Logical Fallacies

I compiled these definitions of fallacies in 1995. – DH

Table of Contents

Fallacies of Authority

...related to debaters and audiences

subjectivism: asserting a proposition as true simply because one wishes it to be true.

asserting a proposition as true simply because one wishes it to be true. appeal to authority: (argumentum ad verecundiam) citing an authority, who is incompetent or non-objective, in an attempt to gain support an argument, or citing an authority when the issue is not technical.

(argumentum ad verecundiam) citing an authority, who is incompetent or non-objective, in an attempt to gain support an argument, or citing an authority when the issue is not technical. quoting out of context: manipulating a quote either from an authority or from one's interlocutor in such a way that the original meaning of the statement is altered.

manipulating a quote either from an authority or from one's interlocutor in such a way that the original meaning of the statement is altered. ad personam: appealing to the misrepresented self-interest of those one is trying to convince.

appealing to the misrepresented self-interest of those one is trying to convince. appeal to the people: (argumentum ad populum) relying on the emotional passion of the crowd in making an argument.

(argumentum ad populum) relying on the emotional passion of the crowd in making an argument. appeal to numbers: (argumentum ad numerum) asserting (implicitly or explicitly) that the acceptance of an idea by a large number of people is reason to believe it.

(argumentum ad numerum) asserting (implicitly or explicitly) that the acceptance of an idea by a large number of people is reason to believe it. cultural fallacy: taking one's own culture as the standard of good by which all cultures should be judged.

taking one's own culture as the standard of good by which all cultures should be judged. appeal to force: (argumentum ad baculum) using any type of threat, physical or non-physical, explicitly or implicitly, in order to gain agreement.

(argumentum ad baculum) using any type of threat, physical or non-physical, explicitly or implicitly, in order to gain agreement. appeal to tradition: (argumentum ad antiquitatem) asserting that something is true or good because it is old(er), or appealing to the very principles that are being questioned.

(argumentum ad antiquitatem) asserting that something is true or good because it is old(er), or appealing to the very principles that are being questioned. appeal to modernity: (argumentum ad novitatem) asserting that something is true or good because it is new(er).

(argumentum ad novitatem) asserting that something is true or good because it is new(er). appeal to money: (argumentum ad crumenam) contending that greater wealth indicates greater good or truth, or asserting that money is the standard by which to judge the true or the good.

(argumentum ad crumenam) contending that greater wealth indicates greater good or truth, or asserting that money is the standard by which to judge the true or the good. appeal to poverty: (argumentum ad lazarum) asserting that greater poverty indicates greater good, virtue, or truth.

...related to arguments

appeal to ignorance: (argumentum ad ignorantiam) asserting that a proposition as true merely because it has not been proven false.

(argumentum ad ignorantiam) asserting that a proposition as true merely because it has not been proven false. s hifting the burden of proof: demanding that the person denying an assertion prove his/her case, whereas the burden of proof is upon the person who argues the positive.

demanding that the person denying an assertion prove his/her case, whereas the burden of proof is upon the person who argues the positive. argumentum ad nauseam: believing that the more times an argument is heard the more likely it is to be true, or simply repeating an assertion instead of arguing for or proving it.

believing that the more times an argument is heard the more likely it is to be true, or simply repeating an assertion instead of arguing for or proving it. argumentum ad logicam: dismissing a proposition to be undeniably false because the argument presented for the proposition was fallacious.

dismissing a proposition to be undeniably false because the argument presented for the proposition was fallacious. ad lapidem: dismissing an statement as absurd without proving it to be false.

Fallacies of Distraction

ad hominem: rejecting or dismissing another person's statement by attacking the person rather than by disproving the statement.

rejecting or dismissing another person's statement by attacking the person rather than by disproving the statement. creating misgivings: stirring up suspicions about a long-forgotten (and possibly completely unsubstantiated) charge against one's interlocutor.

stirring up suspicions about a long-forgotten (and possibly completely unsubstantiated) charge against one's interlocutor. tu quoque: trying to dismiss or downplay an accusation by demonstrating that the accuser himself is guilty of misconduct.

trying to dismiss or downplay an accusation by demonstrating that the accuser himself is guilty of misconduct. poisoning the well: (damning the origin) arguing against an idea by showing that one's interlocutor has a non-rational motive for holding the idea.

