![causal fallacy critical thinking GCFGlobal Logo](https://media.gcflearnfree.org/global/gcfglobal-color.png)
- Get started with computers
- Learn Microsoft Office
- Apply for a job
- Improve my work skills
- Design nice-looking docs
- Getting Started
- Smartphones & Tablets
- Typing Tutorial
- Online Learning
- Basic Internet Skills
- Online Safety
- Social Media
- Zoom Basics
- Google Docs
- Google Sheets
- Career Planning
- Resume Writing
- Cover Letters
- Job Search and Networking
- Business Communication
- Entrepreneurship 101
- Careers without College
- Job Hunt for Today
- 3D Printing
- Freelancing 101
- Personal Finance
- Sharing Economy
- Decision-Making
- Graphic Design
- Photography
- Image Editing
- Learning WordPress
- Language Learning
- Critical Thinking
- For Educators
- Translations
- Staff Picks
- English expand_more expand_less
![](http://writinghelp.online/777/templates/cheerup/res/banner1.gif)
Critical Thinking and Decision-Making - Logical Fallacies
Critical thinking and decision-making -, logical fallacies, critical thinking and decision-making logical fallacies.
![causal fallacy critical thinking GCFLearnFree Logo](https://media.gcflearnfree.org/mobile/GCF_whitelogo.png)
Critical Thinking and Decision-Making: Logical Fallacies
Lesson 7: logical fallacies.
/en/problem-solving-and-decision-making/how-critical-thinking-can-change-the-game/content/
Logical fallacies
If you think about it, vegetables are bad for you. I mean, after all, the dinosaurs ate plants, and look at what happened to them...
![illustration of a dinosaur eating leaves while a meteor falls in the background illustration of a dinosaur eating leaves while a meteor falls in the background](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_dino.jpg)
Let's pause for a moment: That argument was pretty ridiculous. And that's because it contained a logical fallacy .
A logical fallacy is any kind of error in reasoning that renders an argument invalid . They can involve distorting or manipulating facts, drawing false conclusions, or distracting you from the issue at hand. In theory, it seems like they'd be pretty easy to spot, but this isn't always the case.
Watch the video below to learn more about logical fallacies.
Sometimes logical fallacies are intentionally used to try and win a debate. In these cases, they're often presented by the speaker with a certain level of confidence . And in doing so, they're more persuasive : If they sound like they know what they're talking about, we're more likely to believe them, even if their stance doesn't make complete logical sense.
![illustration of a politician saying, "I know for a fact..." illustration of a politician saying, "I know for a fact..."](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacy_politician.jpg)
False cause
One common logical fallacy is the false cause . This is when someone incorrectly identifies the cause of something. In my argument above, I stated that dinosaurs became extinct because they ate vegetables. While these two things did happen, a diet of vegetables was not the cause of their extinction.
![illustration showing that extinction was not caused by some dinosaurs being vegetarians illustration showing that extinction was not caused by some dinosaurs being vegetarians](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_FC.jpg)
Maybe you've heard false cause more commonly represented by the phrase "correlation does not equal causation ", meaning that just because two things occurred around the same time, it doesn't necessarily mean that one caused the other.
A straw man is when someone takes an argument and misrepresents it so that it's easier to attack . For example, let's say Callie is advocating that sporks should be the new standard for silverware because they're more efficient. Madeline responds that she's shocked Callie would want to outlaw spoons and forks, and put millions out of work at the fork and spoon factories.
![illustration of Maddie accusing Callie of wanting to outlaw spoons and forks illustration of Maddie accusing Callie of wanting to outlaw spoons and forks](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_strawman.jpg)
A straw man is frequently used in politics in an effort to discredit another politician's views on a particular issue.
Begging the question
Begging the question is a type of circular argument where someone includes the conclusion as a part of their reasoning. For example, George says, “Ghosts exist because I saw a ghost in my closet!"
![illustration of George claiming that ghosts exists and him seeing one in his closet illustration of George claiming that ghosts exists and him seeing one in his closet](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_begging.jpg)
George concluded that “ghosts exist”. His premise also assumed that ghosts exist. Rather than assuming that ghosts exist from the outset, George should have used evidence and reasoning to try and prove that they exist.
![illustration of George using math and reasoning to try and prove that ghosts exist illustration of George using math and reasoning to try and prove that ghosts exist](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_ghostproof.jpg)
Since George assumed that ghosts exist, he was less likely to see other explanations for what he saw. Maybe the ghost was nothing more than a mop!
![illustration of a splitscreen showing a ghost in a closet on the left, and that same closet with a mop in it on the right illustration of a splitscreen showing a ghost in a closet on the left, and that same closet with a mop in it on the right](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_mop_edit.jpg)
False dilemma
The false dilemma (or false dichotomy) is a logical fallacy where a situation is presented as being an either/or option when, in reality, there are more possible options available than just the chosen two. Here's an example: Rebecca rings the doorbell but Ethan doesn't answer. She then thinks, "Oh, Ethan must not be home."
![illustration showing the false dilemma of either Ethan being home or his home being empty illustration showing the false dilemma of either Ethan being home or his home being empty](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_dilemma1.jpg)
Rebecca posits that either Ethan answers the door or he isn't home. In reality, he could be sleeping, doing some work in the backyard, or taking a shower.
![illustration of Ethan sleeping, doing yard work, and taking a shower illustration of Ethan sleeping, doing yard work, and taking a shower](https://media.gcflearnfree.org/content/5d6e6fb5285a05400868a300_09_03_2019/logical_fallacies_dilemma2.jpg)
Most logical fallacies can be spotted by thinking critically . Make sure to ask questions: Is logic at work here or is it simply rhetoric? Does their "proof" actually lead to the conclusion they're proposing? By applying critical thinking, you'll be able to detect logical fallacies in the world around you and prevent yourself from using them as well.
![causal fallacy critical thinking previous](https://media.gcflearnfree.org/assets/icons/textplus/bottom-nav-left-arrows.png)
![causal fallacy critical thinking Logo for M Libraries Publishing](https://open.lib.umn.edu/app/uploads/2018/10/cropped-ULpressbooks-logo-1.png)
Want to create or adapt books like this? Learn more about how Pressbooks supports open publishing practices.
11.3 Persuasive Reasoning and Fallacies
Learning objectives.
- Define inductive, deductive, and causal reasoning.
- Evaluate the quality of inductive, deductive, and causal reasoning.
- Identify common fallacies of reasoning.
Persuasive speakers should be concerned with what strengthens and weakens an argument. Earlier we discussed the process of building an argument with claims and evidence and how warrants are the underlying justifications that connect the two. We also discussed the importance of evaluating the strength of a warrant, because strong warrants are usually more persuasive. Knowing different types of reasoning can help you put claims and evidence together in persuasive ways and help you evaluate the quality of arguments that you encounter. Further, being able to identify common fallacies of reasoning can help you be a more critical consumer of persuasive messages.
Reasoning refers to the process of making sense of things around us. In order to understand our experiences, draw conclusions from information, and present new ideas, we must use reasoning. We often reason without being aware of it, but becoming more aware of how we think can empower us to be better producers and consumers of communicative messages. The three types of reasoning we will explore are inductive, deductive, and causal.
Inductive Reasoning
Inductive reasoning reaches conclusions through the citation of examples and is the most frequently used form of logical reasoning (Walter, 1966). While introductory speakers are initially attracted to inductive reasoning because it seems easy, it can be difficult to employ well. Inductive reasoning, unlike deductive reasoning, doesn’t result in true or false conclusions. Instead, since conclusions are generalized based on observations or examples, conclusions are “more likely” or “less likely.” Despite the fact that this type of reasoning isn’t definitive, it can still be valid and persuasive.
Some arguments based on inductive reasoning will be more cogent, or convincing and relevant, than others. For example, inductive reasoning can be weak when claims are made too generally. An argument that fraternities should be abolished from campus because they contribute to underage drinking and do not uphold high academic standards could be countered by providing examples of fraternities that sponsor alcohol education programming for the campus and have members that have excelled academically (Walter, 1966). In this case, one overly general claim is countered by another general claim, and both of them have some merit. It would be more effective to present a series of facts and reasons and then share the conclusion or generalization that you have reached from them.
You can see inductive reasoning used in the following speech excerpt from President George W. Bush’s address to the nation on the evening of September 11, 2001. Notice how he lists a series of events from the day, which builds to his conclusion that the terrorist attacks failed in their attempt to shake the foundation of America.
Today, our fellow citizens, our way of life, our very freedom came under attack in a series of deliberate and deadly terrorist acts. The victims were in airplanes or in their offices: secretaries, business men and women, military and federal workers, moms and dads, friends and neighbors. Thousands of lives were suddenly ended by evil, despicable acts of terror. The pictures of airplanes flying into buildings, fires burning, huge—huge structures collapsing have filled us with disbelief, terrible sadness, and a quiet, unyielding anger. These acts of mass murder were intended to frighten our nation into chaos and retreat. But they have failed. Our country is strong. A great people has been moved to defend a great nation. Terrorist attacks can shake the foundations of our biggest buildings, but they cannot touch the foundation of America.
![causal fallacy critical thinking 11.3.0N](https://open.lib.umn.edu/app/uploads/sites/192/2016/09/11.3.0N.jpg)
Using inductive reasoning, speakers reach conclusions through the citation of examples.
Claire Sambrook – UM… – CC BY-NC 2.0.
If a speaker is able to provide examples that are concrete, proxemic, and relevant to the audience, as Bush did in this example, audience members are prompted to think of additional examples that connect to their own lives. Inductive reasoning can be useful when an audience disagrees with your proposition. As you present logically connected examples as evidence that build to a conclusion, the audience may be persuaded by your evidence before they realize that the coming conclusion will counter what they previously thought. This also sets up cognitive dissonance, which is a persuasive strategy we will discuss later.
Reasoning by analogy is a type of inductive reasoning that argues that what is true in one set of circumstances will be true in another (Walter, 1966). Reasoning by analogy has been criticized and questioned by logicians, since two sets of circumstances are never exactly the same. While this is true, our goal when using reasoning by analogy in persuasive speaking is not to create absolutely certain conclusions but to cite cases and supporting evidence that can influence an audience. For example, let’s say you are trying to persuade a university to adopt an alcohol education program by citing the program’s success at other institutions. Since two universities are never exactly the same, the argument can’t be airtight. To better support this argument, you could first show that the program was actually successful using various types of supporting material such as statistics from campus offices and testimony from students and staff. Second, you could show how the cases relate by highlighting similarities in the campus setting, culture, demographics, and previous mission. Since you can’t argue that the schools are similar in all ways, choose to highlight significant similarities. Also, it’s better to acknowledge significant limitations of the analogy and provide additional supporting material to address them than it is to ignore or hide such limitations.
So how do we evaluate inductive reasoning? When inductive reasoning is used to test scientific arguments, there is rigorous testing and high standards that must be met for a conclusion to be considered valid. Inductive reasoning in persuasive speaking is employed differently. A speaker cannot cite every example that exists to build to a conclusion, so to evaluate inductive reasoning you must examine the examples that are cited in ways other than quantity. First, the examples should be sufficient, meaning that enough are cited to support the conclusion. If not, you risk committing the hasty generalization fallacy. A speaker can expect that the audience will be able to think of some examples as well, so there is no set number on how many examples is sufficient. If the audience is familiar with the topic, then fewer examples are probably sufficient, while more may be needed for unfamiliar topics. A speaker can make his or her use of reasoning by example more powerful by showing that the examples correspond to the average case, which may require additional supporting evidence in the form of statistics. Arguing that teacher salaries should be increased by providing an example of a teacher who works side jobs and pays for his or her own school supplies could be effectively supported by showing that this teacher’s salary corresponds to the national average (Walter, 1966).
Second, the examples should be typical, meaning they weren’t cherry-picked to match the point being argued. A speaker who argues to defund the National Endowment for the Arts (NEA) because the organization supports art that is “pornographic and offensive” may cite five examples of grants given for projects that caused such controversy. Failing to mention that these examples were pulled from the more than 128,000 grants issued by the NEA would be an inappropriate use of inductive reasoning since the examples aren’t sufficient or typical enough to warrant the argument. Another way to support inductive arguments is to show that the examples are a fair sample, meaning they are representative of the larger whole. Arguing that college athletes shouldn’t receive scholarships because they do not have the scholastic merit of other students and have less academic achievement could be supported by sharing several examples. But if those examples were not representative, then they are biased, and the reasoning faulty. A speaker would need to show that the athletes used in the example are representative, in terms of their race, gender, sport, and background, of the population of athletes at the university.
Deductive Reasoning
Deductive reasoning derives specifics from what is already known. It was the preferred form of reasoning used by ancient rhetoricians like Aristotle to make logical arguments (Cooper & Nothstine, 1996). A syllogism is an example of deductive reasoning that is commonly used when teaching logic. A syllogism is an example of deductive reasoning in which a conclusion is supported by major and minor premises. The conclusion of a valid argument can be deduced from the major and minor premises. A commonly used example of a syllogism is “All humans are mortal. Socrates is a human. Socrates is mortal.” In this case, the conclusion, “Socrates is mortal,” is derived from the major premise, “All humans are mortal,” and the minor premise, “Socrates is a human.” In some cases, the major and minor premises of a syllogism may be taken for granted as true. In the previous example, the major premise is presumed true because we have no knowledge of an immortal person to disprove the statement. The minor premise is presumed true because Socrates looks and acts like other individuals we know to be human. Detectives or scientists using such logic would want to test their conclusion. We could test our conclusion by stabbing Socrates to see if he dies, but since the logic of the syllogism is sound, it may be better to cut Socrates a break and deem the argument valid. Since most arguments are more sophisticated than the previous example, speakers need to support their premises with research and evidence to establish their validity before deducing their conclusion.
A syllogism can lead to incorrect conclusions if one of the premises isn’t true, as in the following example:
- All presidents have lived in the White House. (Major premise)
- George Washington was president. (Minor premise)
- George Washington lived in the White House. (Conclusion)
In the previous example, the major premise was untrue, since John Adams, our second president, was the first president to live in the White House. This causes the conclusion to be false. A syllogism can also exhibit faulty logic even if the premises are both true but are unrelated, as in the following example:
- Penguins are black and white. (Major premise)
- Some old television shows are black and white. (Minor premise)
- Some penguins are old television shows. (Conclusion)
![causal fallacy critical thinking 11.3.1N](https://open.lib.umn.edu/app/uploads/sites/192/2016/09/11.3.1N.jpg)
Like in the game of Clue, real-life detectives use deductive reasoning to draw a conclusion about who committed a crime based on the known evidence.
Sleepmyf – Lego detective – CC BY-NC-ND 2.0.
Causal Reasoning
Causal reasoning argues to establish a relationship between a cause and an effect. When speakers attempt to argue for a particular course of action based on potential positive or negative consequences that may result, they are using causal reasoning. Such reasoning is evident in the following example: Eating more local foods will boost the local economy and make you healthier. The “if/then” relationship that is set up in causal reasoning can be persuasive, but the reasoning isn’t always sound. Rather than establishing a true cause-effect relationship, speakers more often set up a correlation, which means there is a relationship between two things but there are other contextual influences.
To use causal reasoning effectively and ethically, speakers should avoid claiming a direct relationship between a cause and an effect when such a connection cannot be proven. Instead of arguing that “x caused y,” it is more accurate for a speaker to say “x influenced y.” Causal thinking is often used when looking to blame something or someone, as can be seen in the following example: It’s the president’s fault that the economy hasn’t recovered more. While such a statement may garner a speaker some political capital, it is not based on solid reasoning. Economic and political processes are too complex to distill to such a simple cause-effect relationship. A speaker would need to use more solid reasoning, perhaps inductive reasoning through examples, to build up enough evidence to support that a correlation exists and a causal relationship is likely. When using causal reasoning, present evidence that shows the following: (1) the cause occurred before the effect, (2) the cause led to the effect, and (3) it is unlikely that other causes produced the effect.
Review of Types of Reasoning
- Inductive. Arguing from examples to support a conclusion; includes reasoning by analogy. Examples should be sufficient, typical, and representative to warrant a strong argument.
- Deductive. Deriving specifics from what is already known; includes syllogisms. Premises that lead to a conclusion must be true, relevant, and related for the argument to be valid.
- Causal. Argues to establish a relationship between a cause and an effect. Usually involves a correlation rather than a true causal relationship.
Fallacies of Reasoning
Fallacies are flaws within the logic or reasoning of an argument. Although we will discuss 10 common fallacies, more than 125 have been identified and named. It’s important to note that the presence of a fallacy in an argument doesn’t mean that it can’t be persuasive. In fact, many people are persuaded by fallacious arguments because they do not identify the fallacy within the argument. Fallacies are often the last effort of uninformed or ill-prepared speakers who find that they have nothing better to say. Being aware of the forms of reasoning and fallacies makes us more critical consumers of persuasive messages, which is a substantial benefit of studying persuasive speaking that affects personal, political, and professional aspects of our lives.
Hasty Generalization
The hasty generalization fallacy relates to inductive reasoning and is the result of too few examples being cited to warrant the generalization. Jumping to conclusions is tempting, especially when pressed for time, but making well-researched and supported arguments is key to being an effective and ethical speaker. Making a claim that train travel is not safe and citing two recent derailments that resulted in injury doesn’t produce a strong warrant when viewed in relation to the number of train passengers who travel safely every day.
False Analogy
The false analogy fallacy also relates to inductive reasoning and results when the situations or circumstances being compared are not similar enough. A common false analogy that people make is comparing something to putting a person on the moon: “If we can put a person on the moon, why can’t we figure out a way to make the tax code easier to understand?” This question doesn’t acknowledge the different skill sets and motivations involved in the two examples being compared.
False Cause
The false cause fallacy relates to causal reasoning and occurs when a speaker argues, with insufficient evidence, that one thing caused or causes another. When I was in high school, teachers used to say that wearing baseball caps would make us go bald when we got older. In an attempt to persuade us to not wear hats in the classroom, they were arguing, fallaciously, that wearing baseball caps is what causes baldness. When a false cause argument is made after the “effect,” it is referred to in Latin as post hoc ergo propter hoc , which means “after this, therefore because of this.” Blaming bad fortune on superstitions is a good example of faulty reasoning that tries to argue for a connection between an “effect” that has already occurred and its preceding “cause.” My bad luck is more likely attributable to poor decisions I have made or random interference than the mirror I broke while moving two years ago.
![causal fallacy critical thinking 11.3.2N](https://open.lib.umn.edu/app/uploads/sites/192/2016/09/11.3.2N.jpg)
Superstitious beliefs often exemplify the false cause fallacy. Is the broken mirror really the cause of your bad luck?
Tim Sheerman-Chase – Seven Years Bad Luck – CC BY 2.0.
False Authority
The false authority fallacy results when the person making an argument doesn’t actually have the qualifications to be credible but is perceived as credible because they are respected or admired. Despite the fact that this form of argument is fallacious, it is obviously quite effective. Advertisers spend millions of dollars to get celebrities and athletes to sell us their products because of the persuasive potential these stars carry in their persona, not in their ability to argue a point. Voters might be persuaded to support a candidate because of a famous musician’s endorsement without questioning the political beliefs of either the musician or the politician to see if they match up with their own.
Parents and other sources of guidance in our lives have tried to keep us from falling for the bandwagon fallacy. When your mom responds to your argument that you should get to go to the party because everyone else is by asking, “If everyone else jumped off a bridge, would you?” she is rightfully pointing out the fallacy in your argument. In a public-speaking-related example, I have had students try to persuade their audience to buy and eat more organic foods based on their increasing popularity. In short, popular appeal and frequency of use are not strong warrants to support an argument. Just because something is popular, doesn’t mean it’s good.
False Dilemma
The false dilemma fallacy occurs when a speaker rhetorically backs his or her audience into a corner, presenting them with only two options and arguing that they must choose either one or the other. This is also known as the “either/or” fallacy. Critical thinkers know that the world can’t be simplified to black and white, good and bad, or right and wrong. Yet many people rely on such oversimplifications when making arguments. A speaker who argues that immigrants to the United States should learn English or go back to their own country doesn’t acknowledge that there are many successful immigrants who have successful lives and contribute to society without speaking English fluently. The speaker also ignores the fact that many immigrants do not have access to English language instruction or the time to take such classes because they are busy with their own jobs and families. Granted, such a rhetorical strategy does make it easier to discuss complex issues and try to force people into a decision, but it also removes gray area in the form of context that can be really important for making a decision. Be critical of speakers and messages that claim there are only two options from which to choose.
Ad hominem means “to the person” in Latin and refers to a common fallacy of attacking a person rather than an argument. Elementary school playgrounds and middle school hallways are often sites of ad hominem attacks. When one person runs out of good reasons to support their argument and retorts to the other, “Well you’re ugly!” they have resorted to a fallacious ad hominem argument. You probably aren’t surprised to know that politicians frequently rely on personal attacks, especially when they are sponsored by political action committees (PACs). The proliferation of these organizations resulted in an increase in “attack ads” during the 2012 presidential race. While all fallacious arguments detract from the quality of public communication, ad hominem arguments in particular diminish the civility of our society.
Slippery Slope
The slippery slope fallacy occurs when a person argues that one action will inevitably lead to a series of other actions. If we take one step down an icy hill it becomes difficult to get back up and you slide all the way down even though you only wanted to take one step. A slippery slope fallacy in a speech about US foreign policy might take the form of the following argument: If the United States goes to help this country in need, then we will be expected to intervene any time there’s a conflict in the world.
Red Herring
The red herring fallacy is my favorite because it has an interesting origin—and it was used in Scooby Doo ! The origin of the name of this fallacy comes from old foxhunting practices in England. When the hunters were training their dogs to stay on the trail of a fox, they would mark a trail with fox scent so the dog could practice following the scent. As a further test, they would take the smell of fish (like a red herring) and create a second trail leading in another direction. If a dog left the scent of the fox trail to follow the stronger and more noticeable scent trail left by the red herring, then the dog failed the test. The smartest and best-trained dogs weren’t distracted by the fishy trail and stayed on the path. Basically every episode of Scooby Doo involves a red herring trick—for example, when the ghost at the amusement park turns out to be a distraction created by the owner to cover up his financial problems and shady business practices. A speaker who uses the red herring fallacy makes an argument that distracts from the discussion at hand. Bringing up socialism during an argument about nationalized health care is an example of a red herring fallacy.
