329 - Logical Fallacies | Scoins.net | DJS

## 329 - Logical Fallacies

This page began with the intention of identifying a way to remember the top ten logical fallacies. Then I discovered just how very many there are, perhaps 200 when including the multiple names, so the result is this very long list. I may manage to break the list into classifications.

Many of these fall into the general category of failed syllogisms¹, while some don't even attempt to be syllogisms; the premises are so poorly expressed that they might well be classed as improper premises. The wikipedia article divides the topic into formal and informal fallacies. The informal class includes also the improper premises, faulty generalisations, Questionable causes and relevance fallacies (e.g., red herrings).

A syllogism is a three part deductive argument, consisting of a major premise, a minor premise and a deduced conclusion connecting subject S and predicate P. The two premises refer to a middle term [M] that does not occur in the deduction, such that the major premise describes some relationship between M&P, the minor between S&M. The excellent wikipedia article (yes, I contributed this year, again) defines the AEIO code set per the table to the right here. The middle term (which you might think of as the muddle termcan be either the subject or the predicate of each premise where it appears.

The third of these tables provides the remainder of the required explanation to understand descriptive shorthand codes such as AAA1. This makes four ways of constructing each of the three statements and four figures, giving 4⁴ possibilities, 256 distinct syllogisms. However, many are invalid, in that the conclusion does not follow, and we have the delightful use of names to help sort out what is or is not valid. Of this table, be aware that italics are used to indicate controversial patterns, where the conclusion could be strengthened. I'll let you work out which four are not weakened in this way.. So Barbara refers to AAA1, Disamis to IAI3. In this way one can produce a diagram such as follows. [felapton, darapti, fesapo and bamalip                                               [6]

The table of names (of sorts of names, right, shows that there are only 15 certain combinations and a further nine that may be disputed. For example, AAA1 (Barbara) succeeds, but AAI4 (Barbari) may fail and EOO4 does fail, see exclusive premises below. There is one further issue, of distributive predication, which identifies that some things do or don't distribute. AAA1 fails here: All Brits are animals, animals are numerous, so all Brits are numerous. This fails because numerous is a general term (test: you can't have "is a numerous"). Please argue with this. Obviously we will have a selection of logical failures that look like syllogisms but are not within the solution set of 24 from 256 possibles. We will have some which fail because a premise fails to be true, and some where a label has multiple meanings not all true in the statement given. Testing the major and minor premises for truth is sometimes difficult, such that there are implied premises (effectively, a missing IF); IF major AND minor THEN conclusion. And if not, not, with third ways somehow ignored.  See [7], especially formal syllogistic fallacies.

Set theory is useful here. The logic statements are in one of the tables up and to the right. Much of the difficulty occurs when sets are actually equal, such that intersection is complete, and where the intersection of two sets is empty. Do look at the other types of syllogisms at the foot of [7].

1 Ad Baculum (Scare Tactic) – A fallacy in which terrorising one’s opponent is supposed to give him a reason for believing that your argument is correct.  This is similar to an argument from authority, as it is an argument backed by fear. “Agree with me or I’ll hurt you” is how this argument is phrased. Sometimes it isn’t that direct, such as “Love god or you’ll go to hell.” The threat might not be caused by the person making it, but it changes perspective through vague fear, rather than reasoning. [3] [4]  Argumentum ad baculum (appeal to the stick, appeal to force, appeal to threat) – an argument made through coercion or threats of force to support position.[86]

2 Accident – We often arrive at a generalisation but don’t or can’t list all the exceptions. When we reason with the generalisation s if it has no exceptions, our reasoning contains this fallacy. Connected with this is No true Scotsman, which makes a generalisation true by changing the generalisation to exclude a counterexample.ExamplePerson A: "No Scotsman puts sugar on his porridge." Person B: "But my uncle Angus is a Scotsman and he puts sugar on his porridge." Person A: "But no true Scotsman puts sugar on his porridge." Sometimes called an ad hoc rescue, which strikes me as accurate.

3 Ad Consequentiam (Appeal to Consequences) – Arguing that a belief is false because it implies something you’d rather not believe.

4 Ad Crumenum (Appeal to Money) – The error of supposing that, if something costs a great deal of money, then it must be better. Similarly it’s a mistake to suppose that if something is cheap it must be of inferior quality. Loose end here...The same .................

5 Ad Hoc Rescue – If there is no good reason to accept an assumption other than that it helps to save your cherished belief, then this fallacy is committed.  See Accident.

6 Ad Hominem – An irrelevant attack on the arguer that is supposed to undermine the actual argument. This is a common political manoeuvre where you attack a person, rather than an argument. The assumption is that if you discredit the source, you discredit the point. That’s completely false. Even a completely “wrong” person can make a valid point. Automatically attacking someone, rather than the idea they present, shows you can’t counteract their idea. The geese picture, above. Attacking the arguer instead of the argument. (Note that "ad hominem" can also refer to the dialectical strategy of arguing on the basis of the opponent's own commitments. This type of ad hominem is not a fallacy.)  Ad hominem  [1] [3] [4]  Circumstantial ad hominem – stating that the arguer's personal situation or perceived benefit from advancing a conclusion means that their conclusion is wrong.[67]

7 Ad Populum – The conclusion that a proposition is true because many or most people believe it. See Bandwagoning. [4]

8 Affirming the Consequent – A propositional fallacy with the false assumption that, if you have enough evidence to assert the truth of the consequent of a conditional, then you have enough evidence to affirm the truth of the antecedent. The antecedent in an indicative conditional is claimed to be true because the consequent is true; if A, then B; B, therefore A. [4]

9 Affirming a Disjunct – A propositional fallacy concluding that one disjunct of a logical disjunction must be false because the other disjunct is true; A or B; A, therefore not B. [4]   The problem here is the use of OR, which in set theory is an inclusive term, allowing both to be true because this OR is the same as the union of two sets. Many people use the exclusive OR, where A or B means also that A is in B' and B is in A' and automatically A∩B=∅. There is a related problem [Bifurcation] where defining A and B precludes there being any third possible condition.

