LOGICAL FALLACIES
I've been bothered for a number of years, really for most of my adult life, by how poorly individuals will construct their arguments in everyday life and in academic debate. Along the way, I stumbled upon a collection of fallacies (see references) that I've found to be a convenient yard-stick by which to critique others' arguments. They are offered here in a hypertext form that I originally wrote to be read by my PalmPilot personal digital assistant (PDA).. - Art
Fallacies of Relevance
Accident
Affirmation of the Consequent
Argumentum ad Antiquitam
Argumentum ad Baculum (appeal to force)
Argumentum ad Crumenam
Argumentum ad Hominem (abusive)
Argumentum ad Hominem (circumstantial)
Argumentum ad Ignoratiam (argument from ignorance)
Argumentum ad Lazarum
Argumentum ad Misericordiam (appeal to pity)
Argumentum ad Nauseum
Argumentum ad Novitam
Argumentum ad Numeram
Argumentum ad Populam
Argumentum ad Verecundiam (appeal to authority)
Bifrucation
Complex Question
Converse Accident (hasty generalization)
Denial of the Antecedent
Dicto Simpliciter - Sweeping Generalization
Fallacy of Interrogation
False Analogy
False Cause
Hasty Generalization
Ignoratio Elenchi
Non Causa Pro Causa
Non-Sequitur
Petitio Principii (begging the question)
Plurium Interrogationum - Many Questions
Post Hoc, Ergo Propter Hoc
Quaternio Terminorum
Red Herring
Reification
Shifting the Burden of Proof
Special Pleading
Straw Man
Tu Quoque - Two Wrongs Make a Right
Equivocation
Amphiboly
Accentus - Accent
Composition
Division
Fallacies of Correlation
Affirmation of the Consequent.
Description: An argument from the truth of a hypothetical statement, and the truth of the consequent to the truth of the antecedent. In the syllogism below, P is the antecedent and Q is the consequent: P implies Q Q is true <-- Affirming the consequent ______________ Therefore: P is true.
Description: A fallacy of asserting that something is right or good simply because it is old; that is, because "that's the way it's always been."
Argumentum ad Baculum (appeal to force).
The arguer appeals to force or the threat of force to compel acceptance of the conclusion.
Description: Fallacy of believing that money is a criterion of correctness; that those with more money are more likely to be right.
Argumentum ad Hominem (abusive).
"The phrase argumentum ad hominem translates literally as 'argument directed to the man.'" The abusive variety occurs when one attacks the other person rather than the other persons argument.
. Argumentum ad Hominem (circumstantial).
In this case, one tries to convince the opponent to agree to the conclusion based on the opponents circumstances. For example (from Copi), a hunter may claim an anti-hunter must say hunting is acceptable since the anti-hunter is not a vegetarian.
Argumentum ad Ignoratiam (argument from ignorance).
Description: A fallacy of assuming that because someone is poor he or she is sounder or more virtuous than one who is wealthier. This fallacy is the opposite of the informal fallacy "argumentum ad crumenam."
Argumentum ad Misericordiam (appeal to pity).
The arguer appeals to pity where the conclusion is a matter of reason and not one of sentiment, e.g. referring to a murder suspect's dependent family.
Description: The incorrect belief that an assertion is more likely to be true the more often it is heard. An "argumentum ad nauseum" is one that employs constant repitition in asserting a truth.
Description: A fallacy of asserting that something is more correct simply because it is new or newer than something else. Or that something is better because it is newer. This type of fallacy is the opposite of the "argumentum ad antiquitam" fallacy.
Description: A fallacy that asserts that the more people who support or believe a proposition then the more likely that that proposition is correct; it equates mass support with correctness.
"the attempt to win popular assent to a conclusion by arousing the emotions and enthusiasms of the multitude, rather than by appeal to the relevant facts."
Argumentum ad Verecundiam (appeal to authority).
This is especially the appeal to authority outside the field of that authority's expertise. In the field of the authority's expertise, "this method of argument is in many cases perfectly legitimate, for the reference to an admitted authority in the special field of that authority's competence may carry great weight and constitute relevant evidence. ... Although it does not prove the point, it certainly tends to support it."