Appeal to Tradition
The appeal to tradition fallacy argues that something should continue because “it’s the way things have been done before.” Someone may use this type of argument when they feel threatened by a potential change. People who oppose marriage rights for gay and lesbian people often argue that the definition of marriage shouldn’t change because of its traditional meaning of a “union between one man and one woman.” Such appeals often overstate the history and prevalence of the “tradition.” Within the United States, many departures from traditional views of marriage have led to changes that we accept as normal today. Within the past one hundred years we have seen law changes that took away men’s rights to beat their wives and make decisions for them. And it wasn’t until 1993 that every state made marital rape a crime, which changed the millennia-old “tradition” that women were obligated to have sex with their husbandsf (Coontz, 2006). Many people are resistant to or anxious about change, which is understandable, but this doesn’t form the basis of a good argument.
Review of Fallacies
- Hasty generalization. Inductive reasoning fallacy that occurs when too few examples are cited to warrant a conclusion.
- False analogy. Inductive reasoning fallacy that occurs when situations or circumstances being compared are not similar enough.
- False cause. Causal reasoning fallacy that occurs when a speaker argues with insufficient evidence that one thing caused/causes another.
- False authority. Fallacy that occurs when a person making an argument doesn’t have the knowledge or qualifications to be credible but is perceived as credible because they are respected or admired.
- Bandwagon. Fallacy that relies on arguing for a course of action or belief because it is commonly done or held.
- False dilemma. Fallacy that occurs when a speaker presents an audience only two options and argues they must choose one or the other.
- Ad hominem. Fallacy that occurs when a speaker attacks another person rather than his or her argument.
- Slippery slope. Fallacy that occurs when a person argues that one action will inevitably lead to a series of other actions.
- Red herring. Fallacy that occurs when a speaker poses an argument that is meant to distract from the argument at hand.
- Appeal to tradition. Fallacy that results when a speaker argues that something should continue because “it’s the way things have been done before.”
Key Takeaways
We use reasoning to make sense of the world around us and draw conclusions. Three types of reasoning are inductive, deductive, and causal.
- Inductive reasoning refers to arguments that persuade by citing examples that build to a conclusion. Examples should be sufficient, typical, and representative to warrant a strong argument. Reasoning by analogy argues that what is true in one set of circumstances will be true in another, and is an example of inductive reasoning.
- Deductive reasoning refers to arguments that derive specifics from what is already known and includes syllogisms. Premises that lead to the conclusion must be true and relevant for the argument to be valid.
- Causal reasoning refers to arguments that establish a relationship between a cause and an effect and usually involves a correlation rather than a true causal relationship.
- Fallacies refer to flaws within the logic or reasoning of an argument. Ten fallacies of reasoning discussed in this chapter are hasty generalization, false analogy, false cause, false authority, false dilemma, ad hominem, slippery slope, red herring, and appeal to tradition.
- Identify examples of inductive, deductive, and causal reasoning in the sample persuasive speech on education in prisons included in Section 4.3 “Nonverbal Communication Competence” .
- People often use fallacies in arguments, usually without knowing it. Being able to identify fallacies is an important critical thinking skill. Find a letter to the editor in a paper or online and see if you can identify any of the ten fallacies discussed in this chapter.
- Of the ten fallacies discussed in the chapter, which do you think is the most unethical and why?
Coontz, S., “Traditional Marriage Has Changed a Lot,” Seattle Post Intelligencer , February 23, 2006, accessed March 6, 2012, http://www.seattlepi.com/default/article/Traditional-marriage-has-changed-a-lot-1196563.php .
Cooper, M. D., and William L. Nothstine, Power Persuasion: Moving an Ancient Art into the Media Age (Greenwood, IN: Educational Video Group, 1996), 27.
Walter, O. M., Speaking to Inform and Persuade (New York: Macmillan, 1966), 58.
Communication in the Real World Copyright © 2016 by University of Minnesota is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.
Everyday Psychology. Critical Thinking and Skepticism.
What are Logical Fallacies? | Critical Thinking Basics
Logical fallacies are errors in reasoning or flawed arguments that can mislead or deceive. They often appear plausible but lack sound evidence or valid reasoning, undermining the credibility of an argument. These errors can be categorized into various types, such as ad hominem attacks, strawman arguments, and false cause correlations.
Impact on Critical Thinking, Communication, and Social Interactions
The presence of logical fallacies hampers critical thinking by leading individuals away from rational and evidence-based conclusions. In communication, they can create confusion, weaken the persuasiveness of an argument, and hinder the exchange of ideas.
In social interactions, reliance on fallacious reasoning can strain relationships, impede collaboration, and contribute to misunderstandings.
Benefits of Identifying and Managing Logical Fallacies
Learning to identify logical fallacies enhances critical thinking skills, enabling individuals to analyze arguments more effectively and make informed decisions. In communication, recognizing fallacies empowers individuals to construct more compelling and convincing arguments, fostering clearer and more meaningful exchanges.
Moreover, the ability to manage logical fallacies promotes healthier social interactions by minimizing misunderstandings, encouraging constructive dialogue, and fostering a more intellectually robust and collaborative environment.
RETURN TO THE MAIN RESOURCE PAGE: CRITICAL THINKING BASICS
Share this:
How to teach students to identify logical fallacies
![causal fallacy critical thinking](https://blog.kialo-edu.com/wp-content/uploads/sites/3/2023/08/Philosphical-thinking.jpg)
Teaching students about logical fallacies is a vital step to help them become adept critical thinkers. Logical fallacies can occur in our own thinking — when we jump to conclusions — and can also be employed willfully by people arguing in bad faith!
Students who can identify common logical fallacies will have the tools to both build stronger arguments and identify faulty arguments out in the wild. Let’s see just what makes an argument a logical fallacy before delving into some different examples.
What are logical fallacies (and what are they not)?
Logical fallacies are arguments in which the conclusion is the result of faulty reasoning. They are invalid arguments that can nevertheless sound convincing.
Arguments that can simply be disproved by facts are not logical fallacies. Logical fallacies have an error in how the argument is structured. Take these two examples:
Example 1: If you go out without an umbrella, you will get wet.
Example 2: If you go out without an umbrella, you will get wet. Then, you’ll drip water in the hallway, your father will slip on the puddle, and he’ll break his leg!
Although Example 1 isn’t necessarily a convincing argument — it might be sunny outside! — it isn’t a logical fallacy. Example 2, on the other hand, is a classic slippery slope fallacy: The argument advances from a reasonably plausible conclusion to a highly irrational one!
How to identify common logical fallacies
Below are some common logical fallacies that students might encounter, as well as some techniques for identifying them!
Appeal to emotion fallacy
What is the appeal to emotion fallacy.
![causal fallacy critical thinking](https://blog.kialo-edu.com/wp-content/uploads/sites/3/2023/08/appeal-to-emotion.jpg)
As the name suggests, the appeal to emotion fallacy is an argument that relies on stirring up an emotional response in its audience to compensate for the lack of sound reasoning. You’ll find this fallacy everywhere, from over-sentimental advertisements to political rhetoric.
Inspiring emotion in your audience isn’t always a bad thing, of course. But when it is used in lieu of decent arguments, it can cloud the listener’s judgment.
How to identify an appeal to emotion fallacy
Sometimes outright appeals to emotion are easy to spot. Take this example of a politician’s expressive language:
“If my opponent wins, dark days are ahead. But vote for me and you will be able to breathe easy again!”
Metaphors, analogies, and evocative imagery are often used to appeal to our emotions but can be misleading if they aren’t backed up with facts and data.
Likewise, arguments based on anecdotal evidence or imaginative storytelling often rely on the appeal to emotion. We naturally empathize with the characters in stories, but students should be wary of generalizing arguments based on emotive responses!
Appeal to authority fallacy
![causal fallacy critical thinking](https://blog.kialo-edu.com/wp-content/uploads/sites/3/2023/12/authority_statues_cropped.png)
What is the appeal to authority fallacy?
Appeals to authority fallacies leverage the supposed authority of a third party to persuade an audience. Often, the accredited authority is questionable or downright irrelevant to the point being made.
Take the example:
“My teacher has a PhD in Education and she says you shouldn’t drink coffee because it’s bad for your health.”
In this case, the speaker is not only failing to provide any argument for why coffee is bad for your health but also the supposed authority doesn’t have any expertise in this subject!
How to identify an appeal to authority fallacy
Students should first identify whether the argument relies on the authority of the person invoked. If so, they should assess the credibility of the given authority. Authorities given anonymously such as “scientists” or “experts” are a particularly bright red flag!
When writing essays (or claims on Kialo Edu), students should properly cite sources so that any appeals to authority that they make can be checked by readers. Students should be able to justify their choice of references and practice investigating claims accredited to others, to better avoid fallacious appeals to authority.
False cause fallacy
What is the false cause fallacy.
The false cause fallacy occurs when one incorrectly assumes a causal connection between two events. Take this example:
“Every time I wear these socks, I get a great result on my test! So these socks must be lucky.”
Here, the speaker is drawing a causal link between the socks and the test results without any proof.
The false cause fallacy is captured in the academic adage “correlation is not causation.” After all, there are all kinds of funny and random correlations that exist!
How to identify the false cause fallacy
Students should be on the lookout for claims of a causal relationship between two events when there isn’t conclusive proof that one causes the other. They should be particularly dubious in cases where there isn’t even an attempt to explain the process by which the first event influenced the second.
When talking about possible causal relationships, students should use qualifiers like “might,” “may,” and “could” to acknowledge that there isn’t a proven connection. These arguments will be stronger since they avoid the false cause fallacy!
Slippery slope fallacy
![causal fallacy critical thinking](https://blog.kialo-edu.com/wp-content/uploads/sites/3/2023/12/Slippery_slope_scaled.png)
What is the slippery slope fallacy?
The slippery slope fallacy suggests that once a particular thing happens, it will inevitably lead to something worse. Often, an initially innocuous event leads to potentially catastrophic consequences, as in the example given earlier that going outside without an umbrella will lead to your father breaking his leg!
How to identify the slippery slope fallacy
To identify the slippery slope fallacy, students should investigate whether a predicted chain of events is justified. Slippery slope arguments often also rely on the appeal to emotion, playing on the audience’s fear of the more extreme consequences.
Being clear-headed about the difference between the necessary and potential consequences of an event can help avoid making fallacious slippery slope arguments.
Straw man fallacy
What is the straw man fallacy.
The straw man fallacy involves misrepresenting the opposing position so one can argue easier against it — that is, creating a “straw man” that is easily knocked down. Let’s look at an example:
Student 1: I think school uniforms are good because they help build school spirit.
Student 2: So you think students shouldn’t be able to express their individuality and should all think the same thing?
In this case, Student 2 has completely misrepresented Student 1’s argument in order to make their position against school uniforms seem stronger.
How to identify the straw man fallacy
To identify a straw man fallacy, students should recognize when an argument misrepresents or oversimplifies the opposing view. This also helps students avoid making straw man fallacies when they acknowledge and listen to opposing arguments, even if they are in disagreement.
When defending a particular position, students should try to consider the “steel man” argument against their point. To create convincing arguments, students should try to refute the strongest possible counter-argument.
We hope you found this overview of some of the most common logical fallacies useful. Helping students to build clear, well-reasoned arguments is something we’re passionate about at Kialo Edu. Our platform’s argument-mapping structure is designed to help students visualize and develop complex arguments, making it easier to avoid errors in thinking, from logical fallacies to cognitive bias .
If you’ve used Kialo Edu to teach logical fallacies, we’d love to hear from you! Reach out on any of our social media pages, or contact us at [email protected] .
Want to try Kialo Edu with your class?
Sign up for free and use Kialo Edu to have thoughtful classroom discussions and train students’ argumentation and critical thinking skills.
![causal fallacy critical thinking Develop Good Habits](https://www.developgoodhabits.com/wp-content/uploads/2021/08/revised1-trimmed2.jpg)
7 False Cause Fallacy Examples Throughout Life
There might be affiliate links on this page, which means we get a small commission of anything you buy. As an Amazon Associate we earn from qualifying purchases. Please do your own research before making any online purchase.
Last Updated on March 8, 2022 by Neil Surban
What would happen if you dropped a mirror and it broke?
Well, aside from having to buy a new mirror, you would probably expect seven years of bad luck to be ahead of you.
But, if you think back to our article on the Post Hoc Logical Fallacies , you know this popular belief stems from faulty logic.
But there is more to the post hoc fallacy than just the wrong assumption of temporal ordering defining a cause and effect relationship.
The post hoc fallacy is part of a larger group of logical fallacies called false cause fallacies. And in this article, we will learn more about this common method of faulty logic.
But first, let’s look at what a false cause fallacy is.
Table of Contents
What Is the False Cause Fallacy?
The false cause fallacy is committed when someone makes an argument that tries to establish that factor A causes factor B. The mistake here is that the reasoning behind the conclusion depends on an assumed causal connection that doesn't actually exist (or, at least, not as far as people know).
Using this fallacy doesn't mean the conclusion is definitely false, but it does show that there hasn't been a sufficient amount of proof given to make a strong claim. And, without an adequate amount of proof, the statement is considered to be a false cause argument.
A critical component of any false cause fallacy is an assumed relationship between two events. Most of the time, people are simply noticing a link that looks obvious, but actually isn’t real. While sometimes there is a connection between A and B, it doesn’t mean A causes B. And, of course, when there’s not any sort of link between two events, people don’t assume there’s a cause and effect relationship.
The truth is, when event A and event B are observed to often happen together (or one after the other), this may be a good starting point to research the potential causal relationship between the two events. However, that’s all it is–a subject to research. A causal determination cannot be made just because there is a succession or a correlation. It’s only when the correlation is tested and some background knowledge is gained when a causal relationship can be determined.
While doing this research for proof of causality is a critical component in developing scientific explanations, there typically isn’t enough information readily available to do this type of research during an everyday debate to be sure that a false cause fallacy has been executed.
Lastly, I’d like to note the three types of false cause fallacies: post hoc ergo propter hoc, cum hoc ergo propter hoc, and non causa pro causa . The first, which we reviewed in this article , refers to any faulty logic that concludes just because two events are consecutive, the first must have caused the second. Cum hoc ergo propter hoc assumes causation entirely on the basis of two events happening at the same time. Finally, non causa pro causa (a.k.a questionable cause) concludes one event causes another simply without sufficient evidence.
Let’s take a look at some examples that will clarify this logical fallacy a bit further.
1. Every time I _____, it ______.
These statements are often met with an, “of course!” For example, “Whenever one thing breaks in my house, everything breaks!”
The key here is that the first thing really has no impact on the future events that seem to always occur.
But, the thing is, you probably take a special mental note when the expected subsequent event does occur, and you don't think twice about it when it doesn't. So really, you're just focusing on a few instances in your head and forgetting the much larger sample size. For example:
- “Every time I wash my car, it rains.”
- “Every time I wear my lucky shirt, I win.”
- “Every time spring rolls around, I get sick.”
2. Baby Walkers
Research has shown that many parents believe that putting their babies into baby walkers helps their crawling kiddos learn how to walk. This would make sense, as the babies are building those leg muscles that are necessary to walk and getting some good practice in propelling themselves forward in an upright position on their feet. And, once these children do start to walk, parents often attribute this developed skill to the earlier practice with the walker.
The causal argument here is that because baby walkers teach babies the motion of walking, those who use them learn to walk. However, babies who don’t use baby walkers also learn to walk . And the parents who offer walkers to their children don’t have a control factor–or a standard measure to which they could compare their results–to observe if their children learn to walk sooner or better than they would have without the walker. Rather, their conclusion that the baby walker is effective is really just a confirmation bias.
And, if you look at the research, the American Academy of Pediatrics found that not only are there no benefits to using baby walkers–they can actually delay children from walking independently, and they can lead to serious injuries.
3. If You Eat Healthy, You’ll Live a Long, Healthy Life
It’s true that eating healthy may contribute to one’s prolonged health, but this is not the only factor that goes into living a long life. Consider a life-long smoker who develops cancer but has maintained a healthy diet throughout their life. Or, consider someone who dies at a young age in a tragic accident.
If you eat healthy, you may have a higher chance of staving off chronic disease than if you live off of junk food, but it won’t be the sole factor in your longevity. In fact, check out 192 healthy habits that can help keep you going strong for years to come.
4. The Butterfly Effect
“Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?” — Edward Lorenz
The concept of the butterfly effect is often used as a metaphor to illustrate the large impact that can be made by minute occurrences. However, the developer of this concept, Edward Lorenz, didn’t actually intend for it to be translated this way. Rather, he was trying to demonstrate that some very complex systems (such as weather) have such unpredictable behaviors that small changes in the initial conditions can have a large impact on the system’s outcomes, which is the foundation of chaos theory.
It’s a false cause fallacy to imply that a slight change in initial conditions is the one and only cause of the outcome of a complex event. After all, the exact initial conditions of the processes cannot be completely known, and we must admit that a slight difference of the butterfly’s wing flap would have led to endless other cascading changes as well, and each of these individual variances could be isolated as the cause of the outcome.
5. Night and Day
Since the beginning of time, we have seen night and day occur in succession over and over again. However, just because in our experience day is always followed by night, we know that day doesn’t cause night , the two are just both events following a common cause . Night and day are both consequences of the earth's rotation and the illuminating characteristic of the sun (or lack thereof).
So, if day were ever to occur because of a different cause than this, night may not follow day.
6. Political Debate on Firearm Safety
The National Rifle Association has strong grassroots, caring (and voting) members, and the financial means to support individual political candidates. No matter what their stance on gun safety is, Congress members know they face the vengeance (a financial gain or loss) of this unique group, which causes some to avoid the issue of gun laws.
Some say not addressing this issue has led to the relatively high murder rate in the U.S. when compared to other wealthy nations.
However, this is an oversimplification of the causal factors of gun violence in our country. The NRA lobby hasn’t caused the high murder rate in the United States. While the lobby impacts gun laws, which in turn affect how firearms are sold (which is definitely a major factor in the availability of these weapons) the murder rate is not a direct result of the gun lobby’s actions.
You have to consider other factors, such as:
- U.S. culture
- The constitutional right to bear arms
- Gang violence
- Secular beliefs
- Income inequality
- Widespread gun ownership
- Policies such as “stand-your-ground” laws
- Open carry laws
- Shortcomings in universal background checks
When these factors are also taken into consideration, it can be seen that a gun law by itself cannot solve the U.S.’s murder rate.
7. Social Interaction and Wellbeing
We’ve often talked about the relationship between one’s personal relationships and their overall wellbeing on this site. This is often an example of causal confusion–and I haven’t found an instance in my past writings where I made this false cause fallacy yet , but I’m sure if I keep looking, I will!
It’s often concluded that those who are actively social with other people on a regular basis are happier and healthier than those who stick to themselves. So it’s assumed that social interaction is the cause of overall wellbeing. However, when you look for the true cause and effect in this, the reverse is likely to be correct.
![causal fallacy critical thinking causal fallacy examples | false cause fallacy examples in philosophy | false cause and effect fallacy examples](https://www.developgoodhabits.com/wp-content/uploads/2021/04/social-interactions.jpg)
Having supportive relationships with others is beneficial for one’s mental health. Plus, there are activities that involve social interaction (like volunteering) that have been proven to boost our satisfaction with life . But, which comes first? It’s likely that people who are happier in general want to get out and socialize more frequently than those who are unhappy with themselves or their lives.
Also, one could try to claim that people volunteer in order to boost their wellbeing, but you would be overlooking the more probable fact that people who feel well are more likely to volunteer than those who don’t.
How to Respond to the False Cause Fallacy
In most of your everyday conversations, you can refute this fallacy through asking questions, analyzing the data, or researching. It’s hard to identify the true relationship between co-occurring events in the world, so be mindful of your habit of assuming one event caused another.
Question your assumptions, and, like with other logical fallacies, be open to accepting alternative explanations, and always be prepared to change your mind.
This way, not only will you be less likely to believe someone else’s argument that’s using false cause reasoning, you will also be less likely to commit this logical fallacy yourself.
Learn More About Logical Fallacies
- 5 Appeal to Nature Fallacy Examples in Media and Life
- 6 Outcome Bias Examples That Can Negatively Impact Your Decisions
- 7 Self-Serving Bias Examples You See Throughout Life
- 7 Omission Bias Examples That Negatively Impact Your Life
- 6 Authority Bias Examples That Might Impact Your Decisions
- 5 Burden of Proof Fallacy Examples
- 5 Appeal to Tradition Fallacy Examples in Life
- 5 Appeal to Authority Logical Fallacy Examples
- 7 Appeal to Ignorance Fallacy Examples
- 7 Appeal to Common Sense Logical Fallacy Examples
- Gambler’s Fallacy: 5 Examples and How to Avoid It
- 5 Appeal to Anger Fallacy Examples Throughout Life
- 7 Halo Effect Bias Examples in Your Daily Life
- 7 Poisoning the Well Examples Throughout Your Life
- 7 Survivorship Bias Examples You See in the Real World
- 7 Dunning Kruger Effect Examples in Your Life
- 7 Either Or (“False Dilemma”) Fallacy Examples in Real Life
- 5 Cui Bono Fallacy Examples to Find Out “Who Will Benefit”
- 6 Anchoring Bias Examples That Impact Your Decisions
- 7 Virtue Signaling Examples in Everyday Life
- 7 Cherry Picking Fallacy Examples for When People Ignore Evidence
- 9 Circular Reasoning Examples (or “Begging the Question”) in Everyday Life
- 9 Appeal to Emotion Logical Fallacy Examples
- 9 Appeal to Pity Fallacy (“Ad Misericordiam”) Examples in Everyday Life
- 9 Loaded Question Fallacy Examples in Life and Media
- 9 Bandwagon Fallacy Examples to Prevent Poor Decisions
- 5 Red Herring Fallacy Examples to Fight Irrelevant Information
- 9 Middle Ground Fallacy Examples to Spot During an Argument
- 5 False Equivalence Examples to Know Before Your Next Argument
- 7 Hasty Generalization Fallacy Examples & How to Respond to Them
- 6 Straw Man Fallacy Examples & How You Can Respond
- 6 False Dichotomy Examples & How to Counter Them
- 7 Slippery Slope Fallacy Examples (And How to Counter Them)
- What is the Planning Fallacy?
