The Unseen Danger Fallacy


‘Commonly found in the more fevered corners of political ideology are the various fallacies of danger – those forms of argument that seek to stave off decision by conjuring up all manner of horrors that precipitate change might lead to (or, conversely, the disasters that delay will engender). The 19th-century political thinker and reformer Jeremy Bentham called this “the hobgoblin argument” since it warns of mythical horrors lurking unseen by all but the one kind enough to point them out to us.’

– “Can you spot a rhetorical fallacy?” The Guardian, 13 September 2013

The Limits of Debate Fallacy


‘An increasingly common variant of such a tactic takes the form of a self-designated umpire who joins in with online disputes by asserting their authority to police the limits of debate. They declare that if they (a typical, reasonable and fair-minded person) find something hard to understand then it must be wrong or mere sophistry; that if they find something too extreme it must be completely insane; that if they feel someone has gone too far then they must have.’

– “Can you spot a rhetorical fallacy?” The Guardian, 13 September 2013

The Authority Fallacy


‘A lot of fallacious forms of argument cluster around the use of “authorities”. It is often necessary in argument to make use of some kind of authority – if only because we want to refer to facts and findings. But authorities can also be used as a way to bully opponents by suggesting that in failing to agree with some venerated source they must themselves be weak-minded, ignorant or wildly and dangerously at odds with common standards.’

– “Can you spot a rhetorical fallacy?” The Guardian, 13 September 2013

Correlation Does Not Imply Causation


Why does correlation not imply causation? In other words, why would two things which very much appear to be related, have no connection whatsoever?

The correlation = cause logical fallacy is the claim that two events which occur together must have a cause-and-effect relationship. It is also known as the cum hoc ergo propter hoc fallacy (In Latin, “with this, therefore before this”).

Let us turn to television for a clear illustration of this principle.

In The Simpsons’ episode Much Apu About Nothing, Ned Flanders spots a bear on the street, which prompts the whole town to crusade against bears and to create a so-called Bear Patrol.

Homer: Not a bear in sight. The Bear Patrol must be working like a charm.
Lisa: That’s specious reasoning, Dad.
Homer: Thank you, dear.
Lisa: By your logic I could claim that this rock keeps tigers away.
Homer: Oh, how does it work?
Lisa: It doesn’t work.
Homer: Uh-huh.
Lisa: It’s just a stupid rock.
Homer: Uh-huh.
Lisa: But I don’t see any tigers around, do you?
[Homer thinks for a while, then pulls out some money]
Homer: Lisa, I want to buy your rock.
[Lisa refuses at first, then gives up and takes the exchange]

Garbled Cause and Effect


Rhetorical fallacies are subtle errors in speech and writing. – The manipulation of rhetoric and logical thinking. The following fallacies can be categorised as ‘Garbled Cause and Effect’.

Affirming the consequent

Assuming there’s only one explanation for the observation you’re making.

“Marriage often results in the birth of children. So that’s the reason why it exists.”

Circular logic

A conclusion is derived from a premise based on the conclusion.

“Stripping privacy rights only matters to those with something to hide. You must have something to hide if you oppose privacy protection.”

Cum hoc ergo propter hoc

Claiming two events that occur together must have a cause-and-effect relationship. (Correlation = cause)

“Teenagers in gangs listen to rap music with violent themes. Rap music inspires violence in teenagers.”

Denying the antecedent

There isn’t only one explanation for an outcome. So it’s false to assume the cause based on the effect.

“If you get a degree, you’ll get a good job. If you don’t get a degree, you won’t get a good job.”

Ignoring a common cause

Claiming one event must have caused the other when a third (unlooked for)  event is probably the clause.

“We had the 60s sexual revolution, and now people are dying of AIDS.”

Post hoc ergo propter hoc

Claiming that because one event followed another, it was also caused by it.

“Since the election of the President, more people than ever are unemployed. Therefore the President has damaged the economy.”

Two wrongs make a right

Assuming that if one wrong is committed, another wrong will cancel it out.

“Sure – the conditions in this prison are cruel and dehumanising. But these inmates are criminals.”

See other: Rhetorical Fallacies

Non Sequitur


A non sequitur, literally ‘it does not follow’ in Latin, is an inference that does not follow from the premises; it is a logical fallacy resulting from a simple conversion of a universal affirmative proposition or from the transposition of a condition and its consequent. All formal logical fallacies are special cases of non sequitur.

“Non sequitur: when a train of thought proceeds from A to B and back again to Q.” – Bill Griffith, Zippy the Pinhead

Simply put, it is a statement that does not follow logically from or is not clearly related to anything previously said; it is an invalid argument in which the conclusion cannot be logically deduced from the premises. For example:

  • It has been very cold this weekend. Global warming is a left-wing conspiracy.
  • Many people consider Jesus their personal saviour. The Bible is completely true.
  • She is a lesbian. She hates men.
  • I lived in a house without a basement; that house flooded. Houses without basements will definitely flood.
  • Wood for furniture comes from trees; trees should not be cut down. Therefore, no new furniture should be produced.
  • If you do not buy this type of dog food, you are neglecting your pet.
  • If evolution is true, why help the poor?
  • God does not believe in atheists, therefore atheists do not exist.
  • If man evolved from monkeys, why are there still monkeys?