10 Anecdotal Evidence – Fallacious generalising on the basis of some story that provides an inadequate sample, especially used to discount evidence arrived at by systematic search or by testing in favour of a few firsthand cases. Example: One of our clients doubled their conversions after changing all their landing page text to bright red. Therefore, changing all text to red is a proven way to double conversions. [2]

11 Anthropomorphism – The error of projecting uniquely human qualities onto something that isn’t human. 7 Alphabet Soup – by the use of acronyms, abbreviation and occulted language, bamboozle people into thinking you know what you're talking about and therefore you are right. [1]

12 Appeal to Authority - some so-called authority says <thing> so it must be true, with no evidence required. [1]  [2] 7 Appeal to Ignorance – Two forms: (1) Not knowing that a certain statement is true is taken to be a proof that it is false. (2) Not knowing that a statement is false is taken to be a proof that it is true. [1] Similarly, False Authority or Single Authority, where one uses an expert of dubious or irrelevant credentials or uses only one opinion to promote a product or idea. Appeal to authority (argument from authority, argumentum ad verecundiam) – an assertion is deemed true because of the position or authority of the person asserting it.

13 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 (see below).

14 Appeal to consequences (argumentum ad consequentiam) – 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.[72]

15 Appeal to Emotion – An appeal to accept a claim merely because the appeal arouses your feelings of anger, grief, etc. Closely allied to Misleading vividness, which involves describing an occurrence in vivid detail, even if it is an exceptional occurrence, to convince someone that it is more important. [4]  Manipulating the emotions of the listener rather than using valid reasoning to obtain common agreement.Appeal to emotion [4]

16 Appeal to fear – generating distress, anxiety, cynicism, or prejudice towards the opponent in an argument[74]

17 Appeal to  flattery – using excessive or insincere praise to obtain common agreement.[75]

18 Appeal to motive – dismissing an idea by questioning the motives of its proposer.

19 Appeal to nature – judgment is based solely on whether the subject of judgment is 'natural' or 'unnatural'.[81] (Sometimes also called the "naturalistic fallacy", but is not to be confused with the other fallacies by that name.)

20 Appeal to novelty (argumentum novitatis, argumentum ad antiquitatis) – a proposal is claimed to be superior or better solely because it is new or modern.[82] (opposite of appeal to tradition)

21 Appeal to pity (argumentum ad misericordiam) – generating feelings of sympathy or mercy in the listener to obtain common agreement.[76]

22 Appeal to poverty (argumentum ad Lazarum) – supporting a conclusion because the arguer is poor (or refuting because the arguer is wealthy). (Opposite of appeal to wealth.) [83]

23 Appeal to Probability – a statement that takes something for granted because it would probably be the case (or might be the case). An appeal to probability is the logical fallacy of taking something for granted because it would probably be the case. Inductive arguments lack deductive validity and must therefore be asserted or denied in the premises. One of the formal fallacies. [4]

25 Appeal to spite – generating bitterness or hostility in the listener toward an opponent in an argument.[78]

26 Appeal to the stone (argumentum ad lapidem) – dismissing a claim as absurd without demonstrating proof for its absurdity.[57] A relevance fallacy [4]

27 Appeal to Traditional Wisdom – Implying that a practice must be okay today simply because it has been the apparently wise practice in the past. Appeal to tradition (argumentum ad antiquitatem) – a conclusion supported solely because it has long been held to be true. [84] [4]

28 Appeal to wealth (argumentum ad crumenam) – supporting a conclusion because the arguer is wealthy (or refuting because the arguer is poor).[85] (Sometimes taken together with the appeal to poverty as a general appeal to the arguer's financial situation.)

29 Arguing from Authority  – I know more about this than you do. Does this add any validity to the argument? This is often the opposite of an Ad Hominem attack. Rather than going after the person making a claim, you claim to know better because you have greater “authority.” This is often what happens when someone points to their job as evidence. “I think I would know. After all, I am an attorney.” Doesn't actually mean anything. A person might be correct, and they might have additional information thanks to their job, habits, or hobbies. That doesn’t add validity to their argument. A bad idea is a bad idea no matter who it comes from. [3]

130 Arguing from Confusion – This posits you’re right because no one knows the answer. “Why not believe in the Dharma? No one knows it doesn’t work.” Common in religion, this wrongheaded approach says that no one knows the answer, which makes any answer as good as any other. Not knowing about God or Hell or aliens doesn’t mean any of the above are or are not true. Pointing at nothing and saying it means something is nothing short of insane. Yet we do it all the time. [3]

31 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.[58] A relevance fallacy [4]

32 Argument from Incredulity – arguing that, because something is so incredible or amazing, it must be the result of superior, divine, alien or paranormal agency. Also called Divine Fallacy. "I cannot imagine how this could be true; therefore, it must be false."[59] A relevance fallacy [4] Argument from incredulity (appeal to common sense)

33 Argument from repetition (argumentum ad nauseam, argumentum ad infinitum) – repeating an argument until nobody cares to discuss it any more;  sometimes confused with proof by assertionA relevance fallacy [4]

34 Argument from silence (argumentum ex silentio) – assuming that a claim is true based on the absence of textual or spoken evidence from an authoritative source, or vice versa.[62] A relevance fallacy [4]

35 Association fallacy (guilt by association and honour by association) – arguing that because two things share (or are implied to share) some property, they are the same.[88]

36 Avoiding the Issue – Supposing to address an issue but instead goes off on a tangent.

37 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".[4]

38 Bandwagoning – As with speaking in totality, where you only pay attention to extremes, there’s bandwagon appeals. This is essentially peer pressure to join with everyone else. It doesn’t make an argument better to say more people do it. In fact, it’s right up there with “if all your friends jumped off a bridge…” but it still works. No one wants to be left out, and this claims that by not joining up you’re not on the team. It dovetails with speaking in totality by notions like “if you’re not with us, you’re against us.” As if there are only two sides. Just because a significant population of people believe a proposition is true, doesn't automatically make it true. Popularity alone is not enough to validate an argument, though it's often used as a standalone justification of validity. Arguments in this style don't take into account whether or not the population validating the argument is actually qualified to do so, or if contrary evidence exists. While most of us expect to see bandwagon arguments in advertising (e.g., "Three out of four people think X brand toothpaste cleans teeth best"), this fallacy can easily sneak it's way into everyday meetings and conversations.                                                                                                               Example The majority of people believe advertisers should spend more money on billboards, so billboards are objectively the best form of advertisement. [1] [2] [3] [4]  Argumentum ad populum (appeal to widespread belief, bandwagon argument, appeal to the majority, appeal to the people) – a proposition is claimed to be true or good solely because a majority or many people believe it to be so.[87]

39 Bare Assertion See Ipse Dixit

40 Base Rate Fallacy – making a probability judgment based on conditional probabilities, without taking into account the effect of prior probabilities. The base rate fallacy, also called base rate neglect or base rate bias, is a fallacy. If presented with related base rate information and specific information, people tend to ignore the base rate in favour of the individuating information, rather than correctly integrating the two. One of the formal fallacies. [4]

41 Begging the question (petitio principii) – using the conclusion of the argument in support of itself in a premise (e.g.: saying that smoking cigarettes is deadly because cigarettes can kill you; something that kills is deadly). [4]  Within this is the 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.[45] Also Circular Reasoning.

