1. Fallacies of Relevance
- Ad Hominem
“You can’t trust Dave’s argument on climate change—he failed high school science.”
- Tu Quoque
“You say smoking is bad, but I’ve seen you smoke before!”
- Appeal to Authority
“A famous actor said this vitamin cures cancer, so it must be true.”
- Appeal to Emotion
“Think of the poor children—how can you not support this policy?”
- Appeal to Fear
“If we don’t increase surveillance, terrorists will destroy everything we love.”
- Appeal to Ignorance
“No one has proven aliens don’t exist, so they must be real.”
- Appeal to Popularity (Bandwagon)
“Everyone’s switching to this diet, so it must be the healthiest one.”
- Appeal to Tradition
“We’ve always done it this way, so it must be the best way.”
- Red Herring
“Why worry about pollution when there are people unemployed?”
- Straw Man
“You want to reduce military spending? So you think we should just disband the army?”
- Genetic Fallacy
“That idea came from a communist, so it must be wrong.”
- Guilt by Association
“You supported that idea, and so did that extremist group—are you one of them?”
2. Fallacies of Ambiguity
- Equivocation
“A feather is light. Light can’t be dark. So a feather can’t be dark.”
- Amphiboly
“The burglar threatened the student with a knife. So the student must have had the knife.”
- Accent
“I didn’t say she stole the money.” (Ambiguity depends on what word is emphasized)
- Composition
“Every part of the engine is light, so the engine must be light.”
- Division
“The team is the best in the league, so every player must be the best too.”
3. Fallacies of Presumption
- Begging the Question
“Reading is beneficial because it’s good for you.”
- Complex Question (Loaded Question)
“Have you stopped cheating on exams?”
- False Dilemma / False Dichotomy
“You’re either with us or against us.”
- False Cause (Post Hoc)
“I wore my lucky socks and we won the game, so they caused the win.”
- Slippery Slope
“If we allow one student to redo the test, next thing you know, no one will follow deadlines.”
- Hasty Generalization
“Two of my coworkers are rude. Everyone in this office must be awful.”
- Suppressed Evidence / Cherry Picking
“This study shows coffee is healthy.” (ignores 10 other studies showing negative effects)
4. Statistical & Probabilistic Fallacies
- Gambler’s Fallacy
“It’s been red five times in a row—black must be next.”
- Base Rate Fallacy
“This test says you have a rare disease, so you probably do.” (ignores the disease’s rarity)
- Texas Sharpshooter Fallacy
“This town has a lot of cancer—and look, there’s a cell tower nearby!”
- Misleading Vividness
“I saw a news story about a plane crash. Flying must be dangerous.”
- Overgeneralization
“My neighbor from Canada is rude. Canadians must be rude.”
5. Causal Fallacies
- Post Hoc Ergo Propter Hoc
“The rooster crowed, and then the sun rose. The rooster caused the sunrise.”
- Non Causa Pro Causa
“More people drown when ice cream sales go up—so ice cream causes drowning.”
- Correlation vs. Causation
“Kids who play violent games are more aggressive. Games must be making them violent.”
- Oversimplified Cause
“The car crashed because of bad tires.” (ignores speeding and foggy weather)
6. Fallacies of Logical Structure
- Affirming the Consequent
“If it rains, the ground gets wet. The ground is wet, so it must have rained.”
- Denying the Antecedent
“If it rains, the ground gets wet. It didn’t rain, so the ground isn’t wet.”
- Undistributed Middle
“All cats are mammals. All dogs are mammals. So all dogs are cats.”
7. Informal Strategy Fallacies
- No True Scotsman
“No Scotsman puts sugar in his porridge.”
“I’m Scottish and I do.”
“Then you’re not a true Scotsman.”
- Moving the Goalposts
“You need 10 years’ experience to qualify.”
“I have that.”
“Actually, you also need a PhD.”
- Special Pleading
“Yes, I said no exceptions—but my case is different.”
- Moral Equivalence
“Stealing a pen is just as bad as stealing a car.”
- Whataboutism
“You committed fraud.”
“Well, what about that other guy who did worse?”
- Appeal to Nature
“It’s natural, so it must be good for you.”
- Relative Privation (Not as Bad As)
“You’re upset about the potholes? People in other countries don’t even have roads!”
- Appeal to Consequences
“If there’s no afterlife, life has no meaning. So there must be an afterlife.”
- Argument from Silence
“He didn’t deny the accusation, so he must be guilty.”
