List of fallacies - Informal Fallacies

Informal Fallacies: A Guide to Flawed Reasoning Introduction An informal fallacy is an error in reasoning that occurs because of weak or irrelevant content, even though the logical structure of the argument might appear valid. Unlike formal fallacies, which violate the rules of logical form, informal fallacies trick us through deceptive language, faulty evidence, or appeals to emotion rather than reason. Recognizing these fallacies is essential for critical thinking, debate, and evaluating arguments in everyday life. The key to identifying informal fallacies is asking: Does this argument actually support the conclusion, or does it just seem to? Improper Premise Fallacies These fallacies share a common problem: they build arguments on premises that are themselves questionable or already assume what needs to be proven. Begging the Question (and Circular Reasoning) Begging the question occurs when an argument uses its conclusion as a premise—directly or indirectly—to support itself. The argument appears to prove something, but it's actually just restating the same claim in different words. Example: "We should ban this book because it's inappropriate to read. How do I know it's inappropriate? Because it should be banned." The problem here is obvious: the conclusion ("it should be banned") is used to support the premise ("it's inappropriate"). Nothing actually justifies the claim—the argument just goes in circles. Circular reasoning is closely related but often refers to longer chains of reasoning where the argument eventually loops back to where it started. Imagine Person A says "X is true because Y is true," and Person B says "But why is Y true?" and Person A responds "Because X is true." The reasoning circles back on itself without actually providing evidence. Loaded Labels A loaded label uses emotionally charged or prejudicial language to persuade without providing actual supporting evidence. The goal is to manipulate your feelings about something rather than your reasoning. Example: "Only a heartless monster could oppose this charity program." The label "heartless monster" is designed to make you feel negative emotions toward opponents, not to explain why the charity program is actually good or necessary. The argument substitutes emotional language for logical reasoning. The Fallacy of Many Questions The fallacy of many questions asks a question that presupposes an unproven assumption, trapping the respondent into accepting a false premise. Example: "Have you stopped embezzling company funds?" This question presupposes the respondent is guilty of embezzlement. Whether they answer "yes" or "no," they seem to accept this false assumption. A proper response would be: "I've never embezzled funds, so your question doesn't apply." Faulty Generalizations These fallacies involve drawing conclusions from weak or incomplete evidence, often by selecting information selectively or basing broad claims on limited examples. Hasty Generalization A hasty generalization bases a broad conclusion on a small or unrepresentative sample of evidence. Example: "I met two people from that city and they were both rude, so everyone from that city must be rude." Two people cannot represent an entire city's population. This fallacy jumps to a universal claim ("everyone") based on insufficient data. Cherry Picking Cherry picking selects only the evidence that supports your position while ignoring contradictory evidence. It's a form of selective reasoning designed to create a misleading picture. Example: A pharmaceutical company reports that "90% of patients showed improvement in the first month" while not mentioning that 70% of patients experienced severe side effects, or that the improvement didn't last beyond three months. The selective presentation of positive data distorts the actual picture. The No-True-Scotsman Fallacy The no-true-Scotsman fallacy redefines a group or concept to exclude any counterexamples that might prove the claim wrong. Rather than accepting evidence against your position, you narrow the definition to eliminate the contradiction. Example: Claim: "Scottish people are thrifty." Counterexample: "But my friend Stuart is Scottish and he spends money freely." Fallacious response: "Well, no true Scotsman would spend money like that." By redefining what counts as a "true" Scotsman, the speaker avoids admitting that their generalization is false. The definition changes to protect the claim rather than the claim being tested against reality. Survivorship Bias Survivorship bias draws conclusions by focusing on the successful cases while ignoring the many failures. This creates an overly optimistic or misleading picture. Example: "Look at all these billionaires who dropped out of college—college isn't necessary for success!" This ignores the millions of people who dropped out of college and never became successful. By only looking at the "survivors" (successful dropouts), you get a distorted view of college's actual value. Argument from Anecdote The argument from anecdote treats a single personal story as proof of a general claim. While anecdotes can be interesting, one person's experience doesn't prove a universal truth. Example: "My uncle smoked his whole life and lived to 95, so smoking isn't actually that dangerous." One long-lived smoker doesn't disprove the well-established correlation between smoking and health problems across large populations. False Analogy A false analogy compares two things that are not sufficiently similar, drawing a conclusion based on the comparison that doesn't actually hold. Example: "Raising the minimum wage is like inflating a balloon—it might get bigger, but eventually it will pop and burst the economy." While this sounds clever, a wage and a balloon differ fundamentally in how they operate economically. The analogy oversimplifies complex economics and the comparison breaks down when examined closely. For an analogy to work, the two things compared must be similar in the relevant ways that affect the conclusion. Nut-Picking Nut-picking presents extreme