Grammatical Ambiguities


Formal Fallacies




Failure to State Accent Accident fallacy  Drawing an Affirm. Conclusion From a Neg. Premise
Fast Talking Ambiguous Assertion Argument by Generalization  Exclusive Premises
Repetition Process-Product Ambiguity Arg. from Small Numbers Fallacy of Four Terms
Rhetorical Question Semantical Ambiguity Unrepresentative Sample Illicit Minor
Changing the Subject Type-Token Ambiguity Ignoring Unit Percentages Illicit Major
Argument by Question Amphiboly Hasty Generalization Drawing a Neg. Conclusion from Affirm. Premises
Argumentum ad Exemplum Prestigious Jargon  Appeal to Probability Undistributed Middle
Complex Question Gibberish Pretentiousness Affirming a Disjunct
Meaningless Question Euphemism Stereotyping Affirming the Consequent
Monopolizing the Question Etymological fallacy  Pigeonholing Denying a Conjunct
Wrap Yours. in a Hig. Power Equivocation Tokenism Denying the Antecedent
Smokescreen Sliding Adjectives Group Think Existential fallacy
Admit a Small Fault Variant Imagization Appeal to Money Illicit Conversion 
Apply Time Pressure Fallacies of Definition: Too Broad Spotlight Fallacy Quantifier Shift
Sly Suggestions Too Narrow Undoability Some Are/ Some Are Not
Needling Failure to Elucidate Specificity Modal fallacy 
Pigheadedness Circular Definition Jumping to Conclusions Fallacy of Necessity
Moving the Goal Posts Conflicting Conditions Misleading Vividness  A Priorism
Quibbling   Base Rate Fallacy Every and All fallacy
Argumentum ad Fidentia   Falsified Inductive Generalization Confusing Correlation and Causation
Barking Cat   Appeal to the Moon Fallacy of Negative Premises 
Definist   Appeal to Utility

Disproof by fallacy 

Argument by Scenario  

Fallacy of Composition

Falsifiability fallacy fallacy
Hypnotic Bait and Switch   Fallacy of Division Two Wrongs Make a Right
Pomp and Circumstance   Middle Ground Fallacy Internal Contradiction
Pack the House   Distinction Without A Difference Hooded Man
Having your Cake   Appeal to Ignorance Occam's Razor Fallacy
Statement of Conversion   Shifting the Burden of Proof  
Devil's Advocate   Sherlock Holmes Fallacy  
Lip Service   Argument from Silence  
Preacher's We   Appeal to Intuition  
Sanctioning the Devil   Reductive Fallacy  
Blame the Victim   Causal Reductionism  
Double Bind   Psychologist's Fallacy  
cui bono?   Selective Reading   
Sour Grapes   Half Truth   
    Selective Observation   
Against the Man   Reductio ad Absurdum   
    Golden Hammer Fallacy  
Ad hominem   Amazing Familiarity   
Guilt by Association    Bad Analogy  
Tu Quoque    Extended Analogy   
Ad hominem circumstantial   Naturalistic Fallacy   
Appeal to Motive   Normative Fallacy   
Poisoning the Wells   Word Magic  
Smear Tactic      
Apply Labels      
Hifalutin' Denunciations   False Causes  
Damning with Faint Praise      
    Abductive Fallacy  
Appeals to Emotions   Slippery Slope  
    Argument of the Beard  
Appeal to Emotions    Begging the Question  
Appeal to Personal Interest   Fallacy of Presumption  
Appeal to Pity    Conspiracy Theory  
Galileo Wannabe   Infinite Regress  
Argument from Intimidation   Homunculus Argument  
Scare Tactic    Contradictio in Adjecto  
Appeal to Force    Stolen Concept  
Widespread Belief   Appeal to Faith  
Appeal to the Minority   Fishing for Data  
Appeal to Pride   Subjectivist Fallacy  
Appeal to Envy   Subverted Support  
Appeal to Rridicule   If-by-Whiskey  
Appeal to Desperation   Straw Man   
Personal Charm   Ad Hoc Rescue   
Loaded Language   No True Scotsman   
Style over Substance     Fallacy of Multiplication  
Argument by Slogan   Inflation of Conflict  
to Anon. Authority   Anthropomorphism  
to Authority   Pathetic Fallacy   
to False Authority   Reification Fallacy  
from Authority   Gambler's Fallacy   
Adverse Consequences   Argument from Design  
Norm of Reciprocity   Post Hoc   
Appeal to Flattery   Cum Hoc   
Questionable Premise   Clustering Illusion  
    Package-Deal Fallacy  
Audiatur et Altera Pars   Regression   
Genetic Fallacy    Reversing Causation   
Knights and Knaves   Unfalsifiability  
Not Invented Here    Non Sequitur   
Psychogenetic Fallacy   Sunk-Cost Fallacy   
Argument from Age   Elephant Repellent  
Cliché Thinking    Inconsistency  
Appeal to Common Folk   Relative Privation  
Appeal to Stupidity   Shoehorning  
Lies   Red Herring  
Outdated Information    Semi-Attached Figure  
Spin Doctoring   Chewbacca Defense  
Self-Deception   Lump of Labour  
Self-Righteousness   Far-Fetched Hypothesis  
Misrepresentation   Least Plausible Hypothesis  
Hyp. Contrary to Fact    Superstitious Thinking  
Error of Fact   Retrospective Determinism  
Crucial Experiment    Historian's fallacy  
to the Future   Retrogressive Causation  
Double Standard    Reversal of Reality  
Fantasy Projection      
Exc. that Proves the Rule      
Pious Fraud      
Appeal to Coincidence      
Appeal to Complexity      
Mis. the N. of Statistics      
Anecdotal Evidence       
Argument by Laziness      
Self-Fulfilling Prophecy      
Common Sense      





