It has been suggested that this article or section be merged into Fallacy. (Discuss)

In philosophy, a logical fallacy or a formal fallacy is a pattern of reasoning which is always or at least most commonly wrong. This is due to a flaw in the structure of the argument which renders the argument invalid. A formal fallacy is contrasted with an informal fallacy, which has a valid logical form, but is false due to one or more of its premises being false. Wikipedia does not have an article with this exact name. ... It has been suggested that Logical fallacy be merged into this article or section. ... Philosophical logic is the application of formal logical techniques to problems that concern philosophers. ... In logic, an argument is an attempt to demonstrate the truth of an assertion called a conclusion, based on the truth of a set of assertions called premises. ... In logic, the form of an argument is valid precisely if it cannot lead from true premises to a false conclusion. ... In Philosophical logic, an informal fallacy is a pattern of reasoning which is false due to the falsity of one or more of its premises. ... In discourse, a premise (also premiss in British usage) is a claim which is part of a reason or objection. ...

The term fallacy is often used more generally to mean an argument which is problematic for any reason, whether it be a formal or an informal fallacy. It has been suggested that Logical fallacy be merged into this article or section. ...

The presence of a formal fallacy in a deductive argument does not imply anything about the argument's premises or its conclusion. Both may actually be true, or even more probable as a result of the argument (e.g. appeal to authority), but the deductive argument is still invalid because the conclusion does not follow from the premises in the manner described. By extension, an argument can contain a formal fallacy even if the argument is not a deductive one; for instance an inductive argument that incorrectly applies principles of probability or causality can be said to commit a formal fallacy. An appeal to authority or argument by authority is a type of argument in logic, consisting on basing the truth value of an otherwise unsupported assertion on the authority, knowledge or position of the person asserting it. ... Probability is the extent to which something is likely to happen or be the case[1]. Probability theory is used extensively in areas such as statistics, mathematics, science, philosophy to draw conclusions about the likelihood of potential events and the underlying mechanics of complex systems. ... It has been suggested that this article be split into multiple articles accessible from a disambiguation page. ...

Recognizing fallacies in everyday arguments may be difficult since arguments are often embedded in rhetorical patterns that obscure the logical connections between statements. Informal fallacies may also exploit the emotions or intellectual or psychological weaknesses of the audience. Having the capability to recognize fallacies in arguments is one way to reduce the likelihood of such occurrences. Rhetoric (from Greek , rhêtôr, orator, teacher) is generally understood to be the art or technique of persuasion through the use of oral or written language; however, this definition of rhetoric has been contested since rhetoric emerged as a field of study in Universities. ... Emotional redirects here. ... Psychology is an academic or applied discipline involving the scientific study of mental processes such as perception, cognition, emotion, personality, behavior, and interpersonal relationships. ...

A different approach to understanding and classifying fallacies is provided by argumentation theory; see for instance the van Eemeren, Grootendorst reference below. In this approach, an argument is regarded as an interactive protocol between individuals which attempts to resolve a disagreement. The protocol is regulated by certain rules of interaction and violations of these rules are fallacies. Many of the fallacies in the list below are best understood as being fallacies in this sense. Argumentation theory, or argumentation, studies the arts and sciences of civil debate, dialogue, and conversation, using rules of inference, logic, and procedural rules in both artificial and real world settings. ... In international politics, protocol is the etiquette of diplomacy and affairs of state. ...

These fallacies are used in many forms of modern communication where the intention is to influence behavior and change beliefs. Examples in the mass media today include but are not limited to propaganda, advertisements, politics, and opinion news shows. This article or section does not adequately cite its references or sources. ... An Australian anti-conscription propaganda poster from World War One U.S. propaganda poster, which warns against civilians sharing information on troop movements (National Archives) The much-imitated 1914 Lord Kitchener Wants You! poster Swedish Anti-Euro propaganda for the referendum of 2003. ... Generally speaking, advertising is the paid promotion of goods, services, companies and ideas by an identified sponsor. ... Politics is the process by which groups make decisions. ...

