DOCSLIB.ORG

Logical Fallacies

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Logical Fallacies SAGE Flex for Public Speaking Logical Fallacies Brief: When a logical fallacy in included as part of a persuasive speech argument, there’s a risk of compromising the validity of the argument and undermining credibility with the audience. Learning Objective: Identify different types of logical fallacies. Key Terms: • Ad Hominem: A fallacy of attacking the person making the argument or claim, rather than by addressing the substance of the argument or producing evidence against the claim. • Ad Populum: A fallacy that concludes a proposition must be true because many or most people believe it. • Either/Or fallacy: A fallacy in which the listener is forced to make a choice between two things that are not really related or relevant. • Hasty generalization: A fallacy of examining just one or very few examples and generalizing that to be representative of the whole class of objects or phenomena. • Loaded questions: A fallacy in which more than one question is grouped in the form of a single question, hiding the speaker’s true motivation and setting up a bad outcome for the respondent. • Non sequitur: A fallacy in which there’s an invalid argument whose conclusion does not flow from its premises. • Post hoc ergo propter hoc: A fallacy in which there is a false inference that experiencing one thing after another implies a causal relation. • Red herring: A fallacy in which the speaker intentionally or unintentionally misleads or distracts the audience from the actual issue. • Straw man: A fallacy that creates the illusion of having refuted a proposition by replacing it with a superficially similar proposition (the “straw man”) and refuting it without ever actually refuting the original proposition. What is a Logical Fallacy? A fallacy is a clearly identifiable error in logical reasoning used to support or refute an argument. When you include a logical fallacy as part of your persuasive speech argument, you risk compromising the validity of your argument and undermining your credibility with your audience. Your best protection against unintentionally including a logical fallacy is to be able to identify — and avoid — commonly used fallacies. Types of Logical Fallacies Hasty Generalization When a speaker makes a hasty generalization, they examine just one or very few examples, generalizing that to be representative of the whole class of objects or phenomena. 1 SAGE Flex for Public Speaking Argument: “Every person I’ve met has ten fingers, therefore, all people have ten fingers.” Problem: Just because the speaker has only met people with ten fingers doesn’t mean all people have ten fingers. Ad Hominem When a speaker uses this strategy, they discredit the person making the claim, rather than by addressing the substance of the argument or producing evidence against the claim. Argument: “What do you know about the United States? You aren’t even a citizen.” Problem: The speaker unfairly attacks their opponent instead of focusing on their opponent’s argument. Ad Populum Also known as a band wagon appeal, this is an appeal to the majority or an appeal to loyalty, or a combination of the two. It occurs when a speaker concludes that something must be true because many or most people believe it. Argument: “Everyone’s doing it.” Problem: The speaker suggests that something that is popular is acceptable, even though that might not be the case. Red Herring This is an appeal that intentionally or unintentionally misleads or distracts from the actual issue. Argument: “I think that we should make the academic requirements stricter for students. I recommend that you support this measure because we are in a budget crisis and we don’t want our salaries affected.” Problem: Here the second sentence does not address the topic of the first sentence, instead switching the focus to a different topic. Non Sequitur When a speaker uses a non sequitur, they make an invalid argument whose conclusion is not supported by its premises. Non sequitur is Latin for “it does not follow.” Argument: I hear the rain falling outside my window; therefore, the sun is not shining. Problem: The conclusion is false because the sun can shine while it is raining. 