(damning the origin) arguing against an idea by showing that one's interlocutor has a non-rational motive for holding the idea. forestalling disagreement: attempting to make an opponent or audience unwilling to debate an issue.

attempting to make an opponent or audience unwilling to debate an issue. argument from intimidation: asserting that believing or arguing for a certain idea indicates immorality, in an attempt to intimidate a person into renouncing the idea without discussion.

asserting that believing or arguing for a certain idea indicates immorality, in an attempt to intimidate a person into renouncing the idea without discussion. self-righteousness: confusing good intentions with actual good or truth.

confusing good intentions with actual good or truth. special pleading: refusing to apply the same principles to oneself that one applies to others.

refusing to apply the same principles to oneself that one applies to others. presenting the "good" reason: selecting, as the explanation for one's actions or ideas, a credible fact when other explanations could be had.

...related to emotion

appeal to emotion: attempting to gain support for an idea through an emotional response provoked in the audience

attempting to gain support for an idea through an emotional response provoked in the audience appeal to pity: (argumentum ad misericordiam) appealing to a sense of pity by drawing attention to pathetic conditions in an attempt to get an audience to accept an idea.

(argumentum ad misericordiam) appealing to a sense of pity by drawing attention to pathetic conditions in an attempt to get an audience to accept an idea. emotive language: (colored words): abusing the power of words in order to evoke a desired response from the audience.

(colored words): abusing the power of words in order to evoke a desired response from the audience. glittering generality: using general terms to around pleasurable sentiments in such a way that all meaning is lost.

...related to other issues

oversimplification: reducing a complex situation to a simple, inaccurate statement.

reducing a complex situation to a simple, inaccurate statement. many questions: (plurium interrogation) posing a complex question and demanding a simple answer.

(plurium interrogation) posing a complex question and demanding a simple answer. faulty analogy: assuming either that properties shared between two situations or existents will continue to be found indefinitely or that shared properties will be found in very disparate situations or existents.

assuming either that properties shared between two situations or existents will continue to be found indefinitely or that shared properties will be found in very disparate situations or existents. vague similarities: asserting that two situations or existents are similar without specifying the properties they share.

asserting that two situations or existents are similar without specifying the properties they share. diversion: attempting to support one proposition by arguing for a different one entirely.

attempting to support one proposition by arguing for a different one entirely. strawman: attempting to refute one's opponent's proposition by attacking misrepresentation of the his/her position.

attempting to refute one's opponent's proposition by attacking misrepresentation of the his/her position. wicked alternative: attempting to support one proposition by denouncing another, when the second is not the opposite of the first.

attempting to support one proposition by denouncing another, when the second is not the opposite of the first. false dilemma: representing a situation as having only undesirable alternatives when the facts do not support such a judgment.

representing a situation as having only undesirable alternatives when the facts do not support such a judgment. all-or-nothing mistake: presenting a naked dichotomy when such an evaluation is unwarranted.

presenting a naked dichotomy when such an evaluation is unwarranted. slippery slope: arguing that if one event were to occur, other harmful events would result without showing how the events are linked.

arguing that if one event were to occur, other harmful events would result without showing how the events are linked. impossible conditions: contending that mankind should be changed or even perfected before any remedy for a problem should be considered.

contending that mankind should be changed or even perfected before any remedy for a problem should be considered. nothing but objections: continually objecting to any plan proposed to assure that nothing is done.

...related to minutia

wishful thinking: constructing false expectations though ignoring unpleasant facts.

constructing false expectations though ignoring unpleasant facts. lip service: verbal agreement unsupported in action or true conviction.

verbal agreement unsupported in action or true conviction. prejudicial fallacies: representing whatever position coincides with whatever prejudices the speaker perceives in the audience.

representing whatever position coincides with whatever prejudices the speaker perceives in the audience. red herring: diverting the attention of the audience from the discussion of the real issues to irrelevancies.

diverting the attention of the audience from the discussion of the real issues to irrelevancies. pomp and circumstance: permitting the setting in which the argument takes place to affect the attention paid to the argument.

permitting the setting in which the argument takes place to affect the attention paid to the argument. humor and ridicule: using inappropriate humor to deflect attention away from the discussion.

Conceptual Fallacies

relativism: asserting that there are no real attributes to entities and thus treating conceptualization as grounded in the subjective bias of the individual.

asserting that there are no real attributes to entities and thus treating conceptualization as grounded in the subjective bias of the individual. sweeping generalization: (dicto simpliciter) applying a principle to a specific situation while ignoring the context under which the principle was formed.