Common examples

• Formal fallacies
  • Argument from fallacy "ad logicam"
  • Affirming the consequent or Denying the antecedent
• Faulty generalization Inductive fallacies like
  • Biased sample
  • Half-truths
  • Hasty generalization
  • Misleading vividness
  • Package-deal fallacy or False dilemma
  • Proof by example
• Questionable cause Informal causal fallacies
  • Begging the question, circular logic "petitio principii"
  • Correlation implies causation "Cum hoc ergo propter hoc"
  • Post hoc ergo propter hoc
  • Appeal to consequences "ad consequentiam"
  • Appeal to force "ad baculum"
  • Appeal to probability & Slippery slope
• Informal Relevance fallacies
  • Irrelevant conclusion "Ignoratio elenchi" like Red herring
  • Straw man
  • Association fallacy
  • Ad hoc
  • Argument from ignorance, incredulity, belief, conviction... "ad ignorantiam"
  • Appeal to emotion like Appeal to fear, Appeal to flattery, Appeal to pity, Appeal to spite...
  • Wishful thinking
  • Appeal to authority or Appeal to ridicule
  • "Ad hominem" - Attacking the person rather then the argument
  • Appeal to the majority "ad populum"
  • Appeal to tradition "ad antiquitatem"
• Informal Verbal fallacies
  • Equivocation & Loki's Wager
  • Undistributed middle & No true Scotsman

