles/concerned-parents-demand-removal-of-arsenic-from-p,3765/

Check out

http://berto-meister.blogspot.com/2010/03/jon-stewart-and-glenn-beck-reductio-ad.html

for the full clip

Some food for thought

Stop the slaughter of animals!

Fallaciously reasoning

from the attributes of the parts of a whole

to the attributes of the whole itself,

or from the attributes of the individual elements of a collection

to the attributes of the collection or totality of those elements.

This fallacy turns on an ambiguity between the 'distributive' and the 'collective' use or meaning of general terms.

"If they don't have the guts to come up here

in front of you and say,

'I don't want to represent you,

I want to represent those special interests,

the unions, the trial lawyers ...

if they don't have the guts,

I call them girlie men."

The 2004 Dream Team

Counterexample

Richard Dawkins on the double standard afforded to religious beliefs

These are the best basketball players in the world.

If we recruit them all into the same team,

we'll have the best team in the world!

Ad hominems

(Genetic fallacies)

Those people can't complain that war is indecent

because they themselves are indecent!

Remember that, as Bertrand Russell once said,

"The fact that an opinion has been widely held

is no evidence whatever that it is not utterly absurd.

Indeed in view of the silliness of the majority of mankind,

a widespread belief is more likely to be foolish

than sensible."

Man: I believe in equality... if it's okay for men to walk outside topless, then it should also be okay for women to do the same.

Woman: You're just saying that because you want to see boobs...

Fallacies of

Ambiguity

Native Americans are disappearing.

Oh no! The dancing man in the picture

is a Native American.

He's about to disappear!

Of course, sometimes it does make sense to follow the crowd,

but we have to understand when and why...

Explanation / Refutation

Warning: Contains strong language.

irrelevant

Fallaciously reasoning

from the attributes of a whole

to the attributes of its parts,

or from the attributes of a collection

to the attributes of the members of said collection.

Does it mean this?

What does this mean?

Although his music may have been heavenly,

this argument fails to establish the conclusion

(that Ray Charles is God) because,

as Bill Clinton taught us:

In other words, one sense of "is" is that of identity

(meaning 'identical with'):

"Ray Charles is identical with God."

The other sense of "is" is that of predicate attribution

(meaning 'has the quality of'):

"Ray Charles has the quality of being blind"

(but not "Ray Charles is identical with blindness").

This argument would work only if "is" were used

in every instance as an identity relation.

`

For the original, check out

http://berto-meister.blogspot.com/2008/05/south-park-and-evolution.html

Informal Logical Fallacies

Causal Fallacies

Fallacies of

Presumption

Refutation

(After it, therefore because of it)

Explanation

Some spurious correlations

Bill: You know, those feminists all hate men.

Joe: Really?

Bill: Yeah. I was in my philosophy class the other day

and that Rachel chick gave a presentation.

Joe: Which Rachel?

Bill: You know her. She's the one that runs that feminist group over at the

Women's Center. She said that men are all sexist pigs. I asked her why she

believed this and she said that her last few boyfriends were real sexist pigs. "

Joe: That doesn't sound like a good reason to believe that all of us are pigs.

Bill: That was what I said.

Joe: What did she say?

Bill: She said that she had seen enough of men to know we

are all pigs. She obviously hates all men.

Joe: So you think all feminists are like her?

Bill: Sure. They all hate men.

Learning not to jump to post hoc conclusions.

Refutation

Explanation / Analysis

If those who cut people with knifes are criminals,

and surgeons cut people with knives for a living,

then surgeons are professional criminals!

Stay away from them!

Of course, things can get complicated quite quickly...

When is it okay to use analogies?

NOT

Be careful with your analogies...

Others might want to give them a different use

A faulty analogy is one in which an invalid conclusion is drawn from a comparison between two apparently similar situations.

The justification of an inference based on analogical reasoning depends on the number, strength and relevance of known similarities and dissimilarities of the items being compared.

If there are very few known similarities,

or if there are a few known very great dissimilarities,

then drawing inferences based on the comparison is unjustified.

http://rationallyspeaking.blogspot.com/2011/04/perils-of-metaphorical-thinking.html

The Importance

of Spelling