List of fallacies
In reasoning to argue a claim, a fallacy is reasoning that is evaluated as logically incorrect and that undermines the logical validity of the argument and permits its recognition as unsound. Regardless of their soundness, all registers and manners of speech can demonstrate fallacies.
Because of their variety of structure and application, fallacies are challenging to classify. Fallacies can be classified strictly by either their structure or content. The classification of informal fallacies may be subdivided into categories such as linguistic, relevance through omission, relevance through intrusion, and relevance through presumption. Or, fallacies may be classified by the process by which they occur, such as material fallacies, verbal fallacies, and again formal fallacies. Material fallacies may be placed into the broader category of informal fallacies, while formal fallacies may be placed into the more precise category of logical fallacies. Yet, verbal fallacies may be placed into either informal or deductive classifications; compare equivocation which is a word or phrase based ambiguity to the fallacy of composition which is premise and inference based ambiguity.
The conscious or habitual use of fallacies as rhetorical devices is prevalent in the desire to persuade when the focus is more on communication and eliciting common agreement rather than on correctness of the reasoning. The effective use of a fallacy may be considered clever, but the reasoning should be recognized as unsound and the conclusion regarded as unproven.
Formal fallacies
A formal fallacy is an error in logic that can be seen in the argument's form. All formal fallacies are specific types of Non sequitur.- Appeal to probability – a statement that takes something for granted because it would probably be the case.
- Argument from fallacy – the assumption that if an argument for some conclusion is fallacious, then the conclusion is false.
- Base rate fallacy – making a probability judgment based on conditional probabilities, without taking into account the effect of prior probabilities.
- Conjunction fallacy – the assumption that an outcome simultaneously satisfying multiple conditions is more probable than an outcome satisfying a single one of them.
- Masked-man fallacy – the substitution of identical designators in a true statement can lead to a false one.
Propositional fallacies
Types of propositional fallacies:
- Affirming a disjunct – concluding that one disjunct of a logical disjunction must be false because the other disjunct is true; A or B; A, therefore not B.
- Affirming the consequent – the antecedent in an indicative conditional is claimed to be true because the consequent is true; if A, then B; B, therefore A.
- Denying the antecedent – the consequent in an indicative conditional is claimed to be false because the antecedent is false; if A, then B; not A, therefore not B.
Quantification fallacies
Types of quantification fallacies:
- Existential fallacy – an argument that has a universal premise and a particular conclusion.
Formal syllogistic fallacies
- Affirmative conclusion from a negative premise – a categorical syllogism has a positive conclusion, but at least one negative premise.
- Fallacy of exclusive premises – a categorical syllogism that is invalid because both of its premises are negative.
- Fallacy of four terms – a categorical syllogism that has four terms.
- Illicit major – a categorical syllogism that is invalid because its major term is not distributed in the major premise but distributed in the conclusion.
- Illicit minor – a categorical syllogism that is invalid because its minor term is not distributed in the minor premise but distributed in the conclusion.
- Negative conclusion from affirmative premises – a categorical syllogism has a negative conclusion but affirmative premises.
- Fallacy of the undistributed middle – the middle term in a categorical syllogism is not distributed.
- Modal fallacy – confusing possibility with necessity.
- Modal scope fallacy – a degree of unwarranted necessity is placed in the conclusion.
Informal fallacies
- Argument to moderation – assuming that the compromise between two positions is always correct.
- Continuum fallacy – improperly rejecting a claim for being imprecise.
- Correlative-based fallacies
- * Suppressed correlative – a correlative is redefined so that one alternative is made impossible.
- Definist fallacy – defining a term used in an argument in a biased manner. The person making the argument expects the listener will accept the provided definition, making the argument difficult to refute.
- Divine fallacy – arguing that, because something is so incredible or amazing, it must be the result of superior, divine, alien or paranormal agency.
- Double counting – counting events or occurrences more than once in probabilistic reasoning, which leads to the sum of the probabilities of all cases exceeding unity.
- Equivocation – using a term with more than one meaning in a statement without specifying which meaning is intended.
- *Ambiguous middle term – using a middle term with multiple meanings.
- * Definitional retreat – changing the meaning of a word when an objection is raised.
- *Motte-and-bailey fallacy – conflating two positions with similar properties, one modest and easy to defend and one more controversial. The arguer first states the controversial position, but when challenged, states that they are advancing the modest position.
- * Fallacy of accent – changing the meaning of a statement by not specifying on which word emphasis falls.
- * Persuasive definition – purporting to use the "true" or "commonly accepted" meaning of a term while, in reality, using an uncommon or altered definition.
