Logical Fallacies

Appeal to Fear

An argument is made by increasing fear and prejudice towards the opposing side "Before you know it there will be more mosques than churches."

Argument from Ignorance

An argument stating that something is true because it has never been proven false.

Ambiguity

An event or situation that may be interpreted in more than one way. Also, the manner of expression of such an event or situation may be ambiguous. Artful language may be ambiguous. Unintentional ambiguity is usually vagueness.

Lie

An outright untruth repeated knowingly as a fact "I did not have sexual relations with that woman"

Propaganda

Appeal to Fear Appeal to Pity Bandwagon Appeal to Tradition Appeal to Flattery

Sweeping Generalisation

Applying a general rule too broadly. Those young men rioted because they lacked morally responsible fathers.

Appeal to Consequences of a belief

Arguing a belief is false because it implies something you'd rather not believe. That can't be the Senator on that sextape. If it were, he'd be lying about not knowing her. And he's not the kind of man who would lie.

Personal Incredulity

Arguing that because something is difficult to understand it must necessarily be untrue.

Argument for Ignorance

Arguing that it is better to be ignorant than to know the truth.

Loaded Question

Asking a question that has an assumption built into it so that it cannot be answered without making one appear guilty. "Do you still beat your girlfriend?"

Slippery Slope

Assuming a relatively small first step will inevitably lead to a chain of related (negative) events If we legalize marijuana, more people will start using crack and heroin. Then we'd have to legalize those too.

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!

Appeal to Probability

Assuming because something could happen, it will inevitably happen. There are billions of galaxies with billions of stars in the universe. So there must be another planet with intelligent life on it.

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 the damage. You think I should pay for all the damage. A fair compromise would be to split the bill in half.

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.

The Presentist Fallacy

Assuming that because something is currently a particular way that it is the way that it ought to be.

Design Fallacy

Assuming that because something is nicely designed or beautifully visualised it's more true "Er..."

Nostalgic Fallacy

Assuming that because something was a certain way that is the way that it ought to be.

Division

Assuming that characteristics or beliefs 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-enviroment creationists.

Composition

Assuming that characteristics or beliefs of some of a group applies to the entire group Recent terrorist attacks have been carried out by radical Islamic groups. Therefore all terrorists are Muslims.

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!

Middle-Ground Fallacy

Assuming that the middle position between two others is always the right one.

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 these anti-drunk driving campaign? People are still going to drink and drive no matter what.

Whole to Part or Part to Whole

Assuming that what is true about one part of something is also true about the whole.

Future Fallacy

Assuming the future will be like the present.

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

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."

Genetic Fallacy

Attacking the cause or origin of a claim, rather than its substance. Of course, mainstream liberal media aren't going to say Barack Obama is a Muslim.

Appeal to Pity

Attempt to induce pity to sway opponents. The former dictator is an old, dying man. It's wrong to make him stand trial for these alleged offenses.

Appeal to Incredulity

Because a claim sounds unbelievable, it must not be true. The eye is an incredibly complex biomechanical machine with thousands of interlocking parts. How could that exist without an intelligent designer?

Ad Hominem

Bypassing the argument by launching an irrelevant attack on the person and not their claim. "Anyone that says we should build the Ground Zero Mosque is an American-hating liberal."

Confirmation Bias

Cherry picking evidence that supports your idea while ignoring contradicting evidence. "It's obvious 9-11 was a American-government led conspiracy to justify war in Iraq and Afghanistan. No plane hit the Pentagon. The Twin Towers collapse was a controlled demolition... etc"

Making Assumptions

Circular Reasoning Loaded Question Whole to Part Either-Or (Black or White) Slippery Slope

Ignoring a Common Cause

Claiming one event must have caused the other when a third (unlooked for) event is probably the cause "We had the 60s sexual revolution, and now people are dying of AIDS."

Appeal to (Questionable) Authority

Claiming something is true because an (unqualified or untrustworthy) 'expert' says it is. Over 400 prominent scientists and engineers dispute global warming.

Appeal to Tradition

Claiming something is true because it's (apparently) always been that way. Marriage is the union between man and women. Therefore gay marriage is wrong.

Appeal to Common Practice

Claiming something is true because it's commonly practiced. This bank has some problems with corruption. But there's nothing going on here that doesn't go on in all the other banks.

Appeal to Popular Belief

Claiming something is true because the majority of people believe it. "Milk is good for your bones"

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.

Genetic Fallacy

Condemning an argument because of where it began, how it began, or who began it. Similar in form to ad-hominem.

Straw Man

Creating a distorted or simplified caricature of your opponent's argument, and then arguing against that. You say Israel should stop building settlements on the West Bank in violation of treaty. So you're saying Israel doesn't have the right to be a nation?

Arguing From a False Premise

Deriving a conclusion from at least one false premise.

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"

Anecdotal Evidence

Discounting evidence arrived at by systematic search or testing in favor of a few firsthand stories. "I'm going to carry on smoking. My grandfather smoked 40 a day and he lived until he was 90."

Guilt by Association

Discrediting an idea or claim by associating it with an undesirable person or group. "Oh you want to relax the anti-terrorism laws just like the terrorists want us to do. Are you saying you support terrorism?"

Appeal to Spite

Dismissing a claim by appealing to personal bias against the claimant. Don't you just hate how those rich Liberal Hollywood actors go on TV to promote their agendas?

Tu quoque

Dismissing someone's argument because he or she is being hypocritical.

Hasty Generalization

Drawing a general conclusion from a tiny sample. I just got cut up 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 cover? What a slut!"

Hasty Generalizations

Generalizing based on a small or poor sample population.

