General Principles (Do’s & Don’ts) of Ethical & Effective Debate
15 Types of Logical Fallacies–To SEE and AVOID (excerpt)
[Full Article after next video Below]
1. Ad Hominem
An ad hominem fallacy uses personal attacks rather than logic. This fallacy occurs when someone rejects or criticizes another point of view based on the personal characteristics, ethnic background, physical appearance, or other non-relevant traits of the person who holds it.
Ad hominem arguments are often used in politics, where they are often called “mudslinging.” They are considered unethical because politicians can use them to manipulate voters’ opinions against an opponent without addressing core issues.
Study Tool
See if you can tell which of these is an ad hominem argument and which is just an insult.
EXAMPLE 1
“MacDougal roots for a British football team. Clearly he’s unfit to be a police chief in Ireland.”
EXAMPLE 2
“All people from Crete are liars.”
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Examples: How not to Object to a Cosmological Argument
source: thebestschools.org
15 Logical Fallacies You Should Know Before Getting Into a Debate
What Is a Logical Fallacy?
Logical fallacies are flawed, deceptive, or false arguments that can be proven wrong with reasoning. There are two main types of fallacies:
- A formal fallacy is an argument with a premise and conclusion that doesn’t hold up to scrutiny.
- An informal fallacy is an error in the form, content, or context of the argument.
15 Types of Logical Fallacies
TABLE OF CONTENTS
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Ad Hominem
An ad hominem fallacy uses personal attacks rather than logic. This fallacy occurs when someone rejects or criticizes another point of view based on the personal characteristics, ethnic background, physical appearance, or other non-relevant traits of the person who holds it.
Ad hominem arguments are often used in politics, where they are often called “mudslinging.” They are considered unethical because politicians can use them to manipulate voters’ opinions against an opponent without addressing core issues.
Study Tool
See if you can tell which of these is an ad hominem argument and which is just an insult.
EXAMPLE 1
“MacDougal roots for a British football team. Clearly he’s unfit to be a police chief in Ireland.”
EXAMPLE 2
“All people from Crete are liars.”
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Straw Man
A straw man argument attacks a different subject rather than the topic being discussed — often a more extreme version of the counter argument. The purpose of this misdirection is to make one’s position look stronger than it actually is.
The straw man argument is appropriately named after a harmless, lifeless scarecrow. Instead of contending with the actual argument, they attack the equivalent of a lifeless bundle of straw — an easily defeated puppet that the opponent was never arguing for in the first place.
Study Tool
See if you can detect how both of the following statements could qualify as strawmen arguments.
EXAMPLE 1
“The Senator thinks we can solve all our ecological problems by driving a Prius.”
EXAMPLE 2
“Quite the contrary: The Senator thinks the environment is such a wreck that no one’s car choice or driving habits would make the slightest difference.”
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Appeal to Ignorance
An appeal to ignorance (also known as an “argument from ignorance”) argues that a proposition must be true because it has not been proven false or there is no evidence against it.
The argument can be used to bolster multiple contradictory conclusions at once, such as the following two claims:
- “No one has ever been able to prove that extraterrestrials exist, so they must not be real.”
- “No one has ever been able to prove that extraterrestrials do not exist, so they must be real.”
An appeal to ignorance doesn’t prove anything. Instead, it shifts the need for proof away from the person making a claim.
Study Tool
Which of the following examples is an appeal to ignorance?
EXAMPLE 1
“We have no evidence that the Illuminati ever existed. They must have been so clever that they destroyed all the evidence.”
EXAMPLE 2
“I know nothing about Tank Johnson except that he has a criminal record as long as your leg, but I’ll bet he’s really just misunderstood.”
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False Dilemma/False Dichotomy
A false dilemma or false dichotomy presents limited options — typically by focusing on two extremes — when in fact more possibilities exist. The phrase “America: Love it or leave it” is an example of a false dilemma.
The false dilemma fallacy is a manipulative tool designed to polarize the audience, promoting one side and demonizing another. It’s common in political discourse as a way of strong-arming the public into supporting controversial legislation or policies.
Study Tool
See if you can come up with a third option that these examples failed to mention.
EXAMPLE 1
“Either we go to war or we appear weak.”
