Informal fallacies

 Informal fallacies – arguments that are fallacious for reasons other than structural (formal) flaws and usually require examination of the argument's content.[12]

• Appeal to the stone (argumentum ad lapidem) – dismissing a claim as absurd without demonstrating proof for its absurdity.[13]
• Argument from ignorance (appeal to ignorance, argumentum ad ignorantiam) – assuming that a claim is true because it has not been or cannot be proven false, or vice versa.[14]
  • Argument from incredulity (appeal to common sense) – "I cannot imagine how this could be true, therefore it must be false."[15]
• Argument from repetition (argumentum ad nauseam, argumentum ad infinitum) – signifies that it has been discussed extensively until nobody cares to discuss it anymore;[16][17] sometimes confused with proof by assertion
• Argument from silence (argumentum ex silentio) – where the conclusion is based on the absence of evidence, rather than the existence of evidence.[18][19]
• Argument to moderation (false compromise, middle ground, fallacy of the mean, argumentum ad temperantiam) – assuming that the compromise between two positions is always correct.[20]
• Argumentum ad hominem – the claim that a position is incorrect or an argument invalid because of something not about the position but about the person taking it.
  • ergo decedo – where a critic's perceived affiliation is seen as the underlying reason for the criticism and the critic is asked to stay away from the issue altogether.
• Argumentum verbosium – See Proof by verbosity, below.
• Begging the question (petitio principii) – providing what is essentially the conclusion of the argument as a premise.[21][22][23][24]
• Shifting the burden of proof (see – onus probandi) – I need not prove my claim, you must prove it is false.
• Circular reasoning (circulus in demonstrando) – when the reasoner begins with what he or she is trying to end up with; sometimes called assuming the conclusion.
• Circular cause and consequence – where the consequence of the phenomenon is claimed to be its root cause.
• Continuum fallacy (fallacy of the beard, line-drawing fallacy, sorites fallacy, fallacy of the heap, bald man fallacy) – improperly rejecting a claim for being imprecise.[25]
• Correlative-based fallacies
  • Correlation proves causation (post hoc ergo propter hoc) – a faulty assumption that correlation between two variables implies that one causes the other.[26]
  • Suppressed correlative – where a correlative is redefined so that one alternative is made impossible.[27]
• Divine fallacy (argument from incredulity) – arguing that, because something is so incredible/amazing/ununderstandable, it must be the result of superior, divine, alien or paranormal agency.[28]
• 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 – the misleading use of a term with more than one meaning (by glossing over which meaning is intended at a particular time).[29]
  • Ambiguous middle term – a common ambiguity in syllogisms in which the middle term is equivocated.[30]
  • Definitional retreat – changing the meaning of a word to deal with an objection raised against the original wording.[31]
• Ecological fallacy – inferences about the nature of specific individuals are based solely upon aggregate statistics collected for the group to which those individuals belong.[32]
• Etymological fallacy – which reasons that the original or historical meaning of a word or phrase is necessarily similar to its actual present-day usage.[33]
• Fallacy of accent – a specific type of ambiguity that arises when the meaning of a sentence is changed by placing an unusual prosodic stress, or when, in a written passage, it's left unclear which word the emphasis was supposed to fall on.
• Fallacy of composition – assuming that something true of part of a whole must also be true of the whole.[34]
• Fallacy of division – assuming that something true of a thing must also be true of all or some of its parts.[35]
• 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 (contextomy) – refers to the selective excerpting of words from their original context in a way that distorts the source's intended meaning.[36]
• False authority (single authority) – using an expert of dubious credentials or using only one opinion to sell a product or idea. Related to the appeal to authority fallacy.
• False dilemma (false dichotomy, fallacy of bifurcation, black-or-white fallacy) – two alternative statements are held to be the only possible options, when in reality there are more.[37]
• False equivalence – describing a situation of logical and apparent equivalence, when in fact there is none.
• Fallacy of many questions (complex question, fallacy of presupposition, loaded question, plurium interrogationum) – 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.
• Fallacy of the single cause (causal oversimplification[38]) – 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.[39]
• Historian's fallacy – occurs when one assumes that decision makers of the past viewed events from the same perspective and having the same information as those subsequently analyzing the decision.[40] (Not to be confused with presentism, which is a mode of historical analysis in which present-day ideas, such as moral standards, are projected into the past.)
