Logical fallacy
In
philosophy, the term
logical fallacy properly refers to a
formal fallacy : a flaw in the structure of a
deductive argument which renders the argument
invalid. However, it is often used more generally in informal discourse to mean an argument which is problematic for any reason, and thus encompasses
informal fallacies – valid but
unsound claims or bad nondeductive argumentation – as well as formal fallacies.
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.
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 occurences.
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.
*
Ad baculum*
Ad hoc*
Ad hominem*
Affirming the consequent*
Appeal to authority*
Appeal to fear*
Appeal to pity*
Appeal to probability*
Appeal to tradition*
Appeal to the majority*
Argument from ignorance*
Begging the question*
Biased sample*
Correlation implies causation*
Denying the antecedent*
Equivocation*
False dilemma*
Hasty generalization*
Loki's Wager*
No true scotsman*
Post hoc ergo propter hoc*
Slippery slope*
Straw man*
Undistributed middleFor 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).*
Anecdotal evidence*
Apophasis*
Cogency*
Cognitive bias*
Demagogy*
Fallacy*
Fallacies of definition*
False statement*
Informal logic*
Invalid proof*
Paradox*
Sophism*
Soundness*
Spurious relationship*
Validity*
Vacuous truth*
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 8799101378
* 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.
*
Logical Fallacies-a semi ordered list with definitions*
The Fallacy Files by
Gary N. Curtis*
Logical Fallacies .Info * Bruce Thompson's
Fallacy Page *
Doug Walton's books and papers on Argumentation.
*
Logical Fallacies and the Art of Debate*
Logical Fallacies Quiz Ten common fallicies in an interactive test format.
*
List of fallacies with links to real examples.
*
Examples of a straw man, a double standard, an unfair accusation, a factual errors, and a tangents -
Richard Stallman responding to
Alan Cox about "
GNU/Linux"
*
42 informal logical fallacies explained by Dr. Michael C. Labossiere, including examples.*
The NonSequitur: online analysis of fallacies in political argument