2 SAGE Flex for Public Speaking Post Hoc Ergo Propter Hoc Latin for “because of this, therefore that,” this is a false inference that experiencing one thing after another implies a causal relation. Argument: It rained just before the car died. The rain caused the car to break down. Problem: There may be no connection between the two events. Loaded Questions In a loaded question, more than one question is grouped in the form of a single question, hiding the speaker’s true motivation and setting up a bad outcome for the respondent. Argument: Have you broken your bad habits? Problem: Either a yes or no answer is an admission of guilt. Straw Man A straw man creates the illusion of having refuted a proposition by replacing it with a superficially similar proposition (the “straw man”), and refuting it, without ever actually refuting the original. Argument: Person A: “Sunny days are good.” Person B: “If all days were sunny, we’d never have rain, and without rain, we’d have famine and death. Therefore, you are wrong.” Problem: Person B has misrepresented A’s claim by falsely suggesting that A claimed that only sunny days are good, and then B refuted the misrepresented version of the claim, rather than refuting A’s original assertion. Either/Or Fallacy In this case, the listener is forced to make a choice between two things that are not really related or relevant. Argument: If you are not with us, you are against us. Problem: The presentation of a false choice often reflects a deliberate attempt to eliminate any middle ground. From Concept to Action After you’ve identified your proposition, chosen your line of reasoning, and selected and organized your main and sub-points, conduct a review of your evidence for logical fallacies. Using the list above, compare your logic to each of the logical fallacies. Did you unintentionally use one or more of these fallacies? If so, how can you change your reasoning to eliminate the fallacies? Specifically, are you able to remove the fallacies and still make the point you’re trying to make? Perhaps you need more or different sources of evidence? Or, maybe your best choice is to start over and develop an entirely new line of reasoning with fresh support? 3 SAGE Flex for Public Speaking OER TEXT SOURCES: “ad hominem.” Wiktionary. https://en.wiktionary.org/wiki/ad_hominem. Accessed 17 June 2019. [CC BY-SA 3.0] “Faulty generalization.” Wikipedia. https://en.wikipedia.org/wiki/Faulty_generalization. Accessed 17 June 2019. [CC BY-SA 3.0] “Formal fallacy.” Wikipedia. https://en.wikipedia.org/wiki/Formal_fallacy. Accessed 16 June 2019. [CC BY-SA 3.0] “Logical fallacy.” Wiktionary. https://en.wiktionary.org/wiki/logical_fallacy Accessed 7 June 2019. [CC BY-SA 3.0] “Logical Fallacies.” Lumen Learning. https://lumen.instructure.com/courses/218897/pages/linkedtext54322. Accessed 7 June 2019. [CC BY-SA 3.0] 4 .
Load more

Recommended publications
  • Accountability and the Promise of Performance: in Search of The
    Accountability and the Promise of Performance: In Search of the Mechanisms Melvin J. Dubnick Professor of Political Science & Public Administration Rutgers University – Newark & Visiting Professor Institute of Governance, Public Policy and Social Research Queen’s University, Belfast [email protected] Prepared for delivery at the 2003 Annual Meeting of the American Political Science Association, August 28-31, Philadelphia, PA & Conference of the European Group of Public Administration (EGPA) September 3-6, 2003, Lisbon, Portugal ver: 8/29/03 Self-evident truths are frequently invoked when scholars and policymakers propose political reforms. We often hear: "It is obvious that X is true, therefore we need to do Y." The implication of this assertion is that common sense dictates our understanding of the problem and the solution. But is it really the case that X is true? And is Y really the best response? The fact that something is widely believed does not make it correct. (Ostrom 2000) Introduction: The Promise of Performance Among the pervasive notions characterizing contemporary public administration rhetoric and scholarship is the idea of accountability as the solution to a wide range of problems. According to proponents of accountability-centered reforms, enhanced accountability will (among other things) result in · greater transparency and openness in a world threatened by the powerful forces of hierarchy and bureaucratization (the promise of democracy) (O'Donnell 1998; Schedler, Diamond, and Plattner 1999); · access to impartial arenas where abuses of authority can be challenged and judged (the promise of justice) (Borneman 1997; Miller 1998; Ambos 2000); · pressures and oversight that will promote appropriate behavior on the part of public officials (the promise of ethical behavior) (Gray and Jenkins 1993; Anechiarico and Jacobs 1994; Morgan and Reynolds 1997; Dubnick 2003c); and · improvements in the quality of government services (the promise of performance).