42 Bifurcation (False Dilemma) – A fallacy that unfairly limits you to only two choices.

43 Bulverism (psychogenetic fallacy) – 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.[36]

44 Burden of proof – If a person claims that X is true, it is their responsibility to provide evidence in support of that assertion. It is invalid to claim that X is true until someone else can prove that X is not true. Similarly, it is also invalid to claim that X is true because it's impossible to prove that X is false.  In other words, just because there is no evidence presented against something, that doesn't automatically make that thing true. Example: Barbara believes the marketing agency's office is haunted, since no one has ever proven that it isn't haunted. [2]

45 Causal Oversimplification – 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.  This is a questionable cause fallacy. Fallacy of the single cause (causal oversimplification  [55])  [4]

46 Circular Reasoning – Most arguments between couples fall into this category. Here, you’re using your own logic to support your argument in an endless cycle. It works well with arguing from confusion. “If you wouldn’t do X I wouldn’t do Y. And you wouldn’t do X if I didn’t do Y.” is one of the most common arguments. It absolves the person of responsibility, constantly referring back to another idea. “Allah is real because the Koran says so, and the Koran says so because it is true” is another example. One thing points forever to another, creating a loop. Also called circular argument, Petitio Principle and Begging the Question. [1] [3] [4]

47 Cherry picking  – using individual cases or data that confirm a particular position, while ignoring related cases or data that may contradict that position. Also (suppressed evidence, incomplete evidence. [4] Cherry picking

48 Chronological snobbery – a thesis is deemed incorrect because it was commonly held when something else, known to be false, was also commonly held. [91][92]  [4]

49 Circumstantial Ad Hominem – A person is said to be guilty of error because of the group he or she associates with. Example: because you voted Leave you're assumed to also agree with the beliefs of the most extreme Leavers, such as that no refugees will be accepted. Division is similar.

50 Composition – Mistakenly assuming that a characteristic of some or all the individuals in a group is also a characteristic of the group itself, the group “composed” of those members. [4]

51 Confirmation Bias – The tendency to look only for evidence in favour of one’s controversial hypothesis and not to look for disconfirming evidence, or to pay insufficient attention to it.

52 Confusing Correlation and Causation – Many things happen all at the same time. Sometimes one thing causes another. It snows, and the ground gets wet. That’s one thing causing another. However, assuming that one thing leads to another isn’t always correct, which is where superstition comes from. Think of sports fanatics who believe they must wear a jersey, must eat out of a bowl, must perform a ritual or their team will lose. It’s controlled madness to say that the Seahawks’ terrible performance was the fault of Jimmy who didn’t drink out of the right side of the glass. [2] [3]

53 Confusing an Explanation with an Excuse – Treating someone’s explanation of a fact as if it were a justification of the fact. Explaining a crime should not be confused with excusing the crime, but it too often is.

54 Conjunction Fallacy  – the assumption that an outcome simultaneously satisfying multiple conditions is more probable than an outcome satisfying a single one of them.  The conjunction fallacy is a formal fallacy that occurs when it is assumed that specific conditions are more probable than a single general one. [4]

55 Continuum Fallacy – improperly rejecting a claim for being imprecise. Also called fallacy of the beard, line-drawing fallacy, sorites fallacy, fallacy of the heap, bald man fallacy, decision-point fallacy. See. Somewhere in this argument is the problem that something discrete can have many states: when does a pile of sand from which you remove grains, stop being a pile? When is a room cold? Does a single day's growth a facial hair constitute a beard? If it doesn't after how many days does it suddenly exist? The underlying issue here is that a statement demanding a binary state true/false does not occur. Possibly a language problem, but not sufficient reason to reject a conclusion.

56 Converse Accident –  – improperly rejecting a claim for being imprecise. Considering certain exceptional cases and generalising to a rule that fits them alone; a type of hasty generalisation.

57 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.

58 Cum Hoc, Ergo Propter Hoc – "With this, therefore because of this.” A false cause fallacy that doesn’t depend on time order (as does the post hoc fallacy), but on any other chance correlation of the supposed cause being in the presence of the supposed effect. Correlation implies causation; faulty cause/effect, coincidental correlation, correlation without causation) – a faulty assumption that, because there is a correlation between two variables, one caused the other.Cum hoc ergo propter hoc (Latin for "with this, therefore because of this". This is a questionable cause fallacy. [4]

59 Definist  – Occurs when someone unfairly defines a term so that a controversial position is made easier to defend. A term used in an argument in a biased manner (e.g., using "loaded terms"). The person making the argument expects that the listener will accept the provided definition, making the argument difficult to refute.

60 Denying the Antecedent – the propositional fallacy where 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. [4]

61 Division – Merely because a group as a whole has a characteristic, it often doesn’t follow that individuals in the group have that characteristic. If you suppose that it does follow your reason, when it doesn’t, then your reasoning is false. [4]  This might be the same as Circumstantial Ad Hominem.

62  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. See. Pretty stupid.

63 Ecological Fallacy – inferring about the nature of an entity based solely upon aggregate statistics collected for the group to which that entity belongs. Also population fallacy. Look at the fallacy of division and at the four statistical ecological fallacies; confusion between ecological correlations and individual correlations, confusion between group average and total average, Simpson's paradox, and confusion between higher average and higher likelihood.

64 Equivocation – The illegitimate switching of the meaning of a term during the reasoning. This is an example of Quaternio Terminorum. We can include here using an ambiguous middle term, definitional retreat (changing the meaning when challenged), motte and bailey fallacy (see), fallacy of accent (changing the meaning of a statement by moving the emphasis or not making the emphasis) and persuasive definition, where the definition actually used conflicts with that commonly accepted – a semantic problem.