Failure to State - if you make enough attacks, you may never have to defend your own position


Argument by Fast Talking - rapid delivery does not leave people time to reject what they hear


Argument by Repetition - if you say something often enough, people will begin to believe it (Proof by Assertion)


Argument by Rhetorical Question - asking a question in a way that leads to a particular answer


Changing the Subject - is used to avoid having to defend a claim (Answering a Question that Was Not Asked)


Argument by Question - asking a question instead of admitting the opponent's point (Avoiding the Question, Changing the Subject)


Argumentum ad Exemplum - arguing against a particular example cited rather than the question itself (Argument to the Example)


Complex Question - unrelated points treated as if they should be accepted or rejected together: Mr. President: Are you going to continue your policy of wasting taxpayer's money on missile defence? (Fallacy of Presupposition)


Meaningless Question - if God is omnipotent, can he create a stone that is so heavy that even he could not lift it?


Monopolizing the Question - asking a question and then immediately giving the answer


Wrap Yourself In A Higher Power - the two most popular styles are "Wrap Yourself in the Flag" and "Wrap Yourself in the Bible”


Smokescreen - occurs by offering too many details in order either to obscure the point or to cover-up counter-evidence. In the latter case it would be an example

of the fallacy of suppressed evidence. If you produce a smokescreen by bringing up an irrelevant issue, then you produce a red herring fallacy (Clouding the Issue)


Admit a Small Fault to Cover a Big Denial - President Bush today said mistakes were made in planning for the Iraq invasion, but he defended the troop level he ordered in the initial strike, saying he would have committed the same number if given a second chance


Apply Time Pressure - applying time pressure to get someone to do something. Advertisements and commercials use this trick all of the time: "This offer is only good for 5 days" "This sale ends on Sunday"


Sly Suggestions - not making solid statements which can be proven wrong; rather, just suggesting that your ideas may be true. Then, often, perhaps a little while later, you might suddenly start assuming that all of your suggestions are really true. This technique is basically the old strategy of first just getting your toe in the door. For instance:  You may have already won $10,000,000. Just subscribe to a bunch of magazines and see...


Needling - attempting to make the other person angry


Argument by Pigheadedness - dismissing a valid inference as absurd without giving a reason (Throw Stones, Ad lapidem fallacy, Slothful Induction, Obtuseness, Refuse to See the Point)


Moving the Goal Posts - demanding impossible perfection: asking an opponent to address more and more points (Gravity Game)


Quibbling - occurs when someone complains about a minor point and falsely believes that this complaint somehow undermines the main point (Trivial Objections, Megatrifle, Splitting Hairs, Nit-Picking)


Argumentum ad Fidentia - if you cannot directly refute someone's principles, you strike indirectly with an attack on their confidence in those principles. Question their certainty of the principles' validity: How can you be sure you're right? (Against Self-Confidence)


Barking Cat - demanding that a problem should not be solved before other, more important problems are solved


Definist - let's define 'atheist' as someone who doesn't yet realize that God exists (Persuasive Definition, Redefinition)


Argument by Scenario - telling a story, which ties together unrelated facts


Hypnotic Bait and Switch - to lull the listener into uncritically accepting more statements, by starting out with a series of unchallengably true statements, creating the expectation that what follows will also be unquestionably true, when it will actually be false


Pomp and Circumstance - permitting the setting in which the argument takes place to affect the attention paid to the argument


Pack the House - with crowds of sycophant followers, shills, and hand-picked audiences


Having your Cake - almost claiming something but backing out: I don’t necessarily agree with 2+2=3 (Argument by Innuendo, Instant Denial)


Statement of Conversion - I used to believe in x


Devil's Advocate - arguing for a position that one does not necessarily believe in, simply for the sake of arguing or to test the quality of the original argument and identify weaknesses in its structure


Lip Service - pretending to agree when it's clear that you don't really agree


Preacher's We - to veil accusations of others by saying "We" or "Us" when you really mean "You". 

Preachers routinely deliver sermons where they say, "We are all sinners, may God have mercy on us..."


Sanctioning the Devil - avoiding debate with someone because debating him would give him undue credit


Blame the Victim - blaming the victim rather than the cause of the problem, when something goes wrong: The program doesn't fail people; people fail the program


Double Bind - is a trap where you are damned if you do, and damned if you don't. Classic double binds are the tests for whether a woman is a witch: If she

confesses (under torture) to being a witch, then she is one. If she denies being a witch, then that proves that she is an evil witch who lies about being a witch


cui bono? - to what good: the "So what?" argument


Sour Grapes - denigrating something one can't have



Against the man


Ad hominem - in order to maintain a civil debate I will not mention my opponent’s drinking problem (Name Calling)


Guilt by Association - a person is said to be guilty of error because of the group he or she associates with (Ad Hominem)


Tu Quoque - to conclude that someone's argument not to perform some act must be faulty because the arguer himself or herself has performed it


Ad hominem circumstantial - arguing that someone is in circumstances (e.g. self interest) such that he is disposed to take a particular position


Appeal to motive - is a pattern of argument which consists in challenging a thesis by calling into question the motives of its proposer. It can be considered as a special case of the ad hominem circumstantial argument


Poisoning the Wells - discrediting the sources used by your opponent


Smear Tactic - an unfair characterization either of the opponent (ad hominem) or the opponent's position (straw man)


Apply Labels - applying labels to things or people -- especially derogatory labels. This is very similar to name-calling. If someone talks about universal health care, scream "That's Socialism!" If someone talks about peace and freedom and justice, complain, "That's a Liberal agenda"


Hifalutin' Denunciations - denouncing your opponent with vague, grand-sounding generalized accusations that don't have very specific meanings: "the proposal shows a failure of initiative"..."he exhibits a lack of vision"...


