This list of logical fallacies and examples covers the reasoning errors you will see most often in arguments, ads, debates, and LSAT- or GRE-style questions. For each fallacy, learn the pattern, a plain-English example, and the clue that should make you pause. The goal is not to memorize labels for their own sake; it is to spot when a conclusion has not earned its support.
Quick list of common logical fallacies
| Fallacy | What goes wrong | Short example |
|---|---|---|
| Ad hominem | Attacks the person instead of the claim | “Don’t listen to Maya’s budget plan; she failed math once.” |
| Straw man | Distorts a claim into an easier target | “You want fewer meetings, so you want nobody to communicate.” |
| False dilemma | Pretends there are only two options | “Either support this rule or you do not care about safety.” |
| Hasty generalization | Draws a broad conclusion from too little evidence | “Two rude tourists were from City X, so people from City X are rude.” |
| Post hoc | Treats sequence as proof of causation | “I wore new socks and we won; the socks caused the win.” |
| Slippery slope | Claims a small step must trigger an extreme result | “If we extend the deadline one day, deadlines will become meaningless.” |
| Circular reasoning | Uses the conclusion as its own support | “This source is reliable because it always tells the truth.” |
| Appeal to authority | Treats status as proof outside relevant expertise | “A famous actor says this supplement works, so it works.” |
| Bandwagon | Treats popularity as proof | “Millions bought it, so it must be the best choice.” |
| Red herring | Diverts attention from the issue | “Why discuss the late report when our team has worked so hard?” |
| Equivocation | Shifts the meaning of a word during an argument | “Feathers are light. What is light cannot be dark. So feathers cannot be dark.” |
| Loaded question | Builds an unproved assumption into a question | “Have you stopped ignoring customer complaints?” |
| No true Scotsman | Redefines a group to protect a sweeping claim | “No real fan would criticize the team.” |
| Composition | Assumes parts’ traits belong to the whole | “Every ingredient is cheap, so the meal must be cheap.” |
| Division | Assumes the whole’s traits belong to every part | “The university is wealthy, so every student is wealthy.” |
The fallacies you should recognize first
1. Ad hominem
An ad hominem argument dismisses a claim by attacking the person making it rather than addressing the reasons or evidence.
Example: “Jon’s argument for later school start times is worthless because he is always late.”
Jon may be late, but that fact does not answer his argument. A sound response would examine research, scheduling constraints, or the effects on students.
Recognition clue: Ask, “If a different person made the exact same claim, would this objection still work?” If not, the response may be ad hominem.
2. Straw man
A straw man replaces a real position with a weaker or more extreme version, then attacks that replacement.
Example: Person A: “We should limit work messages after 7 p.m.” Person B: “Person A wants employees to ignore urgent problems.”
The original proposal allowed for many possible exceptions. Person B has made it easier to reject by changing it.
Recognition clue: Compare the reply with the actual claim. Is the reply addressing the same scope, wording, and conditions?
3. False dilemma
A false dilemma presents two choices as if they exhaust all possibilities when other reasonable options exist.
Example: “Either you take every advanced class available, or you are not serious about college.”
A student could take a balanced course load, focus deeply on selected subjects, or make a different plan based on their goals.
Recognition clue: Look for phrases such as “either/or,” “only two choices,” or “if you are not with us, you are against us.” Then ask what option was left out.
4. Hasty generalization
A hasty generalization reaches a broad conclusion from an unrepresentative, limited, or otherwise weak sample.
Example: “I met three unfriendly people at the conference. Everyone in that industry must be unfriendly.”
Three encounters cannot establish a conclusion about an entire industry. The issue is not merely that the sample is small; it may also be biased or atypical.
Recognition clue: Identify the jump from the observed cases to the broader group. Does the evidence justify that jump?
5. Post hoc ergo propter hoc
Post hoc reasoning assumes that because one event happened after another, the earlier event caused the later one.
Example: “After the café changed its logo, sales rose. The new logo caused the increase.”
Sales might have risen because of a holiday, a new menu, a promotion, or many other factors. Timing alone is not enough to establish causation.
Recognition clue: When an argument says “after this, therefore because of this,” look for missing alternatives and missing evidence of a causal mechanism.
6. Slippery slope
A slippery slope claims that allowing one step will inevitably produce a dramatic chain of consequences, without adequately supporting each link.
Example: “If students can revise one assignment, they will demand unlimited revisions, and grades will become meaningless.”
That conclusion might be possible, but the argument must explain why each later step would actually follow. Policies can include limits.
Recognition clue: Break the chain apart. Which claimed step has not been supported?
7. Circular reasoning
Circular reasoning assumes what it is trying to prove. The conclusion appears in the premise, often in slightly different language.
Example: “This rule is fair because it treats everyone fairly.”
The premise just restates the conclusion. It does not provide an independent reason to accept it.