65 Etymological – Occurs whenever someone falsely assumes that the meaning of a word can be discovered from its etymology or origins. This is especially so when the meaning has changed with time. Example:  Major premise: Nothing is better than eternal happiness. Minor premise: A ham sandwich is better than nothing. Conclusion: A ham sandwich is better than eternal happiness.  This is false because 'nothing' is used with two different meanings, so there are four terms here, Quarternio Terminorum. [4]

66 Exclusive premises – The fallacy of exclusive premises is a syllogistic fallacy committed in a categorical syllogism that is invalid because both of its premisesare negative. Syllogisms require the two initial statements assumed to be positive and true.  Example 1:  an EOO-4 type invalid syllogism. E Proposition: No cats are dogs. O Proposition: Some dogs are not pets. O Proposition: Therefore, some pets are not cats. Example 2:  an EOO-4 type invalid syllogism. E Proposition: No planets are dogs. O Proposition: Some dogs are not pets. O Proposition: Therefore, some pets are not planets.      [4]

67 Existential Fallacy – an argument that has a universal premise and a particular conclusion. This is a quantification fallacy, which is an error in logic where the quantifiers of the premises are in contradiction to the quantifier of the conclusion. One example would be: "Every unicorn definitely has a horn on its forehead". It does not imply that there are any unicorns at all in the world, and thus it cannot be assumed that, if the statement were true, somewhere there is a unicorn in the world (with a horn on its forehead). The statement, if assumed true, implies only that if there were any unicorns, each would definitely have a horn on its forehead.         Example 2: All trespassers will be prosecuted.Therefore, some of those prosecuted will have trespassed. This is a fallacy because the first statement does not require the existence of any actual trespassers (stating only what would happen in the event that some do exist), and therefore does not prove the existence of any. Note that this is a fallacy whether or not anyone has trespassed.[4]

68 False Analogy – The fallacy occurs when the analogy is irrelevant or very weak or when there is a more relevant disanalogy. [4]

69 False Attribution – appealing to an irrelevant, unqualified, unidentified, biased or fabricated source in support of an argument. Also Fallacy of quoting out of context (contextotomy, contextomy; quotation mining), which is selective excerpting of words from their original context to distort the intended meaning. [4]

70 False Dichotomy – Saying things ‘must’ be one way or they ‘must’ be another is a huge failure in arguments. Nature vs. Nurture is a good example of a fake dichotomy. It’s not one or the other, but a combination of both that plays into the totality of the world. Plus, there’s many factors outside of the two diametrically opposed forces. “Love vs. Fear” is another that comes up frequently. These assume zero sum games where you must be subtracting from one side to feed the other. The world is bigger than that. Also called the  False Dilemma, Example: We can either agree with Barbara's plan, or just let the project fail. There is no other option.  [1] [2] [3] [4] Easy to confuse with Division.

71 False Equivalence - describing two things as equal or nearly so when they are not. [4]

72 Fallacy Fallacy – Here's something vital to keep in mind when sniffing out fallacies: just because someone's argument relies on a fallacy doesn't necessarily mean that their claim is inherently untrue. Making a fallacy-riddled claim doesn't automatically invalidate the premise of the argument -- it just means the argument doesn't actually validate their premise. In other words, their argument sucks, but they aren't necessarily wrong.  Example: John's argument in favour of redesigning the company website clearly relied heavily on cherry-picked statistics in support of his claim, so Lola decided that redesigning the website must not be a good decision.  Argument from fallacy is the formal fallacy of analysing an argument and inferring that, since it contains a fallacy, its conclusion must be false. It is also called argument to logic, the fallacy fallacy, the fallacist's fallacy, and the bad reasons fallacy. [2] [4]

73 Far-Fetched Hypothesis – This is the fallacy of offering a bizarre hypothesis as the correct explanation without first ruling out more mundane explanations.

74 Faulty Comparison – When two or more items are compared, but the items are not in the same category.

75 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. [4]

76 Four Terms – Occurs when four rather than three categorical terms are used in a standard-form syllogism. Quarternio Terminorum

77 Furtive fallacy – outcomes are asserted to have been caused by the malfeasance of decision makers.  This is a questionable cause fallacy [4]

78 Gambler’s – Assumes that the history of outcomes will affect future outcomes. 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.This is a questionable cause fallacy [4] Gambler's fallacy. There is also the Inverse gambler's fallacy which assumes that some observed effect has a lot of previous events before it, for example that if we argue that our universe is suited to the existence of life that there were obviously a load of previous universes (cycles with big bangs) slightly less suited. This is another questionable cause fallacy [4].

79 Genetic – Discrediting or support a claim or an argument because of its origin when such an appeal to origins is irrelevant.  A  conclusion is suggested based solely on something or someone's origin rather than its current meaning or context. Genetic fallacy [4]

80 Groupthink – Substituting pride of membership in the group for reasons to support the group’s policy.

81 Hasty Generalisation – A fallacy of jumping to conclusions in which the conclusion is a generalisation. Example: Two members of my team have become more engaged employees after taking public speaking classes. That proves we should have mandatory public speaking classes for the whole company to improve employee engagement. [2] [4]

82 Hedging – Refining your claim simply to avoid counter-evidence and then acting as if your revised claim is the same as the original.

83 Historian's Fallacy – assuming that decision makers of the past had identical information as those subsequently analysing the decision. This should not to be confused with presentism, in which present-day ideas and perspectives are anachronistically projected into the past.

84 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.  [4] Example [4] A man loses his wallet but has an idea of where it might be. He looks for his wallet and finds it where he thought it may have been. The man [falsely] concludes that he knew where his wallet was the entire time. This man incorrectly assumes that he knew where the wallet was all along, and believes that knowing where to look for it led to his finding the wallet.

85 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 (e.g.: explaining thought as something produced by a little thinker – a homunculus – inside the head simply identifies an intermediary actor and does not explain the product or process of thinking).[4]

86 Hypostatisation – The error of inappropriately treating an abstract term as if it were a concrete one.

87 Ignoratio elenchi (irrelevant conclusion, missing the point) – an argument that may in itself be valid, but does not address the issue in question.[63] A relevance fallacy [4]

88 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. [89][90] [4] Also the Bare Assertion Fallacy. What happens here is that, in baldly asserting that it is "just how it is" distorts any argument by opting out of it entirely: the claimant declares an issue to be intrinsic, and not changeable. Further confused by the translation "what he said", which is a modern way of expressing agreement and nothing to do with logical argument. The issue is that the conclusion stated is treated as unchangeable and without reasoning. I can live with this when presented as "I've had a long think about this and I concluded <statement>", with implied argument not revisited.