Damning with Faint Praise - to attack a person by formally praising him, but for an achievement that shouldn't be praised



Appeals to Emotions


Appeal to Emotions - [the speaker knows he is talking to an aggrieved person whose house is worth much more than $100,000.] You need cash. I can help you. Here is a check for $100,000. (Wishful Thinking)


Appeal to Personal Interest - appeal to the personal preferences, dislikes, or weaknesses of those one wants to convince (Appeal to Motives in Place of Support)


Appeal to Pity - if you don’t give me an A, I don’t get into grad school


Galileo Wannabe - to compare yourself to Galileo Galilei or another scientist suppressed by authorities or disbelieved by your peers (Appeal to Pity)


Argument From Intimidation - aren't you ashamed for having that opinion? (Political Correctness, Appeal to Patriotism, Appeal to Guilt, Bullying)


Scare Tactic - to suppose that terrorizing your opponent is giving him a reason for believing that you are correct:

David: My father owns the department store that gives your newspaper fifteen percent of all its advertising revenue, so I'm sure you won't want to publish any story of my arrest for spray painting the college. Newspaper editor: Yes, David, I see your point. The story really isn't newsworthy. (Appeal to Fear)


Appeal to Force - threats: lawsuits; religious: Hell (Appeal to the Stick: Argumentum ad Baculum)


Appeal to Widespread Belief - the claim that many people believe it, as evidence for an idea (Peer Pressure, Appeal to the People, Sacred Cows, Ostracism, Bandwagon Fallacy)


Appeal to the Minority - most people don't believe this, it must be right (Snob Appeal)


Appeal to Pride - those who accept this are the smarter ones


Appeal to Envy - don't believe them, they have all the power and influence


Appeal to Ridicule - presents the opponent's argument in a way that appears ridiculous, often to the extent of creating a straw man of the actual argument: If Einstein's theory of relativity is right, that would mean that when I drive my car it gets shorter and heavier the faster I go. That's crazy!


Appeal to Desperation - arguing that we Must do something, that we cannot just do nothing, and since we don't know what to do, let's do what I want


Argument by Personal Charm - charm may create trust, the desire to win the winning team


Loaded Language - emotive terminology that expresses value judgments. When used in what appears to be an objective description, the terminology can cause the listener to adopt those values when in fact no good reason has been given for doing so (Argument by Emotive Language, Style over Substance, Red Herring)


Style over Substance fallacy - if it sounds or looks good, it must be right


Argument by Slogan - if it’s short, and connects to an argument, it must be an argument


Appeal to Anonymous Authority - rumours


Appeal to Authority - Albert Einstein was impressed with this theory


Appeal to False Authority - the authority alluded to is outside of the arguer’s area of experience: 99% of family dentists say regular brushing is good; use Crest

Argument from Authority - the speaker is an expert, and so should be trusted


Argument by Adverse Consequences - saying an opponent must be wrong, because if he’s right, then bad things ensue


Norm of Reciprocity - is a technique that exploits people's natural tendency to want to repay debts: The Hari Krishnas discovered that when they gave travelers a flower, "...because we love you, and you are so beautiful...", and then hit up the traveler for a donation, they got a lot more money. The act of giving the flower made the traveler feel indebted and embarrassed, and vulnerable to the request for money


Appeal to Flattery - trying to compliment people into an opinion (Apple Polishing, Sucking Up)



Questionable Premise


Audiatur et Altera Pars - is the principle that all of the premises of an argument should be stated explicitly. It is a fallacy when one is arguing from unstated premises: There's too much violence on TV. No wonder we have so much violence among kids these days


Genetic Fallacy - holding that if an argument has a particular origin, it must be right


Knights and Knaves - treating information coming from other persons as if some people were always right and some were always wrong


Not Invented Here - ideas from elsewhere are made unwelcome


Psychogenetic Fallacy - taking an argument to be wrong because you learned the psychological reason why someone uses it


Argument from Age - snobbery that very old (or very young) arguments are superior (Appeal to Common Practice, Fallacy of Traditional Wisdom, Willed Ignorance, Converse: Appeal to Novelty)


Cliché Thinking - wise sayings taken for granted


Appeal to Common Folk - arguing that you are just a regular guy, and what you say is just common folk wisdom


Appeal to Stupidity - flaunting an anti-intellectual attitude, and belittling knowledge, wisdom, intelligence and education


Lies - intentional errors of fact


Outdated Information - not the latest information is given


Spin Doctoring - often, how people take the news depends on how it is presented


Self-Deception - the process or fact of misleading ourselves to accept as true or valid what is false or invalid


Self-Righteousness - I have the heart at the right spot, so I must be right


Misrepresentation - is an example of lying when it occurs on purpose. It will be a case of the straw man fallacy if an opponent's claim is misrepresented during a debate


Hypothesis Contrary to Fact - arguing from something that might have happened, but didn’t (Counterfactual Fallacy, Speculative Fallacy, "What if" Fallacy, Wouldchuck)


Error of Fact - no one knows how old the pyramids of Egypt are (some do)


Fallacy of the Crucial Experiment - claiming some idea has been proved by a pivotal discovery