• Historical fallacy – where a set of considerations holds good only because a completed process is read into the content of the process which conditions this completed result.[41]
• Homunculus fallacy – where a "middle-man" is used for explanation, this sometimes leads to regressive middle-men. Explains without actually explaining the real nature of a function or a process. Instead, it explains the concept in terms of the concept itself, without first defining or explaining the original concept. Explaining thought as something produced by a little thinker, a sort of homunculus inside the head, merely explains it as another kind of thinking (as different but the same).[42]
• Inflation of conflict – The experts of a field of knowledge disagree on a certain point, so the scholars must know nothing, and therefore the legitimacy of their entire field is put to question.[43]
• If-by-whiskey – an argument that supports both sides of an issue by using terms that are selectively emotionally sensitive.
• Incomplete comparison – in which insufficient information is provided to make a complete comparison.
• Inconsistent comparison – where different methods of comparison are used, leaving one with 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 (e.g. a work of fiction that is widely received as a blatant allegory must necessarily not be regarded as such if the author intended it not to be so.)[44]
• Ignoratio elenchi (irrelevant conclusion, missing the point) – an argument that may in itself be valid, but does not address the issue in question.[45]
• Kettle logic – using multiple, jointly inconsistent arguments to defend a position.[dubious – discuss]
• Ludic fallacy – the belief that the outcomes of non-regulated random occurrences can be encapsulated by a statistic; a failure to take into account unknown unknowns in determining the probability of events taking place.[46]
• McNamara fallacy (quantitative fallacy) – making a decision based only on quantitative observations, discounting all other considerations.
• Moral high ground fallacy – in which one assumes a "holier-than-thou" attitude in an attempt to make oneself look good to win an argument.
• 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 (raising the bar) – argument in which evidence presented in response to a specific claim is dismissed and some other (often greater) evidence is demanded.
• Naturalistic fallacy – inferring evaluative conclusions from purely factual premises[47] in violation of fact–value distinction. For instance, inferring ought from is (sometimes referred to as the is-ought fallacy) is an instance of naturalistic fallacy. Also naturalistic fallacy in a stricter sense as defined in the section "Conditional or questionable fallacies" below is an instance of naturalistic fallacy. Naturalistic fallacy is the inverse of moralistic fallacy.
• Naturalistic fallacy[48] (anti-naturalistic fallacy[49]) – inferring 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 would falsely declare such an inference invalid. Naturalistic fallacy is an instance of argument from fallacy.
• Nirvana fallacy (perfect solution fallacy) – when solutions to problems are rejected because they are not perfect.
• Onus probandi – from Latin "onus probandi incumbit ei qui dicit, non ei qui negat" the burden of proof is on the person who makes the claim, not on the person who denies (or questions the claim). It is a particular case of the argumentum ad ignorantiam fallacy, here the burden is shifted on the person defending against the assertion.
• Petitio principii – see begging the question.
• Post hoc ergo propter hoc Latin for "after this, therefore because of this" (faulty cause/effect, coincidental correlation, correlation without causation) – X happened, then Y happened; therefore X caused Y. The Loch Ness Monster has been seen in this loch. Something tipped our boat over; it's obviously the Loch Ness Monster.[50]
• Proof by assertion – a proposition is repeatedly restated regardless of contradiction; sometimes confused with argument from repetition (argumentum ad infinitum, argumentum ad nauseam)
• Proof by verbosity (argumentum verbosium, proof by intimidation) – submission of others to an argument too complex and verbose to reasonably deal with in all its intimate details. (See also Gish Gallop and argument from authority.)
• Prosecutor's fallacy – a low probability of false matches does not mean a low probability of some false match being found.
• Proving too much – using a form of argument that, if it were valid, could be used to reach an additional, undesirable conclusion.
• Psychologist's fallacy – an observer presupposes the objectivity of his own perspective when analyzing a behavioral event.
• Red herring – a speaker attempts to distract an audience by deviating from the topic at hand by introducing a separate argument the speaker believes is easier to speak to.[51]
• Referential fallacy[52] – 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 we use them.
• Regression fallacy – ascribes cause where none exists. The flaw is failing to account for natural fluctuations. It is frequently a special kind of the post hoc fallacy.
• Reification (concretism, hypostatization, or the fallacy of misplaced concreteness) – a fallacy of ambiguity, when an abstraction (abstract belief or hypothetical construct) is treated as if it were a concrete, real event or physical entity. In other words, it is the error of treating as a "real thing" something that is not a real thing, but merely an idea.
• Retrospective determinism – the argument that because an event has occurred under some circumstance, the circumstance must have made its occurrence inevitable.
• Shotgun argumentation – the arguer offers such a large number of arguments for a position that the opponent can't possibly respond to all of them. (See "Argument by verbosity" and "Gish Gallop", above.)
• Special pleading – where a proponent of a position attempts to cite something as an exemption to a generally accepted rule or principle without justifying the exemption.
• Wrong direction – cause and effect are reversed. The cause is said to be the effect and vice versa.[53]