89 Irrelevant Conclusion – The conclusion that is drawn is immaterial to the premises; it misses the point.

90 Illicit Affirmative  – the premises are positive but the conclusion is negative, an invalid AAE form of syllogism. A⊆B, B⊆C therefore notA⊆C, which is clearly wrong; the true statement would be A⊆C. Less easy to spot is the AAO-4 form: All A is B, All B is C [A⊆B, B⊆C again], conclusion some C is not A which is possible only if A=B=C is not true. The true logic would be  A⊂B, B⊂C , so A⊂C, [especially A≠C] so some C is not A is true. The acceptable forms of AEE are AEE2 and AEE4, Camestres and Calames respectively.

91 Illicit Major – a categorical syllogism that is invalid because its major term is not distributed in the major premise but distributed in the conclusion.  This fallacy has the following argument form: All A are B; No C are A; Therefore, no C are B, which is not true, for C can intersect A and could be wholly inside it. Example: All dogs are mammals, no cats are dogs, therefore no cats are mammals. Wrong: 'mammals is distributed in the conclusion but not in the major premise, which refers to some mammals. See above for the permitted forms of AEE, 2 and 4. Slightly different but true is: All A are B; no B are C; therefore no C are A. The minor premise puts C outside B so it is also outside A. Which is, I think, another AEE4.

92 Illicit Minor – a categorical syllogism that is invalid because its minor term is not distributed in the minor premise but distributed in the conclusion. All A are B; All A are C; Therefore, all C are B. Example: All cats are felines, all cats are mammals, therefore all mammals are felines. Wrong, because the cats ⊂ mammals statement is not distributed, while in the conclusion C⊂B or C⊆B, this is distributed, and so the result is untrue. What is true is that the intersection of felines and mammals contains 'all cats'.

93 Illicit Negative –  Affirmative conclusion from a negative premise is a formal fallacy that is committed when a categorical syllogism has a positive conclusion and one or two negative premises. For example: No fish are dogs, and no dogs can fly, therefore all fish can fly. The only thing that can be properly inferred from these premises is that some things that are not fish cannot fly, provided that dogs exist. Or: We don't read that trash. People who read that trash don't appreciate real literature. Therefore, we appreciate real literature.  This could be illustrated mathematically as If A⋂B=φ and B⋂C = φ then A⊂C. Which is untrue. It is a fallacy because any valid forms of categorical syllogism that assert a negative premise must have a negative conclusion. This is a formal syllogistic fallacy; EEA does not fly. [4]

94 Illicit Substitution of Identicals – Confusing the knowing of a thing (extension) with the knowing of it under all its various names or descriptions (intension).

95 Inconsistency – The fallacy occurs when we accept an inconsistent set of claims, that is, when we accept a claim that logically conflicts with other claims we hold.

96 Inductive Conversion – Improperly reasoning from a claim of the form “All As are Bs” to “All Bs are As” or from one of the form “Many As are Bs” to “Many Bs are As” and so forth.  Inductive fallacy  is a more general name for a class of fallacies, including hasty generalisation and its relatives. A fallacy of induction happens when a conclusion is draw from premises that only lightly support it. [4]

97 Inflation of conflict – 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.[36] [4]

98  If-by-whiskey – an argument that supports both sides of an issue by using terms that are emotionally sensitive and ambiguous. [4]

99 Incomplete comparison – insufficient information is provided to make a complete comparison.[4]

100 Inconsistent comparison – different methods of comparison are used, leaving a false impression of the whole comparison.

101 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).[37][4]

102 Is-Ought – Occurs when a conclusion expressing what ought to be so is inferred from premises expressing only what is so, in which it is supposed that no implicit or explicit ought-premises are need. Claims about what ought to be, on the basis of what is.  Inferring an impossibility to infer any instance of ought from is from the general invalidity of is-ought fallacy, mentioned above. For instance, is P ∨¬P does imply ought P∨¬P for any proposition P, although the naturalistic fallacy fallacy (see below) would falsely declare such an inference invalid.  Is–ought fallacy[98]   [4]

103 Judgmental language – using insulting or pejorative language in an argument.

104 Kafka-trapping – 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.[69]

105 Kettle logic – using multiple, jointly inconsistent arguments to defend a position.] Far from logical fallacy [4]

106 Loaded Question – Framing a question so that some controversial presupposition is made by the wording of the question.

107 Lack of Proportion – Either exaggerating or downplaying a point that is a crucial step in a piece of reasoning.

108 Loaded Language – Emotive terminology that expresses value judgments. When used in what appears to be an objective description, the terminology unfortunately can cause the listener to adopt those values when in fact no good reason has been given for doing so. See also Many Questions.

109 Loaded label: See Begging the Question

110 Logic Chopping – Using the technical tools of logic in an unhelpful and pedantic manner by focusing on trivial details instead of directly addressing the main issue in a dispute.

111 Lost Contrast  – a correlative is redefined so that one alternative is made impossible (e.g., "I'm not fat because I'm thinner than him"). Also, the Suppressed correlative, suppressed relative.  This is to do with definition of terms and so tends to produce ridiculous statements that we generally recognise as jokes. Example: define brakes as "a method to quickly stop a vehicle"; however, this permits all vehicles to be described as having brakes. Any car could be driven into a sturdy barrier to stop it, but to therefore say the car has brakes seems absurd.

112 Ludic fallacy – failing to take into account that non-regulated random occurrences unknown unknowns can affect the probability of an event taking place.[39][4]

113 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.[38][4]

114 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. This is a questionable cause fallacy [4]

115 Many questions (complex question, fallacy of presuppositions, 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. [4]

116 Masked-man fallacy (illicit substitution of identicals) – the substitution of identical designators in a true statement can lead to a false one. In philosophical logic, the masked-man fallacy  is committed when one makes an illicit use of Leibniz's law in an argument. Leibniz's law states that if A and B are the same object, then A and B are indiscernible (that is, they have all the same properties). By modus tollens, this means that if one object has a certain property, while another object does not have the same property, the two objects cannot be identical. The fallacy is "epistemic" because it posits an immediate identity between a subject's knowledge of an object with the object itself, failing to recognise that Leibniz's Law is not capable of accounting for intensional contexts. Also known as the Intensional fallacy and the Epistemic fallacy)  [4] Examples.