Argument to the Future - arguing that evidence will some day be discovered


Double Standard - making allowances in one's own case, but not in other's


Fantasy Projection - an attempt to impose one’s own intellectual or moral context on another person by someone who has closed his mind to reality and manufactured a fantasy, then expects (or if he is a tyrant, demands) others to share it and help him sustain it. He ignores the objective realities of the situation, concentrating instead on subjective perceptions that are false: If you were terminally ill, you too would advocate life preservation (Context imposition)


Exception that Proves the Rule - pointing out that a rule doesn’t always hold, is countered by the claim that this exception proves the rule


Pious Fraud - a fraud done for a good end, on the theory that the end justifies the means


Rationalization - using plausible-sounding but usually false reasons (excuses) to justify a particular position that is held on other less respectable grounds


Appeal to Coincidence - asserting some fact is due to chance

Appeal to Complexity - if the arguer doesn’t understand the topic, he concludes no one understands it


Misunderstanding the Nature of Statistics - some people get fearful when they learn that their doctor wasn’t in the top half of his class (but that’s half of them)


Anecdotal Evidence - my brother smokes and he says he's never been sick a day in his life, so I know smoking can't really hurt you. (Misunderstanding the nature of statistics)


Argument by Laziness - the arguer is not informed on the topic, but has an opinion


Self-Fulfilling Prophecy - occurs when the act of prophesying will itself produce the effect that is prophesied, but the reasoner doesn't recognize this and believes the prophecy is a significant insight


Common Sense - each side thinks their answer is common sense. One is wrong though



Grammatical ambiguities


Accent fallacy - ambiguity due to the different ways a word is emphasized or accented. E.g.: I'm in favour of a missile defence system that effectively defends America


Ambiguous Assertion - a statement left sufficiently unclear


Process-Product Ambiguity - the ambiguity resulting from a statement that could refer to either a process or to its product and it is unclear from the context which of the two is intended. Example: "John is checking the new employee's work." The word work can refer to act of working (a process) or to the completed work (a product)


Semantical Ambiguity - an ambiguity that results from using a word or words which can have more than one meaning in a statement when the intended meaning is in doubt. Example: "Paul rented two rooms." It is unclear if Paul rented two rooms for himself (from someone else), or Paul rented two of his own rooms (to someone else)


Type-Token Ambiguity - when a word can refer to either a type (tiger, lion, leopard) or token (any cats) is used in way that makes it unclear which it refers to, the statement is ambiguous. Examples: Interviewer: "How many cats do you have in your zoo?" Zoo spokesman: "At the moment, only two."


Amphiboly - Dog for sale. Will eat anything. Especially fond of children. (Syntactic Ambiguity)


Argument by Prestigious Jargon - using complicated words so that you will seem to be an expert


Argument by Gibberish - agglomerating several different superficial aspects of a subject, in hopes that the resulting verbal structure will be comprehensible: Each autonomous individual emerges holographical within egoless ontological consciousness as a non-dimensional geometrical point (Shingle Speech)


Euphemism - use of words that sound better: sacrifice, ethnic cleansing, collateral damage


Etymological fallacy - occurs whenever someone falsely assumes that the meaning of a word can be discovered from its etymology or origins.


Equivocation - the divine is omnipotent, this ice cream is divine, therefore...


Sliding Adjectives - use a sequence of descriptors, usually adjectives, where the value, quality, and characteristics of what is being described slip and slide from one thing to another, often to the exact opposite. For example: genuine simulated leather, high-quality plastic, honest politicians, Compassionate Conservatism


Variant Imagization - generating dissimilar images from similar concepts. Certain kinds of crops, such as corn, are "harvested", but other kinds, such as trees, are "slashed" or "devastated". Who would forbid farmers to "harvest" a crop of beets? But who would willingly allow men armed with chainsaws to "devastate" the ecology?


Fallacies of Definition:

Too Broad - the definition includes items which should not be included


Too Narrow - the definition does not include all the items which should be included


Failure to Elucidate - the definition is more difficult to understand than the word or concept being defined


Circular Definition - the definition includes the term being defined as a part of the definition


Conflicting Conditions - the definition is self-contradictory



Oversimplifications (Inductive Fallacies)


Accident Fallacy - to reason with the generalization as if it has no exceptions: Birds normally can fly. Tweety the Penguin is a bird. Therefore, Tweety can fly. (Fallacy of the General Rule, Dicto simpliciter)


Argument by Generalization - drawing a broad conclusion from a small number of cases (Converse of the Accident Fallacy)


Argument from Small Numbers - after treatment with the drug, one third were cured, one third died, and the third escaped (therefore, if we treated 1000 people, 333 would be cured) (Unrepresentative Sample)


Unrepresentative Sample - we've polled over 400,000 Southern Baptists and asked them whether the best religion in the world is Southern Baptist. We have over 99% agreement, which proves our point about which religion is best (Biased Sample)


Ignoring Unit Percentages - "You are safer walking down a dark alley than sitting in your living room with friends, because most murders are committed in the victim's home by his acquaintances." This ignores the fact that most people spend much more of their time at home than walking down alleys


Hasty Generalization - This car is really cheap. I'll buy it. (Jumping to Conclusions)


Appeal to Probability - assuming that because something could happen, it is inevitable that it will happen. This is flawed logic, regardless of the likelihood of the event in question


Pretentiousness - the speaker assumes omniscience with respect to the subject under consideration. He assumes also that he speaks for the entire human race. "We don't know what life is" (or insanity, intelligence, etc). "My contention must be true because we can think of no alternative mechanism as a cause for this phenomenon"