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- Ecological fallacy – inferences about the nature of specific individuals are based solely upon aggregate statistics collected for the group to which those individuals belong.
- Etymological fallacy – reasoning that the original or historical meaning of a word or phrase is necessarily similar to its actual present-day usage.
- Fallacy of composition – assuming that something true of part of a whole must also be true of the whole.
- Fallacy of division – assuming that something true of a thing must also be true of all or some of its parts.
- False attribution – an advocate appeals to an irrelevant, unqualified, unidentified, biased or fabricated source in support of an argument.
- * Fallacy of quoting out of context – refers to the selective excerpting of words from their original context in a way that distorts the source's intended meaning.
- False authority – using an expert of dubious credentials or using only one opinion to sell a product or idea. Related to the appeal to authority.
- False dilemma – two alternative statements are held to be the only possible options when in reality there are more.
- False equivalence – describing two or more statements as virtually equal when they are not.
- Feedback fallacy - believing in the objectivity of an evaluation to be used as the basis for improvement without verifying that the source of the evaluation is a disinterested party.
- Historian's fallacy – assuming that decision makers of the past had identical information as those subsequently analyzing the decision. This should not to be confused with presentism, in which present-day ideas and perspectives are anachronistically projected into the past.
- Historical fallacy – a set of considerations is thought to hold good only because a completed process is read into the content of the process which conditions this completed result.
- * Baconian fallacy - using pieces of historical evidence without the aid of specific methods, hypotheses, or theories in an attempt to make a general truth about the past. Commits historians "to the pursuit of an impossible object by an impracticable method".
- Homunculus fallacy – using a "middle-man" for explanation; this sometimes leads to regressive middle-men. It explains a concept in terms of the concept itself without explaining its real nature.
- – arguing that, if experts in a field of knowledge disagree on a certain point within that field, no conclusion can be reached or that the legitimacy of that field of knowledge is questionable.
- If-by-whiskey – an argument that supports both sides of an issue by using terms that are selectively emotionally sensitive.
- Incomplete comparison – insufficient information is provided to make a complete comparison.
- Inconsistent comparison – different methods of comparison are used, leaving a false impression of the whole comparison.
- Intentionality fallacy – the insistence that the ultimate meaning of an expression must be consistent with the intention of the person from whom the communication originated
- Lump of labour fallacy – the misconception that there is a fixed amount of work to be done within an economy, which can be distributed to create more or fewer jobs.
- Kettle logic – using multiple, jointly inconsistent arguments to defend a position.
- Ludic fallacy – the belief that the outcomes of non-regulated random occurrences can be encapsulated by a statistic; a failure to take into account that unknown unknowns have a role in determining the probability of events taking place.
- McNamara fallacy – making a decision based only on quantitative observations, discounting all other considerations.
- Mind projection fallacy – subjective judgments are "projected" to be inherent properties of an object, rather than being related to personal perceptions of that object.
- Moralistic fallacy – inferring factual conclusions from purely evaluative premises in violation of fact–value distinction. For instance, inferring is from ought is an instance of moralistic fallacy. Moralistic fallacy is the inverse of naturalistic fallacy defined below.
- Moving the goalposts – argument in which evidence presented in response to a specific claim is dismissed and some other evidence is demanded.
- Nirvana fallacy – solutions to problems are rejected because they are not perfect.
- Proof by assertion – a proposition is repeatedly restated regardless of contradiction; sometimes confused with argument from repetition
- Prosecutor's fallacy – a low probability of false matches does not mean a low probability of false match being found.
- Proving too much – an argument that results in an overly-generalized conclusion.
- Psychologist's fallacy – an observer presupposes the objectivity of their own perspective when analyzing a behavioral event.
- Referential fallacy – assuming all words refer to existing things and that the meaning of words reside within the things they refer to, as opposed to words possibly referring to no real object or that the meaning of words often comes from how they are used.
- Reification – treating an abstract belief or hypothetical construct as if it were a concrete, real event or physical entity.
- Retrospective determinism – the argument that because an event has occurred under some circumstance, the circumstance must have made its occurrence inevitable.
- Slippery slope – asserting that a proposed. relatively small, first action will inevitably lead to a chain of related events resulting in a significant and negative event and, therefore, should not be permitted.
- Special pleading – the arguer attempts to cite something as an exemption to a generally accepted rule or principle without justifying the exemption.
Improper premise
- Begging the question – using the conclusion of the argument in support of itself in a premise.