or fringe statements from an opposing group as representative of that group's actual position. It's like cherry-picking, but focused on opponent's weakest arguments rather than your own strongest ones. Example: Citing the most extreme comments from social media to claim that everyone supporting a cause holds those extreme views, when the majority of supporters hold much more moderate positions. Questionable Cause Fallacies These fallacies involve errors in reasoning about causation—mistaking correlation for causation, reversing cause and effect, or oversimplifying the causes of an outcome. Correlation vs. Causation: Cum Hoc and Post Hoc Two of the most common cause-related fallacies involve confusing correlation (two things occurring together) with causation (one thing causing another). Cum hoc ergo propter hoc ("with this, therefore because of this") assumes that because two things occur together, one must have caused the other. Example: "Ice cream sales increase when swimming pool drownings increase, so ice cream must cause drowning." These both increase during summer—there's a common cause (warm weather)—but neither causes the other. Post hoc ergo propter hoc ("after this, therefore because of this") assumes that because event X happened before event Y, X must have caused Y. Example: "Ever since I started wearing my lucky socks, my team has won three games, so my socks are causing the wins." The temporal order (socks → wins) does not establish causation. Many things precede other things without causing them. The Wrong-Direction Fallacy The wrong-direction fallacy reverses the actual direction of causation. It assumes that if A causes B, then B must cause A. Example: "People with depression are more likely to sleep poorly, therefore poor sleep must cause depression." While the first part might be true, the reversed conclusion reverses the causal relationship. In reality, both may be related, but we can't flip the direction without evidence. Ignoring a Common Cause This fallacy attributes an effect to one factor while overlooking a shared underlying cause that actually explains both observations. Example: "Hospitals have the highest mortality rates, therefore hospitals are killing people." The overlooked common cause: seriously ill people go to hospitals. The hospitals don't cause the deaths; the underlying illnesses do. Hospitals appear correlated with death because they treat the sickest patients. Faulty Generalizations (Continued) Misleading Vividness Misleading vividness dramatizes an unusual or extreme event to make it seem more common or significant than it actually is. Example: A news story about a rare shark attack is broadcast extensively, leading viewers to overestimate how often shark attacks actually occur. The vivid imagery makes the event seem more probable than statistics warrant. Overwhelming Exception An overwhelming exception adds so many qualifications and exceptions to a claim that the original statement becomes meaningless or useless. Example: "Exercise is always good for you, except if you have heart disease, or joint problems, or are recovering from surgery, or have certain neurological conditions, or are extremely overweight, or..." At some point, a claim with this many exceptions no longer makes a clear or useful statement. Thought-Terminating Cliché A thought-terminating cliché ends debate with a popular but uninformative phrase, preventing further discussion or critical examination. Example: "It is what it is" or "Boys will be boys" when used to shut down discussion rather than actually address an issue. These phrases feel conclusive but actually avoid engaging with the real question at hand. <extrainfo> Inductive Fallacy An inductive fallacy occurs when a conclusion is only weakly supported by its premises, even though the argument's structure might look reasonable. Unlike deductive arguments that claim certainty, inductive arguments claim probability—and an inductive fallacy fails to establish reasonable probability. Example: "Three people I know have had good experiences with that restaurant, so I'm certain I'll have a good experience there too." Three positive experiences might suggest the restaurant is probably good, but they don't establish certainty. The conclusion claims too much based on the evidence. </extrainfo> Questionable Cause Fallacies (Continued) Statistical Fallacies P-hacking (or data dredging) inflates statistical significance by selectively reporting only the most favorable results from multiple statistical tests. By running many analyses, some will appear significant by random chance alone. Example: A researcher runs 20 different statistical tests on a dataset and publishes only the 2 tests that show "significant" results, without acknowledging the other 18 tests that showed nothing. At a standard significance level of 0.05, you'd expect 1 in 20 tests to appear significant by random chance alone. Publishing only the significant results misrepresents the actual findings. The regression fallacy (also called regression to the mean) attributes cause to what is actually natural statistical variation. After an extreme event, things often naturally move back toward average—this isn't caused by anything, it's just how variation works. Example: "The student scored exceptionally high on the test, so I gave him extra tutoring. His next score was lower, proving that my tutoring wasn't effective." The student's first score was likely an outlier. Regression to the mean predicts his next score will be closer to his average—not because tutoring failed, but because extreme scores rarely repeat. Relevance Fallacies These fallacies fail because their premises are logically irrelevant to their conclusions—even if the premises are true or well-supported, they don't actually address the issue at hand. Argument from Ignorance The argument from ignorance claims that a proposition is true simply because it hasn't been proven false, or vice versa—that something is false because it hasn't been proven true. Example: "Scientists haven't proven that UFOs don't exist, therefore UFOs must