Stereotyping - generalizing from a common prejudice: is deductively valid, but unsound because it rests on a false, stereotypical premise


Pigeonholing - an attempt to subsume something into a frame-of-reference that is too small to incorporate the thing


Tokenism - to interpret a merely token gesture as an adequate substitute for the real thing: How can you call our organization racist? After all, our receptionist is African American


Group Think - to substitute pride of membership in the group for reasons to support the group's policy: e.g. 'Blind' patriotism


Appeal to Money - supposing that, if something costs a great deal of money, then it must be better, or supposing that if someone has a great deal of money, then they're a better person in some way unrelated to having a great deal of money (Converse: Appeal to Poverty)


Spotlight Fallacy - is committed when a person uncritically assumes that all members or cases of a certain class or type are like those that receive the most attention or coverage in the media. This line of "reasoning" has the following form: Events e with quality q receive a great deal of attention or coverage in the media. Therefore all events e have quality q


Undoability - saying "this is un-xxx-able" instead of "I can't xxx it"


Specificity - drawing an overly specific conclusion from the evidence (Jumping to Conclusions)

Jumping to Conclusions - using a premise for an argument without stating the premise


Misleading Vividness - occurs when the fallacy of jumping to conclusions is committed due to a special emphasis on an anecdote or other piece of evidence


Base Rate Fallacy - preferring available interesting single cases to statistics


Falsified Inductive Generalization - to restrict a wide abstraction to a narrow set of particulars and then conclude that an attribute of these particulars must be definitive of the abstraction, thus negating the entire principled structure underlying the abstraction. A similar fallacy is that of equating opposites by substituting nonessentials for their essential characteristics. Conservatives always do this when they claim to be Objectivists or libertarians


Appeal to the Moon - if we can put a man on the moon, we must also be able to...


Appeal to Utility - it's much more practical that way (Appeal to Convenience, Pragmatic Fallacy)


Fallacy of Composition - assuming a whole has the same simplicity as its constituent parts: atoms are colourless; a cat is made up of atoms, therefore ... (Category Error, Distributive Fallacy)


Fallacy of Division - assuming what is true of the whole must be true of each part: humans are made of atoms, humans are conscious, atoms must be conscious (Converse of the Composition Fallacy)


Excluded Middle - assuming there are only two alternatives when there are more, e.g. holding that atheism is the only alternative to fundamentalism (False Dichotomy/Dilemma, All-Or-Nothing Mistake, Bifurcation, Black-or-White Fallacy, Either/Or Fallacy)

Middle Ground Fallacy - to agree on a compromise between two extreme points of view (False Compromise, Argumentum ad temperantiam)


Distinction Without A Difference - appeals to a distinction that ultimately cannot be explained or defended in a meaningful way. As in: He was just a heavy drinker, not a real alcoholic. Okay, he was drinking enough alcohol to wreck his health and his brain and eventually kill himself, but he wasn't a real alcoholic, because he managed to quit drinking without A.A. or the 12 Steps (Phantom Distinction, Sham Distinctions)


Appeal to Ignorance - not knowing that a certain statement is true, is taken to be a proof that it is false (Nobody has ever proved to me there's a God, so I know there is no God)


Shifting the Burden of Proof - not knowing that a statement is false, is taken to be a proof that it is true (Negative Proof)


Sherlock Holmes Fallacy - when you have eliminated the impossible, whatever remains, however improbable, must be the truth. To apply this method, you first have to find explanations, then eliminate them one by one. Both steps require omniscience to make it right (Category: Appeal to Ignorance)


Argument from Silence - the silence of a speaker or writer about X is taken to prove that the speaker or writer is ignorant of X


Appeal to Intuition - to conclude that because a proposition does not match one's experience of how things work in general, or how we believe they should work, then that proposition is not true


Reductive Fallacy - oversimplifying: Taxation is Theft


Causal Reductionism - trying to use one cause to explain something, when it had several causes


Psychologist's Fallacy - assuming every event has some psychological cause or explanation


Argument by Selective Reading - making it seem as if the weakest of an opponent’s argument was the best he had


Argument by Half Truth - suppressed evidence


Argument by Selective Observation - counting the hits and forgetting the misses: Technology brings happiness (Special Pleading, Confirmation Bias, Suppressed evidence, Cherry picking, Eclecticism, Slanting, Cover-up, One-Sidedness)


Reductio ad Absurdum - showing your opponent’s argument leads to an absurd conclusion


Golden Hammer Falacy - to propose the same type of solution to every problem you encounter (Exclusivity, Very Simple Answer)


Amazing Familiarity - the captain fingered his lucky charm, later the ship sank, and therefore the captain is responsible


Bad Analogy - the suggestion that resemblance is proof of a relationship: Minds like rivers can be broad. The broader the river, the shallower it is (Argument form Spurious Similarity)


Extended Analogy - the claim that two things, analogous to a third thing, are therefore analogous to each other


Naturalistic Fallacy - is to ought: This behaviour is natural; therefore, this behaviour is morally acceptable (Appeal to Nature)


Normative Fallacy - ought to is (Appeal to Hope, Wishful Thinking, Moralistic Fallacy)


Word Magic - if there is a word for it, it must exist (Category: Wishful Thinking)



False Causes (Retroductive Fallacies)


Abductive Fallacy - where retroduction goes wrong. Retroduction (also called Abduction) means that you are trying to find which explanation is the right one for a known fact (Abductive Fallacy, Fallacy of Explanation)


Slippery Slope - the assumption that something is wrong (or bad) because it could develop into something that is wrong (or bad). But it depends on the likelihood of the trouble in question occurring, that determines whether the argument is going to be fallacious or not (Fallacious Reductio ad absurdum)


