— Describing inconsistencies
A fallacy is a kind of error in reasoning. This course names common fallacies and provides brief explanations and examples of each of them. Because they are errors in reasoning it is surprising they are as common as they are. Fallacies often go unrecognized and unchallenged. Fallacies may be created unintentionally, or they may be created with the intent to deceive other people. We think more clearly when we can identify fallacies and correct the underlying logic error. We can avoid committing fallacies by developing critical thinking.
Exploring inconsistencies can bring us to the threshold of insight. This course can help you identify inconsistencies, correct the error, and use correct reasoning.
The objectives of this course are to help students:
- Identify invalid arguments,
- Recognize common fallacies,
- Name and analyze common errors in reasoning,
- Describe inconsistencies,
- Identify fallacies in real arguments,
- Think more clearly.
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Although there are no prerequisites to this course, students may benefit by first completing the related course on Deductive Logic. It can be helpful to understand correct logical forms before studying logical fallacies.
The course contains many hyperlinks to further information. Use your judgment and these link following guidelines to decide when to follow a link, and when to skip over it. Each of the top level headings below are linked to course materials; it is important to follow these links.
This course is part of the Applied Wisdom curriculum and of the Clear Thinking curriculum.
If you wish to contact the instructor, please click here to send me an email or leave a comment or question on the discussion page.
This Quick Reference on recognizing fallacies may provide a helpful summary and reference.
The Nature of FallaciesEdit
When the conclusion of an argument is not supported by the premises, then the argument contains a logical fallacy. In this case, the conclusion could be false, even if all of the premises are true. A fallacy is an error in reasoning, as contrasted with a more general error in inquiry.
Because there are only a few valid argument forms and an unlimited number of logic errors that can occur, there are many possible fallacies. Various attempts to name, list, and classify fallacies include more than 100 named fallacies. This course emphasizes the most commonly encountered fallacies and defines a fallacy as “a type of argument that may seem to be correct but which proves, on examination, not to be so.” An alternative definition of a fallacy is: a violation of rules for a critical discussion.
Fallacies are especially tricky because they often seem to be correct and are often overlooked.
There is no well accepted categorization of fallacies. This course adapts a respected and workable categorization provided by Copi and others recognizing that it has several shortcomings.
After introducing the most common fallacies the course turns attention to identifying fallacies in “the wild”—in real arguments made by real people who are attempting to communicate their understanding of a fact, position, or opinion, or win an argument.
We begin by introducing several informal fallacies, and go on to introduce formal fallacies. The list here is necessarily incomplete. For a more complete list of fallacies, see the Wikipedia list of fallacies, or other sources identified in the Resources section of this course.
Fallacies of RelevanceEdit
Fallacies of PresumptionEdit
Fallacies of AmbiguityEdit
Taming Wild FallaciesEdit
These resources have been used in developing this course, and provide opportunities for further study.
- Wikipedia's list of formal fallacies.
- Wikipedia's more exhaustive list of formal and informal fallacies.
- Nizkor's list of fallacies.
- The Fallacy Files is a very exhaustive list.
- Hansen, Hans, "Fallacies", The Stanford Encyclopedia of Philosophy (Summer 2015 Edition), Edward N. Zalta (ed.), http://plato.stanford.edu/archives/sum2015/entries/fallacies/
- Dowden, Bradley, Fallacies, entry in the Internet Encyclopedia of Philosophy.
- RationalWiki, entries on Logical fallacy.
- Philosophy.lander.edu pages on fallacy topics.
- Forty Two Fallacies (For Free) By Dr. Michael C. LaBossiere
- Logically Fallacious, the ultimate collection of over 300 Logical Fallacies, Bo Bennett, PhD
- Your logical fallacy is
Many books on logic include sections on logical fallacies. Search for these and choose any that seem helpful. The following books were used to develop this course.
- Almossawi, Ali (September 23, 2014). An Illustrated Book of Bad Arguments. The Experiment. pp. 64. ISBN 978-1615192250. Available on-line at: https://bookofbadarguments.com/
- Copi, Irving M.; Cohen, Carl (June 20, 2001). Introduction to Logic. Prentice Hall. pp. 647. ISBN 978-0130337351.
- Michalos, Alex C. (November 1, 1969). Principles of Logic. Prentice Hall. pp. 433. ISBN 978-0137094028.
- Fisher, Alec (October 25, 2004). The Logic of Real Arguments. Cambridge University Press. pp. 234. ISBN 978-0521654814.
- Weston, Anthony (November 14, 2008). Rulebook for Arguments. Hackett Publishing Co, Inc. pp. 104. ISBN 978-0872209541.
- Van Cleave, Matthew J.. Introduction to Logic and Critical Thinking. BCcampus OpenEd. pp. 242.
- Pinker, Steven (September 28, 2021). Rationality: What It Is, Why It Seems Scarce, Why It Matters. Viking. pp. 432. ISBN 978-0525561996.
I have not yet read the following books, but they seem interesting and relevant. They are listed here to invite further research.
- Pitfalls: A quick guide to identifying logical fallacies for families, by J.D. Camorlinga
- Critical Thinking: Consider the Verdict by Bruce Waller
- The Art of Always Being Right: Thirty Eight Ways to Win When You Are Defeated, by Grayling, A. C.
- ↑ The Internet Encyclopedia of Philosophy entry on fallacies.
- ↑ David H. Fischer’s book Historian’s Fallacies names more than 112 fallacies. The Internet Encyclopedia of Philosophy entry on fallacies lists 216 names of the most common fallacies. The Wikipedia list of fallacies includes more than I care to count. Bo Bennett’s book Logically Fallacious: The Ultimate Collection of over 300 Logical Fallacies describes and names more than 300.
- ↑ Copi, Irving M.; Cohen, Carl (June 20, 2001). Introduction to Logic. Prentice Hall. pp. 647. ISBN 978-0130337351. Chapter 4.
- ↑ The Pragma-Dialectical Approach to Fallacies, Frans H. Van Eemeren and Rob Grootendorst, published in Fallacies: Classical and Contemporary Readings, edited by Hans V. Hansen and Robert C. Pinto (1995).http://www.ditext.com/eemeren/pd.html
- ↑ Copi, Irving M.; Cohen, Carl (June 20, 2001). Introduction to Logic. Prentice Hall. pp. 647. ISBN 978-0130337351.
- ↑ A very similar scheme is used by Michalos, Alex C. (November 1, 1969). Principles of Logic. Prentice Hall. pp. 433. ISBN 978-0137094028. Chapter 10.
- ↑ The Stanford Encyclopedia entry on Fallacies.
- ↑ The Pragma-Dialectical Approach to Fallacies, Frans H. Van Eemeren and Rob Grootendorst, published in Fallacies: Classical and Contemporary Readings, edited by Hans V. Hansen and Robert C. Pinto