For a list of types of formal and informal fallacy, as well as examples of fallacious arguments, see Fallacy. For a concise list of "appeal to" fallacies, see Appeal (disambiguation). The argument from fallacy, also known as argumentum ad logicam or fallacy fallacy, is a logical fallacy which assumes that if an argument is fallacious, its conclusion must be false. ... Affirming the consequent is a logical fallacy in the form of a hypothetical proposition. ... Denying the antecedent (also known as vacuous implication) is a type of logical fallacy. ... A faulty generalization, also known as an inductive fallacy, is any of several errors of inductive inference: Hasty generalization is the fallacy of examining just one or very few examples or studying a single case, and generalizing that to be representative of the whole class of objects or phenomena. ... A biased sample is one that is falsely taken to be typical of a population from which it is drawn. ... Half-truths are deceptive statements, that include some element of truth. ... Hasty generalization, also known as fallacy of insufficient statistics, fallacy of insufficient sample, fallacy of the lonely fact, leaping to a conclusion, hasty induction, law of small numbers, unrepresentative sample or secundum quid, is the logical fallacy of reaching an inductive generalization based on too little evidence. ... The logical fallacy of misleading vividness involves describing some occurrence in vivid detail, even if it is an exceptional occurrence, to convince someone that it is a problem. ... The logical fallacy of the package deal consists of assuming that things often grouped together by tradition or culture must always be grouped that way. ... The logical fallacy of false dilemma (in some sources falsified dilemma), which is also known as fallacy of the excluded middle, false dichotomy, either/or dilemma or bifurcation, involves a situation in which two alternative points of view are held to be the only options, when in reality there exist... Proof by example (also known as inappropriate generalisation) is a logical fallacy whereby one or more examples are claimed as proof for a more general statement. ... Fallacies of questionable cause, also known as causal fallacies, non causa pro causa (non-cause for cause in Latin) or false cause, are informal fallacies where a cause is incorrectly identified. ... This article or section does not adequately cite its references or sources. ... Correlation does not imply causation is a phrase used in statistics to indicate that correlation between two variables does not imply there is a cause-and-effect relationship between the two. ... Post hoc ergo propter hoc, Latin for after this, therefore because of this, is a logical fallacy (of the questionable cause variety) which assumes or asserts that if one event happens after another, then the first must be the cause of the second. ... Appeal to consequences, also known as argumentum ad consequentiam (Latin: argument to the consequences), is an argument that concludes a premise (typically a belief) to be either true or false based on whether the premise leads to desirable or undesirable consequences. ... Argumentum ad baculum (Latin: argument to the cudgel or appeal to the stick), also known as appeal to force, is said by some to be a United States who opposed the Vietnam War were told that they should not hold such a view, because they would face discrimination from potential... The appeal to probability is a logical fallacy, often used in conjunction with other fallacies. ... In debate or rhetoric, the slippery slope is an argument for the likelihood of one event given another. ... Ignoratio elenchi (also known as irrelevant conclusion) is the logical fallacy of presenting an argument that may in itself be valid, but which proves or supports a different proposition than the one it is purporting to prove or support. ... Look up red herring in Wiktionary, the free dictionary. ... A straw man, or straw person, argument is a logical fallacy based on misrepresentation of an opponents position. ... An association fallacy is a type of logical fallacy which asserts that qualities of one are inherently qualities of another, merely by association. ... Ad hoc is a Latin phrase which means for this [purpose]. It generally signifies a solution that has been tailored to a specific purpose, such as a tailor-made suit, a handcrafted network protocol, and specific-purpose equation and things like that. ... The argument from ignorance, also known as argumentum ad ignorantiam (appeal to ignorance [1]) or argument by lack of imagination, is a logical fallacy in which it is claimed that a premise is true only because it has not been proven false, or that a premise is false only because... Appeal to emotion is a logical fallacy wherein the arguer (who is using this fallacy) takes advantage of emotion to prove his or her argument. ... An appeal to fear (also called argumentum ad metum or argumentum in terrorem) is a logical fallacy in which a person attempts to create support for his or her idea by playing on existing fears and prejudices. ... Appeal to flattery is a logical fallacy in which a person uses flattery in an attempt to win support for his side. ... An appeal to pity (also called argumentum ad misericordiam) is a logical fallacy in which someone tries to win support for their argument or idea by exploiting their opponents feelings of pity or guilt. ... Appeal to spite (also called argumentum ad odium) is a logical fallacy in which someone attempts to win favor for an argument by exploiting existing feelings of bitterness or spite in the opposing party: By voting for my proposal instead of Jims, youll finally have a chance to... Wishful thinking is the formation of beliefs and making decisions according to what might be pleasing to imagine instead of by appealing to evidence or rationality. ... An appeal to authority or argument by authority is a type of argument in logic, consisting on basing the truth value of an otherwise unsupported assertion on the authority, knowledge or position of the person asserting it. ... Appeal to ridicule is a logical fallacy which presents the opponents argument in a way that appears ridiculous, often to the extent of creating a straw man of the actual argument. ... It has been suggested that Personal attack be merged into this article or section. ... An argumentum ad populum (Latin: appeal to the people), in logic, is a fallacious argument that concludes a proposition to be true because many or all people believe it; it alleges that In ethics this argument is stated, This type of argument is known by several names[1], including appeal... Appeal to tradition, also known as appeal to common practice or argumentum ad antiquitatem is a common logical fallacy in which someone proclaims his or her accuracy by noting that this is how its always been done. ... Equivocation is a logical fallacy. ... Lokis Wager is a form of logical fallacy. ... The fallacy of the undistributed middle is a logical fallacy that is committed when the middle term in a categorical syllogism isnt distributed. ... It has been suggested that this article or section be merged with Special Pleading . ... It has been suggested that Logical fallacy be merged into this article or section. ... Look up appeal in Wiktionary, the free dictionary. ...

