Fallacies

Formal fallacies

Formal fallacies are arguments that are fallacious due to an error in their form or technical structure. All formal fallacies are specific types of non sequiturs.

• Appeal to probability: because something could happen, it is inevitable that it will happen. This is the premise on which Murphy's Law is based.
• Argument from fallacy: if an argument for some conclusion is fallacious, then the conclusion must necessarily be false.
• Bare assertion fallacy: premise in an argument is assumed to be true purely because it says that it is true.
• Base rate fallacy: using weak evidence to make a probability judgment without taking into account known empirical statistics about the probability.
• Conjunction fallacy: assumption that specific conditions are more probable than a single general one.
• Correlative based fallacies
  • Denying the correlative: where attempts are made at introducing alternatives where there are none
  • Suppressed correlative: where a correlative is redefined so that one alternative is made impossible
• Fallacy of necessity: a degree of unwarranted necessity is placed in the conclusion based on the necessity of one or more of its premises
• False dilemma (false dichotomy): where two alternative statements are held to be the only possible options, when in reality there are several
• If-by-whiskey: An answer that takes side of the questioner's suggestive question
• Ignoratio elenchi (irrelevant conclusion or irrelevant thesis)
• Homunculus fallacy: where a "middle-man" is used for explanation, this usually leads to regressive middle-man explanations without actually explaining the real nature of a function or a process
• Masked man fallacy: the substitution of identical designators in a true statement can lead to a false one
• Naturalistic fallacy: a fallacy that claims that if something is natural, then it is "good" or "right"
• Nirvana fallacy: when solutions to problems are said not to be right because they are not perfect
• Negative proof fallacy: that because a premise cannot be proven true, that premise must be false
• Package-deal fallacy: when two or more things have been linked together by tradition or culture are said to stay that way forever

Propositional fallacies

Propositional fallacies:

• Affirming a disjunct: concluded that one logical disjunction must be false because the other disjunct is true.
• Affirming the consequent: the antecedent in an indicative conditional is claimed to be true because the consequent is true. Has the form if A, then B; B, therefore A
• Denying the antecedent: the consequent in an indicative conditional is claimed to be false because the antecedent is false; if A, then B; not A, therefore not B

Quantificational fallacies

Quantificational fallacies:

• Existential fallacy: an argument has two universal premises and a particular conclusion, but the premises do not establish the truth of the conclusion
• Illicit conversion: the invalid conclusion that because a statement is true, the inverse must be as well
• Proof by example: where things are proved by giving an example

Formal syllogistic fallacies

Syllogistic fallacies are logical fallacies that occur in syllogisms.

• Affirmative conclusion from a negative premise
• Fallacy of exclusive premises: a categorical syllogism that is invalid because both of its premises are negative
• Fallacy of four terms: a categorical syllogism has four terms
• Illicit major: a categorical syllogism that is invalid because its major term is undistributed in the major premise but distributed in the conclusion
• Illicit minor: a categorical syllogism that is invalid because its minor term is undistributed in the minor premise but distributed in the conclusion.
• Fallacy of the undistributed middle: the middle term in a categorical syllogism is not distributed
• Categorical syllogism: an argument with a positive conclusion, but one or two negative premises

Informal fallacies

Informal fallacies are arguments that are fallacious for reasons other than structural ("formal") flaws.