- How to Overcome the “Sunk Cost Fallacy” Mindset
Final Thoughts on the False Cause Fallacy
Our brains like to find causal relationships. We like to know why things happen and how things in the world are related. But, while these types of explanations help us link facts together, all too often, they’re inaccurate.
In general, we overestimate our capability to understand the relationships and connections in the world. So remember the examples in this article next time you’re assigning a cause and effect.
Finally, if you want a simple process to counter the logical fallacies and cognitive biases you encounter in life, then follow this 7-step process to develop the critical thinking skills habit .
![causal fallacy critical thinking causal fallacy critical thinking](https://www.developgoodhabits.com/wp-content/uploads/2019/08/connie-profile-pic.png)
Connie Mathers is a professional editor and freelance writer. She holds a Bachelor's Degree in Marketing and a Master’s Degree in Social Work. When she is not writing, Connie is either spending time with her daughter and two dogs, running, or working at her full-time job as a social worker in Richmond, VA.
![causal fallacy critical thinking false cause fallacy examples | false cause fallacy examples in media | questionable cause fallacy examples](https://www.developgoodhabits.com/wp-content/uploads/2020/07/false-cause-fallacy-examples-683x1024.jpg)
![causal fallacy critical thinking Logo for OPEN OKSTATE](https://open.library.okstate.edu/app/uploads/2019/09/cropped-OSU-Library-Horizontal-BLACK-2.png)
3 Fallacies
I. what a re fallacies 1.
Fallacies are mistakes of reasoning, as opposed to making mistakes that are of a factual nature. If I counted twenty people in the room when there were in fact twenty-one, then I made a factual mistake. On the other hand, if I believe that there are round squares I believe something that is contradictory. A belief in “round squares” is a mistake of reasoning and contains a fallacy because, if my reasoning were good, I would not believe something that is logically inconsistent with reality.
In some discussions, a fallacy is taken to be an undesirable kind of argument or inference. In our view, this definition of fallacy is rather narrow, since we might want to count certain mistakes of reasoning as fallacious even though they are not presented as arguments. For example, making a contradictory claim seems to be a case of fallacy, but a single claim is not an argument. Similarly, putting forward a question with an inappropriate presupposition might also be regarded as a fallacy, but a question is also not an argument. In both of these situations though, the person is making a mistake of reasoning since they are doing something that goes against one or more principles of correct reasoning. This is why we would like to define fallacies more broadly as violations of the principles of critical thinking , whether or not the mistakes take the form of an argument.
The study of fallacies is an application of the principles of critical thinking. Being familiar with typical fallacies can help us avoid them and help explain other people’s mistakes.
There are different ways of classifying fallacies. Broadly speaking, we might divide fallacies into four kinds:
- Fallacies of inconsistency: cases where something inconsistent or self-defeating has been proposed or accepted.
- Fallacies of relevance: cases where irrelevant reasons are being invoked or relevant reasons being ignored.
- Fallacies of insufficiency: cases where the evidence supporting a conclusion is insufficient or weak.
- Fallacies of inappropriate presumption: cases where we have an assumption or a question presupposing something that is not reasonable to accept in the relevant conversational context.
II. Fallacies of I nconsistency
Fallacies of inconsistency are cases where something inconsistent, self-contradictory or self-defeating is presented.
1. Inconsistency
Here are some examples:
- “One thing that we know for certain is that nothing is ever true or false.” – If there is something we know for certain, then there is at least one truth that we know. So it can’t be the case that nothing is true or false.
- “Morality is relative and is just a matter of opinion, and so it is always wrong to impose our opinions on other people.” – But if morality is relative, it is also a relative matter whether we should impose our opinions on other people. If we should not do that, there is at least one thing that is objectively wrong.
- “All general claims have exceptions.” – This claim itself is a general claim, and so if it is to be regarded as true we must presuppose that there is an exception to it, which would imply that there exists at least one general claim that does not have an exception. So the claim itself is inconsistent.
![](http://writinghelp.online/777/templates/cheerup/res/banner1.gif)
2. Self- D efeating C laims
A self-defeating statement is a statement that, strictly speaking, is not logically inconsistent but is instead obviously false. Consider these examples:
- Very young children are fond of saying “I am not here” when they are playing hide-and-seek. The statement itself is not logically consistent, since it is not logically possible for the child not to be where she is. What is impossible is to utter the sentence as a true sentence (unless it is used for example in a telephone recorded message.)
- Someone who says, “I cannot speak any English.”
- Here is an actual example: A TV program in Hong Kong was critical of the Government. When the Hong Kong Chief Executive Mr. Tung was asked about it, he replied, “I shall not comment on such distasteful programs.” Mr. Tung’s remark was not logically inconsistent, because what it describes is a possible state of affairs. But it is nonetheless self-defeating because calling the program “distasteful” is to pass a comment!
III. Fallacies of R elevance
1. taking irrelevant considerations into account.
This includes defending a conclusion by appealing to irrelevant reasons, e.g., inappropriate appeal to pity, popular opinion, tradition, authority, etc. An example would be when a student failed a course and asked the teacher to give him a pass instead, because “his parents will be upset.” Since grades should be given on the basis of performance, the reason being given is quite irrelevant.
Similarly, suppose someone criticizes the Democratic Party’s call for direct elections in Hong Kong as follows: “These arguments supporting direct elections have no merit because they are advanced by Democrats who naturally stand to gain from it.” This is again fallacious because whether the person advancing the argument has something to gain from direct elections is a completely different issue from whether there ought to be direct elections.
2. Failing to T ake R elevant C onsiderations into A ccount
For example, it is not unusual for us to ignore or downplay criticisms because we do not like them, even when those criticisms are justified. Or sometimes we might be tempted to make a snap decision, believing knee-jerk reactions are the best when, in fact, we should be investigating the situation more carefully and doing more research.
Of course, if we fail to consider a relevant fact simply because we are ignorant of it, then this lack of knowledge does not constitute a fallacy.
IV. Fallacies of Insufficiency
Fallacies of insufficiency are cases where insufficient evidence is provided in support of a claim. Most common fallacies fall within this category. Here are a few popular types:
1. Limited S ampling
- Momofuku Ando, the inventor of instant noodles, died at the age of 96. He said he ate instant noodles every day. So instant noodles cannot be bad for your health.
- A black cat crossed my path this morning, and I got into a traffic accident this afternoon. Black cats are really unlucky.
In both cases the observations are relevant to the conclusion, but a lot more data is needed to support the conclusion, e.g., studies show that many other people who eat instant noodles live longer, and those who encounter black cats are more likely to suffer from accidents.
2. Appeal to I gnorance
- We have no evidence showing that he is innocent. So he must be guilty.
If someone is guilty, it would indeed be hard to find evidence showing that he is innocent. But perhaps there is no evidence to point either way, so a lack of evidence is not enough to prove guilt.
3. Naturalistic F allacy
- Many children enjoy playing video games, so we should not stop them from playing.
Many naturalistic fallacies are examples of fallacy of insufficiency. Empirical facts by themselves are not sufficient for normative conclusions, even if they are relevant.
There are many other kinds of fallacy of insufficiency. See if you can identify some of them.
V. Fallacies of Inappropriate Presumption
Fallacies of inappropriate presumption are cases where we have explicitly or implicitly made an assumption that is not reasonable to accept in the relevant context. Some examples include:
- Many people like to ask whether human nature is good or evil. This presupposes that there is such a thing as human nature and that it must be either good or bad. But why should these assumptions be accepted, and are they the only options available? What if human nature is neither good nor bad? Or what if good or bad nature applies only to individual human beings?
- Consider the question “Have you stopped being an idiot?” Whether you answer “yes” or “no,” you admit that you are, or have been, an idiot. Presumably you do not want to make any such admission. We can point out that this question has a false assumption.
- “Same-sex marriage should not be allowed because by definition a marriage should be between a man and a woman.” This argument assumes that only a heterosexual conception of marriage is correct. But this begs the question against those who defend same-sex marriages and is not an appropriate assumption to make when debating this issue.
VI. List of Common Fallacies
A theory is discarded not because of any evidence against it or lack of evidence for it, but because of the person who argues for it. Example:
A: The Government should enact minimum-wage legislation so that workers are not exploited. B: Nonsense. You say that only because you cannot find a good job.
ad ignorantiam (appeal to ignorance)
The truth of a claim is established only on the basis of lack of evidence against it. A simple obvious example of such fallacy is to argue that unicorns exist because there is no evidence against their existence. At first sight it seems that many theories that we describe as “scientific” involve such a fallacy. For example, the first law of thermodynamics holds because so far there has not been any negative instance that would serve as evidence against it. But notice, as in cases like this, there is evidence for the law, namely positive instances. Notice also that this fallacy does not apply to situations where there are only two rival claims and one has already been falsified. In situations such as this, we may justly establish the truth of the other even if we cannot find evidence for or against it.
ad misericordiam (appeal to pity)
In offering an argument, pity is appealed to. Usually this happens when people argue for special treatment on the basis of their need, e.g., a student argues that the teacher should let them pass the examination because they need it in order to graduate. Of course, pity might be a relevant consideration in certain conditions, as in contexts involving charity.
ad populum (appeal to popularity)
The truth of a claim is established only on the basis of its popularity and familiarity. This is the fallacy committed by many commercials. Surely you have heard of commercials implying that we should buy a certain product because it has made to the top of a sales rank, or because the brand is the city’s “favorite.”
Affirming the consequent
Inferring that P is true solely because Q is true and it is also true that if P is true, Q is true.
The problem with this type of reasoning is that it ignores the possibility that there are other conditions apart from P that might lead to Q. For example, if there is a traffic jam, a colleague may be late for work. But if we argue from his being late to there being a traffic jam, we are guilty of this fallacy – the colleague may be late due to a faulty alarm clock.
Of course, if we have evidence showing that P is the only or most likely condition that leads to Q, then we can infer that P is likely to be true without committing a fallacy.
Begging the question ( petito principii )
In arguing for a claim, the claim itself is already assumed in the premise. Example: “God exists because this is what the Bible says, and the Bible is reliable because it is the word of God.”
Complex question or loaded question
A question is posed in such a way that a person, no matter what answer they give to the question, will inevitably commit themselves to some other claim, which should not be presupposed in the context in question.
A common tactic is to ask a yes-no question that tricks people into agreeing to something they never intended to say. For example, if you are asked, “Are you still as self-centered as you used to be?”, no matter whether you answer “yes” or ”no,” you are bound to admit that you were self-centered in the past. Of course, the same question would not count as a fallacy if the presupposition of the question were indeed accepted in the conversational context, i.e., that the person being asked the question had been verifiably self-centered in the past.
Composition (opposite of division)
The whole is assumed to have the same properties as its parts. Anne might be humorous and fun-loving and an excellent person to invite to the party. The same might be true of Ben, Chris and David, considered individually. But it does not follow that it will be a good idea to invite all of them to the party. Perhaps they hate each other and the party will be ruined.
Denying the antecedent
Inferring that Q is false just because if P is true, Q is also true, but P is false.
This fallacy is similar to the fallacy of affirming the consequent. Again the problem is that some alternative explanation or cause might be overlooked. Although P is false, some other condition might be sufficient to make Q true.
Example: If there is a traffic jam, a colleague may be late for work. But it is not right to argue in the light of smooth traffic that the colleague will not be late. Again, his alarm clock may have stopped working.
Division (opposite of composition)
The parts of a whole are assumed to have the same properties as the whole. It is possible that, on a whole, a company is very effective, while some of its departments are not. It would be inappropriate to assume they all are.
Equivocation
Putting forward an argument where a word changes meaning without having it pointed out. For example, some philosophers argue that all acts are selfish. Even if you strive to serve others, you are still acting selfishly because your act is just to satisfy your desire to serve others. But surely the word “selfish” has different meanings in the premise and the conclusion – when we say a person is selfish we usually mean that he does not strive to serve others. To say that a person is selfish because he is doing something he wants, even when what he wants is to help others, is to use the term “selfish” with a different meaning.
False dilemma
Presenting a limited set of alternatives when there are others that are worth considering in the context. Example: “Every person is either my enemy or my friend. If they are my enemy, I should hate them. If they’re my friend, I should love them. So I should either love them or hate them.” Obviously, the conclusion is too extreme because most people are neither your enemy nor your friend.
Gambler’s fallacy
Assumption is made to take some independent statistics as dependent. The untrained mind tends to think that, for example, if a fair coin is tossed five times and the results are all heads, then the next toss will more likely be a tail. It will not be, however. If the coin is fair, the result for each toss is completely independent of the others. Notice the fallacy hinges on the fact that the final result is not known. Had the final result been known already, the statistics would have been dependent.
Genetic fallacy
Thinking that because X derives from Y, and because Y has a certain property, that X must also possess that same property. Example: “His father is a criminal, so he must also be up to no good.”
Non sequitur
A conclusion is drawn that does not follow from the premise. This is not a specific fallacy but a very general term for a bad argument. So a lot of the examples above and below can be said to be non sequitur.
Post hoc, ergo propter hoc (literally, “ after this, therefore because of this ” )
Inferring that X must be the cause of Y just because X is followed by Y.
For example, having visited a graveyard, I fell ill and infer that graveyards are spooky places that cause illnesses. Of course, this inference is not warranted since this might just be a coincidence. However, a lot of superstitious beliefs commit this fallacy.
Red herring
Within an argument some irrelevant issue is raised that diverts attention from the main subject. The function of the red herring is sometimes to help express a strong, biased opinion. The red herring (the irrelevant issue) serves to increase the force of the argument in a very misleading manner.
For example, in a debate as to whether God exists, someone might argue that believing in God gives peace and meaning to many people’s lives. This would be an example of a red herring since whether religions can have a positive effect on people is irrelevant to the question of the existence of God. The positive psychological effect of a belief is not a reason for thinking that the belief is true.
Slippery slope
Arguing that if an opponent were to accept some claim C 1 , then they have to accept some other closely related claim C 2 , which in turn commits the opponent to a still further claim C 3 , eventually leading to the conclusion that the opponent is committed to something absurd or obviously unacceptable.
This style of argumentation constitutes a fallacy only when it is inappropriate to think if one were to accept the initial claim, one must accept all the other claims.
An example: “The government should not prohibit drugs. Otherwise the government should also ban alcohol or cigarettes. And then fatty food and junk food would have to be regulated too. The next thing you know, the government would force us to brush our teeth and do exercises every day.”
Attacking an opponent while falsely attributing to them an implausible position that is easily defeated.
Example: When many people argue for more democracy in Hong Kong, a typical “straw man” reply is to say that more democracy is not warranted because it is wrong to believe that democracy is the solution to all of Hong Kong’s problems. But those who support more democracy in Hong Kong never suggest that democracy can solve all problems (e.g., pollution), and those who support more democracy in Hong Kong might even agree that blindly accepting anything is rarely the correct course of action, whether it is democracy or not. Theses criticisms attack implausible “straw man” positions and do not address the real arguments for democracy.
Suppressed evidence
Where there is contradicting evidence, only confirming evidence is presented.
VII. Exercises
Identify any fallacy in each of these passages. If no fallacy is committed, select “no fallacy involved.”
1. Mr. Lee’s views on Japanese culture are wrong. This is because his parents were killed by the Japanese army during World War II and that made him anti-Japanese all his life.
2. Every ingredient of this soup is tasty. So this must be a very tasty soup.
3. Smoking causes cancer because my father was a smoker and he died of lung cancer.
4. Professor Lewis, the world authority on logic, claims that all wives cook for their husbands. But the fact is that his own wife does not cook for him. Therefore, his claim is false.
5. If Catholicism is right, then no women should be allowed to be priests. But Catholicism is wrong. Therefore, some women should be allowed to be priests.
6. God does not exist because every argument for the existence of God has been shown to be unsound.
7. The last three times I have had a cold I took large doses of vitamin C. On each occasion, the cold cleared up within a few days. So vitamin C helped me recover from colds.
8. The union’s case for more funding for higher education can be ignored because it is put forward by the very people – university staff – who would benefit from the increased money.
9. Children become able to solve complex problems and think of physical objects objectively at the same time that they learn language. Therefore, these abilities are caused by learning a language.
10. If cheap things are no good then this cheap watch is no good. But this watch is actually quite good. So some good things are cheap.
Critical Thinking Copyright © 2019 by Brian Kim is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted.
Share This Book
![causal fallacy critical thinking SEP home page](https://plato.stanford.edu/symbols/sep-man-red.png)
- Table of Contents
- Random Entry
- Chronological
- Editorial Information
- About the SEP
- Editorial Board
- How to Cite the SEP
- Special Characters
- Advanced Tools
- Support the SEP
- PDFs for SEP Friends
- Make a Donation
- SEPIA for Libraries
- Entry Contents
Bibliography
Academic tools.
- Friends PDF Preview
- Author and Citation Info
- Back to Top
Two competing conceptions of fallacies are that they are false but popular beliefs and that they are deceptively bad arguments. These we may distinguish as the belief and argument conceptions of fallacies. Academic writers who have given the most attention to the subject of fallacies insist on, or at least prefer, the argument conception of fallacies, but the belief conception is prevalent in popular and non-scholarly discourse. As we shall see, there are yet other conceptions of what fallacies are, but the present inquiry focuses on the argument conception of fallacies.
Being able to detect and avoid fallacies has been viewed as a supplement to criteria of good reasoning. The knowledge of fallacies is needed to arm us against the most enticing missteps we might take with arguments—so thought not only Aristotle but also the early nineteenth century logicians Richard Whately and John Stuart Mill. But as the course of logical theory from the late nineteenth-century forward turned more and more to axiomatic systems and formal languages, the study of reasoning and natural language argumentation received much less attention, and hence developments in the study of fallacies almost came to a standstill. Until well past the middle of the twentieth century, discussions of fallacies were for the most part relegated to introductory level textbooks. It was only when philosophers realized the ill fit between formal logic, on the one hand, and natural language reasoning and argumentation, on the other, that the interest in fallacies has returned. Since the 1970s the utility of knowing about fallacies has been acknowledged (Johnson and Blair 1993), and the way in which fallacies are incorporated into theories of argumentation has been taken as a sign of a theory’s level of adequacy (Biro and Siegel 2007, van Eemeren 2010).
In modern fallacy studies it is common to distinguish formal and informal fallacies. Formal fallacies are those readily seen to be instances of identifiable invalid logical forms such as undistributed middle and denying the antecedent. Although many of the informal fallacies are also invalid arguments, it is generally thought to be more profitable, from the points of view of both recognition and understanding, to bring their weaknesses to light through analyses that do not involve appeal to formal languages. For this reason it has become the practice to eschew the symbolic language of formal logic in the analysis of these fallacies; hence the term ‘informal fallacy’ has gained wide currency. In the following essay, which is in four parts, it is what is considered the informal-fallacy literature that will be reviewed. Part 1 is an introduction to the core fallacies as brought to us by the tradition of the textbooks. Part 2 reviews the history of the development of the conceptions of fallacies as it is found from Aristotle to Copi. Part 3 surveys some of the most recent innovative research on fallacies, and Part 4 considers some of the current research topics in fallacy theory.
1. The core fallacies
2.1 aristotle, 2.3 arnauld and nicole, 2.6 bentham, 2.7 whately, 2.9 sidgwick, 3.1 renewed interest, 3.2 doubts about fallacies, 3.3 the informal logic approach to fallacies, 3.4 the formal approach to informal fallacies, 3.5 the epistemic approach to fallacies, 3.6 dialectical/dialogical approaches to fallacies, 4.1 the nature of fallacies, 4.2 the appearance condition, 4.3 teaching, other internet resources, related entries.
Irving Copi’s 1961 Introduction to Logic gives a brief explanation of eighteen informal fallacies. Although there is some variation in competing textbooks, Copi’s selection captured what for many was the traditional central, core fallacies. [ 1 ] In the main, these fallacies spring from two fountainheads: Aristotle’s Sophistical Refutations and John Locke’s An Essay Concerning Human Understanding (1690). By way of introduction, a brief review of the core fallacies, especially as they appear in introductory level textbooks, will be given. Only very general definitions and illustrations of the fallacies can be offered. This proviso is necessary first, because, the definitions (or identity conditions) of each of the fallacies is often a matter of contention and so no complete or final definition can be given in an introductory survey; secondly, some researchers wish that only plausible and realistic instances of each fallacy be used for illustration. This also is not possible at this stage. The advantage of the stock examples of fallacies is that they are designed to highlight what the mistake associated with each kind of fallacy is supposed to be. Additional details about some of the fallacies are found in Sections 2 and 3. As an initial working definition of the subject matter, we may take a fallacy to be an argument that seems to be better than it really is.
1. The fallacy of equivocation is an argument which exploits the ambiguity of a term or phrase which has occurred at least twice in an argument, such that on the first occurrence it has one meaning and on the second another meaning. A familiar example is:
The end of life is death. Happiness is the end of life. So, death is happiness.
‘The end of life’ first means ceasing to live, then it means purpose. That the same set of words is used twice conceals the fact that the two distinct meanings undermine the continuity of the reasoning, resulting in a non-sequitur .
2. The fallacy of amphiboly is, like the fallacy of equivocation, a fallacy of ambiguity; but here the ambiguity is due to indeterminate syntactic structure. In the argument:
The police were told to stop drinking on campus after midnight. So, now they are able to respond to emergencies much better than before
there are several interpretations that can be given to the premise because it is grammatically ambiguous. On one reading it can be taken to mean that it is the police who have been drinking and are now to stop it; this makes for a plausible argument. On another reading what is meant is that the police were told to stop others (e.g., students) from drinking after midnight. If that is the sense in which the premise is intended, then the argument can be said to be a fallacy because despite initial appearances, it affords no support for the conclusion.
3 & 4. The fallacies of composition and division occur when the properties of parts and composites are mistakenly thought to be transferable from one to the other. Consider the two sentences:
- Every member of the investigative team was an excellent researcher.
- It was an excellent investigative team.
Here it is ‘excellence’ that is the property in question. The fallacy of composition is the inference from (a) to (b) but it need not hold if members of the team cannot work cooperatively with each other. The reverse inference from (b) to (a)—the fallacy of division—may also fail if some essential members of the team have a supportive or administrative role rather than a research role.