exist." The absence of proof that something doesn't exist is not evidence that it does exist. These are two different burdens of proof. The fallacy assumes that burden of proof doesn't matter. Appeal to the Stone The appeal to the stone dismisses a claim as absurd or ridiculous without providing actual evidence or counterargument. It's a rhetorical way of refusing to engage. Example: Person A: "Could there be life on distant planets?" Person B: "That's absurd!" (with no further explanation) Person B hasn't actually refuted the claim; they've just declared it ridiculous and refused to discuss it. Invincible Ignorance Invincible ignorance refuses to consider any evidence that contradicts a pre-existing belief. No amount of evidence will change the mind, so the person is essentially closed off to reasoning. Example: No matter what evidence is presented about vaccine safety, a person insists "They're lying to us" without engaging with the actual evidence. Argument from Incredulity The argument from incredulity declares a claim false simply because the speaker cannot imagine how it could be true. Example: "I can't imagine how evolution could produce such a complex eye, therefore evolution must be false." Personal inability to understand something doesn't prove it's wrong. Many true things are difficult to imagine (quantum mechanics, the age of the universe, etc.). Argument from Repetition The argument from repetition repeats a claim over and over until opposition ceases, treating silence as agreement or proof. Example: A claim is stated repeatedly in a debate until the opponent stops arguing, then the speaker claims victory because the opponent didn't respond further. Silence or fatigue doesn't validate a claim. Repetition is not evidence. Argument from Silence The argument from silence infers truth or falsity from the absence of evidence. Because something isn't mentioned, it's assumed to be true or false. Example: "The document doesn't mention any safety concerns, so there must be no safety concerns." Absence of mention is not the same as absence of reality. The safety concerns might not have been included in the document for many reasons. Ignoratio Elenchi (Irrelevant Conclusion) Ignoratio elenchi (also called irrelevant conclusion or missing the point) presents a valid argument that doesn't actually address the real issue being debated. Example: Claim: "We should hire more police officers to reduce crime" Counterargument: "Police officers work hard and deserve good salaries" The counterargument is true and even valid, but it's irrelevant to whether we should hire more officers. It misses the actual point of debate. Red Herring A red herring introduces an irrelevant argument or topic to divert attention from the original issue. It's a distraction technique. Example: During a debate about education funding, one side says: "You know, the other side also opposes tax increases in general, which shows they don't care about public services." This statement, even if true, is irrelevant to the education funding question. It's a distraction—a red herring—designed to shift focus away from the original topic. Ad Hominem Fallacies An ad hominem fallacy attacks the person making an argument rather than addressing the argument itself. Even if the attack on the person is true, it doesn't logically prove the argument wrong. Direct Ad Hominem Attack A direct ad hominem attack targets personal characteristics, flaws, or background to dismiss someone's argument. Example: "You're just saying that because you didn't go to college, so I'm not going to listen to your argument about education policy." Whether or not the speaker went to college, their argument about education policy stands on its own merits. The personal attack is irrelevant. Circumstantial Ad Hominem The circumstantial ad hominem rejects a claim because the speaker has a personal stake in the outcome. Example: "Of course the tobacco company says cigarettes aren't harmful—they profit from selling them. Therefore, their claim must be false." While the tobacco company certainly has a financial interest, this doesn't automatically make their claim false. The claim itself would need to be addressed with evidence, not just dismissed based on motivation. Poisoning the Well Poisoning the well presents negative information about a person before they make their argument, designed to discredit everything they say. Example: "Before my opponent speaks, I should mention they've been convicted of fraud. So whatever they say, you can't trust them." By introducing damaging information in advance, you've "poisoned" how the audience receives everything the person says. Even if the information is true, it's a fallacy because it prevents fair evaluation of the actual argument. Appeal to Motive The appeal to motive dismisses an idea by questioning the proposer's motives, assuming that bad motives make the idea wrong. Example: "You're only supporting environmental regulations because you want to increase your company's market share, so your ideas about environmental protection must be wrong." Even if the motive is purely self-interested, the actual idea about environmental protection needs to be evaluated on its own merits, not on why someone believes it. Tone Policing Tone policing attacks the emotional delivery or manner of communication instead of engaging with the actual content. Example: "You're too angry about this issue, so your argument isn't valid." How someone expresses their point might be unfortunate, but it doesn't determine whether they're right or wrong. Address the argument, not the attitude. Appeal to Authority and Related Fallacies Appeal to Authority An appeal to authority asserts that a proposition is true because a prominent figure, expert, or authority endorses it, without providing independent evidence for the claim itself. Important distinction: Citing a relevant expert is often reasonable and not a fallacy. The fallacy occurs when: The authority is not an expert in the relevant field The claim is outside that expert's area of expertise You rely entirely on authority without