EXAMPLE 2
“Either you love me or you hate me.”
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Slippery Slope
A slippery slope argument assumes that a certain course of action will necessarily lead to a chain of future events. The slippery slope fallacy takes a benign premise or starting point and suggests that it will lead to unlikely or ridiculous outcomes with no supporting evidence.
You may have used this fallacy on your parents as a teenager: “But you have to let me go to the party! If I don’t go to the party, I’ll be a loser with no friends. Next thing you know, I’ll end up alone and jobless, living in your basement when I’m 30!”
Study Tool
Which of these examples is a slippery slope fallacy and which is not?
EXAMPLE 1
“Your coach’s policy is that no one can be a starter on game day if they miss practice. So if you miss basketball practice today, you won’t be a starter in Friday’s game. Then you won’t be the first freshman to start on the varsity basketball team at our school.”
EXAMPLE 2
“If you miss practice, it means you were probably goofing off. People who goof off drop out of school and end up penniless.”
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Circular Argument
Circular arguments occur when a person’s argument repeats what they already assumed before without arriving at a new conclusion. For example, if someone says, “According to my brain, my brain is reliable,” that’s a circular argument.
Circular arguments often use a claim as both a premise and a conclusion. This fallacy only appears to be an argument when in fact it’s just restating one’s assumptions.
Study Tool
See if you can identify which of these is a circular argument.
EXAMPLE 1
“Smoking pot is against the law because it’s wrong; I know it’s wrong because it is against the law.”
EXAMPLE 2
“Smoking pot is against the law; this leads many to believe it is wrong.”
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Hasty Generalization
A hasty generalization is a claim based on a few examples rather than substantial proof. Arguments based on hasty generalizations often don’t hold up due to a lack of supporting evidence: The claim might be true in one case, but that doesn’t mean it’s always true.
Hasty generalizations are common in arguments because there’s a wide range of what’s acceptable for “sufficient” evidence. The rules for evidence can change based on the claim you’re making and the environment where you are making it — whether it’s rooted in philosophy, the sciences, a political debate, or discussing house rules for using the kitchen.
Study Tool
Which of the following is a hasty generalization?
EXAMPLE 1
“Some people vote without seriously weighing the merits of the candidate.”
EXAMPLE 2
“People nowadays only vote with their emotions instead of their brains.”
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Red Herring
A red herring is an argument that uses confusion or distraction to shift attention away from a topic and toward a false conclusion. Red herrings usually contain an unimportant fact, idea, or event that has little relevance to the real issue.
Red herrings are a common diversionary tactic when someone wants to shift the focus of an argument to something easier or safer to address. But red herrings can also be unintentional.
Study Tool
Which of the following examples is a red herring fallacy?
EXAMPLE 1
“My roommate wants to talk about cleaning out the garage, so I asked her what she wants to do with our patio furniture. Now she’s shopping for new patio furniture and not asking me about the garage.”
EXAMPLE 2
“My wife wants to talk about cleaning out the garage, so I asked her what she wants to do with the patio furniture, because it’s just sitting in the garage taking up space.”
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Appeal to Hypocrisy
An appeal to hypocrisy — also known as the tu quoque fallacy — focuses on the hypocrisy of an opponent. The tu quoque fallacy deflects criticism away from oneself by accusing the other person of the same problem or something comparable.
The tu quoque fallacy is an attempt to divert blame. The fallacy usually occurs when the arguer uses apparent hypocrisy to neutralize criticism and distract from the issue.
Study Tool
Which of the following is an appeal to hypocrisy?
EXAMPLE 1
“But, Dad, I know you smoked when you were my age, so how can you tell me not to do it?”
EXAMPLE 2
“Son, yes, I smoked when I was your age. It was dumb then and it’s dumb now. That’s why I forbid you to smoke, chew, vape, use nicotine gum, or do whatever you kids do with tobacco these days.”
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Causal Fallacy
Causal fallacies are informal fallacies that occur when an argument incorrectly concludes that a cause is related to an effect. Think of the causal fallacy as a parent category for other fallacies about unproven causes.
One example is the false cause fallacy, which is when you draw a conclusion about what the cause was without enough evidence to do so. Another is the post hoc fallacy, which is when you mistake something for the cause because it came first — not because it actually caused the effect.