Argument of the Beard - assuming that two ends of a spectrum are the same: as being clean shaven must be the same as having a big beard, since in betweens exist (Sorites Fallacy, Barefoot, Bald Man Fallacy, Paradox of the Heap, Sorites Fallacy, Continuum Fallacy, Line-Drawing Fallacy)

Begging the Question - tautology, reasoning in a circle: A couch is a sofa. A sofa is a davenport. A davenport is a couch (Petitio Principii, Circularity)


Fallacy of Presumption - when a doubtful assertion is made, most people will plunge into arguing about the assertion without further thought about the underlying assumptions (Assume the Major Premise)


Conspiracy Theory - the evidence is not there because someone hid it (Category: Circular Explanation, Ad hoc, Synonym: Canceling Hypotheses)


Infinite Regress - is an argument which proposes an explanation, when the mechanism proposed stands just as much in need of explanation as the original fact to be explained (Category: Circular Explanation)


Homunculus Argument - accounts for a phenomenon in terms of the very phenomenon that it is supposed to explain: Ryle's regress (Infinite Regress)


Contradictio in Adjecto - a self-contradictory argument: All generalizations are false


Stolen Concept - using science to show that science is wrong


Appeal to Faith - is a form of circular reasoning: Once you believe it, you will understand!


Fishing for Data - after experimentally finding a correlation you didn't expect, you commit this fallacy if you claim that the correlation is proven: Three of my four children were born in February, and all three were left-handed. Apparently most people born in February are left-handed (Category: Circular Evidence) (Post Designation)


Subjectivist Fallacy - occurs when it is mistakenly supposed that a good reason to reject a claim is that truth on the matter is relative to the person or group: That's perhaps true for you, but it's not true for me (Relativist Fallacy, Category: Begging the Question)


Subverted Support - an explanation is intended to explain why some phenomenon happens. The explanation is fallacious if the phenomenon does not actually happen of if there is no evidence that it does happen: The reason why most bachelors are timid is that their mothers were domineering. This attempts to explain why most bachelors are timid. However, it is not the case that most bachelors are timid (Begging the Question, Questionable Cause)


If-by-Whiskey - is a relativist fallacy where the response to a question is contingent on the questioner's opinion. An if-by-whiskey argument affirms both sides of an issue, and agrees with whichever side the questioner supports: If when you say whiskey you mean the devil's brew, then certainly I am against it. But, if when you say whiskey you mean the oil of conversation, then certainly I am for it


Straw Man - attacking an exaggerated version of your opponent’s position, my parents are not monkeys, Darwin was wrong (Quoting out of Context, Pseudo Rebuttal)


Ad Hoc Rescue - when faced with conflicting data, an arguer is likely to mention how the conflict will disappear if some new assumption is taken into account: I bet you bought some bad tablets (because you still got a cold after taking Vitamin C) (Questionable Explanation, Just So Story)


No True Scotsman - is a kind of ad hoc rescue of one's generalization in which the reasoner re-characterizes the situation solely in order to escape refutation of the generalization


Fallacy of Multiplication - is an argument that tries to include additional causal influences which are ultimately irrelevant to the matter at hand (Exaggeration, Converse of the Reductive Fallacy)


Inflation of Conflict - arguing that scholars debate a point, therefore no conclusions or knowledege in the whole field in question can be reached at all


Anthropomorphism - is the error of projecting uniquely human qualities onto something that isn't human. My dog is wagging his tail and running around me. Therefore, he knows that I love him


Pathetic Fallacy - is a mistaken belief due to attributing peculiarly human qualities to inanimate objects (Personification)


Reification Fallacy - to treat an abstract belief or hypothetical construct as if it represented a concrete event or physical entity: Santa Claus (Concretism, Objectification, Hypostatization)


Gambler's Fallacy - occurs when the gambler falsely assumes that the history of outcomes will affect future outcomes:

I know this is a fair coin, but it has come up heads five times in a row now, so tails is due on the next toss (respectively the Inverse: It will be heads again)


Argument from Design - this looks designed to me, it must be designed


Post Hoc - concluding that A causes B if B occurs after A, or if A and B are otherwise statistically correlated (Coincidental Correlation, affirming the consequent)


Cum Hoc - correlation implies causation: The advance of modern medicine underlies the present population explosion (Faulty Causal Presumption, Spurious Causation, Gratutious Inculpation, Scapegoating)


Juxtaposition - placing two items next to each other in order to imply a correlation, without actually claiming one


Clustering Illusion - the illusion that random events occurring in clusters are not really random events (Texas Sharpshooter Fallacy)


Package-Deal fallacy - to assume that things often grouped together by tradition or culture must always be grouped that way


Regression - attributing a regression to the mean (i.e. a natural fluctuation) to another reason


Reversing Causation - the sun sets because we have turned on the street lights


Unfalsifiability - occurs when the explanation contains claims that are not falsifiable, because there is no way to show them to be true or false. For example, they cannot be tested and cannot be deduced from other well accepted claims: There are demons in the world, which many have seen, but, strangely, they only appear to those who believe in them (Untestability, Floating Abstraction Fallacy)


Non Sequitur - something that just does not follow, Bill lives in a large building, so his apartment must be big (Irrelevant Reason) (Invalid Inference)


Sunk-Cost Fallacy - when one makes a hopeless investment, one sometimes reasons: I can’t stop now, otherwise what I’ve invested so far will be lost. This is true, of course, but irrelevant to whether one should continue to invest in the project (Concorde Fallacy)