    [Show full text]
  • Logical Reasoning
    Chapter 2 Logical Reasoning All human activities are conducted following logical reasoning. Most of the time we apply logic unconsciously, but there is always some logic ingrained in the decisions we make in order to con- duct day-to-day life. Unfortunately we also do sometimes think illogically or engage in bad reasoning. Since science is based on logical thinking, one has to learn how to reason logically. The discipline of logic is the systematization of reasoning. It explicitly articulates principles of good reasoning, and system- atizes them. Equipped with this knowledge, we can distinguish between good reasoning and bad reasoning, and can develop our own reasoning capacity. Philosophers have shown that logical reasoning can be broadly divided into two categories—inductive, and deductive. Suppose you are going out of your home, and upon seeing a cloudy sky, you take an umbrella along. What was the logic behind this commonplace action? It is that, you have seen from your childhood that the sky becomes cloudy before it rains. You have seen it once, twice, thrice, and then your mind has con- structed the link “If there is dark cloud in the sky, it may rain”. This is an example of inductive logic, where we reach a general conclusion by repeated observation of particular events. The repeated occurrence of a particular truth leads you to reach a general truth. 2 Chapter 2. Logical Reasoning What do you do next? On a particular day, if you see dark cloud in the sky, you think ‘today it may rain’. You take an um- brella along.
    [Show full text]
  • Logical Fallacies Moorpark College Writing Center
    Logical Fallacies Moorpark College Writing Center Ad hominem (Argument to the person): Attacking the person making the argument rather than the argument itself. We would take her position on child abuse more seriously if she weren’t so rude to the press. Ad populum appeal (appeal to the public): Draws on whatever people value such as nationality, religion, family. A vote for Joe Smith is a vote for the flag. Alleged certainty: Presents something as certain that is open to debate. Everyone knows that… Obviously, It is obvious that… Clearly, It is common knowledge that… Certainly, Ambiguity and equivocation: Statements that can be interpreted in more than one way. Q: Is she doing a good job? A: She is performing as expected. Appeal to fear: Uses scare tactics instead of legitimate evidence. Anyone who stages a protest against the government must be a terrorist; therefore, we must outlaw protests. Appeal to ignorance: Tries to make an incorrect argument based on the claim never having been proven false. Because no one has proven that food X does not cause cancer, we can assume that it is safe. Appeal to pity: Attempts to arouse sympathy rather than persuade with substantial evidence. He embezzled a million dollars, but his wife had just died and his child needed surgery. Begging the question/Circular Logic: Proof simply offers another version of the question itself. Wrestling is dangerous because it is unsafe. Card stacking: Ignores evidence from the one side while mounting evidence in favor of the other side. Users of hearty glue say that it works great! (What is missing: How many users? Great compared to what?) I should be allowed to go to the party because I did my math homework, I have a ride there and back, and it’s at my friend Jim’s house.
    [Show full text]
  • 35 Fallacies
    THIRTY-TWO COMMON FALLACIES EXPLAINED L. VAN WARREN Introduction If you watch TV, engage in debate, logic, or politics you have encountered the fallacies of: Bandwagon – "Everybody is doing it". Ad Hominum – "Attack the person instead of the argument". Celebrity – "The person is famous, it must be true". If you have studied how magicians ply their trade, you may be familiar with: Sleight - The use of dexterity or cunning, esp. to deceive. Feint - Make a deceptive or distracting movement. Misdirection - To direct wrongly. Deception - To cause to believe what is not true; mislead. Fallacious systems of reasoning pervade marketing, advertising and sales. "Get Rich Quick", phone card & real estate scams, pyramid schemes, chain letters, the list goes on. Because fallacy is common, you might want to recognize them. There is no world as vulnerable to fallacy as the religious world. Because there is no direct measure of whether a statement is factual, best practices of reasoning are replaced be replaced by "logical drift". Those who are political or religious should be aware of their vulnerability to, and exportation of, fallacy. The film, "Roshomon", by the Japanese director Akira Kurisawa, is an excellent study in fallacy. List of Fallacies BLACK-AND-WHITE Classifying a middle point between extremes as one of the extremes. Example: "You are either a conservative or a liberal" AD BACULUM Using force to gain acceptance of the argument. Example: "Convert or Perish" AD HOMINEM Attacking the person instead of their argument. Example: "John is inferior, he has blue eyes" AD IGNORANTIAM Arguing something is true because it hasn't been proven false.
