Logical fallacy

A logical fallacy may mean nothing more than a fallacy or it may mean an error in deductive reasoning, i.e., a formal fallacy. In the latter case, it is a flaw in the structure of a deductive argument as opposed to an error in the premises. When there is a formal fallacy in a deductive argument it is said to be invalid. The presence of a fallacy in a deductive argument does not imply anything about the argument's premises or its conclusion. Both may actually be true, but the deductive argument is still invalid because the conclusion does not follow from the premises. By extension, an argument can have a logical 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 logical fallacy.

Recognizing fallacies in everyday arguments may be difficult since arguments are often imbedded 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 will hopefully reduce the likelihood of such an occurrence.

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.

(for examples of fallacious arguments see the article on Fallacy)

List of fallacies

The entries in the following list are neither exhaustive nor mutually exclusive, that is, several distinct entries may refer to the same pattern. As noted in the introduction, these fallacies describe erroneous or at least suspect patterns of argument in general, not necessarily argument based on formal logic. Many of the fallacies listed are traditionally recognized and discussed in works on critical thinking; others are more specialized.

• Ad hominem (also called argumentum ad hominem or personal attack) Including:
  • ad hominem abusive (also called argumentum ad personam)
  • ad hominem circumstantial (also called ad hominem circumstantiae)
  • ad hominem tu quoque (also called you too argument)
• Amphibology (also called amphiboly)
• Appeal to authority (also called argumentum ad verecundiam or argument by authority)
• Appeal to belief
• Appeal to consequences (also called argumentum ad consequentiam)
• Appeal to emotion including:
  • Appeal to fear (also called argumentum ad metum or argumentum in terrorem)
  • Appeal to flattery
  • Appeal to the majority (also called argumentum ad populum)
  • Appeal to pity (also called argumentum ad misericordiam)
  • Appeal to ridicule
  • Appeal to spite (also called argumentum ad odium)
  • Two wrongs make a right
  • Wishful thinking
• Appeal to motive
• Appeal to novelty (also called argumentum ad novitatem)
• Appeal to probability
• Appeal to tradition (also called argumentum ad antiquitatem or appeal to common practice)
• Argument from fallacy (also called argumentum ad logicam)
• Argument from ignorance (also called argumentum ad ignorantiam or argument by lack of imagination)
• Argument from silence (also called argumentum ex silentio)
• Argumentum ad baculum (also called appeal to force)
• Argumentum ad crumenam (also called appeal to wealth)
• Argumentum ad lazarum (also called appeal to poverty)
• Argumentum ad nauseam (also called argument from repetition)
• Argumentum ad numerum
• Asking the question
• Bandwagon fallacy (also called appeal to popularity, appeal to the people, or argumentum ad populum)
• Base rate fallacy
• Begging the question (also called petitio principii, circular argument or circular reasoning)
• Cartesian fallacy
• Conjunction fallacy
• Continuum fallacy (also called fallacy of the beard)
• Correlative based fallacies including:
  • Fallacy of many questions (also called complex question, fallacy of presupposition, loaded question or plurium interrogationum)
  • False dilemma (also called false dichotomy or bifurcation)
  • Denying the correlative
  • Suppressed correlative
• Dicto simpliciter, including:
  • Accident (also called a dicto simpliciter ad dictum secundum quid)
  • Converse accident (also called a dicto secundum quid ad dictum simpliciter)
• Equivocation
• Fallacies of distribution:
  • Composition
  • Division
  • Ecological fallacy
• False analogy
• False premise
• False compromise
• Faulty generalization including:
  • Biased sample
  • Hasty generalization (also called fallacy of insufficient statistics, fallacy of insufficient sample, fallacy of the lonely fact, leaping to a conclusion, hasty induction, secundum quid)
  • Overwhelming exception
  • Statistical special pleading
• Gambler's fallacy/Inverse gambler's fallacy
• Genetic fallacy
• Guilt by association
• Historian's fallacy
• Homunculus fallacy
• Ideology over reality
• If-by-whiskey (argues both sides)
• Ignoratio elenchi (also called irrelevant conclusion)
• Inappropriate interpretations or applications of statistics including:
  • Biased sample
  • Correlation implies causation
  • Gambler's fallacy
  • Prosecutor's fallacy
  • Screening test fallacy
• Incomplete comparison
• Inconsistent comparison
• Intentional fallacy
• Invalid proof
• Judgemental language
• Juxtaposition
• Lump of labour fallacy (also called the fallacy of labour scarcity)
• Meaningless statement
• Middle ground (also called argumentum ad temperantiam)
• Misleading vividness
• Naturalistic fallacy
• Negative proof
• Non sequitur including:
  • Affirming the consequent
  • Denying the antecedent
• No true Scotsman
• Package deal fallacy
• Pathetic fallacy
• Perfect solution fallacy
• Poisoning the well
• Proof by assertion
• Proof by verbosity
• Questionable cause (also called non causa pro causa) including:
  • Correlation implies causation (also called cum hoc ergo propter hoc)
  • Fallacy of the single cause
  • Joint effect
  • Post hoc (also called post hoc ergo propter hoc)
  • Regression fallacy
  • Texas sharpshooter fallacy
  • Wrong direction
• Red herring (also called irrelevant conclusion)
• Reification (also called hypostatization)
• Relativist fallacy (also called subjectivist fallacy)
• Retrospective determinism (it happened so it was bound to)
• Shifting the Burden of proof
• Slippery slope
• Special pleading
• Straw man
• Style over substance fallacy
• Syllogistic fallacies, including:
  • Affirming a disjunct
  • Affirmative conclusion from a negative premise
  • Existential fallacy
  • Fallacy of exclusive premises
  • Fallacy of four terms (also called quaternio terminorum)
  • Fallacy of the undistributed middle
  • Illicit major
  • Illicit minor

See also

• Anecdotal evidence
• Cogency
• Cognitive bias
• College logic
• Critical thinking
• Demagogy
• Fallacy
• Fallacies of definition
• False statement
• Good argument
• Informal logic
• Invalid proof
• Sophism
• Soundness
• Spurious relationship
• Validity

References

• Aristoteles, 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.
• 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.
• "Logic", an article from Philosophical Society.com

External links

• The Fallacy Files by Gary N. Curtis
• Logical Fallacies from Philosophical Society.com
• Logical Fallacies Online edition of Madsen Pirie's Book of the Fallacy
• Logic & Fallacies, from Atheism Web (no strict relation to Atheism)
• Logic and fallacies: How to spot a problem argument
• Stephen's Guide to the Logical Fallacies (Mirror)(Mirror)
• Bruce Thompson's table of fallacies
• Logical fallacies on WikiWikiWeb
• The Woolly-Thinker's Guide to Rhetoric
• The Autonomist's Logical Fallacies
• A list of Fallacious Arguments
• Propaganda techniques at Disinfopedia
• Logical fallacies > Bad logic or propaganda? connection between logical fallacy and propaganda
• Informal Fallacies by Michael Connelly, contributed to the Critical Thinking Across the Curriculum Project.
• Papers on fallacies and argumentation by Douglas N. Walton.
• A Guide to Logical Fallacies by Paul Newall, aimed at beginners.
• Geometric Fallacies