5. The fallacy of begging the question ( petitio principii ) can occur in a number of ways. One of them is nicely illustrated with Whately’s (1875 III §13) example: “to allow everyman an unbounded freedom of speech must always be, on the whole, advantageous to the State; for it is highly conducive to the interest of the Community, that each individual should enjoy a liberty perfectly unlimited, of expressing his sentiments.” This argument begs the question because the premise and conclusion are the very same proposition, albeit expressed in different words. It is a disguised instance of repetition which gives no reason for its apparent conclusion.
Another version of begging the question can occur in contexts of argumentation where there are unsettled questions about key terms. Suppose, for example, that everyone agrees that to murder someone requires doing something that is wrong, but not everyone agrees that capital punishment is a form of ‘murder’; some think it is justified killing. Then, should an arguer gives this argument:
Capital punishment requires an act of murdering human beings. So, capital punishment is wrong.
one could say that this is question-begging because in this context of argumentation, the arguer is smuggling in as settled a question that remains open. That is, if the premise is accepted without further justification, the arguer is assuming the answer to a controversial question without argument.
Neither of these versions of begging the question are faulted for their invalidity, so they are not charged with being non-sequitors like most of the core fallacies; they are, however, attempted proofs that do not transparently display their weakness. This consideration, plus its ancient lineage back to Aristotle, might explain begging the question’s persistent inclusion among fallacies. But, given our allegiance to the modern conception of logic as being solely concerned with the following-from relation, forms of begging the question should be thought of as epistemic rather than logical fallacies.
Some versions of begging the question are more involved and are called circular reasoning. They include more than one inference. Descartes illustrated this kind of fallacy with the example of our belief in the Bible being justified because it is the word of God, and our belief in God’s existence being justified because it is written in the Bible. [ 2 ] The two propositions lead back and forth to each other, in a circle, each having only the support of the other.
6. The fallacy known as complex question or many questions is usually explained as a fallacy associated with questioning. For example, in a context where a Yes or No answer must be given, the question, “Are you still a member of the Ku Klux Klan?” is a fallacy because either response implies that one has in the past been a member of the Klan, a proposition that may not have been established as true. Some say that this kind of mistake is not really a fallacy because to ask a question is not to make an argument.
7. There are a number of fallacies associated with causation, the most frequently discussed is post hoc ergo propter hoc , (after this, therefore because of this). This fallacy ascribes a causal relationship between two states or events on the basis of temporal succession. For example,
Unemployment decreased in the fourth quarter because the government eliminated the gasoline tax in the second quarter.
The decrease in unemployment that took place after the elimination of the tax may have been due to other causes; perhaps new industrial machinery or increased international demand for products. Other fallacies involve confusing the cause and the effect, and overlooking the possibility that two events are not directly related to each other but are both the effect of a third factor, a common cause. These fallacies are perhaps better understood as faults of explanation than faults of arguments.
8. The fallacy of ignoratio elenchi , or irrelevant conclusion, is indicative of misdirection in argumentation rather than a weak inference. The claim that Calgary is the fastest growing city in Canada, for example, is not defeated by a sound argument showing that it is not the biggest city in Canada. A variation of ignoratio elenchi , known under the name of the straw man fallacy, occurs when an opponent’s point of view is distorted in order to make it easier to refute. For example, in opposition to a proponent’s view that (a) industrialization is the cause of global warming, an opponent might substitute the proposition that (b) all ills that beset mankind are due to industrialization and then, having easily shown that (b) is false, leave the impression that (a), too, is false. Two things went wrong: the proponent does not hold (b), and even if she did, the falsity of (b) does not imply the falsity of (a).
There are a number of common fallacies that begin with the Latin prefix ‘ ad ’ (‘to’ or ‘toward’) and the most common of these will be described next.
9. The ad verecundiam fallacy concerns appeals to authority or expertise. Fundamentally, the fallacy involves accepting as evidence for a proposition the pronouncement of someone who is taken to be an authority but is either not really an authority or a relevant authority. This can happen when non-experts parade as experts in fields in which they have no special competence—when, for example, celebrities endorse commercial products or social movements. Similarly, when there is controversy, and authorities are divided, it is an error to base one’s view on the authority of just some of them. (See also 2.4 below.)
10. The fallacy ad populum is similar to the ad verecundiam , the difference being that the source appealed to is popular opinion, or common knowledge, rather than a specified authority. So, for example:
These days everyone (except you) has a car and knows how to drive; So, you too should have a car and know how to drive.
Often in arguments like this the premises aren’t true, but even if they are generally true they may provide only scant support for their conclusions because that something is widely practised or believed is not compelling evidence that it is true or that it should be done. There are few subjects on which the general public can be said to hold authoritative opinions. Another version of the ad populum fallacy is known as “playing to the gallery” in which a speaker seeks acceptance for his view by arousing relevant prejudices and emotions in his audience in lieu of presenting it with good evidence.
11. The ad baculum fallacy is one of the most controversial because it is hard to see that it is a fallacy or even that it involves bad reasoning. Ad baculum means “appeal to the stick” and is generally taken to involve a threat of injury of harm to the person addressed. So, for example,
If you don’t join our demonstration against the expansion of the park, we will evict you from your apartment; So, you should join our demonstration against the expansion of the park.
Such threats do give us reasons to act but, unpleasant as the interlocutor may be, there seems to be no fallacy here. In labour disputes, and perhaps in international relations, using threats such as going on strike, or cutting off trade routes, are not normally considered fallacies, even though they do involve intimidation and the threat of harm. However, if we change to doxastic considerations, then the argument that you should believe that candidate \(X\) is the one best suited for public office because if you do not believe this you will be evicted from your apartment, certainly is a good instance of irrelevant evidence.
12. The fallacy ad misericordiam is a companion to the ad baculum fallacy: it occurs not when threats are out of place but when appeals for sympathy or pity are mistakenly thought to be evidence. To what extent our sympathy for others should influence our actions depends on many factors, including circumstances and our ethical views. However, sympathy alone is generally not evidence for believing any proposition. Hence,
You should believe that he is not guilty of embezzling those paintings; think of how much his family suffered during the Depression.
Ad misericordiam arguments, like ad baculum arguments, have their natural home in practical reasoning; it is when they are used in theoretical (doxastic) argumentation that the possibility of fallacy is more likely.
13. The ad hominem fallacy involves bringing negative aspects of an arguer, or their situation, to bear on the view they are advancing. There are three commonly recognized versions of the fallacy. The abusive ad hominem fallacy involves saying that someone’s view should not be accepted because they have some unfavorable property.
Thompson’s proposal for the wetlands may safely be rejected because last year she was arrested for hunting without a license.
The hunter Thompson, although she broke the law, may nevertheless have a very good plan for the wetlands.
Another, more subtle version of the fallacy is the circumstantial ad hominem in which, given the circumstances in which the arguer finds him or herself, it is alleged that their position is supported by self-interest rather than by good evidence. Hence, the scientific studies produced by industrialists to show that the levels of pollution at their factories are within the law may be undeservedly rejected because they are thought to be self-serving. Yet it is possible that the studies are sound: just because what someone says is in their self-interest, does not mean it should be rejected.
The third version of the ad hominem fallacy is the tu quoque . It involves not accepting a view or a recommendation because the espouser him- or herself does not follow it. Thus, if our neighbor advises us to exercise regularly and we reject her advice on the basis that she does not exercise regularly, we commit the tu quoque fallacy: the value of advice is not wholly dependent on the integrity of the advisor.
We may finish our survey of the core fallacies by considering just two more.
14. The fallacy of faulty analogy occurs when analogies are used as arguments or explanations and the similarities between the two things compared are too remote to support the conclusion.
If a child gets a new toy he or she will want to play with it; So, if a nation gets new weapons, it will want to use them.
In this example (due to Churchill 1986, 349) there is a great difference between using (playing with) toys and using (discharging) weapons. The former is done for amusement, the latter is done to inflict harm on others. Playing with toys is a benign activity that requires little justification; using weapons against others nations is something that is usually only done after extensive deliberation and as a last resort. Hence, there is too much of a difference between using toys and using weapons to conclude that a nation, if it acquires weapons, will want to use them as readily as children will want to play with their toys.
15. The fallacy of the slippery slope generally takes the form that from a given starting point one can by a series of incremental inferences arrive at an undesirable conclusion, and because of this unwanted result, the initial starting point should be rejected. The kinds of inferences involved in the step-by-step argument can be causal, as in:
You have decided not to go to college; If you don’t go to college, you won’t get a degree; If you don’t get a degree, you won’t get a good job; If you don’t get a good job, you won’t be able to enjoy life; But you should be able to enjoy life; So, you should go to college.
The weakness in this argument, the reason why it is a fallacy, lies in the second and third causal claims. The series of small steps that lead from an acceptable starting point to an unacceptable conclusion may also depend on vague terms rather than causal relations. Lack of clear boundaries is what enables the puzzling slippery slope arguments known as “the beard” and “the heap.” In the former, a person with a full beard eventually becomes beardless as hairs of the beard are removed one-by-one; but because the term ‘beard’ is vague it is unclear at which intermediate point we are to say that the man is now beardless. Hence, at each step in the argument until the final hair-plucking, we should continue to conclude that the man is bearded. In the second case, because ‘heap’ is vague, it is unclear at what point piling scattered stones together makes them a heap of stones: if it is not a heap to begin with, adding one more stone will not make it a heap, etc. In both these cases apparently good reasoning leads to a false conclusion.
Many other fallacies have been named and discussed (see, e.g., Nickerson 2021, ch. 6), some of them quite different from the ones mentioned above, others interesting and novel variations of the above. Some of these will be mentioned in the review of historical and contemporary sources that follows.
2. History of Fallacy Theory
The history of the study of fallacies begins with Aristotle’s work, On Sophistical Refutations . It is among his earlier writings and the work appears to be a continuation of the Topics , his treatise on dialectical argumentation. Although his most extensive and theoretically detailed discussion of fallacies is in the Sophistical Refutations , Aristotle also discusses fallacies in the Prior Analytics and On Rhetoric . Here we will concentrate on summarizing the account given in the Sophistical Refutations . In that work, four things are worth noting: (a) the different conceptions of fallacy; (b) the basic concepts used to explain fallacies; (c) Aristotle’s explanation of why fallacies can be deceptive; and (d) his enumeration and classification of fallacies.
2.1.1 Definitions
At the beginning of Topics (I, i), Aristotle distinguishes several kinds of deductions (syllogisms). They are distinguished first on the basis of the status of their premises. (1) Those that begin from true and primary premises, or are owed to such, are demonstrations. (2) Those which have dialectical premises—propositions acceptable to most people, or to the wise—are dialectical deductions. (3) Deductions that start from premises which only appear to be dialectical, are fallacious deductions because of their starting points, as are (4) those “deductions” that do have dialectical premises but do not really necessitate their conclusions. Other fallacies mentioned and associated with demonstrations are (5) those which only appear to start from what is true and primary ( Top ., I, i 101a5). What this classification leaves out are (6) the arguments that do start from true and primary premises but then fail to necessitate their conclusions; two of these, begging the question and non-cause are discussed in Prior Analytics (II, 16, 17). It is the “fallacious deductions” characterized in (4), however, that come closest to the focus of the Sophistical Refutations . Nevertheless, in many of the examples given what stands out is that the premises are given as answers in dialogue and are to be maintained by the answerer, not necessarily that they are dialectical in the sense of being common opinions. This variation on dialectical deductions Aristotle calls examination arguments ( SR 2 165b4).
2.1.2 The basic concepts
There are three closely related concepts needed to understand sophistical refutations. By a deduction (a syllogism [ 3 ] ) Aristotle meant an argument which satisfies three conditions: it “is based on certain statements made in such a way as necessarily to cause the assertion of things other than those statements and as a result of those statements” ( SR 1 165a1–2). Thus an argument may fail to be a syllogism in three different ways. The premises may fail to necessitate the conclusion, the conclusion may be the same as one of the premises, and the conclusion may not be caused by (grounded in) the premises. The concept of a proof underlying Sophistical Refutations is similar to what is demanded of demonstrative knowledge in Posterior Analytics (I ii 71b20), viz., that the premises must be “true, primary, immediate, better known than, prior to, and causative of the conclusion,” except that the first three conditions do not apply to deductions in which the premises are obtained through questioning. A refutation , Aristotle says, is “a proof of the contradictory” ( SR 6, 168a37)—a proof of the proposition which is the contradictory of the thesis maintained by the answerer. In a context of someone, S , maintaining a thesis, T , a dialectical refutation will consist in asking questions of S , and then taking S ’s answers and using them as the premises of a proof via a deduction of not-T : this will be a refutation of T relative to the answerer ( SR 8 170a13). The concept of contradiction can be found in Categories : it is those contraries which are related such that “one opposite needs must be true, while the other must always be false” (13b2–3). A refutation will be sophistical if either the proof is only an apparent proof or the contradiction is only an apparent contradiction. Either way, according to Aristotle, there is a fallacy. Hence, the opening of his treatise: “Let us now treat of sophistical refutations, that is, arguments which appear to be refutations but are really fallacies and not refutations” ( SR 1 164a20).
2.1.3 The appearance condition
Aristotle observed that “reasoning and refutation are sometimes real and sometimes not, but appear to be real owing to men’s inexperience; for the inexperienced are like those who view things from a distance” ( SR , 1 164b25). The ideas here are first that there are arguments that appear to be better than they really are; and second that people inexperienced in arguments may mistake the appearance for the reality and thus be taken in by a bad argument or refutation. Apparent refutations are primarily explained in terms of apparent deductions: thus, with one exception, Aristotle’s fallacies are in the main a catalogue of bad deductions that appear to be good deductions. The exception is ignoratio elenchi in which, in one of its guises, the deduction contains no fallacy but the conclusion proved only appears to contradict the answerer’s thesis.
Aristotle devotes considerable space to explaining how the appearance condition may arise. At the outset he mentions the argument that turns upon names ( SR 1 165a6), saying that it is the most prolific and usual explanation: because there are more things than names, some names will have to denote more than one thing, thereby creating the possibility of ambiguous terms and expressions. That the ambiguous use of a term goes unnoticed allows the illusion that an argument is a real deduction. The explanation of how the false appearance can arise is in the similarity of words or expressions with different meanings, and the smallness of differences in meaning between some expressions ( SR 7 169a23–169b17).
2.1.4 List and classification
Aristotle discusses thirteen ways in which refutations can be sophistical and divides them into two groups. The first group, introduced in Chapter 4 of On Sophistical Refutations , includes those Aristotle considers dependent on language ( in dictione ), and the second group, introduced in Chapter 5, includes those characterized as not being dependent on language ( extra dictionem ). Chapter 6 reviews all the fallacies from the view point of failed refutations, and Chapter 7 explains how the appearance of correctness is made possible for each fallacy. Chapters 19–30 advise answerers on how to avoid being taken in by sophistical refutations.
The fallacies dependent on language are equivocation, amphiboly, combination of words, division of words, accent and form of expression. Of these the first two have survived pretty much as Aristotle thought of them. Equivocation results from the exploitation of a term’s ambiguity and amphiboly comes about through indefinite grammatical structure. The one has to do with semantical ambiguity, the other with syntactical ambiguity. However, the way that Aristotle thought of the combination and division fallacies differs significantly from modern treatments of composition and division. Aristotle’s fallacies are the combinations and divisions of words which alter meanings, e.g., “walk while sitting” vs. “walk-while-sitting,” (i.e., to have the ability to walk while seated vs. being able to walk and sit at the same time). For division, Aristotle gives the example of the number 5: it is 2 and 3. But 2 is even and 3 is odd, so 5 is even and odd. Double meaning is also possible with those words whose meanings depend on how they are pronounced, this is the fallacy of accent, but there were no accents in written Greek in Aristotle’s day; accordingly, this fallacy would be more likely in written work. What Aristotle had in mind is something similar to the double meanings that can be given to ‘unionized’ and ‘invalid’ depending on how they are pronounced. Finally, the fallacy that Aristotle calls form of expression exploits the kind of ambiguity made possible by what we have come to call category mistakes, in this case, fitting words to the wrong categories. Aristotle’s example is the word ‘flourishing’ which may appear to be a verb because of its ‘ing’ ending (as in ‘cutting’ or ‘running’) and so belongs to the category of actions, whereas it really belongs in the category of quality. Category confusion was, for Aristotle, the key cause of metaphysical mistakes.
There are seven kinds of sophistical refutation that can occur in the category of refutations not dependent on language: accident, secundum quid , consequent, non-cause, begging the question, ignoratio elenchi and many questions.
The fallacy of accident is the most elusive of the fallacies on Aristotle’s list. It turns on his distinction between two kinds of predication, unique properties and accidents ( Top . I 5). The fallacy is defined as occurring when “it is claimed that some attribute belongs similarly to the thing and to its accident” ( SR 5 166b28). What belongs to a thing are its unique properties which are counterpredicable (Smith 1997, 60), i.e., if \(A\) is an attribute of \(B\), \(B\) is an attribute of \(A\). However, attributes that are accidents are not counterpredicates and to treat them as such is false reasoning, and can lead to paradoxical results; for example, if it is a property of triangles that they are equal to two right angles, and a triangle is accidentally a first principle, it does not follow that all first principles have two right angles (see Schreiber 2001, ch. 7).
Aristotle considers the fallacy of consequent to be a special case of the fallacy of accident, observing that consequence is not convertible, i.e., “if \(A\) is, \(B\) necessarily is, men also fancy that, if \(B\) is, \(A\) necessarily is” ( SR 5 169b3). One of Aristotle’s examples is that it does not follow that “a man who is hot must be in a fever because a man who is in a fever is hot” ( SR 5 169b19). This fallacy is sometimes claimed as being an early statement of the formal fallacy of affirming the consequent.
The fallacy of secundum quid comes about from failing to appreciate the distinction between using words absolutely and using them with qualification. Spruce trees, for example, are green with respect to their foliage (they are ‘green’ with qualification); it would be a mistake to infer that they are green absolutely because they have brown trunks and branches. It is because the difference between using words absolutely and with qualification can be minute that this fallacy is possible, thinks Aristotle.
Begging the question is explained as asking for the answer (the proposition) which one is supposed to prove, in order to avoid having to make a proof of it. Some subtlety is needed to bring about this fallacy such as a clever use of synonymy or an intermixing of particular and universal propositions ( Top . VIII, 13). If the fallacy succeeds the result is that there will be no deduction: begging the question and non-cause are directly prohibited by the second and third conditions respectively of being a deduction ( SR 6 168b23).
The fallacy of non-cause occurs in contexts of ad impossibile arguments when one of the assumed premises is superfluous for deducing the conclusion. The superfluous premise will then not be a factor in deducing the conclusion and it will be a mistake to infer that it is false since it is a non-cause of the impossibility. This is not the same fallacy mentioned by Aristotle in the Rhetoric (II 24) which is more akin to a fallacy of empirical causation and is better called false cause (see Woods and Hansen 2001).
Aristotle’s fallacy of many questions occurs when two questions are asked as if they are one proposition. A proposition is “a single predication about a single subject” ( SR 6 169a8). Thus with a single answer to two questions one has two premises for a refutation , and one of them may turn out to be idle, thus invalidating the deduction (it becomes a non-cause fallacy). Also possible is that extra-linguistic part-whole mistakes may happen when, for example, given that something is partly good and partly not-good, the double question is asked whether it is all good or all not-good? Either answer will lead to a contradiction (see Schreiber 2000, 156–59). Despite its name, this fallacy consists in the ensuing deduction, not in the question which merely triggers the fallacy.
On one interpretation ignoratio elenchi is considered to be Aristotle’s thirteenth fallacy, in which an otherwise successful deduction fails to end with the required contradictory of the answerer’s thesis. Seen this way, ignoratio elenchi is unlike all the other fallacies in that it is not an argument that fails to meet one of the criteria of a good deduction, but a genuine deduction that turns out to be irrelevant to the point at issue. On another reading, ignoratio elenchi is not a separate fallacy but an alternative to the language dependent / language independent way of classifying the other twelve fallacies: they all fail to meet, in one way or another, the requirements of a sound refutation.
[A] refutation is a contradiction of one and the same predicate, not of a name but of a thing, and not of a synonymous name but of an identical name, based on the given premises and following necessarily from them (the original point at issue not being included) in the same respect, manner and time. ( SR 5 167a23–27)
Each of the other twelve fallacies is analysed as failing to meet one of the conditions in this definition of refutation ( SR 6). Aristotle seems to favour this second reading, but it leaves the problem of explaining how refutations that miss their mark can seem like successful refutations. A possible explanation is that a failure to contradict a given thesis can be made explicit by adding the negation of the thesis as a last step of the deduction, thereby insuring the contradiction of the thesis, but only at the cost (by the last step) of introducing one of the other twelve fallacies in the deduction.
2.1.5 Different interpretations
I have given only the briefest possible explanation of Aristotle’s fallacies. To really understand them a much longer engagement with the original text and the secondary sources is necessary. The second chapter of Hamblin’s (1970) book is a useful introduction to the Sophistical Refutations , and a defence of the dialectical nature of the fallacies. Hamblin thinks that a dialectical framework is indispensable for an understanding of Aristotle’s fallacies and that part of the poverty of contemporary accounts of fallacies is due to a failure to understand their assumed dialectical setting. This approach to the fallacies is continued in contemporary research by some argumentation theorists, most notably Douglas Walton (1995) who also follows Aristotle in recognizing a number of different kinds of dialogues in which argumentation can occur; Frans van Eemeren and Rob Grootendorst (2004) who combine dialectical and pragmatic insights with an ideal model of a critical discussion; and Jaakko Hintikka who analyses the Aristotelian fallacies as mistakes in question-dialogues (Hintikka 1987; Bachman 1995.) According to Hintikka (1997) it is an outright mistake to think of Aristotle’s fallacies primarily as mistaken inferences, either deductive or inductive. A non-dialogue oriented interpretation of Aristotle fallacies is found in Woods and Hansen (1997 and 2001) who argue that the fallacies (apparent deductions) are basic to apparent refutations, and that Aristotle’s interest in the fallacies extended beyond dialectical contests, as is shown by his interest in them in the Prior Analytics and the Rhetoric (II 24). What gives unity to Aristotle’s different fallacies on this view is not a dialogue structure but rather their dependence on the concepts of deduction and proof. The most thorough recent study of these questions is in Schreiber (2003), who emphasizes Aristotle’s concern with resolving (exposing) fallacies and argues that it is Aristotelian epistemology and metaphysics that is needed for a full understanding of the fallacies in the Sophistical Refutations .