Elephant Repellent - Hey, mister, you better buy a bottle of my Elephant Repellent. If you don't buy it, the elephants will come into the neighbourhood and trample you! My proof that this stuff really works is that there are no elephants around here


Inconsistency - occurs when an arguer accepts an inconsistent set of claims: the declining life expectancy in the Soviet Union is due to communism, while the infant mortality rate in the US is not a failure of capitalism


Relative Privation - to try to make a phenomenon appear good, by comparing it with a worse phenomenon, or to try to make a phenomenon appear bad, by comparing it with a better phenomenon: My government is a good government - because it's not as bad as other governments (Greek Math)


Shoehorning - is the process of force-fitting some current affair into one's personal, political, or religious agenda. It is common, for example, for the defenders of such things as the Bible Code or the "prophecies" of Nostradamus to shoehorn events to the texts rather than truly predict anything

Red Herring - presenting a valid argument, which proves a different proposition than the one it is purporting to support: Mark McGwire just retired. Clearly, he deserves to be in the Hall of Fame. After all, he's such a nice guy (irrelevant conclusion)


Semi-Attached Figure - if you can't prove what you want to prove, demonstrate something else and pretend that they are the same thing: if you can't prove that your nostrum can cure the common cold, advertise that a well-known "independent testing laboratory" has proven that it can kill umpteen zillion germs in a test tube in just a few minutes. Advertise those results by showing a picture of a doctor in a white coat reporting the results. Don't bother to mention the bothersome little fact that killing germs in a test tube isn't the same thing as killing them inside of people. And don't bother to mention the fact that the germs that got zapped in the test tube were something other than cold germs...


Chewbacca Defense - I'm a lawyer defending a major record company, and I'm talkin' about Chewbacca! Does that make sense? Ladies and gentlemen, I am not making any sense! None of this makes sense! And so you have to remember, when you're in that jury room deliberatin' and conjugatin' the Emancipation Proclamation, does it make sense? No! Ladies and gentlemen of this supposed jury, it does not make sense! If Chewbacca lives on Endor, you must acquit!


Lump of Labour - is a fallacy which occurs when an argument relies on the belief that something is fixed in quantity, when really that quantity changes: E.g.: in economics, where one might assume that redistributing income to one person must mean taking it away from someone else. While this is modestly persuasive, economic activities can increase or reduce the amount of wealth in the world, making the economic 'game' non-zero-sum (False Premise, Non-Sequitur)


Far-Fetched Hypothesis - is the fallacy of offering a bizarre (far-fetched) hypothesis as the correct explanation without first ruling out more mundane explanations:
Look at that mutilated cow in the field, and see that flattened grass. Aliens must have landed in a flying saucer and savaged the cow to learn more about the beings on our planet.


Least Plausible Hypothesis - I left a saucer of milk outside, in the morning the milk was gone, clearly my yard was visited by fairies


Superstitious Thinking - is based on reasons that are well known to be unacceptable, usually due to unreasonable fear of the unknown, trust in magic, or an obviously false idea of what can cause what (Escape via Irrationality)


Retrospective Determinism - to hold that because something happened, it was therefore bound to happen


Historian's fallacy - judging a person's decision in the light of new information not available at the time: Julius Caesar should not have seized power because it led to his assassination (Retrospective Determinism)


Retrogressive Causation - an interview with a young woman who had seven children - all of them "crack babies":  Interviewer: "Didn't you ever think about the effect your drug use was having on your children?"  Woman: "Yeah, that thought entered my mind now and then. Whenever it did, I got high so that I wouldn't have to think about it." The cause (drug use) has an effect (remorse). She invokes the cause in order to eliminate the effect. Thus the effect acts retrogressively to induce further implementation of the cause


Reversal of Reality - having the nerve to completely reverse reality, and say the exact opposite of the truth: As evidence accumulated that the Bush administration had lied, fabricated evidence, distorted other evidence, and hidden contradictory facts about the Weapons of Mass Destruction in Iraq in order to manufacture an excuse to go to war, Vice President Dick Cheney declared: "The President and I cannot prevent certain politicians from losing their memory or their backbone, but we're not going to sit by and let them rewrite history"



Formal fallacies (Deductive Fallacies)


Drawing an Affirmative Conclusion From a Negative Premise - is a fallacious inference where the conclusion of a standard form categorical syllogism is affirmative, but at least one of the premises is negative

Some A are B; some B are not C; therefore some A are C

Some A are not B; some B are C; therefore some A are C

Some A are not B; some B are not C; therefore some A are C

where any "some" can be replaced by an "all"

All mice are animals, and some animals are not dangerous, therefore some mice are dangerous.


Exclusive Premises - No A are B. No B are C. Therefore, no A are C.


Fallacy of Four Terms - occurs most frequently by equivocation: using the same word or phrase but with a different meaning each time, creating a fourth term even though only three distinct words are used.