Manipulating Content


Rhetorical fallacies are subtle errors in speech and writing. – The manipulation of rhetoric and logical thinking. The following fallacies can be categorised as ‘Manipulating Content’.

Ad hoc rescue

Trying to save a cherished belief by repeatedly revising the argument to explain away problems.

“… But apart from better sanitation, medicine, education, irrigation, public health, roads, a freshwater system and public order… what have the Romans ever done for us?”

Begging the question

Making a claim while leaving out one or more major contributing factors that may affect the conclusion.

“If we label food with warning labels, it will encourage people to eat more healthily.”

Biased generalising

Generalizing from an unrepresentative sample to increase the strength of your argument.

“Our website poll found that 90% of internet users oppose online piracy laws.”

Confirmation bias

Cherry-picking evidence that supports your idea while ignoring contradicting evidence.

“It’s obvious 9-11 was an American-government led conspiracy to justify war in Iraq and Afghanistan. No plane hit the Pentagon.”

False dilemma

Presenting two opposing options as the only two options while hiding alternatives.

“We’re going to have to cut the education budget or go deeper into debt. We can’t afford to go deeper into debt. So we’ll have to cut the education budget.”

Lie

An outright untruth repeated knowingly as a fact.

“I did not have sexual relations with that woman.”

Misleading vividness

Describing an occurrence in vivid detail, even if it is a rare occurrence, to convince someone that it is a problem.

“After a court decision to legalise gay marriage, school libraries were required to stock same-sex literature; primary schoolchildren were given homosexual fairy stories and even manuals of explicit homosexual advocacy.”

Red herring

Introducing irrelevant material to the argument to distract and lead towards a different conclusion.

“The Senator needn’t account for irregularities in his expenses. After all, there are other senators who have done far worse things.”

Slippery slope

Assuming a relatively small first step will inevitably lead to a chain of related (negative) events.

“If we legalise marijuana, more people will start using crack and heroin. Then we’d have to legalise those too.”

Suppressed evidence

Intentionally failing to use significant and relevant information which counts against one’s own conclusion.

“The Iraqi regime possesses and produces chemical and biological weapons. It is seeking nuclear weapons.”

Unfalsifiability

Offering a claim that cannot be proven false, because there is no way to check of it is false or not.

“He lied because he’s possessed by demons.”

See other: Rhetorical Fallacies

Faulty Deduction


Rhetorical fallacies are subtle errors in speech and writing. – The manipulation of rhetoric and logical thinking. The following fallacies can be categorised as ‘Faulty Deduction’.

Anecdotal evidence

Discounting evidence arrived at by systematic search or testing in favour of a few firsthand stories.

“I’m going to carry on smoking. My grandfather smoked 40 a day and lived until he was 90!”

Composition

Assuming that characteristics or beliefs of some or all of a group applies to the entire group.

“Recent terrorists attacks have been carried out by radical Islamic groups. Therefore all terrorists are Muslims.”

Division

Assuming that characteristics or belief of a group automatically apply to any individual member.

“Many Conservatives wish to ban gay marriage, discredit climate change, and deny evolution. Therefore all conservatives are homophobic, anti-environmental creationists.”

Design fallacy

Assuming that because something is nicely designed or beautifully visualised it’s more true.”

“Everything Shakespeare has written must be true.”

Gambler’s fallacy

Assuming the history of outcomes will affect future outcomes.

“I’ve flipped this coin 10 times in a row, and it’s been heads. Therefore the next coin flip is more likely to come up tails.”

Hasty generalisation

Drawing a general conclusion from a tiny sample.

“I just got cut off by the woman driver in front. Women can’t drive.”

Jumping to conclusions

–Drawing a quick conclusion without fairly considering relevant (and easily available) evidence.

“She wants birth control in her medical coverage? What a slut!”

Middle ground

Assuming because two opposing arguments have merit, the answer must lie somewhere between them.

“I rear ended your car but I don’t think I should pay for all the damage. A fair compromise would be split the bill in half.”

Perfectionist fallacy

Assuming that the only option on the table is perfect success, then rejecting anything that will not work perfectly.

“What’s the point of this anti-drunk driving campaign? People are still going to drink and drive no matter what.”

Relativist fallacy

Rejecting a claim because of a belief that truth is relative to a person or group.

“That’s perhaps true for you. But it’s not true for me.”

Spotlight

Assuming an observation from a small sample size applies to an entire group.

“This large shoe manufacturer employs children in sweatshops. Therefore all shoe companies are evil child-slave owners!”

Sweeping generalisation

Applying a general rule too badly.

“Those young men rioted because they lacked morally responsible fathers.”

Undistributed middle

Assuming because two things share a property, that makes them the same thing.

“A theory can mean an unproven idea. Scientists use the term evolutionary theory. Therefore evolution is an unproven idea.”

See other: Rhetorical Fallacies