An error in reasoning that renders an argument invalid.
Ad Hominem, Ad Misericordiam, Amphiboly, Appeal to Authority, Appeal to Force, Appeal to Humor, Appeal to Ignorance, Appeal to the People, Bandwagon, Begging the Question, Circular Argument, Complex Question, Contradictory Premises, Dicto Simpliciter, Equivocation, Etymological Fallacy, False Analogy, False Dilemma, Gambler's Fallacy, Hasty Generalization, Misleading Vividness, Name-Calling, Non Sequitur, Paralepsis, Poisoning the Well, Post Hoc, Red Herring, Slippery Slope, Stacking the Deck, Straw Man, Tu Quoque, Undistributed Middle
Etymology:From the Latin, "deceive"
- "In logic and the generalized study of reasoning, there are
generally understood to be such things as good reasoning and bad reasoning. Typically, bad reasoning is characterized by falling into one or more of the classically compiled logical fallacies. A logical fallacy is simply a failure of logic. Arguments that are said to be fallacious have gaping holes or misleading leaps in their structure and reasoning."
(J. Meany and K. Shuster, Art, Argument, and Advocacy. IDEA, 2002)
- "There's a mighty big difference between good, sound reasons and reasons that sound good."
- "Logical errors are, I think, of greater practical importance than many people believe; they enable their perpetrators to hold the comfortable opinion on every subject in turn."
- "A fallacy is so conceived that if an argument exhibits a fallacy, it is probably a bad one, but if the argument exhibits no such violation, it is a good one.
"Fallacies are mistakes in reasoning that do not seem to be mistakes. Indeed, part of the etymology of the word 'fallacy' comes from the notion of deception. Fallacious arguments usually have the deceptive appearance of being good arguments. That perhaps explains why we are so often misled by them."
(T. Edward Damer, Attacking Faulty Reasoning, 2001)
- "[O]ne clear sense of fallacy that we will encounter will involve a shift away from the correct direction in which an argumentative dialogue is progressing. By various means, an arguer may impede the other party from making her point or may attempt to draw the discussion off track. In fact, one popular modern approach to understanding fallacious reasoning is to see it as involving violations of rules that should govern disputes so as to ensure that they are well conducted and resolved. This approach, put forward by [Frans] van Eemeren and [Rob] Grootendorst in several works, goes by the name of 'pragma-dialectics.' Not only is each of the traditional fallacies understood as a violation of a discussion rule, but new fallacies emerge to correspond to other violations once we focus on this way of conducting arguments."
(Christopher W. Tindale, Fallacies and Argument Appraisal. Cambridge Univ. Press, 2007)