    [Show full text]
  • False Dilemma Wikipedia Contents
    False dilemma Wikipedia Contents 1 False dilemma 1 1.1 Examples ............................................... 1 1.1.1 Morton's fork ......................................... 1 1.1.2 False choice .......................................... 2 1.1.3 Black-and-white thinking ................................... 2 1.2 See also ................................................ 2 1.3 References ............................................... 3 1.4 External links ............................................. 3 2 Affirmative action 4 2.1 Origins ................................................. 4 2.2 Women ................................................ 4 2.3 Quotas ................................................. 5 2.4 National approaches .......................................... 5 2.4.1 Africa ............................................ 5 2.4.2 Asia .............................................. 7 2.4.3 Europe ............................................ 8 2.4.4 North America ........................................ 10 2.4.5 Oceania ............................................ 11 2.4.6 South America ........................................ 11 2.5 International organizations ...................................... 11 2.5.1 United Nations ........................................ 12 2.6 Support ................................................ 12 2.6.1 Polls .............................................. 12 2.7 Criticism ............................................... 12 2.7.1 Mismatching ......................................... 13 2.8 See also
    [Show full text]
  • Chapter 4: Answers and Comments
    Chapter 4: Answers and Comments Answers: I. True or False 1. See textbook. 2. False. One of the most common mistakes. The focus should be even if the premise is true, the reasoning is weak. 3. See textbook. 4. True. We could criticize the truth of the premise as well, but this would not be relevant to the focus of a fallacy of relevance. 5. True. There is nothing inherently wrong with loyalty as a behavior or an emotion. The point is there should be good reasons, which we have thought about, for our loyalty commitments. 6. FALSE! Two Wrongs is a fallacy of relevance, so the focus is not on the truth of the premise. The focus should be on the reasoning. Usually the premise is true, but irrelevant to why either item compared should be considered good. 7. See textbook. 8. False. The name-calling is always in the premise. 9. False. In our age many in-group appeals are aimed at sub-cultural groups. People who believe they are more intelligent than most, more cool, more modern, etc. 10. True. 11. True. For a complete argument analysis, these two points must be made. 12. False. It was used as an example for structuring arguments. It will be covered in Chapter 5. We will see that it is a fallacy of relevance and it always has a premise that is relevant to the conclusion. 13. False. There could be very good reasons for a particular act of loyalty. 14. True. In this chapter there will be situations where the difference between one label and another is inconsequential.
    [Show full text]
  • Some Common Fallacies of Argument Evading the Issue: You Avoid the Central Point of an Argument, Instead Drawing Attention to a Minor (Or Side) Issue
    Some Common Fallacies of Argument Evading the Issue: You avoid the central point of an argument, instead drawing attention to a minor (or side) issue. ex. You've put through a proposal that will cut overall loan benefits for students and drastically raise interest rates, but then you focus on how the system will be set up to process loan applications for students more quickly. Ad hominem: Here you attack a person's character, physical appearance, or personal habits instead of addressing the central issues of an argument. You focus on the person's personality, rather than on his/her ideas, evidence, or arguments. This type of attack sometimes comes in the form of character assassination (especially in politics). You must be sure that character is, in fact, a relevant issue. ex. How can we elect John Smith as the new CEO of our department store when he has been through 4 messy divorces due to his infidelity? Ad populum: This type of argument uses illegitimate emotional appeal, drawing on people's emotions, prejudices, and stereotypes. The emotion evoked here is not supported by sufficient, reliable, and trustworthy sources. Ex. We shouldn't develop our shopping mall here in East Vancouver because there is a rather large immigrant population in the area. There will be too much loitering, shoplifting, crime, and drug use. Complex or Loaded Question: Offers only two options to answer a question that may require a more complex answer. Such questions are worded so that any answer will implicate an opponent. Ex. At what point did you stop cheating on your wife? Setting up a Straw Person: Here you address the weakest point of an opponent's argument, instead of focusing on a main issue.