- * Loaded label – while not inherently fallacious, use of evocative terms to support a conclusion is a type of begging the question fallacy. When fallaciously used, the term's connotations are relied on to sway the argument towards a particular conclusion. For example, an organic foods advertisement that says "Organic foods are safe and healthy foods grown without any pesticides, herbicides, or other unhealthy additives." Use of the term "unhealthy additives" is used as support for the idea that the product is safe.
- Circular reasoning – the reasoner begins with what he or she is trying to end up with.
- Fallacy of many questions – someone asks a question that presupposes something that has not been proven or accepted by all the people involved. This fallacy is often used rhetorically so that the question limits direct replies to those that serve the questioner's agenda.
Faulty generalizations
- Accident – an exception to a generalization is ignored.
- * No true Scotsman – makes a generalization true by changing the generalization to exclude a counterexample.
- Cherry picking – act of pointing at individual cases or data that seem to confirm a particular position, while ignoring a significant portion of related cases or data that may contradict that position.
- * Survivorship bias – a small number of successes of a given process are actively promoted while completely ignoring a large number of failures
- False analogy – an argument by analogy in which the analogy is poorly suited.
- Hasty generalization – basing a broad conclusion on a small sample or the making of a determination without all of the information required to do so.
- Inductive fallacy – A more general name to some fallacies, such as hasty generalization. It happens when a conclusion is made of premises that lightly support it.
- Misleading vividness – involves describing an occurrence in vivid detail, even if it is an exceptional occurrence, to convince someone that it is a problem; this also relies on the appeal to emotion fallacy.
- Overwhelming exception – an accurate generalization that comes with qualifications that eliminate so many cases that what remains is much less impressive than the initial statement might have led one to assume.
- Thought-terminating cliché – a commonly used phrase, sometimes passing as folk wisdom, used to quell cognitive dissonance, conceal lack of forethought, move on to other topics, etc. – but in any case, to end the debate with a cliché rather than a point.
Questionable cause
- Cum hoc ergo propter hoc – a faulty assumption that, because there is a correlation between two variables, one caused the other.
- * Post hoc ergo propter hoc – X happened, then Y happened; therefore X caused Y.
- * Wrong direction – cause and effect are reversed. The cause is said to be the effect and vice versa. The consequence of the phenomenon is claimed to be its root cause.
- * Ignoring a common cause
- Fallacy of the single cause – it is assumed that there is one, simple cause of an outcome when in reality it may have been caused by a number of only jointly sufficient causes.
- Furtive fallacy – outcomes are asserted to have been caused by the malfeasance of decision makers.
- Gambler's fallacy – the incorrect belief that separate, independent events can affect the likelihood of another random event. If a fair coin lands on heads 10 times in a row, the belief that it is "due to the number of times it had previously landed on tails" is incorrect.
- * Inverse gambler's fallacy
- Magical thinking – fallacious attribution of causal relationships between actions and events. In anthropology, it refers primarily to cultural beliefs that ritual, prayer, sacrifice, and taboos will produce specific supernatural consequences. In psychology, it refers to an irrational belief that thoughts by themselves can affect the world or that thinking something corresponds with doing it.
- Regression fallacy – ascribes cause where none exists. The flaw is failing to account for natural fluctuations. It is frequently a special kind of post hoc fallacy.
Relevance fallacies
- Appeal to the stone – dismissing a claim as absurd without demonstrating proof for its absurdity.
- Argument from ignorance – assuming that a claim is true because it has not been or cannot be proven false, or vice versa.
- Argument from incredulity – "I cannot imagine how this could be true; therefore, it must be false."
- Argument from repetition – repeating an argument until nobody cares to discuss it any more; sometimes confused with proof by assertion
- Argument from silence – assuming that a claim is true based on the absence of textual or spoken evidence from an authoritative source, or vice versa.
- Ignoratio elenchi – an argument that may in itself be valid, but does not address the issue in question.
Red herring fallacies
Red herring – introducing a second argument in response to the first argument that is irrelevant and draws attention away from the original topic. See also irrelevant conclusion.
- Ad hominem – attacking the arguer instead of the argument.
- *Circumstantial ad hominem - stating that the arguer's personal situation or perceived benefit from advancing a conclusion means that their conclusion is wrong.
- * Poisoning the well – a subtype of ad hominem presenting adverse information about a target person with the intention of discrediting everything that the target person says.
- * Appeal to motive – dismissing an idea by questioning the motives of its proposer.
- * – a sophistical and unfalsifiable form of argument that attempts to overcome an opponent by inducing a sense of guilt and using the opponent's denial of guilt as further evidence of guilt.