117 McNamara fallacy  – making an argument using only quantitative observations (measurements, statistical or numerical values) and discounting subjective information that focuses on quality (traits, features, or relationships). Also  [4]

118 Middle Ground Fallacy – This fallacy assumes that a compromise between two extreme conflicting points is always true. Arguments of this style ignore the possibility that one or both of the extremes could be completely true or false -- rendering any form of compromise between the two invalid as well. Example: Lola thinks the best way to improve conversions is to redesign the entire company website, but John is firmly against making any changes to the website. Therefore, the best approach is to redesign some portions of the website. [2] Example 2: Alan says the sky is blue, Betty says the sky is yellow, so the conclusion is that the sky is green. Therefor the middle position of the statements does not lead to any truth. One might also argue that at least one of the two premises is opinion not truth. I found this also called Argument to moderation, false compromise, fallacy of the mean, and argumentum ad temperantiam.

119 Mind projection fallacy – assuming that a statement about an object describes an inherent property of the object, rather than a personal perception. [4]

120 Misconditionalisation – The error of treating modal conditionals as if the modality applies only to the then-part of the conditional when it more properly applies to the entire conditional.

52 Misleading Vividness – When the fallacy of jumping to conclusions is due to a special emphasis on an anecdote or other piece of evidence, then this fallacy has occurred.

121 Modal Fallacy - basically, confusing necessity with sufficiency. I found this difficult, especially the examples, which are either poor or I'm being thick. I think that the issue is whether statements can have a state that is a sort of temporary truth, such as "I win", with quite when I win unsaid where the logic demands that it remains true. I found other examples here and I still think this is silly. I think, from here, that this is a language problem, possibly even an American English issue. perhaps the problem is that the conclusion is not a result, merely a repetition. I therefore abandoned the idea of modal scope fallacy.

122 Moralistic fallacy – inferring factual conclusions from evaluative premises in violation of fact–value distinction (e.g.,: inferring is from ought). Moralistic fallacy is the inverse of naturalistic fallacy. [4]

123 Motte and Bailey Fallacy – where an arguer conflates two positions which share similarities, one modest and easy to defend (the "motte") and one much more controversial (the "bailey").The arguer advances the controversial position, but when challenged, they insist that they are only advancing the more modest position. Upon retreating to the motte, the arguer can claim that the bailey has not been refuted (because the critic refused to attack the motte) or that the critic is unreasonable (by equating an attack on the bailey with an attack on the motte). Source. This may be a doctrine not a fallacy and is a form of Equivocation, elsewhere here.

124 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. [4]

125 Naturalistic fallacy – inferring evaluative conclusions from purely factual premises  in violation of fact-value distinction. Naturalistic fallacy (sometimes confused with appeal to nature) is the inverse of moralistic fallacy. Naturalistic fallacy fallacy[99] (anti-naturalistic fallacy) [100] Naturalistic fallacy  fallacy is a type of argument from fallacy.

126 Nirvana fallacy  – solutions to problems are rejected because they are not perfect. Also the perfect-solution fallacy; see perfectionist. [4]

127  The "No True Scotsman" Fallacy – Often used to protect assertions that rely on universal generalisations (like "all Marketers love pie") this fallacy inaccurately deflects counterexamples to a claim by changing the positioning or conditions of the original claim to exclude the counterexample. In other words, instead of acknowledging that a counterexample to their original claim exists, the speaker amends the terms of the claim. In the example below, when Barbara presents a valid counterexample to John's claim, John changes the terms of his claim to exclude Barbara's counterexample. Example: John: No marketer would ever put two call-to-actions on a single landing page. Barbara: Lola, a marketer, actually found great success putting two call-to-actions on a single landing page for our last campaign.  John: Well, no true marketer would put two call-to-actions on a single landing page, so Lola must not be a true marketer. [2]

128 Non Sequitur – When a conclusion is supported only by extremely weak reasons or by irrelevant reasons. AKA a Red Herring, this is when you throw a spanner into the works to derail an argument. The goal is to distract or change the narrative, since you’re unable to make your point. Quick subject changes such as “Forget about our issues. Look at Dave and Shelia! Those people are really a mess!” stops a fight and redirects it. Hoping no one will notice. [3]

129 Nut Picking – using individual cases or data that falsifies a particular position, while ignoring related cases or data that may support. Different from Cherry Picking, but still suppressed or incomplete evidence. [4]

130 Observational Selection – A pretty simple mistake, this is when we pretend the bad things that don’t support our argument don’t exist. “The drug saves lives!” might be true, but if it’s only saving a single person while making hundreds of others extremely sick, it’s still not good. You’re speaking partial truths with this one, which is another name for it. [3]

131 Opinion – I'm entitled to my opinion – a person discredits any opposition by claiming that they are entitled to their opinion.

132 Overwhelming exception – an accurate generalisation 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.[51] [4]

133 Perfectionist – Rejecting a proposal or claim solely because it doesn’t solve the problem perfectly, in cases where perfection isn’t really required.

134 – Personal Incredulity – If you have difficulty understanding how or why something is true, that doesn't automatically mean the thing in question is false. A personal or collective lack of understanding isn't enough to render a claim invalid. Example: I don't understand how redesigning our website resulted in more conversions, so there must have been another factor at play. [2]

135 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.[68]

136 Political Correctness – Changing the nature of something by giving it a new name. Turning the 'poor' into the 'disadvantaged', 'bad debt' becomes 'underperforming asset', 'u[titles' instead of 'pay rises'. Also called Language Control and the Name-calling Fallacy Very close to name-calling strategies; they help move the argument down carefully constructed mental pathways.

137 Pooh-pooh – stating that an opponent's argument is unworthy of consideration.[79]

138 Post Hoc – Concluding that A caused B simply because A preceded B. Post hoc ergo propter hoc (Latin for "after this, therefore because of this"; temporal sequence implies causation) – X happened, then Y happened; therefore X caused Y.  This is a questionable cause fallacy [4].  See also Cum Hoc and Questionable Cause. And here.