    [Show full text]
  • Chapter 4: INFORMAL FALLACIES I
    Essential Logic Ronald C. Pine Chapter 4: INFORMAL FALLACIES I All effective propaganda must be confined to a few bare necessities and then must be expressed in a few stereotyped formulas. Adolf Hitler Until the habit of thinking is well formed, facing the situation to discover the facts requires an effort. For the mind tends to dislike what is unpleasant and so to sheer off from an adequate notice of that which is especially annoying. John Dewey, How We Think Introduction In everyday speech you may have heard someone refer to a commonly accepted belief as a fallacy. What is usually meant is that the belief is false, although widely accepted. In logic, a fallacy refers to logically weak argument appeal (not a belief or statement) that is widely used and successful. Here is our definition: A logical fallacy is an argument that is usually psychologically persuasive but logically weak. By this definition we mean that fallacious arguments work in getting many people to accept conclusions, that they make bad arguments appear good even though a little commonsense reflection will reveal that people ought not to accept the conclusions of these arguments as strongly supported. Although logicians distinguish between formal and informal fallacies, our focus in this chapter and the next one will be on traditional informal fallacies.1 For our purposes, we can think of these fallacies as "informal" because they are most often found in the everyday exchanges of ideas, such as newspaper editorials, letters to the editor, political speeches, advertisements, conversational disagreements between people in social networking sites and Internet discussion boards, and so on.
    [Show full text]
  • Rethinking Logical Reasoning Skills from a Strategy Perspective
    Rethinking Logical Reasoning Skills from a Strategy Perspective Bradley J. Morris* Grand Valley State University and LRDC, University of Pittsburgh, USA Christian D. Schunn LRDC, University of Pittsburgh, USA Running Head: Logical Reasoning Skills _______________________________ * Correspondence to: Department of Psychology, Grand Valley State University, 2117 AuSable Hall, One Campus Drive, Allendale, MI 49401, USA. E-mail: [email protected], Fax: 1-616-331-2480. Morris & Schunn Logical Reasoning Skills 2 Rethinking Logical Reasoning Skills from a Strategy Perspective Overview The study of logical reasoning has typically proceeded as follows: Researchers (1) discover a response pattern that is either unexplained or provides evidence against an established theory, (2) create a model that explains this response pattern, then (3) expand this model to include a larger range of situations. Researchers tend to investigate a specific type of reasoning (e.g., conditional implication) using a particular variant of an experimental task (e.g., the Wason selection task). The experiments uncover a specific reasoning pattern, for example, that people tend to select options that match the terms in the premises, rather than derive valid responses (Evans, 1972). Once a reasonable explanation is provided for this, researchers typically attempt to expand it to encompass related phenomena, such as the role of ‘bias’ in other situations like weather forecasting (Evans, 1989). Eventually, this explanation may be used to account for all performance on an entire class of reasoning phenomena (e.g. deduction) regardless of task, experience, or age. We term this a unified theory. Some unified theory theorists have suggested that all logical reasoning can be characterized by a single theory, such as one that is rule-based (which involves the application of transformation rules that draw valid conclusions once fired; Rips, 1994).