Francis Bacon deserves a brief mention in the history of fallacy theory, not because he made any direct contribution to our knowledge of the fallacies but because of his attention to prejudice and bias in scientific investigation, and the effect they could have on our beliefs. He spoke of false idols (1620, aphorisms 40–44) as having the same relation to the interpretation of nature that fallacies have to logic. The idol of the tribe is human nature which distorts our view of the natural world (it is a false mirror). The idol of the cave is the peculiarity of each individual man, our different abilities and education that affect how we interpret nature. The idols of the theatre are the acquired false philosophies, systems and methods, both new and ancient, that rule men’s minds. These three idols all fall into the category of explanations of why we may misperceive the world. A fourth of Bacon’s idols, the idol of the market place, is the one that comes closest to the Aristotelian tradition as it points to language as the source of our mistaken ideas: “words plainly force and overrule the understanding, and throw all into confusion, and lead men away into numberless empty controversies and idle fancies” (1620, aphorism 43). Although Bacon identifies no particular fallacies in Aristotle’s sense, he opens the door to the possibility that there may be false assumptions associated with the investigation of the natural world. The view of The New Organon is that just as logic is the cure for fallacies, so will the true method of induction be a cure for the false idols.
Antoine Arnauld and Pierre Nicole were the authors of Logic, or the Art of Thinking (1662), commonly known as the Port-Royal Logic. According to Benson Mates (1965, 214) it “is an outstanding early example of the ‘how to think straight’ genre.” The work includes chapters on sophisms, with the justification that “examples of mistakes to be avoided are often more striking than the examples to be imitated” (Bk. III, xix). The Port-Royal Logic does not continue Aristotle’s distinction between fallacies that are dependent on language and those that are not; instead there is a division between sophisms associated with scientific subjects (ibid.)—these are nearly all from the Sophistical Refutations —and those committed in everyday life and ordinary discourse (Bk III, xx). The division is not exclusive, with some of the sophisms fitting both classes.
The Port-Royal Logic includes eight of Aristotle’s original thirteen fallacies, several of them modified to fit the bent to natural philosophy rather than dialectical argumentation. Several kinds of causal errors are considered under the broad heading, non causa pro causa and they are illustrated with reference to scientific explanations that have assigned false causes for empirical phenomena. Also identified as a common fallacy of the human mind is post hoc, ergo propter hoc : “This happened following a certain thing, hence that thing must be its cause” (Bk. III, xix 3). Begging the questions is included and illustrated, interestingly, with examples drawn from Aristotelian science. Two new sophisms are included: one is imperfect enumeration, the error of overlooking an alternative, the other is a faulty (incomplete) induction, what we might call hasty generalization. Although the discussions here are brief, they mark the entry of inductive fallacies into the pool of present day recognized fallacies. Ignoratio elenchi retains its dialogical setting but is extended beyond the mere failure to contradict a thesis, “to attribut[ing] to our adversaries something remote from their views to gain an advantage over them, or to impute to them consequences we imagine can be drawn from their doctrines, although they disavow and deny them” (Bk. III, xix 1). The other Aristotelian fallacies included are accident, combination and division, secundum quid and ambiguity.
The sophisms of everyday life and ordinary discourse are eight in number and two of them, the sophisms of authority and manner, should be noticed. In these sophisms, external marks of speakers contribute to the persuasiveness of their arguments. Although authority is not to be doubted in church doctrines, in matters that God has left to the discernment of humans we can be led away from the truth by being too deferential. Here we find one of the earliest statements of the modern appeal to false authority: people are often persuaded by certain qualities that are irrelevant to the truth of the issue being discussed. Thus there are a number of people who unquestioningly believe those who are the oldest and most experienced, even in matters that depend neither on age nor experience, but only on mental insight (Bk. III, xx 6). To age and experience Arnauld and Nicole add noble birth as an unwarranted source of deference in matters intellectual (Bk. III, xx 7), and towards the end of their discussion they add the sophism of manner, cautioning that “grace, fluency, seriousness, moderation and gentleness” is not necessarily a mark of truth (Bk. III, xx 8). The authors seem to have the rhetorical flourishes of royal courtiers especially in mind.
It is John Locke who is credited with intentionally creating a class of ad -arguments, and inadvertently giving birth to the class of ad -fallacies. In An Essay Concerning Human Understanding (1690), he identified three kinds of arguments, the ad verecundiam , ad ignorantiam , and ad hominem arguments, each of which he contrasted with ad judicium arguments which are arguments based on “the foundations of knowledge and probability” and are reliable routes to truth and knowledge. Locke did not speak of ad -arguments as fallacies—that was left to others to do later—but rather as kinds of arguments “that men, in their reasoning with others, do ordinarily make use of to prevail on their assent; or at least so to awe them as to silence their opposition.” (Bk IV, xvii, 19–22).
Two of the ad arguments have developed beyond how Locke originally conceived them. His characterization of the ad verecundiam is considered the locus classicus of appeal-to-authority arguments. When it is a fallacy it is either on the ground that authorities (experts) are fallible or for the reason that appealing to authority is an abandonment of an individual’s epistemic responsibility. It seems unlikely, however, that Locke thought we should never rely on the expertise and superior knowledge of others when engaged in knowledge-gathering and argumentation. This leads us to consider what kind of authority Locke might have had in mind. In addition to epistemic and legal (command) authority there is also what might be called social authority, demanding respect and deference from others due to one’s higher social standing, something much more a part of seventeenth-century society than it is a part of ours. The language that Locke used in connection with the ad verecundiam , words like ‘eminency’, ‘dignity’, ‘breach of modesty’, and ‘having too much pride’ suggests that what he had in mind was the kind of authority that demands respect for the social standing of sources rather than for their expertise; hence, by this kind of authority a person could be led to accept a conclusion because of their modesty or shame, more so than for the value of the argument (see Goodwin 1998). Hence, we understand Locke better when we translate ad verecundiam literally, as “appeal to modesty.”
The argumentum ad hominem , as Locke defined it, has subsequently developed into three different fallacies. His original description was that it was a way “to press a man with consequences drawn from his own principles or concessions.” That is, to argue that an opponent’s view is inconsistent, logically or pragmatically, with other things he has said or to which he is committed. Locke’s observation was that such arguments do not advance us towards truth, but that they can serve to promote agreement or stall disagreement. To argue that way is not a fallacy but an acceptable mode of argumentation. Henry Johnstone (1952) thought it captured the essential character of philosophical argumentation. The modern descendants of the Lockean ad hominem are the abusive ad hominem which is an argument to the effect that a position should not be accepted because of some telling negative property of its espouser; the circumstantial ad hominem , an argument to the effect that someone’s position should be rejected because circumstances suggest that their view is the result of self-interested bias; and finally, the tu quoque ad hominem argument which attempts to deflect a criticism by pointing out that it applies equally to the accuser. Recent scholarship suggests that these post-Lockean kinds of ad hominem arguments are sometimes used fairly, and sometimes fallaciously; but none of them is what Locke described as the argumentum ad hominem .
Ad ignorantiam translates as “appeal to ignorance.” Locke’s characterization of this kind of argument is that it demands “the adversary to admit what they allege as a proof, or to assign a better.” The ignorance in question is comparative, it is not that the opponent has no evidence, it is that s/he has no better evidence. However, the inability of an opponent to produce a better argument is not sufficient reason to think the proponent’s argument must be accepted. Modern versions of this kind of argument take it as a fallacy to infer a proposition to be true because there is no evidence against it (see Krabbe, 1995).
The introduction and discussion of the ad -arguments appears almost as an afterthought in Locke’s Essay . It is found at the end of the chapter, “Of Reason,” in which Locke devotes considerable effort to criticizing syllogistic logic. Reasoning by syllogisms, he maintained, was neither necessary nor useful for knowledge. Locke clearly thought that the three ad -arguments were inferior to ad judicium arguments, but he never used the term ‘fallacy’ in connection with them, although he did use it in connection with errors of syllogistic reasoning.
Was Locke the first to discuss these kinds of arguments? Hamblin (1970, 161–62) and Nuchelmans (1993) trace the idea of ad hominem arguments back to Aristotle, and Locke’s remark that the name argumentum ad hominem was already known has been investigated by Finocchiaro (1974) who finds the term and the argument kind in Galileo’s writings more than a half-century before the Essay Concerning Human Understanding . And Arnauld and Nicole’s discussion of the sophism of authority, that “people speak the truth because they are of noble birth or wealthy or in high office,” which seems to be part of Locke’s ad verecundiam , was most likely known to him. Subsequently more ad -arguments were added to the four that Locke identified (see Watts, and Copi, below).
Isaac Watts in his Logick; or, The Right Use of Reason (1724), furthered the ad -argument tradition by adding three more arguments: argumentum ad fidem (appeal to faith), argumentum ad passiones (appeal to passion), and argumentum ad populum (a public appeal to passions). Like Locke, Watts does not consider these arguments as fallacies but as kinds of arguments. However, the Logick does consider sophisms and introduces “false cause” as an alternative name for non causa pro causa which here, as in the Port-Royal Logic, is understood as a fallacy associated with empirical causation. According to Watts it occurs whenever anyone assigns “the reasons of natural appearances, without sufficient experiments to prove them” (1796, Pt. III, 3 i 4). Another sophism included by Watts is imperfect enumeration or false induction, the mistake of generalizing on insufficient evidence. Also, the term ‘strawman fallacy’ may have its origins in Watts’s discussion of ignoratio elenchi : after having dressed up the opinions and sentiments of their adversaries as they please to make “images of straw”, disputers “triumph over their adversary as though they had utterly confuted his opinions” (1796, Pt. III 3 i 1).
Jeremy Bentham’s Handbook of Political Fallacies (1824) was written in the years leading up to the first Reform Bill (1832). His interest was in political argumentation, particularly in exposing the different means used by parliamentarians and law makers to defeat or delay reform legislation. Hence, it was not philosophy or science that interested him, but political debate. Fallacies he took to be arguments or topics that would through the use of deception produce erroneous beliefs in people (1824, 3). These tactics he (or his editor) divided into four classes: fallacies of authority, danger, delay and confusion. Bentham was aware of the developing ad -fallacies tradition since each of the thirty or so fallacies he described is also labelled as belonging either to the kind ad verecundiam (appeal to shame or modesty), ad odium (appeal to hate or contempt), ad metum (appeal to fear or threats), ad quietem (appeal to rest or inaction), ad judicium , and ad socordiam (appeal to postponement or delay). Most of Bentham’s fallacies have not become staples of fallacy theory but many of them show interesting insights into the motives and techniques of debaters (see e.g., Rudanko’s (2021) analyses of the ad socordiam ).
Bentham’s Handbook has not taken a central place in the history of fallacy studies (Hamblin 1970, 165–69); nevertheless, it is historically interesting in several respects. It discusses authority at length, identifying four conditions for reliable appeals to authority and maintaining that the failure of any one of them cancels the strength of the appeal. Fallacies of authority in political debate occur when authority “is employed in the place of such relevant arguments as might have been brought forward” (1824, 25). Bentham’s fear is that debaters will resort to “the authority” of traditional beliefs and principles instead of considering the advantages of the reform measures under discussion.
Under the heading “fallacies of danger” Bentham named a number of what he called vituperative fallacies—imputations of bad character, bad motive, inconsistency, and suspicious connections—which have as their common characteristic, “the endeavour to draw aside attention from the measure to the man , in such a way as to cause the latter’s badness to be imputed to the measure he supports, or his goodness to his opposition” (1824, 83). This characterization fits well with the way we have come to think of the ad hominem fallacy as a view disparaged by putting forth a negative characterization of its supporter or his circumstances.
Bentham places the fallacies in the immediate context of debate, identifying ways in which arguers frustrate the eventual resolution of disagreements by using insinuations of danger, delaying tactics, appeals to questionable authorities and, generally, confusing issues. Modern argumentation theorists who hold that any impediment to the successful completion of dialogical discussions is a fallacy, may find that their most immediate precursor was Bentham (see Grootendorst 1997).
Book III of Richard Whately’s Elements of Logic (1826) is devoted to giving an account of fallacies based on “logical principles,”. Whately was instrumental in the revival of interest in logic at the beginning of the nineteenth century and, being committed to deductivism, he maintained that only valid deductive inferences counted as reasoning. Thus, he took every fallacy to belong to either the class of deductive failures (logical fallacies) or the class of non-logical failures (material fallacies).
By ‘fallacy’ Whately meant “any unsound mode of arguing, which appears to demand our conviction, and to be decisive of the question at hand, when in fairness it is not”’ (Bk. III, intro.). The logical fallacies divide into the purely logical and the semi-logical fallacies. The purely logical fallacies are plain violations of syllogistic rules like undistributed middle and illicit process. The semi-logical fallacies mostly trade on ambiguous middle terms and are therefore also logical fallacies, but their detection requires extra-logical knowledge including that of the senses of terms [ 4 ] and knowledge of the subject matter (Bk. III, §2); they include, among others, the fallacies of ambiguity, and division and composition. The non-logical, material fallacies are also divided into two classes: fallacies with premises ‘unduly assumed,’ and fallacies of irrelevant conclusions. Begging the question fits under the heading of a non-logical, material fallacy in which a premise has been unduly assumed, and ignoratio elenchi is a non-logical, material fallacy in which an irrelevant conclusion has been reached. The ad -arguments are all placed under the last division as variants of ignoratio elenchi , but they are said to be fallacies only when they are used unfairly. Whately’s version of the ad hominem argument resembles Locke’s in that it is an ex concessis kind of argument: one that depends on the concessions of the person with whom one is arguing. From the concessions, one might prove that one’s opponent is ‘committed to p, ’ but an attempt to make it seem as if this constitutes a proof of the absolute (non-relative) proposition ‘ p ’ would be a fallacy. This kind of ad hominem fallacy can be seen as falling under the broader ignoratio elenchi category because what is proved is not what is needed.
The creation of the category of non-logical fallacies was not really a break with Aristotle as much as it was a break with what had become the Aristotelian tradition. Aristotle thought that some fallacies were due to unacceptable premises although these are not elaborated in Sophistical Refutations (see section 2.1.1 above). Whately’s creation of the category of non-logical fallacies solved the problem of what to do with begging the question which is not an invalid form of argument, and it also created a place in fallacy taxonomy for the ad -fallacies.
John Stuart Mill’s contribution to the study of fallacies is found in Book V of his comprehensive A System of Logic, Ratiocinative and Inductive , first published in 1843. It stands out most strikingly for placing the study of fallacies within his framework of inductive reasoning, a direct rejection of Whately’s deductivist approach to reasoning and fallacies. Mill held that only inductive reasoning counts as inferring and accordingly he introduces new categories as well as a new classification scheme for fallacies.
Mill drew a division between the moral and the intellectual causes of fallacies. The former are aspects of human nature such as biases and indifference to truth which incline us to make intellectual mistakes. These dispositions are not themselves fallacies. It is the intellectual errors, the actual taking of insufficient evidence as sufficient, that are fallacious. The various ways in which this can happen are what Mill took as the basis for classifying fallacies. “A catalogue of the varieties of evidence which are not real evidence,” he wrote, “is an enumeration of fallacies” (1891, Bk.V iii §1).
Mill divided the broad category of argument fallacies into two groups: those in which the evidence is distinctly conceived and those in which it is indistinctly conceived. Fallacies falling under evidence indistinctly conceived (Bk. V, vii) were further described as fallacies of confusion. These result from an indistinct conception of the evidence leading to a mistaking of its significance and thereby to an unsupported conclusion. Some of the traditional Aristotelian fallacies such as ambiguity, composition and division, petitio principii , and ignoratio elenchi , are placed in this category. Although Mill followed Whately closely in his exposition of the fallacies of confusion, he does not mention any ad -arguments in connection with ignoratio elenchi .
As for the category of fallacies of evidence distinctly conceived, it too is divided. The two sub-classes are fallacies of ratiocination (deduction) and fallacies of induction. The deductive fallacies (Bk.V, vi) are those that explicitly break a rule of the syllogism, such as the three-term rule. But also included are the conversion of universal affirmatives and particular negatives (“All PS” does not follow from “All SP,” and “Some P not S” does not follow from “Some S not P”). Also included in this category is the secundum quid fallacy.
The other sub-class of fallacies distinctly conceived bring out what is distinctive about Mill’s work on the fallacies: that it is the first extensive attempt to deal with fallacies of induction. He divided inductive fallacies into two further groups: fallacies of observation (V, iv) and fallacies of generalization (Bk. V, v). Fallacies of observation can occur either negatively or positively. Their negative occurrence consists in non-observation in which one has overlooked negatively relevant evidence. This is similar to what the Port-Royal Logic considered a faulty enumeration, and one of Mill’s examples is the continued faith that farmers put in the weather forecasts found in almanacs despite their long history of false predictions. Observation fallacies occur positively when the mistake is based on something that is seen wrongly, i.e., taken to be something that it is not. Such mal-observations occur when we mistake our inferences for facts, as in our inference that the sun rises and sets (Bk. V, iv, 5).
Fallacies of generalization, the other branch of inductive fallacies, result from mistakes in the inductive process which can happen in several ways. As one example, Mill pointed to making generalizations about what lies beyond our experience: we cannot infer that the laws that operate in remote parts of the universe are the same as those in our solar system (Bk. V, v, 2). Another example is mistaking empirical laws stating regularities for causal laws—his example was because women as a class have not hitherto equalled men as a class, they will never be able to do so (Bk. V, v, 4). Also placed in the category of fallacies of generalization is post hoc ergo propter hoc , which tends to single out a single cause when there are in reality many contributing causes (Bk. V, v, 5). Analogical arguments are identified as a false basis for generalizations; they are “at best only admissible as an inconclusive presumption, where real proof is unattainable” (Bk. V, v, 6).
Mill also included what he calls fallacies of inspection, or a priori fallacies (Bk. V, iii) in his survey of fallacies. These consist of non-inferentially held beliefs, so they fit the belief conception of fallacies rather than the argument conception. Among Mill’s examples of a priori fallacies are metaphysical assumptions such as that distinctions of language correspond to distinctions in nature, and that objects cannot affect each other at a distance. Even the belief in souls or ghosts is considered an a priori fallacy. Such beliefs will not withstand scrutiny, thought Mill, by the inductive method strictly applied.
A System of Logic is the most extensive work on fallacies since Aristotle’s Sophistical Refutations . Mill’s examples are taken from a wide range of examples in science, politics, economics, religion and philosophy. His classificatory scheme is original and comprehensive. Frederick Rosen (2006) argues that Mill’s pre-occupation with the detection and prevention of fallacies is part of what motivates the celebrated second chapter of On Liberty . Despite these considerations, the Logic is not much referenced by fallacy theorists.
In a series of articles and books beginning in 1878 and continuing well into the twentieth century, Alfred Sidgwick wrote repeatedly about fallacies. Unlike Whately and Mill who thought that searching for fallacies was a supplement to their logical methods (deduction and induction, respectively), Sidgwick wanted to put argument evaluation by fallacies at the centre of logic. In his view, the negative method of evaluating arguments by searching them for fallacies is a more practical and efficient way of judging arguments in actual life than the positive method of trying to match arguments with the positive standards of formal logic. His earliest proposal (1878) was to pass arguments through a sieve, or filter, which would eliminate arguments if they had the marks of any of the fallacies. Sidgwick placed the category of fallacies of confusion (those due to ambiguity or vagueness), including ignoratio elenchi , at the top of the sieve. At the next level down is petitio principii and arguments from occult causes, and below that fallacies of ratiocination (deductive, syllogistic fallacies) and inductive reasoning. An argument that succeeds in passing all the way through the sieve should be considered logically good. He thought most fallacies would be revealed at the top level as fallacies of confusion.
Sidgwick’s contribution is not to the definition of fallacies, nor to the identification of new fallacies, but rather to his promotion of the idea, worked out in some detail in Fallacies: A view of logic from the practical side (1884), that a systematic search for fallacy mistakes could be a comprehensive and practical method of evaluating arguments found in daily life. He was one of the first to argue that the new mathematical interpretations of logic being advanced in the second-half of the nineteenth century could not do justice to natural language arguments, and he was also an advocate for reform in how logic should be taught so as to make it practically valuable to students. Although Sidgwick’s work is little known today, it is fair to say that he anticipated many of the concerns that would occupy informal logic a hundred years later.
Irving Copi’s Introduction to Logic —an influential text book from the mid-twentieth century—defines a fallacy as “a form of argument that seems to be correct but which proves, upon examination, not to be so.” (1961, 52) The term ‘correct’ is sufficiently broad to allow for both deductive invalidity, inductive weakness, as well as some other kinds of argument failure. Of the eighteen informal fallacies Copi discusses, eleven can be traced back to the Aristotelian tradition, and the other seven to the burgeoning post-Lockean ad -fallacy tradition.
The first division in Copi’s classification is between formal and informal fallacies. Formal fallacies are invalid inferences which “bear a superficial resemblance” to valid forms of inference, so these we may think of as deductive fallacies. They include affirming the consequent, denying the antecedent, the fallacy of four terms, undistributed middle, and illicit major. Informal fallacies are not characterized as resembling formally valid arguments; they gain their allure some other way. One division of informal fallacies is the fallacies of relevance which are “errors in reasoning into which we may fall because of carelessness and inattention to our subject matter” (1961, 53). This large class of fallacies includes accident, converse accident, false cause, petitio principii , complex question, ignoratio elenchi , ad baculum , ad hominem abusive, ad hominem circumstantial, ad ignorantiam , ad misericordiam , ad populum , and ad verecundiam . The other division of informal fallacies is called fallacies of ambiguity and it includes equivocation, amphiboly, accent, composition and division.
It seems that Copi took Whately’s category of semi-logical fallacies and moved them under a new heading of ‘informal fallacies,’ presumably for the reason that extra-logical knowledge is needed to uncover their invalidity. This has the result that the new wide category of informal fallacies is a mixed bag: some of them are at bottom logical failures (equivocation, composition, ad misericordiam ) and some are logically correct but frustrate proof (begging the question, ignoratio elenchi ). [ 5 ] Copi’s classification, unlike Whately’s which sought to make a distinction on logical grounds, may be seen as based on three ways that fallacies resemble good arguments: formal fallacies have invalid forms that resemble valid forms, fallacies of ambiguity resemble good arguments through the ambiguity of terms, and fallacies of relevance exploit psychological (non-logical) associations. Hence, we may think of Copi’s divisions as between logical, semantic and psychological fallacies.