(dicto simpliciter) applying a principle to a specific situation while ignoring the context under which the principle was formed. reification: treating an conceptualization as if it represented a concrete.

treating an conceptualization as if it represented a concrete. word magic: using words that imply the existence of entities who existence is unverifiable.

using words that imply the existence of entities who existence is unverifiable. personification: attributing human traits to other creatures or reading purpose into inanimate configurations.

attributing human traits to other creatures or reading purpose into inanimate configurations. apriorism: attempting to deduce facts from abstractions and principles rather than induce from facts.

attempting to deduce facts from abstractions and principles rather than induce from facts. equivocation: using two or more meanings of a key word in the same argument.

using two or more meanings of a key word in the same argument. idiosyncratic language: charging words with personal meaning which alter their meaning.

charging words with personal meaning which alter their meaning. unnecessary vagueness: using a word in such a way that there are no referents of the term or such that the definition is incomprehensible.

using a word in such a way that there are no referents of the term or such that the definition is incomprehensible. ambiguous terms: equivocating between different meanings of a word or phrase.

equivocating between different meanings of a word or phrase. amphibole: using ambiguous syntax.

using ambiguous syntax. shifting of accent: altering the meaning, but not the literal truth, of a reported statement by falsely emphasizing certain words.

altering the meaning, but not the literal truth, of a reported statement by falsely emphasizing certain words. suppressed quantification: omitting quantification that would make an argument appear dubious if included.

omitting quantification that would make an argument appear dubious if included. misuse of etymology: asserting that words should remain close to their etymological roots, and using such to come to a certain conclusion.

asserting that words should remain close to their etymological roots, and using such to come to a certain conclusion. overprecision: rejecting a concept as unusable because it has borderline cases or because the definition is not perfect.

rejecting a concept as unusable because it has borderline cases or because the definition is not perfect. stolen concept: using a concept while denying another concept upon which the former logically depends.

using a concept while denying another concept upon which the former logically depends. begging the question/circular argument: attempting to support a proposition with an argument that presupposes the proposition.

attempting to support a proposition with an argument that presupposes the proposition. complex question: trying to get one's interlocutor to accept a proposition by posing a question that presupposes it.

trying to get one's interlocutor to accept a proposition by posing a question that presupposes it. audiatur et altera pars: arguing from unstated premises.

Logical Fallacies

non sequitur: offering a proposition that does not follow logically from the premises.

offering a proposition that does not follow logically from the premises. affirming the consequent: asserting that because if A then B, therefore if B then A.

asserting that because if A then B, therefore if B then A. denying the antecedent: asserting that because if A then B, therefore if not A then not B.

asserting that because if A then B, therefore if not A then not B. hasty generalization: generalizing from too few particulars that are probably not representative of an entire group.

generalizing from too few particulars that are probably not representative of an entire group. faulty generalization: asserting a universal statement unsupported by evidence.

asserting a universal statement unsupported by evidence. faulty causal generalization: (non causa pro causa) taking one event to be the cause of another when there is not enough evidence, or when there is no causal relationship.

(non causa pro causa) taking one event to be the cause of another when there is not enough evidence, or when there is no causal relationship. assuming the cause: (post hoc ergo propter hoc) assuming that the fact that one event follows another indicates that the two are causally related.

(post hoc ergo propter hoc) assuming that the fact that one event follows another indicates that the two are causally related. cum hoc ergo propter hoc: asserting that the fact that two events occur together means that they are causally related.

asserting that the fact that two events occur together means that they are causally related. fallacy of composition: asserting that what hold true for each member of a class holds true for the class as a whole.

asserting that what hold true for each member of a class holds true for the class as a whole. fallacy of decomposition: asserting that what holds true for a class as a whole holds true for each member of the class.

asserting that what holds true for a class as a whole holds true for each member of the class. fallacy of statistics: (gambler's mistake): misapplying the statistics of a group to a single situation.

Sources

W. Ward Fearnside and William B. Holther. Fallacy: the Counterfeit of Argument. 1959.

Nicholas Capaldi. The Art of Deception. 1971.

Douglas N. Walton. Informal Logic. 1989.

David Kelley. The Art of Reasoning. 1990.



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