139 Proof by assertion – a proposition is repeatedly restated regardless of contradiction; sometimes confused with argument from repetition (argumentum ad infinitum, argumentum ad nauseam) [4]

140 Proof Surrogate – Substituting a distracting comment for a real proof.

141 Prosecutor’s Fallacy – The mistake of over-emphasising the strength of a piece of evidence while paying insufficient attention to the context. Prosecutor's fallacy – a low probability of false matches does not mean a low probability of some false match being found.

142 Proving too much – an argument that results in an overly-generalised conclusion (e.g.,: arguing that drinking alcohol is bad because in some instances it has led to spousal or child abuse).

143 Psychologist's fallacy – an observer presupposes the objectivity of their own perspective when analysing a behavioural event. [4] For Psychogenetic, see Bulverism.

144 Quantifier Shift – Confusing the phrase “For all x there is some y” with “There is some (one) y such that for all x.”

145 Quantitative Fallacy see McNamara

146 Quaternio Terminorum, the fallacy of four terms – a formal syllogistic fallacy that has four or more terms rather than the required three.    [4] See also Four Terms.

147 Questionable Cause The third-cause fallacy (also known as ignoring a common cause[14] or questionable cause[14]) is a logical fallacy where a spurious relationship is confused for causation. It asserts that X causes Y when, in reality, X and Y are both caused by Z. It is a variation on the post hoc ergo propter hoc fallacy and a member of the questionable cause group of fallacies. This is a questionable cause fallacy  Ignoring a common cause Questionable cause is a general type of error with many variants. Its primary basis is the confusion of association with causation, either by inappropriately deducing (or rejecting) causation or a broader failure to properly investigate the cause of an observed effect. [4]

148 Red Herring – A digression that leads the reasoner off the track of considering only relevant information. See Non Sequitur. [1]  A red herring fallacy is one of the main subtypes of fallacies of relevance, an error in logic where a proposition is, or is intended to be, misleading in order to make irrelevant or false inferences. This includes any logical inference based on fake arguments, intended to replace the lack of real arguments or to replace implicitly the subject of the discussion.ntroducing a second argument in response to the first argument that is irrelevant and draws attention away from the original topic (e.g.: saying “If you want to complain about the dishes I leave in the sink, what about the dirty clothes you leave in the bathroom?”).[66] See also irrelevant conclusion.  Red herring. [4]

[40] – assuming that 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 (e.g.: Pegasus) or that the meaning comes from how they are used (e.g.: "nobody" was in the room). [4]

150 Regression – This fallacy occurs when regression to the mean is mistaken for a sign of a causal connection.

151 Reification – Considering an abstract noun to be a term referring to an abstract object, when the meaning of the noun can be accounted for more mundanely without assuming the object exists.  Also concretism, hypostatisation  or the fallacy of misplaced concreteness – treating an abstract belief or hypothetical construct as if it were a concrete, real event or physical entity. Example: saying that evolution selects which traits are passed on to future generations; evolution is not a conscious entity with agency[4] Reification.

152 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. This is a questionable cause fallacy [4]

153 Relative Privation – dismissing an argument or complaint due to what are perceived to be more important problems. First World problems are a subset of this fallacy.[93][94]  Also "appeal to worse problems" or "not as bad as".

154 Retrospective determinism – believing that, because an event has occurred under some circumstance, the circumstance must have made the event inevitable (e.g.: because someone won the lottery while wearing their lucky socks, wearing those socks made winning the lottery inevitable). [4]

155 Reversing Causation – Drawing an improper conclusion about causation due to a causal assumption that reverses cause and effect. Also called Wrong direction because cause and effect are reversed. The cause is said to be the effect and vice versa.[54] The consequence of the phenomenon is claimed to be its root cause.  This is a questionable cause fallacy

156 Self-Fulfilling Prophecy – The fallacy occurs when the act of prophesying will itself produce the effect that is prophesied, but the reasoner doesn’t recognise this and believes the prophesy is a significant insight.

157 Sorites – Rejecting a vague claim because it is not as precise as we’d like.

158 Scope – Caused by improperly changing or misrepresenting the scope of a phrase.

159 Sharpshooter's – The fallacy is caused by overemphasising random results or making selective use of coincidence. This fallacy gets its colourful name from an anecdote about a Texan who fires his gun at a barn wall, and then proceeds to paint a target around the closest cluster of bullet holes. He then points at the bullet-riddled target as evidence of his expert marksmanship. Speakers who rely on the Texas sharpshooter fallacy tend to cherry-pick data clusters based on a predetermined conclusion. Instead of letting a full spectrum of evidence lead them to a logical conclusion, they find patterns and correlations in support of their goals, and ignore evidence that contradicts them or suggests the clusters weren't actually statistically significant.  Example: Lisa sold her first startup to an influential tech company, so she must be a successful entrepreneur. (She ignores the fact that four of her startups have failed since then.) [2]

160 Slippery Slope – Arguing that a relatively small first step leads to a chain of related events culminating in some significant effect. Also called the Domino Theory [1] [3] Also thin edge of the wedge, camel's nose) – 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. [4]

161 Slothful Induction – This fallacy occurs when sufficient logical evidence strongly indicates a particular conclusion is true, but someone fails to acknowledge it, instead attributing the outcome to coincidence or something unrelated entirely. Example: Even though every project Brad has managed in the last two years has run way behind schedule, I still think we can chalk it up to unfortunate circumstances, not his project management skills. The exact inverse of the hasty generalisation fallacy. [2]

162 Socratic Fallacy – where one property has been defined in terms of another. Also definist fallacy. Probably an error in semantics rather than logic or reasoning. We could call this using loaded terms, where one debater implies a definition, encouraging agreement, from whence the argument is hard to refute. Close to the loaded terms fallacy, Definist.

163 Special Pleading – A form of inconsistency in which the reasoner doesn’t apply his or her principles consistently.

164 Speaking in Totality – Anytime someone starts saying “always” or “never” or speaking about “all people” or “most people” they’re making huge assumptions that are automatically untrue. Nothing “always” or “never” happens, and claiming that “most people” or “a lot of people” think a certain way is inaccurate for a few reasons. The most obvious being: This person is making a point with grandiose language.