- * Tone policing – focusing on emotion behind a message rather than the message itself as a discrediting tactic.
- * Traitorous critic fallacy – a critic's perceived affiliation is portrayed as the underlying reason for the criticism and the critic is asked to stay away from the issue altogether. Easily confused with the association fallacy below.
- Appeal to authority – an assertion is deemed true because of the position or authority of the person asserting it.
- * Appeal to accomplishment – an assertion is deemed true or false based on the accomplishments of the proposer. This may often also have elements of appeal to emotion.
- * Courtier's reply – a criticism is dismissed by claiming that the critic lacks sufficient knowledge, credentials, or training to credibly comment on the subject matter.
- Appeal to consequences – the conclusion is supported by a premise that asserts positive or negative consequences from some course of action in an attempt to distract from the initial discussion.
- Appeal to emotion – an argument is made due to the manipulation of emotions, rather than the use of valid reasoning.
- * Appeal to fear – an argument is made by increasing fear and prejudice towards the opposing side
- * Appeal to flattery – an argument is made due to the use of flattery to gather support.
- * Appeal to pity – an argument attempts to induce pity to sway opponents.
- * Appeal to ridicule – an argument is made by presenting the opponent's argument in a way that makes it appear ridiculous.
- * Appeal to spite – an argument is made through exploiting people's bitterness or spite towards an opposing party.
- * Judgmental language – insulting or pejorative language to influence the audience's judgment.
- * Pooh-pooh – dismissing an argument perceived unworthy of serious consideration.
- * Wishful thinking – a decision is made according to what might be pleasing to imagine, rather than according to evidence or reason.
- Appeal to nature – judgment is based solely on whether the subject of judgment is 'natural' or 'unnatural'.
- Appeal to novelty – a proposal is claimed to be superior or better solely because it is new or modern.
- Appeal to poverty – supporting a conclusion because the arguer is poor.
- Appeal to tradition – a conclusion supported solely because it has long been held to be true.
- Appeal to wealth – supporting a conclusion because the arguer is wealthy.
- Argumentum ad baculum – an argument made through coercion or threats of force to support position.
- Argumentum ad populum – a proposition is claimed to be true or good solely because a majority or many people believe it to be so.
- Association fallacy – arguing that because two things share some property, they are the same.
- Ipse dixit – a claim that is presented as true without support, as self-evidently true, or as dogmatically true. This fallacy relies on the implied expertise of the speaker or on an unstated truism.
- Bulverism – inferring why an argument is being used, associating it to some psychological reason, then assuming it is invalid as a result. The assumption that if the origin of an idea comes from a biased mind, then the idea itself must also be a falsehood.
- Chronological snobbery – a thesis is deemed incorrect because it was commonly held when something else, known to be false, was also commonly held.
- – dismissing an argument or complaint due to what are perceived to be more important problems. First World problems are a subset of this fallacy.
- Genetic fallacy – a conclusion is suggested based solely on something or someone's origin rather than its current meaning or context.
- I'm entitled to my opinion – a person discredits any opposition by claiming that they are entitled to their opinion.
- Moralistic fallacy – inferring factual conclusions from evaluative premises, in violation of fact-value distinction; e.g. making statements about what is, on the basis of claims about what ought to be. This is the inverse of the naturalistic fallacy.
- Naturalistic fallacy – inferring evaluative conclusions from purely factual premises in violation of fact-value distinction. Naturalistic fallacy is the inverse of moralistic fallacy.
- * Is–ought fallacy – statements about what is, on the basis of claims about what ought to be.
- – inferring an impossibility to infer any instance of ought from is from the general invalidity of is-ought fallacy, mentioned above. For instance, is does imply ought for any proposition, although the naturalistic fallacy fallacy would falsely declare such an inference invalid. Naturalistic fallacy fallacy is a type of argument from fallacy.
- Straw man fallacy – misrepresenting an opponent's argument by broadening or narrowing the scope of a premise and refuting a weaker version.
- Texas sharpshooter fallacy – improperly asserting a cause to explain a cluster of data.
- Tu quoque – the argument states that a certain position is false or wrong or should be disregarded because its proponent fails to act consistently in accordance with that position.
- Two wrongs make a right – occurs when it is assumed that if one wrong is committed, another wrong will rectify it.
- Vacuous truth – a claim that is technically true but meaningless, in the form of claiming that no A in B has C, when there is no A in B. For example, claiming that no mobile phones in the room are on when there are no mobile phones in the room at all.
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