See also

• Anecdotal evidence
• Apophasis
• Cogency
• Cognitive bias
• Conjunction fallacy
• Demagogy
• Fallacy
• Fallacies of definition
• False statement
• Informal logic
• Invalid proof
• Paradox
• Sophism
• Soundness
• Spurious relationship
• Validity
• Vacuous truth

Anecdotal evidence is an informal account of evidence in the form of an anecdote, or hearsay. ... Apophasis (Late Latin, from Greek apophanai, to say no [1]) refers, in general, to mentioning by not mentioning. Apophasis has specific meanings when used a figure of speech or as a logical device. ... An argument is cogent if and only if the truth of the arguments premises would render the truth of the conclusion probable (i. ... A cognitive bias is any of a wide range of observer effects identified in cognitive science and social psychology including very basic statistical, social attribution, and memory errors that are common to all human beings. ... The conjunction fallacy is a logical fallacy that occurs when it is assumed that specific conditions are more probable than general ones. ... Demagogy (from Greek demos, people, and agogos, leading) refers to a political strategy for obtaining and gaining political power by appealing to the popular prejudices, fears, and expectations of the public — typically via impassioned rhetoric and propaganda, and often using nationalistic or populist themes. ... It has been suggested that Logical fallacy be merged into this article or section. ... Fallacies of definition refer to the various ways in which definitions can fail to have merit. ... This article is being considered for deletion in accordance with Wikipedias deletion policy. ... Informal logic is the study of arguments as presented in ordinary language, as contrasted with the presentations of arguments in an artificial (technical) or formal language (see formal logic). ... In mathematics, there are a variety of spurious proofs of obvious contradictions. ... Look up paradox in Wiktionary, the free dictionary. ... Sophism (gr. ... (This article discusses the soundess notion of informal logic. ... ... In logic, the form of an argument is valid precisely if it cannot lead from true premises to a false conclusion. ... Vacuous truth is a special topic of first-order logic. ... The argument from fallacy, also known as argumentum ad logicam or fallacy fallacy, is a logical fallacy which assumes that if an argument is fallacious, its conclusion must be false. ... In philosophical logic, a modal logic is any logic for handling modalities: concepts like possibility, impossibility, and necessity. ... I know who X is. ... The appeal to probability is a logical fallacy, often used in conjunction with other fallacies. ... In logic and mathematics, a propositional calculus (or a sentential calculus) is a formal system in which formulas representing propositions can be formed by combining atomic propositions using logical connectives, and a system of formal proof rules allows to establish that certain formulas are theorems of the formal system. ... The logical fallacy of affirming a disjunct occurs in a disjunctive syllogism when an argument takes the form: Either A or B (this is the disjunct) A (Affirming the middle term) Therefore, not B The fallacy lies in concluding that B must be false because A is true; in fact... Affirming the consequent is a logical fallacy in the form of a hypothetical proposition. ... Denying the antecedent (also known as vacuous implication) is a type of logical fallacy. ... In language and logic, quantification is a construct that specifies the extent of validity of a predicate, that is the extent to which a predicate holds over a range of things. ... The existential fallacy is a logical fallacy committed in a categorical syllogism that is invalid because it has two universal premises and a particular conclusion. ... Syllogistic fallacies are logical fallacies that occur in syllogisms. ... Affirmative conclusion from a negative premise is a logical fallacy that is committed when a categorical syllogism has a positive conclusion, but one or two negative premises. ... The fallacy of exclusive premises is a formal fallacy committed in a categorical syllogism that is invalid because both of its premises are negative. ... A fallacy of necessity is a fallacy in the logic of a syllogism whereby a degree of unwarranted necessity is placed in the conclusion. ... The fallacy of four terms (Latin: quaternio terminorum) is a logical fallacy that occurs when a three-part syllogism has four terms. ... This article may be too technical for most readers to understand. ... Illicit minor is a logical fallacy committed in a categorical syllogism that is invalid because its minor term is undistributed in the minor premise but distributed in the conclusion. ... The fallacy of the undistributed middle is a logical fallacy that is committed when the middle term in a categorical syllogism isnt distributed. ...