Copi’s treatment of the fallacies is a fair overview of the traditional list of fallacies, albeit he did not pretend to do any more than give an introduction to existing fallacy-lore for beginning logic students. Hamblin (1970, ch. 1) criticized Copi’s work, along with that of several others, and gave it the pejorative name, “the standard treatment of fallacies.” His criticisms rang true with many of his readers, thereby provoking contempt for the traditional treatment of fallacies as well as stimulating research in what we may call the new, or post-Hamblin, era, of fallacy studies. Let us next consider some of these developments.
3. New approaches to fallacies
A common complaint since Whately’s Elements of Logic is that our theory and teaching of fallacies are in want of improvement—he thought they should be put on a more logical footing to overcome the loose and vague treatments others had proffered.
It is on Logical principles therefore that I propose to discuss the subject of Fallacies. … the generality of Logical writers have usually followed so opposite a plan. Whenever they have to treat of anything that is beyond the mere elements of Logic, they totally lay aside all reference to the principles they have been occupied in establishing and explaining, and have recourse to a loose, vague, and popular kind of language … [which is] … strangely incongruous in a professional Logical treatise. (1875, III, intro.)
Charles Hamblin’s 1970 book, Fallacies , revives Whately’s complaint. We may view Fallacies as the dividing line between traditional approaches to the study of fallacies and new, contemporary approaches. At the time of its publication it was the first book-length work devoted to fallacies in modern times. The work opens with a critique of the standard treatment of fallacies as it was found in mid-twentieth century textbooks; then, in subsequent chapters, it takes a historical turn reviewing Aristotle’s approach to fallacies and exploring the tradition it fostered (as in the previous section of this entry). Other historically-oriented chapters include one on the Indian tradition, and one on formal fallacies. Hamblin’s more positive contributions to fallacy studies are concentrated in the book’s later chapters on the concept of argument, formal dialectics, and equivocation.
What Hamblin meant by “the standard treatment of fallacies” was:
The typical or average account as it appears in the typical short chapter or appendix of the average modern textbook. And what we find in most cases, I think it should be admitted, is as debased, worn-out and dogmatic a treatment as could be imagined—incredibly tradition bound, yet lacking in logic and in historical sense alike, and almost without connection to anything else in modern Logic at all. (1970, 12)
Let us consider what came before Hamblin as the traditional approach to fallacies and what comes after him as new approaches. The new approaches (since the 1970’s) show a concern to overcome Hamblin’s criticisms, and they also vie with each to produce the most defensible alternative to the traditional approach. One thing that nearly all the new approaches have in common is that they reject what Hamblin presents as the nearly universally accepted definition of “fallacy” as an argument “that seems to be valid but is not so” (1970, 12). Although this definition of fallacy is not nearly as widely accepted as Hamblin intimated (see Hansen 2002), others have taken to calling it “the standard definition of fallacies” and for convenience we can refer to it as SDF. SDF has three necessary conditions: a fallacy (i) is an argument, (ii) that is invalid, and (iii) appears to be valid. These can be thought of as the argument condition, the invalidity condition and the appearance condition. All three conditions have been brought into question.
Maurice Finocchiaro continued Hamblin’s criticism of the modern textbook treatment of fallacies, observing that they contain very few examples of actual fallacies, leading him to doubt the validity of ‘fallacy’ as a genuine logical category. Although he allows that errors in reasoning are common in real life, he thinks that “types of logically incorrect arguments”—fallacies—are probably not common (1981, 113). For that reason Finocchiaro prefers to speak of fallacious arguments —by which he means arguments in which the conclusion fails to follow from the premises—rather than fallacies (1987, 133). He further distances himself from SDF by not considering the appearance condition.
Finocchiaro distinguishes six ways in which arguments can be fallacious. (1) Formal fallaciousness is simply the case where the conclusion does not follow validly from the premises; this type of error can be demonstrated by producing a suitable analogous counter-example in which the premises are true and the conclusion is false. (2) Explanatory fallaciousness occurs when a specified conclusion follows with no more certainty from the given premises than does a rival conclusion; it occurs most often in the context of proposing explanatory hypotheses. (3) Presuppositional fallaciousness occurs in those cases where an argument depends on a false presupposition; this kind of fallaciousness is demonstrated by making a sound argument showing the presupposition to be false. (4) Positive fallaciousness occurs when the given premises, complemented by other propositions taken as true, are shown to support a conclusion inconsistent with the given conclusion. (5) Semantical fallaciousness results from the ambiguity of terms; the conclusion will follow if the sense given to the term in the premises makes the premises false, but if the other sense is ascribed to the term, making the premises true, the conclusion does not follow (it becomes an instance of formal fallaciousness). (6) Finally, Finocchiaro singles out persuasive fallaciousness , in which the conclusion does not follow from the premises because it is the same as one of the premises. As a test of completeness of this six-fold division of fallaciousness, Finocchiaro (1987) observes that it is adequate to classify all the kinds of errors which Galileo found in the arguments of the defenders of the geocentric view of the solar system.
Gerald Massey (1981) has voiced a strong objection to fallacy theory and the teaching of fallacies. He argues that there is no theory of invalidity—no systematic way to show that an argument is invalid other than to show that it has true premises and a false conclusion (1981, 164). Hence, there is an asymmetry between proving arguments valid and proving them invalid: they are valid if they can be shown to be an instance of a valid form, but they are not proved invalid by showing that they are an instance of an invalid form, because both valid and invalid arguments instantiate invalid forms. Thus, showing that a natural language argument is an instance of an invalid form does not preclude the possibility that it is also an instance of a valid form, and therefore valid. Since upholders of SDF maintain that fallacies are invalid arguments, Massey’s asymmetry thesis has the consequence that no argument can be convicted of being a fallacy on logical grounds. [ 6 ]
The informal logic approach to fallacies is taken in Johnson and Blair’s Logical Self-Defense , a textbook first published in 1977. It was prompted in part by Hamblin’s indictment of the standard treatment and it further develops an initiative taken by Kahane (1971) to develop university courses that were geared to everyday reasoning. Johnson and Blair’s emphasis is on arming students to defend themselves against fallacies in everyday discourse, and a fundamental innovation is in their conception of a good argument. In place of a sound argument—a deductively valid argument with true premises—Johnson and Blair posit an alternative ideal of a cogent argument , one whose premises are acceptable, relevant to and sufficient for its conclusion. Acceptability replaces truth as a premise requirement, and the validity condition is split in to two different conditions, premise relevance and premise sufficiency. Acceptability is defined relative to audiences—the ones for whom arguments are intended—but the other basic concepts, relevance and sufficiency, although illustrated by examples, remain as intuitive, undefined concepts (see Tindale, 2007). Premise sufficiency (strength) is akin to probability in that it is a matter of degree but Johnson and Blair do not pursue giving it numerical expression.
The three criteria of a cogent argument, individually necessary and jointly sufficient, lead to a conception of fallacy as “any argument that violates one of the criteria of good argument … and is committed frequently in argumentative discourse” (1993, 317–18). This shares only one condition with SDF: that a fallacy is an argument. (Deductive) validity is replaced with the broader concept sufficiency, and the appearance condition is not included. Johnson (1987) argued that the appearance condition makes the occurrence of fallacies too subjective since how things appear may vary from perceiver to perceiver, and it should therefore be replaced by a frequency requirement. To be a fallacy, a mistake must occur with sufficient frequency to be worth our attention.
The adoption of the concept of a cogent argument as an ideal has several consequences. The category of fallacies with problematic premises (reminiscent of Whately’s “premises unduly assumed”) shows a concern with argument evaluation over and beyond logical or inference evaluation, drawing the informal logic approach away from purely logical concerns towards an epistemic conception of fallacies. Having both sufficiency and relevance as criteria (instead of the single validity criterion) has the benefit of allowing the making of nuanced judgments about the level of premise support: for example, we might say that an argument’s premises, although insufficient, are nevertheless positively relevant to the conclusion. Irrelevant premise fallacies are those with no premise support at all, whereas insufficient premise fallacies are those in which there is some support, but not enough of it. The informal logicians’ conception of fallacies is meant to be broader and more suitable to natural language argumentation than would be a conception tied only to deductive invalidity.
Johnson and Blair concern themselves exclusively with informal fallacies. Many of the familiar Aristotelian fallacies that are part of the standard treatment are missing from their inventory (e.g., accident, composition and division) and the ones retained find themselves in new categories: begging the question and ambiguity are together under the heading of Problematic Premise; appeals to authority and popularity are placed under the heading of Hasty Conclusion fallacies; ad hominem is among the fallacies that belong in the third category, Fallacies of Irrelevant Reason. This new list of fallacies has a different bent than many earlier lists, being more geared to deal with arguments in popular, everyday communication than philosophical or scientific discourse; this is evident both by the omission of some of the traditional fallacies as well as by the introduction of new ones, such as dubious assumption, two wrongs, slippery slope, and faulty analogy.
The kinds of mistakes one can make in reasoning are generally thought to be beyond enumeration and, hence, it has been maintained that there can be no complete stock of fallacies that will guard against every kind of mistake. Johnson and Blair’s approach is responsive to this problem in that it allows the names of the classes of fallacies — ‘unacceptable premise,’ ‘irrelevant reason’ and ‘hasty conclusion’ — to stand for fallacies themselves, fallacies broad-in-scope; i.e., to serve “both as general principles of organization, and as back-ups to fill in any gaps between specific labels belonging within each genus” (1993, 52). Hence, any violation of one of the criteria of a cogent argument can be considered a fallacy.
In addition to this alternative theoretical approach to fallacies built on the three criteria of a cogent argument—an approach also taken up by others [ 7 ] —informal logic’s contribution to fallacy studies lies in its attempts to provide better analyses of fallacies, a programme pursued by a large number of researchers, including Govier (1982) on the slippery slope, Wreen (1989) on the ad baculum , Walton (1991) on begging the question, Brinton (1995) on the ad hominem , Freeman (1995) on the appeal to popularity, Pinto (1995) on post hoc ergo propter hoc and Finocchiaro (2023) on the fallacy of composition.
John Woods also despairs of the standard treatment but he sees in it something of importance; namely that the fallacies most often reviewed in introductory level logic textbooks “are a kind of caricature of their associated improprieties, which lie deeply imbedded in human practice” (Woods 1992, 25). The fallacies are then behavioural symptoms of kinds of irrationality to which humans are highly susceptible, and that makes them an important subject for study because they say something about human nature. Therefore, the problem with the standard treatment, according to Woods, is not that it is a misdirected research programme, but rather that it has been poorly carried out, partly because logicians have failed to appreciate that a multi-logical approach is necessary to understand the variety of fallacies. This idea, pursued jointly by Woods and Douglas Walton (1989), is that, for many of the fallacies standard formal logic is inadequate to uncover the unique kind of logical mistakes in question—it is too coarse conceptually to reveal the unique character of many of the fallacies. To get a satisfactory analysis of each of the fallacies they must be matched with a fitting logical system, one that has the facility to uncover the particular logical weakness in question. Inductive logic can be employed for analysis of hasty generalization and post hoc ergo propter hoc ; relatedness logic is appropriate for ignoratio elenchi ; plausible reasoning theory for the ad verecundiam , and dialectical game theory for begging the question and many questions. Woods (1992, 43) refers to this approach to studying the fallacies as methodological pluralism. Thus, like the informal logicians, there is here an interest in getting the analyses of each of the fallacies right, but the Woods and Walton approach involves embracing formal methods, not putting them aside.
Woods (2013) has continued his research on fallacies, most recently considering them in the context of what he calls a naturalized logic (modelled on Quine’s naturalized epistemology). The main point of this naturalizing move is that a theory of reasoning should take into account the abilities and motivations of reasoners. Past work on the fallacies has identified them as failing to satisfy the rules of either deductive or inductive logic, but Woods now wants to consider the core fallacies in light of what he calls third-way reasoning (comparable to non-monotonic reasoning), an account of the cognitive practices that closely resemble our common inferential practices. From the perspective of third-way reasoning the “rules” implicit in the fallacies present themselves as heuristic directives to reasoners rather than as fallacies; hence, it may be that learning from feedback (having errors corrected) is less trouble than learning the rules to avoid fallacies in the first place (Woods 2013, p. 215). Woods illustrates his point by recalling many of the fallacies he originally identified in his 1992 paper, and subjecting them to this revised model of analysis thereby overturning the view that these types of argument are always to be spurned.
SDF may be seen as closely tied to the logical approach to fallacies—the fault in arguments it singles out is their deductive invalidity. But this conception of fallacies turns out to be inadequate to cover the variety of the core fallacies in two ways: it is too narrow because it excludes begging the question which is not invalid, and it is too wide because it condemns good but non-deductive arguments as fallacies (given that they also satisfy the appearance condition) because they are invalid. Even if we replace the invalidity condition in SDF with some less stringent standard of logical weakness which could overcome the “too wide” problem, it would still leave the difficulty of accounting for the fallacy of begging the question unsolved.
Siegel and Biro (1992, 1995) hold an epistemic account of fallacies, contrasting their view with dialectical/rhetorical approaches, because matters extraneous to arguments, such as being a practice that leads to false beliefs or not being persuasive, are not in their view a sufficient condition to make an argument a fallacy. They take the position that “it is a conceptual truth about arguments that their central … purpose is to provide a bridge from known truths or justified beliefs to as yet unknown … truths or as yet unjustified beliefs” (1992, 92). Only arguments that are “epistemically serious” can accomplish this; that is, only arguments that satisfy the extra-formal requirement that premises are knowable independently of their conclusions, and are more acceptable epistemically than their conclusions, can fulfill this function. A purely logical approach to argument will not capture this requirement because arguments of the same valid form, but with different contents, may or may not be epistemically serious, depending on whether the premises are epistemically acceptable relative to the conclusion.
Modifying Biro’s (1977, 265–66) examples we can demonstrate how the requirement of epistemic seriousness plays out with begging the question. Consider these two arguments:
All men are mortal; Obama is a man; So, Obama is mortal.
All members of the committee are old Etonians; Fortesque is a member of the committee; Fortesque is an old Etonian.
In the first argument the premises are knowable independently of the conclusion. The major premise can be deduced from other universal premises about animals, and the minor premise, unlike the conclusion which must be inferred, can be known by observation. Hence, this argument does not beg the question. However, in the second argument (due to Biro, 1977) given the minor premise, the major cannot be known to be true unless the conclusion is known to be true. Consequently, on the epistemic approach to fallacies taken by Biro and Siegel, the second argument, despite the fact that it is valid, is non-serious, it begs the question, and it is a fallacy. If there was some independent way of knowing whether the major premise was true, such as that it was a bylaw that only old Etonians could be committee members, the argument would be a serious one, and not beg the question.
Biro and Siegel’s epistemic account of fallacies is distinguishable in at least three ways. First, it insists that the function of arguments is epistemic, and therefore anything that counts as a fallacy must be an epistemic fault, a breaking of a rule of epistemic justification. But since logical faults are also epistemic faults, the epistemic approach to fallacies will include logical fallacies, although these must also be explicable in terms of epistemic seriousness. Second, since the epistemological approach does not insist that all justification must be deductive, it allows the possibility of their being fallacies (as well as good arguments) by non-deductive standards, something precluded by SDF. Finally, we notice that the appearance condition is not considered a factor in this discussion of fallacies.
Ulrike Hahn and Mike Oaksford (2006a, 2006b) see themselves as contributing to the epistemic approach to fallacy analysis by developing a probabilistic analysis of the fallacies. It is part of their programme for a normative theory of natural language argumentation. They are motivated by what they perceive as the shortcomings in other approaches. The logical (deductive) approach falls short in that it simply divides arguments into valid and invalid arguments thereby failing to appreciate that natural language arguments come in various degrees of strength. The alternative approaches to fallacies, given by procedural (dialectical) and consensual accounts, they criticize on the basis that they fail to address the central problem raised by the fallacies: that of the strength of the reason-claim complex. In Hahn and Oaksford’s view the strength or weakness of the classical fallacies (they are concerned mostly with the post-Aristotelian ones) is not a result of their structure or their context of use. It is instead a matter of the relationship between the evidence and the claim (the contents of the premises and the conclusion). Evaluation of this relationship is thought to be best captured by a probabilistic Bayesian account; accordingly, they adapt Bayes’ theorem to arguments evaluation with the proviso that the probabilities are subjective degrees of belief, not frequencies. “An argument’s strength,” they write, “is a function of an individual’s initial level of belief in the claim, the availability and observation of confirmatory (or disconfirmatory) evidence, and the existence and perceived strength of competing hypotheses” (Corner, et al. 1145). With Korb (2003) they view a fallacy as an argument with a low probability on the Bayesian model.
Since the variance in input probabilities will result in a range of outputs in argument strength, this probabilistic approach has the potential to assign argument strengths anywhere between 0 and 1, thereby allowing that different tokens of one argument type can vary greatly in strength, i.e., some will be fallacies and others not. Also, and this seems to concur with our experience, different arguers may disagree on the strength of the same arguments since they can differ in the assignments of the initial probabilities. Hahn and Oaksford also claim as advantages for their normative theory that it gives guidance for persuasion since it takes into account the initial beliefs of audiences. Moreover, their approach contributes to the study of belief change; that is, to what extent our confidence in the conclusion changes with the availability of new evidence.
Some of the most active new researchers on fallacies take a dialectical and/or dialogical approach. This can be traced back to Hamblin (1970, ch. 8) and Lorenzen’s (1969) dialogue theory. The panacea for fallacies that Whately recommended was more logic; Hamblin, however, proposed a shift from the logical to the dialectical perspective.
[W]e need to extend the bounds of Formal Logic; to include features of dialectical contexts within which arguments are put forward. To begin with, there are criteria of validity of argument that are additional to formal ones: for example, those that serve to proscribe question-begging. To go on with, there are prevalent but false conceptions of the rules of dialogue, which are capable of making certain argumentative moves seem satisfactory and unobjectionable when, in fact, they conceal and facilitate dialectical malpractice. (Hamblin 1970, 254)
The proposal here is to shift the study of fallacies from the contexts of arguments to the contexts of dialogues (argumentation), formulate rules for reasonable dialogue activity, and then connect fallacies to failures of rule-following. Barth and Martens’s paper (1977), which studied the argumentum ad hominem by extending Lorenzen’s dialogue tableaux method to include the definitions of the concepts “line of attack” and “winning strategy,” leads to a conception of fallacies as either failures to meet one of the necessary conditions of rational dialogical argumentation, or failures to satisfy sufficient conditions as specified by production rules of the dialogical method (1977, 96).
The Barth and Martens paper is a bridge between the earlier (quasi-) formal and subsequent informal dialectical theories, and is explicitly acknowledged as a major influence by the Pragma-dialectical theory, the brainchild of Frans van Eemeren and Rob Grootendorst (1984). Rather than beginning from a logical or epistemological perspective they start with the role of argumentation in overcoming interpersonal disagreements. The Pragma-dialecticians propose that inter-personal argumentation can be analysed as two-party-discussions having four analytical stages: a confrontation stage in which the participants become aware of the content of their disagreement; an opening stage in which the parties agree (most likely implicitly) to shared starting points and a set of rules to govern the ensuing discussion; an argumentation stage wherein arguments and doubts about arguments are expressed and recognized; and a final stage in which a decision about the initial disagreement is made, if possible, based on what happened in the argumentation stage.
The Pragma-dialectical theory stipulates a normative ideal of a critical discussion which serves both as a guide to the reconstruction of natural language argumentation, as well as a standard for the evaluation of the analysed product of reconstruction. A set of ten rules has been proposed as constitutive of the critical-discussion ideal, and the proponents of the theory believe that rational arguers would accept them. If followed by both parties to the disagreement, the rules constrain the argumentation decision procedure such that any resolution reached will be deemed reasonable, and “every violation of any of the rules of the discussion procedure for conducting a critical discussion” will be a fallacy (2004, 175). The rules range over all the four stages of argumentation: at the confrontation stage there is a rule which says one may not prevent the other party from expressing their view; for the argumentation stage there is a rule which requires argumentation to be logically strong and in accord with one or another of three general argumentation schemes; at the closing stage there is a rule that the participants themselves are to decide which party was successful based on the quality of the argumentation they have made: if the proponent carries the day, the opponent should acknowledge it, and vice versa .
The Pragma-dialectical theory proposes that each of the core fallacies can be assigned a place as a violation of one of the rules of a critical discussion. For example, the ad baculum fallacy is a form of intimidation that violates the rule that one may not attempt to prevent one’s discussion partner from expressing their views; equivocation is a violation of the rule that formulations in arguments must be clear and unambiguous; post hoc ergo propter hoc violates the rule that arguments must be instances of schemes correctly applied. Moreover, on this theory, since any rule violation is to count as a fallacy this allows for the possibility that there may be hitherto unrecognized “new fallacies.” Among those proposed are declaring a standpoint sacrosanct because that breaks the rule against the freedom to criticize points of view, and evading the burden of proof which breaks the rule that you must defend your standpoint if asked to do so (see van Eemeren 2010, 194).
Clearly not all the rules of critical discussions apply directly to arguments. Some govern other goal-frustrating moves which arguers can make in the course of settling a difference of opinion, such as mis-allocating the burden of proof, asking irrelevant questions, suppressing a point of view, or failing to clarify the meaning of one’s argumentation. In short, the Pragma-dialectical rules of a critical discussion are not just rules of logic or epistemology, but rules of conduct for rational discussants, making the theory more like a moral code than a set of logical principles. Accordingly, this approach to fallacies rejects all three of the necessary conditions of SDF: a fallacy need not be an argument, thus the invalidity condition will not apply either, and the appearance condition is excluded because of its subjective character (Van Eemeren and Grootendorst 2004, 175).