Recognition clue: Remove the conclusion from the argument. Is there any separate evidence left?
8. Appeal to authority
An appeal to authority is fallacious when the authority is irrelevant, unqualified on the issue, or treated as conclusive despite stronger contrary evidence.
Example: “A championship athlete recommends this investment strategy, so it is financially sound.”
The athlete may be excellent at sports, but that does not establish expertise in investing.
Not every appeal to authority is bad reasoning. Consulting a qualified expert in the relevant field can be sensible. The flaw appears when status replaces evidence.
Recognition clue: Ask whether the person has relevant expertise and whether the claim is supported by more than their reputation.
Other frequent fallacies and thinking traps
Red herring
A red herring changes the subject instead of addressing the point at issue.
Example: “You say the proposal exceeds the budget, but our organization has a proud history.”
A proud history may be true and worthwhile, yet it does not answer the budget concern.
Equivocation
Equivocation uses the same word in two different senses.
Example: “The sign says parking is free. Free people have rights. Therefore, parking has rights.”
The word “free” first means “without charge” and then means “not controlled.”
No true Scotsman
This move protects a universal claim by redefining the group whenever a counterexample appears.
Example: “No true minimalist owns a television.” “But I know a minimalist who owns one.” “Then they are not a true minimalist.”
The speaker has changed the membership rule only to avoid admitting an exception.
Loaded question
A loaded question forces someone to accept an unproved assumption in order to answer directly.
Example: “Why did you decide to mislead the class?”
Before answering “why,” the speaker should challenge the assumption that they misled anyone.
Appeal to emotion
Emotional language is not automatically a fallacy. It becomes one when emotion is used in place of relevant support.
Example: “If you reject this plan, think of how disappointed the children will be.”
Disappointment may matter, but the argument still needs to show that the plan is effective, fair, or feasible.
A worked logical-reasoning walkthrough
Consider this argument:
> The library began offering free coffee in March. Library attendance rose in April. Therefore, free coffee caused the increase in attendance.
Question: Which objection most strongly weakens the argument?
A. Some visitors prefer tea to coffee. B. The library also extended its opening hours in April. C. Coffee is more expensive at nearby cafés. D. The library’s new coffee machines are easy to clean. E. Many people who visit the library borrow books.
Correct answer: B.
Here is the reasoning:
- The conclusion claims that free coffee caused higher attendance.
- The evidence provides only timing: coffee came first, attendance rose later.
- To weaken a causal claim, look for another plausible cause of the effect.
- Extended hours could independently explain why more people visited in April.
- Choice B therefore exposes the argument’s post hoc error.
Choice A is about preference, not attendance. Choices C and D are peripheral. Choice E may be true, but it does not explain why attendance changed.
This is the habit to build for flaw questions: state the conclusion precisely, identify the evidence, then name the unsupported leap. A logical-fallacies quiz can help you practice that pattern under time pressure.
A quick self-test
Label the main flaw before reading the answers.
- “My cousin used this study method and got a high score. This method guarantees a high score.”
- “If we allow one remote-work day, soon nobody will ever come to the office.”
- “You disagree with my recycling proposal because you drive an old car.”
- “Either we ban phones in class completely or students will never pay attention.”
- “This policy is correct because it is the right policy.”
Answers:
- Hasty generalization, possibly with an unsupported causal claim. One person’s result does not guarantee an outcome for everyone.
- Slippery slope. The later consequences are asserted, not demonstrated.
- Ad hominem. The response attacks the speaker rather than the proposal.
- False dilemma. Other phone policies are possible.
- Circular reasoning. “Correct” and “right” express the same unsupported conclusion.
FAQ: Logical fallacies
What is the difference between a logical fallacy and a cognitive bias?
A logical fallacy is a defect in an argument’s structure or support. A cognitive bias is a predictable tendency in how people notice, interpret, or remember information. They can overlap: confirmation bias can make someone more likely to use weak evidence, but it is not itself always a formal fallacy.
Are all emotional arguments fallacious?
No. Emotion can be relevant, especially in decisions involving harm, relationships, or human welfare. The reasoning fails only when emotion is treated as a substitute for evidence or when it distracts from the actual claim.
Is appealing to an expert always a fallacy?
No. Relevant expertise is often useful evidence. Check the expert’s field, the quality of their reasoning, and whether their view is presented as one piece of evidence rather than unquestionable proof.
How do I get better at spotting fallacies on the LSAT or GRE?
Do not begin by hunting for labels. First identify the conclusion, the evidence, and the missing link between them. Then use labels such as “causation error,” “sample problem,” or “attacks the person” as a compact way to describe that gap.
Conclusion
Use this list of logical fallacies and examples as a diagnostic sheet: isolate the conclusion, inspect the support, and ask what the argument assumes. Once you can name the missing link, you are ready to test that skill with interactive logical-reasoning and cognitive-bias quizzes.