Study Tool
Which kind of causal fallacy is at work in these examples?
EXAMPLE 1
“Jimmy isn’t at school today. He must be on a family trip.”
EXAMPLE 2
“Every time a rooster crows, the sun comes up. Crows must be the creators of the universe.”
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Sunk Cost
A sunk cost fallacy is when someone continues doing something because of the effort they already put in it, regardless of whether the additional costs outweigh the potential benefits. “Sunk cost” is an economic term for any past expenses that can no longer be recovered.
For example: Imagine that after watching the first six episodes of a TV show, you decide the show isn’t for you. Those six episodes are your “sunk cost.” A sunk cost fallacy would be deciding to finish watching anyway because you’ve already invested roughly six hours of your life in it.
Study Tool
Which of these is a sunk cost fallacy and which is not?
EXAMPLE 1
“I know this relationship isn’t working anymore and that we’re both miserable. No marriage. No kids. No steady job. But I’ve been with him for seven years, so I’d better stay with him.”
EXAMPLE 2
“I’m halfway done with college. This is so tough, and it’s not nearly as fun as I thought it would be, but I don’t know. I guess I’ll finish it and get my degree.”
Appeal to authority is the misuse of an authority’s opinion to support an argument. While an authority’s opinion can represent evidence and data, it becomes a fallacy if their expertise or authority is overstated, illegitimate, or irrelevant to the topic.
For example, citing a foot doctor when trying to prove something related to psychiatry would be an appeal to authority fallacy.
Study Tool
How do these statements mishandle authorities?
EXAMPLE 1
“Because Martin Sheen played the president on television, he’d probably make a great president in real life.”
EXAMPLE 2
“One day robots will enslave us all. It’s true. My computer science teacher says so.”
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Equivocation
Equivocation happens when a word, phrase, or sentence is used deliberately to confuse, deceive, or mislead. In other words, saying one thing but meaning another.
When it’s poetic or comical, we call this a “play on words.” But when it’s done in a political speech, an ethics debate, or an economics report — and it’s designed to make the audience think you’re saying something you’re not — that’s when it becomes a fallacy.
Study Tool
How does each of these examples commit an equivocation fallacy?
EXAMPLE 1
“His political party wants to spend your precious tax dollars on big government. But my political party is planning strategic federal investment in critical programs.”
EXAMPLE 2
“I don’t understand why you’re saying I broke a promise. I said I’d never speak to my ex-girlfriend again. And I didn’t. I just sent her some pictures and text messages.”
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Appeal to Pity
An appeal to pity relies on provoking your emotions to win an argument rather than factual evidence. Appealing to pity attempts to pull on an audience’s heartstrings, distract them, and support their point of view.
Someone accused of a crime using a cane or walker to appear more feeble in front of a jury is one example of appeal to pity. The appearance of disability isn’t an argument on the merits of the case, but it’s intended to sway the jury’s opinion anyway.
Study Tool
Which of these is a fallacious appeal to emotion and which one is not?
EXAMPLE 1
“Professor, you have to give me an A on this paper. I know I only turned in a sentence and some clip art, but you have to understand, my grandmother suddenly died while traveling in the Northern Yukon, and her funeral was there so I had to travel, and my parents got divorced in the middle of the ceremony, and all the stress caused me to become catatonic for two weeks. Have some pity — my grandmother’s last wish was that I’d get an A in this class.”
EXAMPLE 2
“Professor, I know this work was subpar, and I feel pretty bad about it. I’d like to schedule a meeting with you to discuss how I can do better on our next assignment.”
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Bandwagon Fallacy
The bandwagon fallacy assumes something is true (or right or good) because others agree with it. In other words, the fallacy argues that if everyone thinks a certain way, then you should, too.
One problem with this kind of reasoning is that the broad acceptance of a claim or action doesn’t mean that it’s factually justified. People can be mistaken, confused, deceived, or even willfully irrational in their opinions, so using them to make an argument is flawed.
Study Tool
Which of these is a bandwagon fallacy?
EXAMPLE 1
“Almost everyone at my school will be at the party Friday night. It must be a popular thing to do.”