165 Special pleading – the arguer attempts to cite something as an exemption to a generally accepted rule or principle without justifying the exemption (e.g.: a defendant who murdered his parents asks for leniency because he is now an orphan). [4]

166 Straw Man – Attributing an easily refuted position to your opponent, one that the opponent wouldn’t endorse, and then proceed to attack the easily refuted position (the straw man) believing you have undermined the opponent’s actual position.  A straw man argument is when you create a false analogy, and then destroy that analogy. “Meat is not murder” is an example of a straw man argument. Eating meat is still killing another creature for food. Merely because it isn’t killing one of your own kind doesn’t make it less of a slaughter. It merely means most of the human race is on board with ignoring the bloodshed. To say one thing is like another when that isn’t entirely true – comparing people to Hitler or groups to the Nazis are prime examples of this – is the Straw Man at work.  Misrepresenting an opponent's argument by broadening or narrowing the scope of a premise and refuting a weaker version (e.g.: saying “You tell us that A is the right thing to do, but the real reason you want us to do A is that you would personally profit from it).  [101][1] [2] [3] [4]

167 Survivorship bias – a small number of successes of a given process are actively promoted while completely ignoring a large number of failures. See Cherry Picking [4] Survivorship bias

168 Texas sharpshooter fallacy – improperly asserting a cause to explain a cluster of data.[102]

169 Third Cause (Common Cause) – A causal connection between two kinds of events is claimed when evidence is available indicating that both are the effect of a common cause.

170 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. [4] Thought-terminating cliché

171 Tokenism – Interpreting a merely token gesture as an adequate substitute for the real thing.

172 Tone policing – focusing on emotion behind (or resulting from) a message rather than the message itself as a discrediting tactic.

173 Traitorous critic fallacy (ergo decedo, 'thus leave') – 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 ("guilt by association") above.

174 Tu Quoque – Concluding that someone’s argument not to perform some act must be faulty because the arguer himself or herself has performed it. In the example below, Lola makes a claim. Instead of presenting evidence against Lola's claim, John levels a claim against Lola. This attack doesn't actually help John succeed in proving Lola wrong, since he doesn't address her original claim in any capacity. Example: Lola: I don't think John would be a good fit to manage this project, because he doesn't have a lot of experience with project management. John: But you don't have a lot of experience in project management either! [2] [4] Tu quoque ('you too' – appeal to hypocrisy, whataboutism) – stating that a position is false, wrong, or should be disregarded because its proponent fails to act consistently in accordance with it.[103]

175 Two wrongs make a right – assuming that, if one wrong is committed, another wrong will rectify it.[104]

176 Undistributed Middle – Failing to distribute the middle term over at least one of the other terms.

177 Vacuous truth – a claim that is technically true but meaningless, in the form 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.

178 Wishful Thinking – Suggesting that a claim is true, or false, merely because the arguer strongly hopes it is. Arguing for a course of action by the listener according to what might be pleasing to imagine rather than according to evidence or reason.Wishful thinking [4]

1 A syllogism is a kind of logical argument that applies deductive reasoning to arrive at a conclusion based on two or more propositions that are asserted or assumed to be true. Here's a javascript engine for inspecting syllogisms. The word syllogism has connotations of badness, which are unwarranted  The construction has three statements, the major premise, the minor premise and the conclusion.  The major premise connects sets M and P, [such that all/some/no M or P are or are not P or M, with no double negatives]; the minor premise does the same for sets S and M; the third concludes a relationship between S and P such that all or no S are P or some S are/are not P.

Aristotle defined four classes of statement, which I then show as  a Venn diagram source and as a semiotic square. There are issues with empty sets, where the oft-quoted example is 'all centaurs'. Or, in the case of our current government, all unicorns. The four letters AIOE can then use three of them to classify a syllogism. [5]

On moving from the general to the abstract, replacing centaurs with X for example, this tends to reduce the complexity; Thus A is not-O and E is not-I, and vice versa. In my mind, at least, this makes the reversion to language other than symbols more fraught.

https://app.memrise.com/course/97301/logical-fallacies-5/1/

https://app.memrise.com/course/97301/logical-fallacies-5/3/?action=next  et seq up to page 5/11. I counted 68 of them, so probably too many for most folk. I've extended that list here and will then look for duplication.

Logical fallacies and how to spot them. Better still, remember them.

[4] https://en.wikipedia.org/wiki/List_of_fallacies  Many of the links that look like [4] are direct to the specific wikipedia entry, so they are not at all the same.

<---- 24 possible syllogism combinations, 9 of which are disputable

Set Theory. Personally, I grew up with this, knowing what an intersection of sets was at about the time I began school as a rising five. Blame Father – or celebrate his ability to teach. Oddly, all four males of the family met Venn diagrams in the same month, as it was introduced at school in all three years at the same time, and as Father had this introduced at university (as staff, not student). Indeed I think the children met the idea just before the parent.

Symbology. the element of set A are all within set B, so set A is contained in set B, A⊂B. If they may also be equal, A⊆B. Similarly, A contains B A⊃B, A⊇B and the negatives A⊄B, A⊅B, A⊈B and A⊉B.  Think of the ⊂ symbol as a set version of <, the smaller one is on the left. We can count the elements in a set, so the number of elements in set A is n(A) and if A⊆B then n(A)≤n(B) follows. I grew up with the idea of a universal set, ξ (but more recently seen as U), so that if you were thinking of numbers, then letters are not in the universal set. A list of elements within a set fits between {curly brackets, called braces} and there is the important idea of the empty set, written as {} or φ (usually italicised). So two distinct sets have a zero intersection, A∩B=φ. With this concept of intersection goes the union, A∪B for example, so that n(A∪B) = n(A) + n(B) -n(A∩B). I was very familiar with this before leaving primary school.    Helpful little listAnother.  Following use of matrices, n(A) was replaced by |A|

The idea of something being in the universal set but not in set A, x∊ξ, x∉A means that x is in not-A, written as x∈A' or x∈¬A. And at this point we have a diversion between the symbols in sets and the symbols in logic. Logic list. Which set of symbols you prefer probably dates to what you first come across (much the same applies with software). Thus the representation of x and y could be x⋅y, x∧y, x&y; x or y could be x+y, x∨y, x|y and not-x could be x', ˉx , ¬x [the x-bar is difficult, as is p-hat for stats; I have not found a unicode character for either]. The use of ∧ and ∨ for and and or is new to me, but then makes sense of nand, ⊼, nor,   ⊽, and xor, ⊻.

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