    [Show full text]
  • The Big Lie” Feedback Responses
    2016 Two More Chains Fall Issue “The Big Lie” Feedback Responses Do you agree or disagree Please elaborate on why you What’s the next step? How do we bring opposing with “The Big Lie” agree or disagree. views together? concepts? Why? 1. (Respondent selected “Other” for job position.) [No Input] Learn how to read wildfires. Agree. Underestimating potential leads to Based on “Personal Experience.” accidents. 2. Firefighter I have over 33 years’ experience working We need to discuss revising the entry level training programs to Agree. for All Risk Fire Departments in California include this information and focus more on the intent of the Fire Based on “Personal Experience.” including CAL FIRE. Qualified as DIVS, Orders (not just memorizing) what they really mean—and how to SOFR, STCR, FAL1 to name a few. mitigate risk to acceptable levels before we engage. Through this experience and studies I What happened to S-133 and S-134? Have these course been have long ago formed the following eliminated and if so why? opinions: With the risk management process, we seek to mitigate risk, but cannot always remove risk. Therefore, manage the risk and decide if the mitigations are acceptable before we engage. I also agree that there is a culture to memorize and recognize the Standard Fire Orders, but in practice the culture does not fully support following the orders or complying with the intent of the orders. With this type of culture, we often set ourselves up for the opportunity to experience catastrophic results. 1 Do you agree or disagree Please elaborate on why you What’s the next step? How do we bring opposing with “The Big Lie” agree or disagree.
    [Show full text]
  • Logical Reasoning
    updated: 11/29/11 Logical Reasoning Bradley H. Dowden Philosophy Department California State University Sacramento Sacramento, CA 95819 USA ii Preface Copyright © 2011 by Bradley H. Dowden This book Logical Reasoning by Bradley H. Dowden is licensed under a Creative Commons Attribution- NonCommercial-NoDerivs 3.0 Unported License. That is, you are free to share, copy, distribute, store, and transmit all or any part of the work under the following conditions: (1) Attribution You must attribute the work in the manner specified by the author, namely by citing his name, the book title, and the relevant page numbers (but not in any way that suggests that the book Logical Reasoning or its author endorse you or your use of the work). (2) Noncommercial You may not use this work for commercial purposes (for example, by inserting passages into a book that is sold to students). (3) No Derivative Works You may not alter, transform, or build upon this work. An earlier version of the book was published by Wadsworth Publishing Company, Belmont, California USA in 1993 with ISBN number 0-534-17688-7. When Wadsworth decided no longer to print the book, they returned their publishing rights to the original author, Bradley Dowden. If you would like to suggest changes to the text, the author would appreciate your writing to him at [email protected]. iii Praise Comments on the 1993 edition, published by Wadsworth Publishing Company: "There is a great deal of coherence. The chapters build on one another. The organization is sound and the author does a superior job of presenting the structure of arguments.
    [Show full text]
  • A Revision of the Morgan Test of Logical Reasoning Fred K
    University of Richmond UR Scholarship Repository Master's Theses Student Research 6-1966 A revision of the Morgan Test of Logical Reasoning Fred K. McCoy Follow this and additional works at: http://scholarship.richmond.edu/masters-theses Recommended Citation McCoy, Fred K., "A revision of the Morgan Test of Logical Reasoning" (1966). Master's Theses. Paper 725. This Thesis is brought to you for free and open access by the Student Research at UR Scholarship Repository. It has been accepted for inclusion in Master's Theses by an authorized administrator of UR Scholarship Repository. For more information, please contact [email protected]. A REVISION OF THE l\10RGAN TEST OF LOGICAL REASONING Fred K. McCoy Approved: tye) ii A REVISION OF THE MORGAN TEST OF LOGICAL REASONWG Fred K. McCoy A thesis submitted in partial :fulfillment of the requirements for the degree of :tvlasters of Arts in Psychology in the Graduate School of the University of Hichmond. June, 1966 iii ACKNOWLEDGEMENTS The author gratefully acknowledges the assistance rendered by Dr. Austin E. Grigg of the Psychology faculty of the University of Richmond, his thesis advisor, whose advice wns invaluilhle at every stage in the planning and execu­ tion of the present study. The study could not have been completed without the assistance given by Dr. Robison James of the Religion faculty of the University of Richmond, who gave his logic students as subjects and his advice and opf.:rJ.ons in measuring logical ability. In a deeper sense the author acknowledges his debt to Dr. William J. Morgan of APTITUDE ASSOCIATES, INC.
    [Show full text]