EXAMPLE 2
“Almost everyone at my school will be at the party Friday night. It must be the right thing to do.”
Final Word
We hope this primer on logical fallacies helps you to navigate future disputes with friends, family, and online acquaintances without descending into vitriol or childish name-calling.
Evan Thompson is a Washington-based writer for TBS covering higher education. He has bylines in the Seattle Times, Tacoma News Tribune, Everett Herald, and others from his past life as a newspaper reporter.
Fallacies: alphabetic list (full list)
Fallacies are statements that are logically false, but which often appear to be true. Here are most of the known fallacies, in alphabetic order (see also the unique list of fallacies, which is shortened by removing the alternative names):
- Absurd Extrapolation: see Slippery Slope
- Abusive Ad Hominem: see Attack the person
- Accent: Emphasis that changes the meaning of the sentence.
- Accident: A general rule used to explain a specific case not covered by it.
- Ad Antiquitatem: see Appeal to Tradition
- Ad Baculum: see Appeal to Fear
- Ad Hominem: see Attack the person
- Ad Hominem Abusive: see Attack the person
- Ad Hominem Tu Quoque: See Personal Inconsistency
- Ad Ignorantium: see Argument from Ignorance
- Ad Metum: see Appeal to Fear
- Ad Misericordiam: see Appeal to Pity
- Ad Nauseam: see Repetition
- Ad Novitam: see Appeal to Novelty
- Ad Numeram: see Appeal to Common Practice
- Ad Populum: see Appeal to Common Belief or Bandwagon
- Ad Ridiculum: see Appeal to Ridicule
- Ad Verecundiam: see Appeal to Authority
- Affirming the Consequent: If A then B. B is true, so A is true.
- Alleged Certainty: see Assertion
- Anger: Using anger as a weapon.
- Amphibology: see Amphiboly
- Amphiboly: A sentence has two different meanings.
- Appeal to Authority: Referencing an ‘expert’.
- Appeal to Belief: see Appeal to Common Belief.
- Appeal to Common Belief: If others believe it to be true, it must be true.
- Appeal to Common Practice: If others do it, it must be ok to do it too.
- Appeal to Consequences of a Belief: see Wishful thinking
- Appeal to Emotion: If it feels good, it must be true.
- Appeal to Fear: Gaining compliance through threat.
- Appeal to Flattery: Make them feel good.
- Appeal to Force: see Appeal to Fear
- Appeal to Ignorance: see Argument from Ignorance.
- Appeal to Majority: see Common Belief
- Argument from Ignorance: Accepting circumstantial evidence.
- Appeal to Novelty: Newer is better.
- Appeal to Pity: Going for the sympathy vote.
- Appeal to Popularity: see Appeal to Common Belief
- Appeal to Ridicule: Mocking the other person’s claim.
- Appeal to Spite: Play on their negative feelings for others.
- Appeal to Sympathy: see Appeal to Pity
- Appeal to Tradition: It has always been done this way, so this way is right.
- Appeal to Trust: Trust me, I’m a doctor.
- Argument from Ignorance: Accepting circumstantial evidence.
- Assertion: What I say is true.
- Attack the Person: Distracting them from their argument.
- Bandwagon: see Appeal to Common Belief
- Begging the Question: Circular reasoning to prove assumed premise.
- Biased Sample: see Unrepresentative Sample
- Bifurcation: see False Dilemma
- Black and White Thinking: see Excluded Middle
- Burden of proof: see Argument from Ignorance
- Butterfly Logic: How people often argue.
- Canceling Hypotheses: see Conspiracy Theory
- Chicken and Egg argument: see Begging the Question
- Circular Definition: see Begging the Question
- Circular Reasoning: see Begging the Question
- Circulus in Demonstrando: see Begging the Question
- Circumstantial Ad Hominem: see Attack the person
- Complex Question: two questions, one answer allowed.
- Composition: Generalizing from a few to the whole set.
- Concretism: see Reification
- Consequences: see Appeal to Fear
- Conspiracy Theory: Reframe refutation as further proof.
- Converse Accident: see Hasty Generalization
- Cum Hoc Ergo Propter Hoc: see False Cause
- Denying the Antecedent: If A then B. A is false, so B is false.
