The Library

Every fallacy, named and explained.

A working reference of 31 logical fallacies — with plain-language definitions, real-world examples, and links to the full guide for each.

31
Fallacies catalogued
5
Categories
155+
Example arguments
May ’26
Last updated
31 results · All
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01Relevance

Ad Hominem

An ad hominem fallacy attacks a person's character instead of addressing their argument.

“You can’t trust his economic plan — he cheats at golf.”
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02Ambiguity

Ambiguity

The ambiguity fallacy relies on vague or shifting meanings to make an argument appear valid.

“I saw a man on a hill with a telescope.”
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03Evidence

Anecdotal

The anecdotal fallacy treats a personal story as proof instead of using reliable evidence.

“My uncle smoked and lived to 95, so smoking’s fine.”
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04Relevance

Appeal to Authority

An appeal to authority claims something is true because an authority figure says it, without adequate evidence.

“A celebrity doctor said it, so it must work.”
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05Relevance

Appeal to Emotion

The appeal to emotion fallacy uses feelings as the primary evidence instead of reasons or facts.

“Think of the children — we must ban it.”
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06Relevance

Appeal to Fear

An appeal to fear tries to persuade by frightening people rather than presenting evidence.

“Vote no or the economy will collapse.”
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07Relevance

Appeal to Ignorance

An appeal to ignorance claims something is true because it has not been proven false (or vice versa).

“No one has proved it’s false, so it must be true.”
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08Relevance

Appeal to Nature

The appeal to nature fallacy assumes something is good or right simply because it is natural.

“It’s natural, so it must be safe.”
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09Relevance

Appeal to Tradition

The appeal to tradition fallacy argues something is right because it has always been done that way.

“We’ve always done it this way — why change?”
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10Relevance

Bandwagon

The bandwagon fallacy treats popularity as proof that a belief or decision is correct.

“Everyone’s investing in it, so it must be a good deal.”
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11Evidence

Burden of Proof

The burden of proof fallacy shifts the responsibility to disprove a claim instead of proving it.

“Prove that my invisible dragon isn’t real.”
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12Structure

Circular Reasoning

Circular reasoning uses the conclusion as one of its premises, providing no independent support.

“The book is true because the book says it’s true.”
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13Structure

Composition

The composition fallacy assumes what is true of parts must be true of the whole.

“Every brick is light, so the wall must be light too.”
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14Causation

Correlation ≠ Causation

The correlation versus causation fallacy assumes that because two things move together, one causes the other.

“Ice-cream sales and drownings both rise in summer — ice cream drowns people.”
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15Structure

Division

The division fallacy assumes what is true of the whole must be true of each part.

“The team is great, so every player must be great.”
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16Ambiguity

Equivocation

Equivocation shifts the meaning of a key word or phrase to make an argument seem valid.

“A feather is light; light can’t be dark; so a feather can’t be dark.”
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17Structure

False Analogy

A false analogy compares two things that are not similar in the ways that matter.

“Running a country is just like running a business.”
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18Causation

False Cause

The false cause fallacy assumes a causal relationship without adequate evidence.

“Crime went up after we built that park — ban parks.”
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19Structure

False Dilemma

A false dilemma fallacy presents only two options when more possibilities exist.

“You’re either with us, or you’re against us.”
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20Causation

Gambler’s Fallacy

The gambler's fallacy assumes past random events make a future outcome more likely.

“Red’s come up five times — black is due.”
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21Relevance

Genetic Fallacy

The genetic fallacy judges a claim based on its source rather than its evidence.

“That idea came from a tabloid, so it’s wrong.”
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22Evidence

Hasty Generalization

A hasty generalization draws a broad conclusion from too little or unrepresentative evidence.

“I met two rude locals. The whole city is rude.”
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23Structure

Middle Ground

The middle ground fallacy assumes a compromise is always correct simply because it is between two extremes.

“Somewhere between the truth and the lie must be right.”
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24Structure

Moving the Goalposts

Moving the goalposts changes the criteria for success after those criteria have been met.

“OK, you met the deadline — but the quality’s off.”
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25Ambiguity

No True Scotsman

The no true Scotsman fallacy redefines a group to exclude counterexamples and protect a claim.

“No real fan would miss the finale.”
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26Causation

Post Hoc

Post hoc fallacy assumes that because one event followed another, the first caused the second.

“I wore my lucky socks and we won — they work.”
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27Relevance

Red Herring

A red herring fallacy distracts from the original issue by introducing an irrelevant topic.

“Why worry about pollution when crime exists?”
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28Structure

Slippery Slope

A slippery slope claims a small step will inevitably lead to extreme outcomes without evidence.

“If we allow this, next it’ll be chaos.”
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29Relevance

Straw Man

A straw man fallacy distorts someone's position to make it easier to attack.

“You want safer streets? So you want a police state.”
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30Evidence

Texas Sharpshooter

The Texas sharpshooter fallacy cherry-picks data that fits a pattern while ignoring the rest.

“Cherry-pick the wins; ignore the losses.”
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31Relevance

Tu Quoque

Tu quoque dismisses a claim by accusing the speaker of hypocrisy instead of addressing the argument.

“You smoke, so your advice on my health doesn’t count.”
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