The Pragma-dialectical analysis of fallacies as rule-breakings in a procedure for overcoming disagreements has recently been expanded to take account of the rhetorical dimension of argumentation. Pragma-dialectics takes the rhetorical dimension to stem from an arguer’s wish to have their view accepted which leads dialoguers to engage in strategic maneuvering vis-à-vis their dialogue partners. However, this desire must be put in balance with the dialectical requirement of being reasonable; that is, staying within the bounds of the normative demands of critical discussions. The ways of strategic maneuvering identified are basically three: topic selection, audience orientation, and the selection of presentational devices, and these can be effectively deployed at each stage of argumentation (Van Eemeren 2010, 94). “All derailments of strategic maneuvering are fallacies,” writes van Eemeren (2010, 198), “in the sense that they violate one or more of the rules for critical discussion and all fallacies can be viewed as derailments of strategic maneuvering.” This means that all fallacies are ultimately attributable to the rhetorical dimension of argumentation since, in this model, strategic maneuvering is the entry of rhetoric into argumentation discussions. “Because each fallacy has, in principle, sound counterparts that are manifestations of the same mode of strategic maneuvering” it may not appear to be a fallacy and it “may pass unnoticed” (Van Eemeren 2010, 199). Nevertheless, Pragma-dialectics prefers to keep the appearance condition outside the definition of ‘fallacy’, treating the seeming goodness of fallacies as a sometime co-incidental property, rather than an essential one.
Although the Pragma-dialectical theory continues to evolve into a more detailed and comprehensive understanding of argumentation (van Eemeren, 2018, ch. 8), it maintains that the model of a critical discussion can be used for argument appraisal across the various fields in which argumentation takes place such as the legal, the political, the interpersonal, etc. Each of the fields has developed its own stylized kind of discourse where different genres of argumentation are favoured (adjudication, deliberation, mediation, etc.), but the reasonableness of arguments in any of the fields will depend on how well they accord with the model of a critical discussion. This approach has been challenged by Douglas Walton who has written more about fallacies and fallacy theory than anyone else. He has published individual monographs on many of the well-known fallacies, among them, Begging the Question (1991), Slippery Slope Arguments (1992), Ad Hominem Arguments (1998), and a comprehensive work on fallacy theory, A Pragmatic Theory of Fallacy (1995). Over the years his views have evolved. He has referred to his theory as “the Pragmatic theory,” and like the Pragma-dialectical theory it has a dialectical/dialogical basis; however, Walton envisions a number of distinct normative dialectical frameworks (persuasion dialogue, inquiry dialogue, negotiation dialogue, etc.) rather than the single model of a critical discussion proposed by Pragma-dialectics. Postulating different kinds of dialogues with different starting points and different goals, thinks Walton, will bring argumentation into closer contact with argumentation reality. At one point Walton had the idea that fallacies happened when there was an illicit shift from one kind of a dialogue to another (1995, 118–23), for example, using arguments appropriate for a negotiation dialogue in a persuasion dialogue, but more recently he has turned to other ways of explicating fallacies.
Although Walton recognizes the class of formal fallacies, his main interest is in informal fallacies, especially the ones associated with argumentation schemes. The idea of an argumentation scheme is central to Walton’s theory. Schemes are patterns of commonly used kinds of defeasible reasoning/argumentation such as appeals to expert opinion and ad hominem arguments. Schemes do not identify fallacies but rather argument kinds that are sometimes used fairly, and, other times, fallaciously. With each kind of scheme is associated a set of critical questions which guide us in deciding whether a given use of an argument is correct, weak or fallacious. So, if we consider:
\(E\) is an expert in subject area \(S\); \(E\) asserts \(p\) based on \(E\)’s knowledge of \(S\); So, \(p\).
to be the scheme for the appeal-to-expertise kind of argument, [ 8 ] then there will be a question for each premise: Is \(E\) really an expert in \(S\)? Did \(E\) say \(p\) when s/he was acting in her/his professional capacity? (… or did s/he blurt it out while drunk at an association party?). If the answer to both questions is Yes, then the argument creates a presumption for the conclusion—but not a guarantee, for the reasoning is defeasible: other information may come to light that will override the presumption. If one of the questions cannot be answered clearly this is an indication that the argument is weak, and answering No to either of the two questions cancels the presumption for the conclusion, i.e., makes the argument into a bad argument from expert opinion. If the bad argument has “a semblance of correctness about it in [the] context, and poses a serious obstacle to the realization of the goal of the dialog,” then it is a fallacy (2011, 380). [ 9 ]
The definition of fallacy Walton proposes (1995, 255) has five parts. A fallacy:
- an argument (or at least something that purports to be an argument) that
- falls short of some standard of correctness;
- is used in a context of dialogue;
- has a semblance of correctness about it; and
- poses a serious problem to the realization of the goal of the dialogue.
Here we find that Walton has relaxed two of the necessary conditions of SDF. Purporting to be an argument is enough (it doesn’t really have to be an argument), while falling short of a standard (one that will vary with the kind of dialogue under consideration) replaces the invalidity condition. However, the appearance condition, here expressed as fallacies having a semblance of correctness about them, remains in full force. The two extra conditions added to fallacy are that they occur only in contexts of dialogue and that they frustrate the realization of the goal of the kind of dialogue in which they occur. In insisting on this dialogical dimension, Walton is in full sympathy with those who think that fallacies can only be rightly analysed within a dialectical framework similar to the ones Aristotle originally studied, and later better defined by Hamblin and Lorenzen. Walton volunteers a shorter version of the definition of a fallacy as “a deceptively bad argument that impedes the progress of a dialogue” (1995, 256).
Walton divides fallacies into two kinds: paralogisms and sophisms. A paralogism is “the type of fallacy in which an error of reasoning is typically committed by failing to meet some necessary requirement of an argumentation scheme” whereas “the sophism type of fallacy is a sophistical tactic used to try to unfairly get the best of a speech partner in an exchange of arguments” (2010, 171; see also 1995, 254). Paralogisms are instances of identifiable argumentation schemes, but sophisms are not. The latter are associated more with infringing a reasonable expectation of dialogue than with failing some standard of argument (2011, 385; 2010, 175). A further distinction is drawn between arguments used intentionally to deceive and arguments that merely break a maxim of argumentation unintentionally. The former count as fallacies; the latter, less condemnable, are blunders (1995, 235).
Among the informal paralogisms Walton includes: ad hominem , ad populum , ad misericordiam , ad ignorantiam , ad verecundiam , slippery slope, false cause, straw man, argument from consequences, faulty analogy, composition and division. In the category of sophisms he places ad baculum , complex question, begging the question, hasty generalization, ignoratio elenchi , equivocation, amphiboly, accent, and secundum quid . He also has a class of formal fallacies very much the same as those identified by Whately and Copi. The largest class in Walton’s classification is the one associated with argumentation schemes and ad -arguments, and these are the ones that he considers to be the most central fallacies. Nearly all the Aristotelian fallacies included find themselves relegated to the less studied categories of sophisms. Taking a long look at the history of fallacies, then, we find that the Aristotelian fallacies are no longer of central importance. The main focus of interest is now the list of fallacies that have grown out of Locke’s creation of the ad -argument genre.
Another recent approach comes from virtue argumentation theory (modelled on virtue epistemology). Virtue argumentation theory is characterized by a distinct set of virtues thought to be essential to good argumentation: willingness to engage in argumentation, willingness to listen to others and willingness to modify one’s own position (see, e.g., Cohen 2009). These may be supplemented with epistemic virtues and even in some cases moral virtues. Although virtues and vices are dispositions of arguers and fallacies are arguments, it is claimed that good argumentation generally results from the influence of argumentation virtues and bad argumentation (including the fallacies) arise because of the vices of arguers.
Taking the Aristotelian view that virtues are a mean between opposite kinds of vices, fallacious arguments can be seen as resulting from arguers moving in one or another direction away from a mean of good argumentation. Aberdein (2013, 2016) especially has developed this model for understanding many of the fallacies. We can illustrate the view by considering appeals to expertise: the associated vices might be too little respect for reliable authorities at one extreme and too much deference to authorities at the other extreme. Aberdein develops the fallacies-as-argumentation-vices analysis in some detail for other of the ad-arguments and sketches how it might be applied to the other core fallacies, suggesting it can profitably be extended to all of them.
All the fallacies, it is claimed, can be fitted in somewhere in the classification of argumentational vices, but the converse is not true although it is possible to bring to light other shortcomings to which we may fall prey in argumentation. Another aspect of the theory is that it distributes argumentation vices among both senders and audiences. Speakers may infect their arguments with vices when they are, for example, closed minded or lack respect for persons, and audiences can contribute to fallaciousness by letting their receptivity be influenced by naïvety, an over-reliance on common sense, or an unfounded bias against a speaker. Perhaps the development of the virtue argumentation theory approach to fallacies provides a supplement to Mill’s theory of fallacies. He distinguished (1891, V, i, 3) what he called the moral (dispositional) and intellectual causes of fallacy. The study of the argumentative vices envisioned above seems best included under the moral study of fallacies as the vices can be taken to be the presdisposing causes to commit intellectual mistakes, i.e., misevaluations of the weight of evidence.
Finocchiaro (2023, 24) has introduced a distinction between ground-level arguments and meta-argument. The former are about natural phenomena, historical events, human actions, abstract entities, etc. and the latter are about one or more arguments, or about argumentation in general. When we justify our judgments that an argument, x , has committed a fallacy we are making a meta-argument about x . Finocchiaro uses the fallacy of composition as an example saying it is primarily a meta-argument concept used to assess an argument at the ground-level as a fallacy.
Akin and Casey take this line of analysis further, arguing that there are indeed fallacies best understood as fallacies of meta-argumentation. They have studied three of them: the straw man fallacy (2022a), bothsiderism (2022b), and what they call the free-speech fallacy (2023). These are all fallacies that may occur in the process of argumentation, i.e., exchanges between arguers. On this view, straw man fallacies happen when someone in the course of argumentation inaccurately and unfavourable distorts a ground-level argument in an attempt to refute it or discredit its source. In the case of bothsiderism, there are conflicting arguments each drawing on prima facie evidence. This can lead to the meta-argument that the truth lies somewhere in the middle between the opposed ground-level conclusions. This is considered a fallacy because purported contrary evidence noticed at the meta-level is insufficient reason to abandon both the ground-level conclusions in favour of a compromise. Cases where people claim their right to free speech is infringed, say Akin and Casey, also admit of the possibility of meta-argumentation fallacies. One of the ways is when criticism of a view is mistaken for censorship of that view; another is when parties are excluded from participation in a discussion for good reasons such as lack of qualifications or holding repugnant social views. From their exclusion they may make the meta-argument that the outcome of the discussion is epistemically unwarranted because of evidence not taken into consideration, or they may even think that the fact that their view was excluded is a sign that it has merit its opponents would rather not admit. The authors say that these kinds of mistakes are meta-argumentation fallacies and anticipate that there are more of them waiting for analysis.
4. Current issues in fallacy theory
A question that continues to dog fallacy theory is how we are to conceive of fallacies. There would be advantages to having a unified theory of fallacies. It would give us a systematic way of demarcating fallacies and other kinds of mistakes; it would give us a framework for justifying fallacy judgments, and it would give us a sense of the place of fallacies in our larger conceptual schemes. Some general definition of ‘fallacy’ is wanted but the desire is frustrated because there is disagreement about the identity of fallacies. Are they inferential, logical, epistemic or dialectical mistakes? Some authors insist that they are all of one kind: Biro and Siegel, for example, that they are epistemic, and Pragma-dialectics that they are dialectical. There are reasons to think that all fallacies do not easily fit into one category.
Together the Sophistical Refutations and Locke’s Essay are the dual sources of our inheritance of fallacies. However, for four reasons they make for uneasy bedfellows. First, the ad fallacies seem to have a built-in dialectical character, which, it can be argued, Aristotle’s fallacies do not have (they are not sophistical refutations but are in sophistical refutations). Second, Aristotle’s fallacies are logical mistakes: they have no appropriate employment outside eristic argumentation whereas the ad -fallacies are instances of ad -arguments, often appropriately used in dialogues. Third, the appearance condition is part of the Aristotelian inheritance but it is not intimately connected with the ad -fallacies tradition. A fourth reason that contributes to the tension between the Aristotelian and Lockean traditions in fallacies is that the former grew out of philosophical problems, largely what are logical and metaphysical puzzles (consider the many examples in Sophistical Refutations ), whereas the ad -fallacies are more geared to social and political topics of popular concern, the subject matter that most intrigues modern researchers on fallacy theory.
As we look back over our survey we cannot help but observe that fallacies have been identified in relation to some ideal or model of good arguments, good argumentation, or rationality. Aristotle’s fallacies are shortcomings of his ideal of deduction and proof, extended to contexts of refutation. The fallacies listed by Mill are errors of reasoning in a comprehensive model that includes both deduction and induction. Those who have defended SDF as the correct definition of ‘fallacy’ [ 10 ] take logic simpliciter or deductive validity as the ideal of rationality. Informal logicians view fallacies as failures to satisfy the criteria of what they consider to be a cogent argument. Defenders of the epistemic approach to fallacies see them as shortfalls of the standards of knowledge-generating arguments. Finally, those who are concerned with how we are to overcome our disagreements in a reasonable way will see fallacies as failures in relation to ideals of debate or critical discussions.
The standard treatment of the core fallacies has not emerged from a single conception of good argument or reasonableness but rather, like much of our unsystematic knowledge, has grown as a hodgepodge collection of items, proposed at various time and from different perspectives, that continues to draw our attention, even as the standards that originally brought a given fallacy to light are abandoned or absorbed into newer models of rationality. Hence, there is no single conception of good argument or argumentation to be discovered behind the core fallacies, and any attempt to force them all into a single framework, must take efforts to avoid distorting the character originally attributed to each of them.
From Aristotle to Mill the appearance condition was an essential part of the conception of fallacies. However, some of the new, post-Hamblin, scholars have either ignored it (Finocchiaro, Biro and Siegel) or rejected it because appearances can vary from person to person, thus making the same argument a fallacy for the one who is taken in by the appearance, and not a fallacy for the one who sees past the appearances. This is unsatisfactory for those who think that arguments are either fallacies or not. Appearances, it is also argued, have no place in logical or scientific theories because they belong to psychology (van Eemeren and Grootendorst, 2004). But Walton (e.g., 2010) continues to consider appearances an essential part of fallacies as does Powers (1995, 300) who insists that fallacies must “have an appearance, however quickly seen through, of being valid.” If the mistake in an argument is not masked by an ambiguity that gives it the appearance of being a better argument than it really is, Powers denies it is a fallacy.
The appearance condition of fallacies serves at least two purposes. First, it can be part of explanations of why reasonable people make mistakes in arguments or argumentation: it may be due in part to an argument’s appearing to be better than it really is. Second, it serves to divide mistakes into two groups: those which are trivial or the result of carelessness (for which there is no cure other than paying better attention), and those which we need to learn to detect through an increased awareness of their seductive nature. Without the appearance condition, it can be argued, no division can be made between these two kinds of errors: either there are no fallacies or all mistakes in argument and/or argumentation are fallacies; a conclusion that some are willing to accept, but which runs contrary to tradition. One can also respond that there is an alternative to using the appearance condition as the demarcation property between fallacies and casual mistakes, namely, frequency. Fallacies are those mistakes we must learn to guard against because they occur with noticeable frequency. To this it may be answered that ‘noticeable frequency’ is vague, and is perhaps best explained by the appearance condition.
Oswald and Herman (2020) explain the possibility that an argument might seem better than it really is by appealing to both cognitive and rhetorical factors. The cognitive factor is that the information set of a sender making a fallacious argument might be greater than the information set of an argument receiver, thus potentially putting the receiver in a position to be deceived. Persuasive skills can exploit such a difference in information sets by manipulating the relevant contextual evidence; that is, by bringing forward what favours the fallacious argument and holding back critical factors against it. The receiver may thus be taken in by a fallacy because of the way the argument was presented to them. Hansen (2023) considers the causal factors that might lead to misperception of bad arguments as good arguments. They include structural properties of arguments, perceptual perspectives, the social atmosphere in which the arguments are presented, and misperceptions due to abnormalities in the argument receiver.
On the more practical level, there continues to be discussion about the value of teaching the fallacies to students. Is it an effective way for them to learn to reason well and to avoid bad arguments? One reason to think that it is not effective is that the list of fallacies is not complete, and that even if the group of core fallacies was extended to incorporate other fallacies we thought worth including, we could still not be sure that we had a complete prophylactic against bad arguments. Hence, we are better off teaching the positive criteria for good arguments/ argumentation which give us a fuller set of guidelines for good reasoning. But some (Pragma-dialectics and Johnson and Blair) do think that their stock of fallacies is a complete guard against errors because they have specified a full set of necessary conditions for good arguments/argumentation and they hold that fallacies are just failures to meet one of these conditions.
Another consideration about the value of the fallacies approach to teaching good reasoning is that it tends to make students overly critical and lead them to see fallacies where there are not any; hence, it is maintained we could better advance the instilling of critical thinking skills by teaching the positive criteria of good reasoning and arguments (Hitchcock, 1995). In response to this view, it is argued that, if the fallacies are taught in a non-perfunctory way which includes the explanations of why they are fallacies—which normative standards they transgress—then a course taught around the core fallacies can be effective in instilling good reasoning skills (Blair 1995).
In more recent work, Blair (2023) has moved closer to Hitchcock’s recommendation that fallacies not be taught in introductory level courses, but his reason is that the study of fallacies has become so complex with many dimensions and overlapping approaches that it has become a subject too challenging for undergraduate students; moreover, few instructors are familiar with the extensive literature that has developed on fallacies. Hitchcock (2023) has followed up his earlier article with a study of six of the most widely used textbooks (each having at least ten editions) that have a section on the fallacies and asked whether they have benefitted from Hamblin’s (1970) critique of the standard treatment (see above section 3.1). He finds that by the standard implicit in Hamblin’s critique, there has been little improvement in the analysis and presentation of fallacies in those textbooks.
Biases are “inclinations to see things one way rather than another,” explains Nickerson (2021, 208). He reviews the literature on biases that can affect reasoning, discussing both the motivational and cognitive factors that may lead to the presence of biases (ch. 7). Like fallacies, there is no fixed definitive list, and the individuation of biases largely depends on the goal of our inquiries. Correia (2011) has taken Mill’s insight that biases are predisposing causes of fallacies a step further by connecting identifiable biases with particular fallacies. Biases can influence the committing of fallacies even where there is no intent to be deceptive, he observes. Taking biases to be “systematic errors that invariably distort the subject’s reasoning and judgment,” the picture drawn is that particular biases are activated by desires and emotions (motivated reasoning) and once they are in play, they negatively affect the fair evaluation of evidence. Thus, for example, the “focussing illusion” bias inclines a person to focus on just a part of the evidence available, ignoring or denying evidence that might lead in another direction. Correia (2011, 118) links this bias to the fallacies of hasty generalization and straw man, suggesting that it is our desire to be right that activates the bias to focus more on positive or negative evidence, as the case may be. Other biases he links to other fallacies.
Thagard (2011) is more concerned to stress the differences between fallacies and biases than to find connections between them. He claims that the model of reasoning articulated by informal logic is not a good fit with the way that people actually reason and that only a few of the fallacies are relevant to the kinds of mistakes people actually make. Thagard’s argument depends on his distinction between argument and inference. Arguments, and fallacies, he takes to be serial and linguistic, but inferences are brain activities and are characterized as parallel and multi-modal. By “parallel” is meant that the brain carries out different processes simultaneously, and by “multi-modal” that the brain uses non-linguistic and emotional, as well as linguistic representations in inferring. Biases (inferential error tendencies) can unconsciously affect inferring. “Motivated inference,” for example, “involves selective recruitment and assessment of evidence based on unconscious processes that are driven by emotional considerations of goals rather than purely cognitive reasoning” (2011, 156). Thagard volunteers a list of more than fifty of these inferential error tendencies. Because motivated inferences result from unconscious mental processes rather than explicit reasoning, the errors in inferences cannot be exposed simply by identifying a fallacy in a reconstructed argument. Dealing with biases requires identification of both conscious and unconscious goals of arguers, goals that can figure in explanations of why they incline to particular biases. “Overcoming people’s motivated inferences,” Thagard concludes, “is therefore more akin to psychotherapy than informal logic” (157), and the importance of fallacies is accordingly marginalized.
In response to these findings, one can admit their relevance to the pedagogy of critical thinking but still recall the distinction between what causes mistakes and what the mistakes are. The analysis of fallacies belongs to the normative study of arguments and argumentation, and to give an account of what the fallacy in a given case is will involve making reference to some relevant norm of argument or argumentation. It will be an explanation of what the mistake in the argument is. Biases are relevant to understanding why people commit fallacies, and how we are to help them get past them, but they do not help us understand what the fallacy-mistakes are in the first place—this is not a question of psychology. Continued research at this intersection of interests will hopefully shed more light on both biases and fallacies.
- Aberdein, A., 2013, “Fallacy and argumentational vice,” Ontario Society for the Study of Argumentation (OSSA Conference Archive: OSSA 10), available online .
- –––, 2016, “The vices of argument,” Topoi , 25: 413–22.
- Akin, S.F., and J. Casey, 2022a, Straw Man Arguments: A Study in Fallacy Theory , London: Bloomsbury.
- –––, 2022b, “Bothsiderism,” Argumentation , 36: 249–68.
- –––, 2023, “Free speech fallacies as meta-argumentative errors,” Argumentation , 37: 295–305.
- Aristotle, Categories , H.P. Cooke (trans.), Cambridge, MA: Harvard University Press, 1938.
- –––, On Sophistical Refutations , E. S. Forster (trans.), Cambridge, MA: Harvard University Press, 1955.
- –––, Posterior Analytics , H. Tredennick (trans.), Cambridge, MA: Harvard University Press, 1960.
- –––, Topics , Books I and VIII , R. Smith (trans.), Oxford: Clarendon Press, 1997.
- Arnauld, A., and P. Nicole, 1685, Logic, or the Art of Thinking , 5 th edition, J. V. Buroker (trans.), Cambridge: Cambridge University Press, 1996.
- Bachman, J., 1995, “Appeal to authority,” in Hansen and Pinto, 1995, pp. 274–86.
- Bacon, F., 1620, The New Organon , Indianapolis: Bobbs-Merrill, 1960.
- Barth, E. M., and J. L. Martens, 1977, “ Argumentum ad hominem , from chaos to formal dialectic,” Logique et Analyse , 20: 76–96.