- Destroying the Exception: see Accident
- Dicto Simpliciter: see Accident
- Discredit: see Poisoning the Well
- Division: Assuming the parts have the characteristics of the whole.
- Double Bind: see Complex Question
- Ecological fallacy: Conclusion about individual from group data.
- Exception fallacy: Conclusions about group from individual data.
- Either/Or: see False Dilemma
- Emphasis: see Accent
- Equivocation: A single word with more than one meaning.
- Excluded Middle: Only extreme views are valid.
- Fallacy of Exclusion: see Unrepresentative Sample
- False Analogy: X has property Y. Z is like X. So Z has property Y.
- False Cause: A causes B (but no proof).
- False Compromise: Extreme views are wrong. The middle way is right.
- False Dichotomy: see False Dilemma or Excluded Middle
- False Dilemma: Choice is A or B. Rejecting A is selecting B.
- False Division: see Division
- False Effect: A is assumed to cause B. B is proven wrong, so A is wrong.
- False Metaphor: see False Analogy
- False Question: see Complex Question
- Faulty Induction: see Composition
- Faulty Deduction: see Division
- Four Terms: All A is B. All C is D. So all A is D.
- From Ignorance: see Argument from ignorance
- Gambler’s Fallacy: Chance can be predicted.
- Generalization: see Composition
- Hasty Generalization: Generalizing from too-small a sample.
- Hasty Induction: see Hasty Generalization
- Hypostatisation: see Reification
- Ignorance of Refutation: see Missing the Point
- Ignoratio Elenchi: see Missing the Point
- Illicit Major: All X is Y. No P (which is a subset of Y) is X. Therefore no P is Y.
- Illicit Minor: All X are Y. All X are P. Therefore all P are Y.
- In a Certain Respect and Simply: Extending assumed boundaries too far.
- Inconsistency: see Logical Inconsistency
- Inductive Generalization: see Hasty Generalization
- Insignificance: Making a minor cause seem major.
- Insufficient Sample: see Hasty Generalization
- Insufficient Statistics: see Hasty Generalization
- In Terrorem: see Appeal to Fear
- Irrelevant Conclusion: see Missing the Point
- Leaping to Conclusion: see Hasty Generalization
- Loaded Question: see Complex Question
- Logical Inconsistency: Arguments that contradict one another.
- Lonely Fact: see Hasty Generalization
- Many Questions: overloading them with lots of questions.
- Misleading Vividness: a memorable few events prove high probability.
- Misplaced Concreteness: see Reification
- Missing the Point: Drawing the wrong conclusion.
- Nagging: see Repetition
- Non Causa Pro Causa: see False Effect
- Non Sequitur: See Affirming the Consequent, Denying the Antecedent or Missing the Point.
- Petitio Principii: see Begging the Question
- Personal Inconsistency: Past words or deeds do not match claim.
- Plurium Interrogationum: see Many Questions
- Poisoning the Well: Discrediting the person before they speak.
- Polarization: see Excluded Middle
- Post Hoc: X follows Y. Therefore X is caused by Y.
- Post hoc, ergo propter hoc: see Post Hoc
- Questionable Cause: see False Cause
- Reasoning in a Circle: see Begging the Question
- Red Herring: Distracting with an irrelevancy.
- Reductio ad Absurdum: A false X is silly, so X is true.
- Reification: Treating a concept as concrete reality.
- Repetition: Repeating something makes it more true.
- Scare Tactics: see Appeal to Fear
- Secundum quid et simpliciter: see In a Certain Respect and Simply
- Slippery Slope: Loosely connected statements with ridiculous conclusion.
- Social Conformance: Agree with me or be socially isolated.
- Splitting the Difference: see False Compromise
- Statistical Generalization: see Hasty Generalization
- Strawman: Attack a weak argument used by the other person.
- Style over Substance: An attractive presentation makes it more right.
- Sweeping Generalization: see Accident
- Undistributed Middle: All A is B. All C is B. Therefore all C is A.
- Unrepresentative Sample: What is true about any sample is also true about the population.
- Value of Community: see Appeal to Common Belief
- Weak Analogy: see False Analogy
- Wishful Thinking: A is true because I want it to be true.
- You too: See Personal Inconsistency
See also