Illicit Minor - the minor term is distributed in the conclusion but not in the minor premise:

All P are Q, All P are X, therefore, all Q are X


Illicit Major - the major term is distributed in the conclusion, but not in the major premise:

All dogs are animals, No cats are dogs, therefore, no cats are animals


Drawing a Negative Conclusion from Affirmative Premises -

Some A are B; some B are C; therefore some A are not C

Some A are B; some B are C; therefore no A are C

where any "some" can be replaced by an "all"

(Illicit Negative/Affirmative, Positive Conclusion/Negative Premises)


Undistributed Middle - is the formal fallacy of failing to distribute the middle term over at least one of the other terms: All collies are animals. All dogs are animals. Therefore, all collies are dogs. (A is based on B fallacy)


Affirming a Disjunct – occurs when concluding that one disjunct must be false because the other disjunct is true: P or Q. P. Therefore, not-Q. (modus tollendo ponens misunderstood)


Affirming the Consequent - to interpret an "if" as an "if and only if": if p then q, q therefore p (mistaken for modus ponendo ponens)

If she's Brazilian, then she speaks Portuguese. Hey, she does speak Portuguese. So, she is Brazilian. (Commutation of Conditionals)


Denying a Conjunct – to infer from knowing one of the conjuncts as false, that the other is true: Not both P and Q. Not P. Therefore, Q. or: It can't be too hot and too cold. It's not too hot. Therefore, it's too cold. (Modus Ponendo Tollens misunderstood)


Denying the Antecedent - occurs when the antecedent and consequent of a Transposition are switched: If p then q. Therefore, if not-p then not-q (mistaken for modus tollendo tollens) If she were Brazilian, then she would know that Brazil's official language is Portuguese. She isn't Brazilian; she's from London. So, she surely doesn't know this about Brazil's language. (Improper Transposition)

Existential fallacy - is committed in a categorical syllogism that is invalid because it has two universal premises and a particular conclusion. In other words, for the conclusion to be true a member of the class must exist, but the premises do not establish this: All inhabitants of another planet are friendly people, and all Martians are inhabitants of another planet. Therefore, some Martians are friendly people. (The conclusion assumes there really are some Martians in existence.) (Existential Instantiation, Category: Syllogistic)


Illicit Conversion - All P are Q. Therefore, all Q are P. (or Some P are not Q, Therefore, some Q are not P.)


Quantifier Shift Fallacy - You commit this fallacy if you shift the scope of a quantifier ("some" or "all") during an argument


Some Are/Some Are Not - Some S are P. Therefore, some S are not P (Unwarranted Contrast)


Modal fallacy - the error of treating modal conditionals as if the modality applies only to the consequent of the conditional: E.g. If a proposition is true, then it cannot be false. But if a proposition can not be false, then it is not only true but necessarily true. Therefore, if a proposition is true, then it's necessarily true


Fallacy of Necessity - is a fallacy in the logic of a syllogism whereby a degree of unwarranted necessity is placed in the conclusion: a) Bachelors are necessarily unmarried. b) John is a bachelor. c) John is necessarily unmarried.

This example seems watertight, but the problem lies with the necessarily in c). c) suggests that it is inconceivable for John to marry - however b) does not state this; merely that, at present, John happens to be a bachelor. For c) to hold true, both a) and b) would have to be necessarily true, but only a) is, since it is a tautology


A Priorism - you commit this fallacy if you reason from abstract principles to facts instead of vice versa. You do not commit this fallacy if you draw conclusions from abstract principles, unless you call the conclusions "facts" (Deductive fallacy)


Every and All Fallacy – is due to the order or scope of the quantifiers 'every' and 'all' and 'any':

E.g. Aristotle held: Every action of ours has some final end. So, there is some common final end to all our actions. (Scope fallacy)


Confusing Correlation and Causation - the bigger the child’s shoe size, the better his handwriting (it’s age, not size of feet that is the cause) (Common Cause)


Fallacy of Negative Premises - is committed when a categorical syllogism has a positive conclusion, but one or two negative premises: No fish are dogs, and no dogs can fly, therefore all fish can fly.


Disproof by fallacy - if a conclusion is reached in a fallacious way, the conclusion is incorrectly declared wrong (Appeal to Logic, Fallacy Fallacy)


Falsifiability fallacy fallacy - lately we have seen the notion of falsifiability represented as a fallacy. This is itself, a fallacy. The concept of falsifiability is a greatly misunderstood but legitimate part of the scientific method (a rigorous application of reason to evidence). Consider this statement made as an objection to falsifiability, "Falsifiability can be a valuable intellectual tool: it can help you to disprove ideas which are incorrect. But it does not enable you to prove ideas which are correct." In fact, that is exactly what "falsifiability" does do, and without it, no scientific hypothesis can be proven. In science, a proposed hypothesis is not considered valid if there is no experiment that can be performed that would, if the hypothesis is incorrect, fail. If such an experiment can be performed, and it "fails to fail," it is proof (or at least very good evidence) the hypothesis is correct


Two Wrongs Make a Right - is the fallacy that supposes if one wrong is committed, another wrong will cancel it out


Alternative Advance - provide two or more choices which do not cover the range of possibilities, but which only reflect essentially the same proposition: A Jehovah's Witness recruiter may say, "If you don't agree with me, let's study this book I've brought along. If you do agree, let's go to the Kingdom Hall this Sunday."Both choices expose you to indoctrination in their religion. One obvious logical choice is missing: If we don't agree about religion, we can just drop the matter and part company amicably (Hobson's Choice)


Internal Contradiction - I never borrowed his car, and it had that dent when I got it


Hooded Man - the formal fallacy of Illicit Substitution of Identicals is an error in reasoning due to confusing the knowing of a thing with the knowing of it under all its various names or descriptions: You claim to know Socrates, but you must be lying. You admitted you didn't know the hooded man over there in the corner, but the hooded man is Socrates. (Intensional fallacy)


Occam's Razor Fallacy - (violating the principle of Occam's Razor) an argument defending an overly complex explanation or an additional hypothesis for something which can be or is already explained more simply




Don Lindsay

Internet Encyclopedia of Philosophy



Bruce Thompson

Fallacy Files

European Society for General Semantics


Agent Orange

Humanist Discussion Group

Skeptic's Dictionary