References

• Aristotle, On Sophistical Refutations, De Sophistici Elenchi.
• William of Ockham, Summa of Logic (ca. 1323) Part III.4.
• John Buridan, Summulae de dialectica Book VII.
• Francis Bacon, the doctrine of the idols in Novum Organum Scientiarum, Aphorisms concerning The Interpretation of Nature and the Kingdom of Man, XXIIIff.
• The Art of Controversy | Die Kunst, Recht zu behalten - The Art Of Controversy (bilingual), by Arthur Schopenhauer
• John Stuart Mill, A System of Logic - Raciocinative and Inductive. Book 5, Chapter 7, Fallacies of Confusion.
• C. L. Hamblin, Fallacies. Methuen London, 1970.
• Fearnside, W. Ward and William B. Holther, Fallacy: The Counterfeit of Argument, 1959.
• Vincent F. Hendricks, Thought 2 Talk: A Crash Course in Reflection and Expression, New York: Automatic Press / VIP, 2005, ISBN 87-991013-7-8
• D. H. Fischer, Historians' Fallacies: Toward a Logic of Historical Thought, Harper Torchbooks, 1970.
• Douglas N. Walton, Informal logic: A handbook for critical argumentation. Cambridge University Press, 1989.
• F. H. van Eemeren and R. Grootendorst, Argumentation, Communication and Fallacies: A Pragma-Dialectical Perspective, Lawrence Erlbaum and Associates, 1992.
• Warburton Nigel, Thinking from A to Z, Routledge 1998.
• T. Edward Damer. Attacking Faulty Reasoning, 5th Edition, Wadsworth, 2005. ISBN 0-534-60516-8
• Sagan, Carl, "The Demon-Haunted World: Science As a Candle in the Dark". Ballantine Books, March 1997 ISBN 0-345-40946-9, 480 pgs. 1996 hardback edition: Random House, ISBN 0-394-53512-X, xv+457 pages plus addenda insert (some printings).

Aristotle (Greek: Aristotélēs) (384 BC – March 7, 322 BC) was a Greek philosopher, a student of Plato and teacher of Alexander the Great. ... William of Ockham William of Ockham (also Occam or any of several other spellings) (c. ... Arthur Schopenhauer (February 22, 1788 – September 21, 1860) was a German philosopher. ... 1970 (MCMLXX) was a common year starting on Thursday. ... Vincent F. Hendricks is a philosopher and logician. ... 1989 (MCMLXXXIX) was a common year starting on Sunday of the Gregorian calendar. ... 1992 (MCMXCII) was a leap year starting on Wednesday. ... 1998 (MCMXCVIII) was a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean [1]. // Coated in ice, power and telephone lines sag and often break, resulting in power outages. ... Attacking Faulty Reasoning is a textbook on logical fallacies by T. Edward Damer that has been used for many years in a number of college courses on logic, critical thinking, argumentation, and philosophy. ... Insert non-formatted text here Carl Edward Sagan (November 9, 1934 – December 20, 1996) was an American astronomer and astrobiologist and a highly successful popularizer of astronomy, astrophysics, and other natural sciences. ... The Demon-Haunted World: Science as a Candle in the Dark is a 1997 book by Carl Sagan. ... Ballantine Books, founded in 1952 by Ian Ballantine, is a major book publisher and is currently owned by Random House. ... Random House is a publishing division of the German media conglomerate Bertelsmann based in New York City. ...

External links

• Logical Fallacies-a semi ordered list with definitions
• The Fallacy Files by Gary N. Curtis - real examples posted regularly.
• Fallacies - ESGS. Europeean Society for General Semantics
• Logical Fallacies .Info
• Bruce Thompson's Fallacy Page
• Stephen Downes Guide to the Logical Fallacies
• Logical Fallacies and the Art of Debate
• Logic & Fallacies: Constructing a Logical Argument
• Logical Fallacies Quiz Ten common fallicies in an interactive test format.
• Humbug! Online List of fallacies with links to real examples - posted regularly.
• 42 informal logical fallacies explained by Dr. Michael C. Labossiere, including examples.
• On Informal Fallacies is a collection of one-off fallacies coined for specific, rhetorical purposes.
• Marilyn vos Savant explains Logical Fallacies
• Some paradoxes - an anthology