"The fallacy of accident consists in applying a general rule to a particular case whose 'accidental' circumstances render the rule inapplicable." For instance, while generally one should not exceed the speed limit, it is acceptable for emergency vehicles to do so.
Description: Also referred to as the "black and white" fallacy, bifurcation is the presentation of a situation or condition with only two alternatives, whereas in fact other alternatives exist or can exist.
Converse Accident (hasty generalization).
Making a general rule based on a few atypical cases. For instance, considering the effect of alcohol only on those who indulge to excess, and concluding that liquor is harmful and should be outlawed.
Description: An argument in which one infers the falsity of the consequent from the truth of a hypothetical proposition, and the falsity of its antecedent. P implies Q Not-P ____________ Therefore: Not-Q.
Dicto Simpliciter - Sweeping Generalization.
Description: Sweeping Generalization occurs when a general rule is applied to a particular situation in which the features of that particular situation render the rule inapplicable. A sweeping generalization is the opposite of a hasty generalization.
Description: The question asked has a presupposition which the answerer may wish to deny, but which he/she would be accepting if he/she gave anything that would count as an answer. Any answer to the question "Why does such-and-such happen?" presupposes that such-and-such does indeed happen.
Description: An argument in which a proposition is used as a premise without attention given to some obvious condition that would affect the proposition's application. This fallacy is also known as the "hasty generalization." It is a fallacy that takes evidence from several, possibly unrepresentative, cases to a general rule; generalizing from few to many. Note the relation to statistics: Much of statistics concerns whether or not a sample is representative of a larger population. The larger the sample size, the better the representativeness. Note also that the opposite of a hasty generalization is a sweeping generalization.
Description: An argument to reject a proposition because of the falsity of some other proposition that seems to be a consequence of the first, but really is not.
Description: An argument in which the conclusion is not a necessary consequence of the premises. Another way of putting this is: A conclusion drawn from premises that provide no logical connection to it.
Petitio Principii (begging the question).
Plurium Interrogationum - Many Questions.
Description: A demand for a simple answer to a complex question.
Description: An argument from a premise of the form "A preceded B" to a conclusion of the form "A caused B." Simply because one event precedes another event in time does not mean that the first event is the cause of the second event. This argument resembles a fallacy known as a Hasty Generalization.
Description: An argument of the syllogistic form in which there occur four or more terms. In a standard categorical syllogism there are only three terms: a subject, a predicate, and a middle term.
Description: A fallacy when irrelevant material is introduced to the issue being discussed, such that everyone's attention is diverted away from the points being made, and toward a different conclusion. It is not logically valid to divert a chain of reasoning with extraneous points.
Description: To reify something is to convert an abstract concept into a concrete thing. Reification is a Fallacy of Ambiguity. Reification is also sometimes known as a fallacy of "hypostatization".
Description: The burden of proof is always on the person making the assertion or proposition. Shifting the burden of proof, a special case of "argumentum ad ignorantium," is a fallacy of putting the burden of proof on the person who denies or questions the assertion being made. The source of the fallacy is the assumption that something is true unless proven otherwise.
Description: Special pleading is a logical fallacy wherein a double standard is employed by the person making the assertion. Special pleading typically happens when one insists upon less strict treatment for the argument he/she is making than he or she would make when evaluating someone else's arguments.
Description: It is a fallacy to misrepresent someone else's position for the purposes of more easily attacking it, then to knock down that misrepresented position, and then to conclude that the original position has been demolished. It is a fallacy because it fails to deal with the actual arguments that one has made.
Tu Quoque - Two Wrongs Make a Right.
Description: Two wrongs never add up to a right; you cannot right a wrong by applying yet another wrong. Such a fallacy is a misplaced appeal to consistency. It is a fallacy because it makes no attempt to deal with the subject under discussion.
Description: An argument in the course of which at least one term is used in different senses. Also known as equivocation. There are several types of "fallacies of ambiguity," including REIFICATION, EQUIVOCATION, AMPHIBOLY, COMPOSITION, DIVISION, and ACCENTUS.
Description: A fallacy of correlation that links events because they occur simultaneously; one asserts that because two events occur together they are causally related, and leaves no room for other factors that may be the cause(s) of the events. This fallacy is similar to the "post hoc" fallacy.
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