any independent reasoning Example of fallacy: "A famous actor says this supplement cures cancer, so it must work." The actor's fame doesn't make them a medical expert. Example of reasonable authority: "Multiple peer-reviewed medical studies show this supplement has no proven effect on cancer." Here, the expertise is relevant and appropriate. Appeal to Accomplishment The appeal to accomplishment judges a claim's truth based on the proposer's past achievements, as if success in one area validates claims in completely different areas. Example: "Steve Jobs was successful in technology, so his views on alternative medicine must be correct." Accomplishment in one field doesn't transfer to expertise in unrelated fields. Each claim needs support appropriate to that specific domain. Courtier's Reply The courtier's reply dismisses criticism by claiming the critic lacks sufficient expertise or credentials to speak on the issue. Example: An expert in climate science publishes valid criticism of a particular climate model, and the response is "You're not qualified to criticize this—you'd need a PhD specifically in climate modeling." This creates an impossible standard where only practitioners within a narrow specialty can criticize anything. It's used to shield ideas from outside scrutiny under the guise of expertise. Appeal to Consequences An appeal to consequences supports or refutes a conclusion by describing desirable or undesirable outcomes, rather than providing evidence for whether the claim is actually true. Example: "If we accept that theory, it would destroy the entire field of study, so the theory must be false." Whether the consequences would be bad doesn't determine whether the theory is true or false. A true statement can have bad consequences. A false statement can have good consequences. Consequences are separate from truth. This is sometimes called "argumentum ad consequentiam." Appeal to Emotion Fallacies These fallacies manipulate feelings rather than relying on logical evidence and reasoning. Appeal to Emotion (General) An appeal to emotion manipulates your feelings—fear, anger, joy, guilt—to persuade you, rather than using logical evidence or reasonable argument. Example: A political advertisement shows sad images of struggling families while soft music plays, asking you to vote for a candidate without explaining what policies they actually support. The images and music trigger emotional responses that bypass critical thinking. Appeal to Fear An appeal to fear generates anxiety or prejudice to persuade an audience toward a conclusion. Example: "If you don't buy this home security system, criminals will definitely break into your house and hurt your family." The emotional fear response is triggered regardless of whether the actual risk is statistically significant. Appeal to Flattery An appeal to flattery uses excessive praise or compliments to win agreement, appealing to vanity rather than reason. Example: "Smart people like you obviously understand why this policy is the right choice." The flattery ("smart people like you") makes the person more likely to agree, regardless of whether the policy is actually sound. Appeal to Pity An appeal to pity evokes sympathy to influence acceptance of a claim, shifting focus from the actual evidence. Example: "This student should pass the course because they've had such a difficult semester." While sympathy is a natural response, whether the student deserves to pass should depend on whether they've met the learning objectives, not on their hardships. Appeal to Ridicule An appeal to ridicule mocks an opposing position to avoid engaging with its actual merits. Example: "That's such a stupid idea—I can't believe anyone would actually think that." Ridiculing something isn't the same as refuting it. The actual argument is never addressed. Appeal to Spite An appeal to spite incites hostility toward an opponent to strengthen one's own stance, using anger against the person rather than evidence for the position. Example: "Those greedy politicians only care about themselves, so we should definitely vote against their proposal." Even if politicians are greedy, this doesn't prove the proposal is bad. The hostility is misdirected. <extrainfo> Additional Emotion-Based Fallacies Judgmental language employs insulting or pejorative terms to undermine an argument rather than address it. For example, calling an idea "insane" or "barbaric" substitutes emotional language for actual critique. Pooh-pooh dismisses an argument as unworthy of consideration without actually critiquing it. "That's beneath discussion" or "I'm not going to dignify that with a response" shut down conversation without engagement. Style over substance relies on compelling, eloquent, or technically impressive language rather than logical merit. A well-written argument can be persuasive even if it's logically flawed. Wishful thinking argues for a course of action because it's pleasant to imagine rather than because evidence supports it. "It would be nice if renewable energy solved all our problems, so we should bet our entire economy on it immediately." </extrainfo> Summary: Recognizing and Avoiding Informal Fallacies When evaluating an argument, ask these key questions: Does the premise actually support the conclusion? Or does it just seem to? (Begging the question, circular reasoning) Is the evidence strong enough? Or is it based on too small a sample, selective reporting, or a single story? (Hasty generalization, cherry-picking, argument from anecdote) Does correlation prove causation? Or could there be other explanations? (Cum hoc, post hoc, common cause) Is the argument attacking the idea or the person? (Ad hominem fallacies) Is emotional language substituting for evidence? (Appeals to emotion, loaded labels) Is someone citing an expert appropriately? Or are they appealing to irrelevant authority? (Appeal to authority, appeal to accomplishment) Understanding these fallacies helps you think more critically, construct stronger arguments, and identify when others are using tricks rather than logic to persuade you.