• Argument from repetition (argumentum ad nauseam)
• Appeal to ridicule: a specific type of appeal to emotion where an argument is made by presenting the opponent's argument in a way that makes it appear ridiculous
• Argument from ignorance ("appeal to ignorance"): The fallacy of assuming that something is true/false because it has not been proven false/true. For example: "The student has failed to prove that he didn't cheat on the test, therefore he must have cheated on the test."
• Begging the question ("petitio principii"): where the conclusion of an argument is implicitly or explicitly assumed in one of the premises
• Burden of proof
• Circular cause and consequence
• Continuum fallacy (fallacy of the beard)
• Correlation does not imply causation (cum hoc ergo propter hoc)
• Equivocation
• Fallacies of distribution
  • Division: where one reasons logically that something true of a thing must also be true of all or some of its parts
  • Ecological fallacy
• Fallacy of many questions (complex question, fallacy of presupposition, loaded question, plurium interrogationum)
• Fallacy of the single cause
• Historian's fallacy
• False attribution
  • Fallacy of quoting out of context
• False compromise/middle ground
• Gambler's fallacy: the incorrect belief that the likelihood of a random event can be affected by or predicted from other, independent events
• Incomplete comparison
• Inconsistent comparison
• Intentional fallacy
• Loki's Wager
• Lump of labour fallacy (fallacy of labour scarcity, zero-sum fallacy)
• Moving the goalpost
• No true Scotsman
• Perfect solution fallacy: where an argument assumes that a perfect solution exists and/or that a solution should be rejected because some part of the problem would still exist after it was implemented
• Post hoc ergo propter hoc: also known as false cause, coincidental correlation or correlation not causation.
• Proof by verbosity (argumentum verbosium)
• Psychologist's fallacy
• Regression fallacy
• Reification (hypostatization)
• Retrospective determinism (it happened so it was bound to)
• 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
• Suppressed correlative: an argument which tries to redefine a correlative (two mutually exclusive options) so that one alternative encompasses the other, thus making one alternative impossible
• Sunk cost fallacy
• Wrong direction

Faulty generalizations

Faulty generalizations:

• Accident (fallacy): when an exception to the generalization is ignored
• Cherry picking
• Composition: where one infers that something is true of the whole from the fact that it is true of some (or even every) part of the whole
• Dicto simpliciter
  • Converse accident (a dicto secundum quid ad dictum simpliciter): when an exception to a generalization is wrongly called for
• False analogy
• Hasty generalization (fallacy of insufficient statistics, fallacy of insufficient sample, fallacy of the lonely fact, leaping to a conclusion, hasty induction, secundum quid)
• Loki's Wager: insistence that because a concept cannot be clearly defined, it cannot be discussed
• Misleading vividness
• Overwhelming exception
• Spotlight fallacy
• Thought-terminating cliché: a commonly used phrase, sometimes passing as folk wisdom, used to quell cognitive dissonance.

Red herring fallacies

A red herring is an argument, given in response to another argument, which does not address the original issue. See also irrelevant conclusion

• Ad hominem: attacking the personal instead of the argument. A form of this is reductio ad Hitlerum.
• Argumentum ad baculum ("appeal to force", "appeal to the stick"): where an argument is made through coercion or threats of force towards an opposing party
• Argumentum ad populum ("appeal to belief", "appeal to the majority", "appeal to the people"): where a proposition is claimed to be true solely because many people believe it to be true
• Association fallacy & Guilt by association
• Appeal to authority: where an assertion is deemed true because of the position or authority of the person asserting it
• Appeal to consequences: a specific type of appeal to emotion where an argument concludes a premise is either true or false based on whether the premise leads to desirable or undesirable consequences for a particular party
• Appeal to emotion: where an argument is made due to the manipulation of emotions, rather than the use of valid reasoning
  • Appeal to fear: a specific type of appeal to emotion where an argument is made by increasing fear and prejudice towards the opposing side
  • Wishful thinking: a specific type of appeal to emotion where a decision is made according to what might be pleasing to imagine, rather than according to evidence or reason
  • Appeal to spite: a specific type of appeal to emotion where an argument is made through exploiting people's bitterness or spite towards an opposing party
  • Appeal to flattery: a specific type of appeal to emotion where an argument is made due to the use of flattery to gather support
• Appeal to motive: where a premise is dismissed, by calling into question the motives of its proposer
• Appeal to novelty: where a proposal is claimed to be superior or better solely because it is new or modern
• Appeal to poverty (argumentum ad lazarum)
• Appeal to wealth (argumentum ad crumenam)
• Argument from silence (argumentum ex silentio)
• Appeal to tradition: where a thesis is deemed correct on the basis that it has a long standing tradition behind it
• Chronological snobbery: where a thesis is deemed incorrect because it was commonly held when something else, clearly false, was also commonly held
• Genetic fallacy
• Judgmental language
• Poisoning the well
• Sentimental fallacy: it would be more pleasant if; therefore it ought to be; therefore it is
• Straw man argument
• Style over substance fallacy
• Texas sharpshooter fallacy
• Two wrongs make a right
• Tu quoque

Conditional or questionable fallacies

• Definist fallacy
• Slippery slope