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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.

Statistical Fallacies

Hasty Generalizations Weak Analogies

Burden of Proof

I don't need to prove my claim - you must prove it is false. I maintain long-term solar cycles are the cause of global warming. Show me I'm wrong

Ad-hominem

In an argument, this is an attack on the person rather than on the opponent's ideas. It comes from the Latin meaning "turn to the man."

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."

Red Herring

Introducing irrelevant material to the argument to distract and lead towards a different conclusion. "Why should the senator account for irregularities in his expenses? After all, there are senators who have done far worse things."

Texas Sharpshooter

Jumping to the conclusion that a cluster in some data must be the result of a cause.

Post Hoc Ergo Propter Hoc

Latin for "after this therefore because of this." Arguing that because something follows something else it necessarily is the cause.

Non-Sequitur

Latin for "does not follow." An argument in which the conclusion does not follow from the premises.

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"

No True Scotsman

Making what could be called an appeal to purity as a way to dismiss relevant criticisms or flaws of an argument. John: "No Scotsman would ever drink wine." Jim: "But McDougal is a Scotsman and he drinks wine." John: "Well, no true Scotsman would ever drink wine."

Appeal to Nature

Making your claim seem more true by drawing a comparison with the "good" natural world. Of course homosexuality is unnatural. You don't see same-sex animals copulating.

Strawman

Misrepresenting or exaggerating someone else's argument to make it easier to attack.

Appeal to Emotion

Occurs when emotions or emotionally-charged language is used in an attempt to persuade the reader. Using manipulative emotion instead of valid argument to convince.

Unfalsifiability

Offering a claim that cannot be proven false, because there is no way to check if it is false or not. He lied because he's possessed by demons.

Appeal to Ridicule

Presenting the opponent's argument in a way that makes it appear absurd. Faith in God is like believing in Santa Claus and the Tooth Fairy.

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.

The Fallacy Fallacy

Presuming that because a claim has been poorly argued, or a fallacy has been made, that the conclusion is necessarily wrong.

Avoiding the Question

Red Herring Fallacy Ad Hominem Tu Quoque Faulty Appeal to Authority Appeal to the People Straw Man

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.

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

Circumstance Ad Hominem

Stating a claim isn't credible only because of the advocate's interests in their claim. A study into the health risks of mobile phones involved mobile phone companies. Therefore, the study cannot be trusted.

Appeal to Wishful Thinking

Suggesting a claim is true or false just because you strongly hope it is. "The President wouldn't lie. He's our leader and a good American"

Appeal to Novelty

Supposing something is better because it is new or newer. "Awesome! The latest version of this operating system is going to make my computer faster and better.."

Appeal to Money

Supposing that, if someone is rich or something is expensive, then it affects the truth of the claim. "If it costs more, it must be better"

Post Hoc Ergo Propter Hoc

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

Appeal to Ignorance

A claim is true simply because it has not been proven false (or false because it has not been proven true.) Nobody has proved to me there is a God. So I know there is no God.

Circular Logic

A conclusion is derived from premises 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.

Equivocation

A fallacy by which a key word or phrase in an argument is used with more than one meaning. "I trust you so I trust that you'll be home by 9." The word "trust" is used in two different ways.

Faulty Appeal to Authority

A fallacy in which a speaker or writer seeks to persuade not by giving evidence but by appealing to the respect people have for a famous person or institution.

Special Pleading

A fallacy of logical argument in which the writer suppresses evidence that contradicts the conclusion in an inductive argument.

Slippery Slope

A fallacy that assumes that taking a first step will lead to subsequent steps that cannot be prevented.

False Cause

A fallacy that occurs when the alleged cause fails to be related to, or to produce the effect: "the black cat crossing the street brought me bad luck, so I had an accident."

Bandwagon

A fallacy which assumes that because something is popular, it is therefore good, correct, or desirable.

Circular Reasoning

A logical fallacy in which the conclusion is hidden within the premises. Typically called "circular reasoning." From Plato's Euthyphro - something is pious because it is loved by the gods. That which is loved by the gods is pious.

Red Herring

A red herring is the introduction of an irrelevant or random point into an argument mean to change the subject.

Weak Analogy

An analogy is a comparison. They can be weak because no two things are alike.

Burden of Proof Reversal

An argument in which one who asserts a position fails to prove it, but rather tries to get the interlocutor to disprove it. A good argument is proven by the one who asserts it and it doesn't fall upon one who is skeptical of the claim to disprove it, but rather the asserter of the position to prove it.

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.

Appeal to Nature

This argument goes that because something is natural, it must be better.

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 done for us?"

Special Pleading

Universal principles do not apply to me or my argument. No one is above the law. But I wouldn't rat on anybody

Appeal to Flattery

Using an irrelevant compliment to slip in an unfounded claim which is accepted along with the compliment Intelligent and sophisticated readers will of course recognise a fallacy like this when they read one.

Appeal to Anonymous Authority

Using evidence from an unnamed 'expert' or 'study' or generalized group (like 'scientists') to claim something is true. "They say that it takes 7 years to digest chewing gum."

Anecdotal

Using personal experience or an isolated example instead of a valid argument especially to dismiss statistics.

Black or White

When two alternative states are presented as the only possibilities, when in fact more possibilities exist.

Appeal to People

When we assume a viewpoint is correct because many people agree with it.

Causation/Correlation

the arguer takes two things that happen at the same time (correlation) and concludes that one of those things caused the other (causation). The arguer overlooks two important possibilities: 1) a third, unaccounted-for thing could actually be the cause, and 2) the cause-and-effect could actually be in the reverse order of what the arguer believes.