- Bentham, J., 1824, The Handbook of Political Fallacies , page references to reprint, H. A. Larrabee (ed.), New York: Harper and Brothers, 1962.
- Biro, J., 1977, “Rescuing ‘begging the question’,” Metaphilosophy , 8: 257–71.
- Biro, J., and H. Siegel, 1992, “Normativity, argumentation and an epistemic theory of fallacies,” in Frans H. van Eemeren, et al., editors, Argumentation Illuminated , Amsterdam: Sic Sat, pp. 85–103.
- –––, 1997, “Epistemic normativity, argumentation and fallacies,” Argumentation , 11: 277–293.
- –––, 2006, “In defence of the objective epistemic approach to argumentation,” Informal Logic , 26: 91–102.
- Blair, J. A., 1995, “The place of teaching informal fallacies in teaching reasoning skills or critical thinking,” in Hansen and Pinto 1995, pp. 328–38.
- –––, 2023, “Teaching the fallacies,” Argumentation , 37: 247–251.
- Brinton, A., 1995, “The ad hominem ,” in Hansen and Pinto 1995, pp. 213–22.
- Churchill, R. P., 1986, Becoming Logical , New York: St Martin’s Press.
- Cohen, D.H., 2009, “Keeping an open mind and having a sense of proportion as virtues in argumentation,” Cogency , 1: 49–64.
- Copi, I. M., 1961, Introduction to Logic , (2 nd ed.), New York: Macmillan.
- Corcoran, J., 1974, “Remarks on Stoic deduction,” in J. Corcoran (ed.), Ancient Logic and its Modern Interpretations , Dordrecht: Reidel, pp. 169–81.
- Corner, A., U. Hahn, and M. Oaksford, 2006, “The slippery slope argument—probability, utility and category reappraisal,” Proceedings of the Annual Meeting of the Cognitive Science Society , 28: 1145–1150, available online .
- Correia, V., 2011, “Biases and fallacies: The role of motivated irrationality in fallacious reasoning,” Cogency , 3: 107–26.
- Finocchiaro, M. A., 1974, “The concept of ad hominem argument in Galileo and Locke,” Philosophical Forum , 5: 394–404; page references are to Finocchiaro 2005, pp. 329–39.
- –––, 1981, “Fallacies and the evaluation of reasoning,” American Philosophical Quarterly 18: 13–22; page references are to Finocchiaro 2005, pp. 109–27.
- –––, 1987, “Six types of fallaciousness: towards a realistic theory of logical criticism,” Argumentation 1: 263–82; page references are to Finocchiaro 2005, pp. 128–47.
- –––, 2005, Arguments about Arguments . Cambridge: Cambridge University Press.
- –––, 2023, The Fallacy of Composition: Critical Reviews, ConceptualAanalyses, and Case Studies , London: College Publications.
- Freeman, J. B., 1988, Thinking Logically: Basic Concepts for Reasoning , Englewood Cliffs: Prentice-Hall.
- –––, 1995, “The appeal to popularity and presumption by common knowledge,” in Hansen and Pinto 1995, pp. 265–73.
- Goodwin, J., 1998, “Forms of authority,” Argumentation , 12: 267–80.
- Govier, T., 1982, “What’s wrong with slippery slope fallacies?” Canadian Journal of Philosophy , 12: 303–16.
- –––, 1987, “Four reasons there are no fallacies?” in Problems in Argument Analysis and Evaluation , Dordrecht: Foris; page references to reprint as “Reply to Massey” in Hansen and Pinto 1995, pp. 172–80.
- –––, 1988, A Practical Study of Argument , 2nd edition, Belmont: Wadsworth.
- Grootendorst, R., 1997, “Jeremy Bentham’s Handbook of Political Fallacies ,” in Historical Foundations of Informal Logic , D. Walton and A. Brinton (eds.), Aldershot: Ashgate, pp. 114–24.
- Hahn, U., and M. Oaksford, 2006a, “A normative theory of argument strength,” Informal Logic , 26: 1–24.
- –––, 2006b, “A Bayesian approach to informal argument fallacies,” Synthese , 152: 207–236.
- Hamblin, C. L., 1970, Fallacies , London: Methuen.
- Hansen, H. V., 2002, “The straw thing of fallacy theory: the standard definition of ‘fallacy’,” Argumentation , 16: 134–55.
- –––, 2023, “Committing fallacies and the appearance condition,” Argumentation , 37: 253–267.
- –––, and R. C. Pinto (eds.), 1995, Fallacies: Classical and Contemporary Readings , University Park: Penn State Press.
- Hintikka, J., 1987, “The fallacy of fallacies,” Argumentation , 1: 211–38.
- –––, 1997, “What was Aristotle doing in his early logic, anyway? A reply to Woods and Hansen,” Synthese , 113: 241–49.
- Hitchcock, D., 1995, “Do fallacies have a place in the teaching of reasoning skills or critical thinking?” in Hansen and Pinto 1995, pp. 319–27.
- –––, 2000, “Fallacies and formal logic in Aristotle,” History and Philosophy of Logic , 21: 2017–21.
- –––, 2023. “Textbook treatments of fallacies,” Argumentation , 37: 233–245.
- Irwin, T., and G. Fine, 1996, Aristotle, Introductory Readings , Indianapolis: Hackett.
- –––, 1987, “The blaze of her splendors: Suggestions about revitalizing fallacy theory,” Argumentation , 1: 239–53; page references to reprint in Hansen and Pinto 1995, pp. 107–19.
- Johnson, R., and J. A. Blair, 1993, Logical Self-Defence , 3 rd ed., Toronto: McGraw-Hill Ryerson.
- Johnstone, H. W., Jr., 1952, “Philosophy and argumentum ad hominem ,” Journal of Philosophy , 49: 489–98.
- Kahane, H., 1971, Logic and Contemporary Rhetoric , Belmont: Wadsworth.
- Korb, K., 2003, “Bayesian informal logic and fallacy,” Informal Logic , 23: 41–70.
- Krabbe, E. C. W., 1995, “Appeal to ignorance,” in Hansen and Pinto 1995, pp. 251–64.
- Locke, J., 1690, An Essay Concerning Human Understanding . Many editions.
- Lorenzen, P., 1969, Normative Logic and Ethics , Mannheim: Bibliographisches Institut; 2nd annotated edition, 1984.
- Massey, G. J., 1981, “The fallacy behind fallacies,” Midwest Studies in Philosophy , 6: 489–500; page references are to reprint in Hansen and Pinto 1995, pp. 159–71.
- Mates, B., 1965, Elementary Logic , Oxford: Oxford University Press.
- Mill, J. S., 1891, A System of Logic, Ratiocinative and Inductive , 8 th edition, New York: Harper and Brothers; first edition 1843.
- Nickerson, R.S., 2021, Argumentation: The Art of Persuasion , Cambridge: Cambridge University Press.
- Nuchelmans, G., 1993, “On the fourfold root of argumentum ad hominem ,” in E. C. W. Krabbe, R. J. Dalitz, and P. A. Smit (eds.), Empirical Logic and Public Debate , Amsterdam: Rodopi, pp. 37–47.
- Oswald, S., and T. Herman, 2020, “Give the standard treatment of fallacies a chance! Cognitive and rhetorical insights into fallacy processing,” in F.H. van Eemeren and B. Garssen (eds.), From Argument Schemes to Argumentative Relations in the Wild , Cham: Springer, pp. 41–62.
- Pinto, R. C., 1995, Post hoc, ergo propter hoc , in Hansen and Pinto, pp. 302–11.
- Powers, L., 1995, “Equivocation,” in Hansen and Pinto 1995, pp. 287–301.
- Rosen, F., 2006, “The philosophy of error and liberty of thought: J. S. Mill on logical fallacies,” Informal Logic , 26: 121–47.
- Rudanko, J., 2021, Fallacies and Free Speech , New York: Palgrave MacMillan.
- Salmon, W., 1963, Logic , Englewood-Cliffs: Prentice-Hall.
- Schreiber, S. G., 2003, Aristotle on False Reasoning , Albany: State University of New York Press.
- Sidgwick, A., 1878, “The negative character of logic,” Mind , 3: 350–357.
- ––, 1884, Fallacies: A View of Logic from the Practical Side , New York: D. Appleton and Co.
- Smith, R., 1997, “Commentary,” Aristotle: Topics, Books I and VIII , Oxford: Clarendon Press.
- Thagard, P., 2011, “Critical thinking and informal logic: neuropsychological perspectives,” Informal Logic , 31: 152–70.
- Tindale, C. W., 1996, “Fallacies in transition: An assessment of the Pragma-dialectical perspective,” Informal Logic , 18: 17–33.
- –––, 2007, “On Fallacy,” in Reason Reclaimed: Essays in Honor of J. Anthony Blair and Ralph H. Johnson , H.V. Hansen and R. C. Pinto (eds.), Newport News: Vale Press, pp. 155–70.
- Van Eemeren, F. H., 2010, Strategic Maneuvering in Argumentative Discourse , Amsterdam: John Benjamins.
- –––, and Rob Grootendorst, 1984, Speech Acts in Argumentative Discussions , Dordrecht: Foris.
- –––, 1992, Argumentation, Communication and Fallacies , Hillsdale: Erlbaum.
- –––, 2004, A Systematic Theory of Argumentation , Cambridge: Cambridge University Press.
- ___, 2018, Argumentation Theory: A Practical Dialectical Perspective , Cham: Springer.
- Walton, D. N., 1991, Begging the Question , New York: Greenwood.
- –––, 1995, A Pragmatic Theory of Fallacies , Tuscaloosa: University of Alabama Press.
- –––, 1998, Ad hominem arguments , Tuscaloosa, University of Alabama Press.
- –––, 2010, “Why fallacies appear to be better arguments than they are,” Informal Logic , 30: 159–84.
- –––, 2011, “Defeasible reasoning and informal fallacies,” Synthese , 179: 377–407.
- Watts, I., 1796, Logick: or, the Right Use of Reason , 2 nd edition; page references to reprint, New York: Garland, 1984.
- Whately, R., 1875, Elements of Logic , 9 th ed., London: Longmans, Green and Company; first edition 1826.
- Woods, J., 1992, “Who cares about the fallacies?” in Argumentation Illuminated , F. H. van Eemeren, et al. (eds.), Amsterdam: SicSat, pp. 23–48.
- –––, 2013, Errors of Reasoning: Naturalizing the Logic of Inference , London: College Publications.
- –––, and H. V. Hansen, 1997, “Hintikka on Aristotle’s fallacies,” Synthese , 113: 217–39.
- –––, 2001, “The subtleties of Aristotle on non-cause,” Logique et analyse , 176: 395–415.
- Woods, J., and D. N. Walton, 1989, Fallacies: Selected Papers, 1972–1982 , Dordrecht: Foris.
- Wreen, M., 1989, “A bolt of fear,” Philosophy and Rhetoric , 22: 131–40.
How to cite this entry . Preview the PDF version of this entry at the Friends of the SEP Society . Look up topics and thinkers related to this entry at the Internet Philosophy Ontology Project (InPhO). Enhanced bibliography for this entry at PhilPapers , with links to its database.
- Curtis, Gary N., Fallacy Files
- Dowden, Bradley, Fallacies , entry in the Internet Encyclopedia of Philosophy .
- Hansen, H.V., and C. Fioret, 2016. A searchable bibliography of fallacies—2016 , Informal Logic , 36: 432–72.
- Informal Logic , an open-access journal.
- Labossiere, Michael C., Fallacies , hosted by The Nizkor Project.
- RAIL , a blog about Reasoning, Argumentation, and Informal Logic.
logic: informal | relativism
Acknowledgments
The author would like to thank the executive and subject editors who suggested a way to improve the discussion of begging the question .
Copyright © 2024 by Hans Hansen < hhansen @ uwindsor . ca >
- Accessibility
Support SEP
Mirror sites.
View this site from another server:
- Info about mirror sites
The Stanford Encyclopedia of Philosophy is copyright © 2024 by The Metaphysics Research Lab , Department of Philosophy, Stanford University
Library of Congress Catalog Data: ISSN 1095-5054
Have a language expert improve your writing
Check your paper for plagiarism in 10 minutes, generate your apa citations for free.
- Knowledge Base
- Logical Fallacies | Definition, Types, List & Examples
Logical Fallacies | Definition, Types, List & Examples
Published on April 20, 2023 by Kassiani Nikolopoulou . Revised on October 9, 2023.
A logical fallacy is an argument that may sound convincing or true but is actually flawed. Logical fallacies are leaps of logic that lead us to an unsupported conclusion. People may commit a logical fallacy unintentionally, due to poor reasoning, or intentionally, in order to manipulate others.
Because logical fallacies can be deceptive, it is important to be able to spot them in your own argumentation and that of others.
Table of contents
Logical fallacy list (free download), what is a logical fallacy, types of logical fallacies, what are common logical fallacies, logical fallacy examples, other interesting articles, frequently asked questions about logical fallacies.
There are many logical fallacies. You can download an overview of the most common logical fallacies by clicking the blue button.
Logical fallacy list (Google Docs)
A logical fallacy is an error in reasoning that occurs when invalid arguments or irrelevant points are introduced without any evidence to support them. People often resort to logical fallacies when their goal is to persuade others. Because fallacies appear to be correct even though they are not, people can be tricked into accepting them.
The majority of logical fallacies involve arguments—in other words, one or more statements (called the premise ) and a conclusion . The premise is offered in support of the claim being made, which is the conclusion.
There are two types of mistakes that can occur in arguments:
- A factual error in the premises . Here, the mistake is not one of logic. A premise can be proven or disproven with facts. For example, If you counted 13 people in the room when there were 14, then you made a factual mistake.
- The premises fail to logically support the conclusion . A logical fallacy is usually a mistake of this type. In the example above, the students never proved that English 101 was itself a useless course—they merely “begged the question” and moved on to the next part of their argument, skipping the most important part.
In other words, a logical fallacy violates the principles of critical thinking because the premises do not sufficiently support the conclusion, while a factual error involves being wrong about the facts.
There are several ways to label and classify fallacies, such as according to the psychological reasons that lead people to use them or according to similarity in their form. Broadly speaking, there are two main types of logical fallacy, depending on what kind of reasoning error the argument contains:
Informal logical fallacies
Formal logical fallacies.
An informal logical fallacy occurs when there is an error in the content of an argument (i.e., it is based on irrelevant or false premises).
Informal fallacies can be further subdivided into groups according to similarity, such as relevance (informal fallacies that raise an irrelevant point) or ambiguity (informal fallacies that use ambiguous words or phrases, the meanings of which change in the course of discussion).
“ Some philosophers argue that all acts are selfish . Even if you strive to serve others, you are still acting selfishly because your act is just to satisfy your desire to serve others.”
A formal logical fallacy occurs when there is an error in the logical structure of an argument.
Premise 2: The citizens of New York know that Spider-Man saved their city.
Conclusion: The citizens of New York know that Peter Parker saved their city.
This argument is invalid, because even though Spider-Man is in fact Peter Parker, the citizens of New York don’t necessarily know Spider-Man’s true identity and therefore don’t necessarily know that Peter Parker saved their city.
A logical fallacy may arise in any form of communication, ranging from debates to writing, but it may also crop up in our own internal reasoning. Here are some examples of common fallacies that you may encounter in the media, in essays, and in everyday discussions.
![causal fallacy critical thinking Logical fallacies](https://www.scribbr.com/wp-content/uploads/2023/10/logical-fallacies-1.webp)
Red herring logical fallacy
The red herring fallacy is the deliberate attempt to mislead and distract an audience by bringing up an unrelated issue to falsely oppose the issue at hand. Essentially, it is an attempt to change the subject and divert attention elsewhere.
Bandwagon logical fallacy
The bandwagon logical fallacy (or ad populum fallacy ) occurs when we base the validity of our argument on how many people believe or do the same thing as we do. In other words, we claim that something must be true simply because it is popular.
This fallacy can easily go unnoticed in everyday conversations because the argument may sound reasonable at first. However, it doesn’t factor in whether or not “everyone” who claims x is in fact qualified to do so.
Straw man logical fallacy
The straw man logical fallacy is the distortion of an opponent’s argument to make it easier to refute. By exaggerating or simplifying someone’s position, one can easily attack a weak version of it and ignore their real argument.
Person 2: “So you are fine with children taking ecstasy and LSD?”
Slippery slope logical fallacy
The slippery slope logical fallacy occurs when someone asserts that a relatively small step or initial action will lead to a chain of events resulting in a drastic change or undesirable outcome. However, no evidence is offered to prove that this chain reaction will indeed happen.
Hasty generalization logical fallacy
The hasty generalization fallacy (or jumping to conclusions ) occurs when we use a small sample or exceptional cases to draw a conclusion or generalize a rule.
A false dilemma (or either/or fallacy ) is a common persuasion technique in advertising. It presents us with only two possible options without considering the broad range of possible alternatives.
In other words, the campaign suggests that animal testing and child mortality are the only two options available. One has to save either animal lives or children’s lives.
People often confuse correlation (i.e., the fact that two things happen one after the other or at the same time) with causation (the fact that one thing causes the other to happen).
It’s possible, for example, that people with MS have lower vitamin D levels because of their decreased mobility and sun exposure, rather than the other way around.
It’s important to carefully account for other factors that may be involved in any observed relationship. The fact that two events or variables are associated in some way does not necessarily imply that there is a cause-and-effect relationship between them and cannot tell us the direction of any cause-and-effect relationship that does exist.
If you want to know more about fallacies , research bias , or AI tools , make sure to check out some of our other articles with explanations and examples.
- ChatGPT vs human editor
- ChatGPT citations
- Is ChatGPT trustworthy?
- Using ChatGPT for your studies
- Sunk cost fallacy
- Straw man fallacy
- Slippery slope fallacy
- Either or fallacy
- Appeal to emotion fallacy
- Non sequitur fallacy
Research bias
- Implicit bias
- Framing bias
- Cognitive bias
- Optimism bias
- Hawthorne effect
- Affect heuristic
An ad hominem (Latin for “to the person”) is a type of informal logical fallacy . Instead of arguing against a person’s position, an ad hominem argument attacks the person’s character or actions in an effort to discredit them.
This rhetorical strategy is fallacious because a person’s character, motive, education, or other personal trait is logically irrelevant to whether their argument is true or false.
Name-calling is common in ad hominem fallacy (e.g., “environmental activists are ineffective because they’re all lazy tree-huggers”).
An appeal to ignorance (ignorance here meaning lack of evidence) is a type of informal logical fallacy .
It asserts that something must be true because it hasn’t been proven false—or that something must be false because it has not yet been proven true.
For example, “unicorns exist because there is no evidence that they don’t.” The appeal to ignorance is also called the burden of proof fallacy .
People sometimes confuse cognitive bias and logical fallacies because they both relate to flawed thinking. However, they are not the same:
- Cognitive bias is the tendency to make decisions or take action in an illogical way because of our values, memory, socialization, and other personal attributes. In other words, it refers to a fixed pattern of thinking rooted in the way our brain works.
- Logical fallacies relate to how we make claims and construct our arguments in the moment. They are statements that sound convincing at first but can be disproven through logical reasoning.
In other words, cognitive bias refers to an ongoing predisposition, while logical fallacy refers to mistakes of reasoning that occur in the moment.
Sources in this article
We strongly encourage students to use sources in their work. You can cite our article (APA Style) or take a deep dive into the articles below.
Nikolopoulou, K. (2023, October 09). Logical Fallacies | Definition, Types, List & Examples. Scribbr. Retrieved September 3, 2024, from https://www.scribbr.com/fallacies/logical-fallacy/
Jin, Z., Lalwani, A., Vaidhya, T., Shen, X., Ding, Y., Lyu, Z., Sachan, M., Mihalcea, R., & Schölkopf, B. (2022). Logical Fallacy Detection. arXiv (Cornell University) . https://doi.org/10.48550/arxiv.2202.13758
Is this article helpful?
![causal fallacy critical thinking Kassiani Nikolopoulou](https://www.scribbr.com/wp-content/uploads/2022/06/kassianin.png)
Kassiani Nikolopoulou
Other students also liked, slippery slope fallacy | definition & examples, what is a red herring fallacy | definition & examples, what is straw man fallacy | definition & examples, "i thought ai proofreading was useless but..".
I've been using Scribbr for years now and I know it's a service that won't disappoint. It does a good job spotting mistakes”
PHIL102: Introduction to Critical Thinking and Logic
Causal Reasoning
Read this section to investigate the complications of causality, particularly as it relates to correlation. Sometimes, two correlated events share a common cause, and sometimes, correlation is accidental. Complete the exercises to practice determining sufficient evidence for causation and determining accidental correlation. Check your answers against the key.
Causal reasoning
When I strike a match, it will produce a flame. It is natural to take the striking of the match as the cause that produces the effect of a flame. But what if the matchbook is wet? Or what if I happen to be in a vacuum in which there is no oxygen (such as in outer space)? If either of those things is the case, then the striking of the match will not produce a flame. So it isn't simply the striking of the match that produces the flame, but a combination of the striking of the match together with a number of other conditions that must be in place in order for the striking of the match to create a flame. Which of those conditions we call the "cause" depends in part on the context. Suppose that I'm in outer space striking a match (suppose I'm wearing a space suit that supplies me with oxygen but that I'm striking the match in space, where there is no oxygen). I continuously strike it but no flame appears (of course). But then someone (also in a space suit) brings out a can of compressed oxygen that they spray on the match while I strike it. All of a sudden a flame is produced. In this context, it looks like it is the spraying of oxygen that causes flame, not the striking of the match. Just as in the case of the striking of the match, any cause is more complex than just a simple event that produces some other event. Rather, there are always multiple conditions that must be in place for any cause to occur. These conditions are called background conditions . That said, we often take for granted the background conditions in normal contexts and just refer to one particular event as the cause. Thus, we call the striking of the match the cause of the flame. We don't go on to specify all the other conditions that conspired to create the flame (such as the presence of oxygen and the absence of water). But this is more for convenience than correctness. For just about any cause, there are a number of conditions that must be in place in order for the effect to occur. These are called necessary conditions (recall the discussion of necessary and sufficient conditions from chapter 2, section 2.7). For example, a necessary condition of the match lighting is that there is oxygen present. A necessary condition of a car running is that there is gas in the tank. We can use necessary conditions to diagnose what has gone wrong in cases of malfunction. That is, we can consider each condition in turn in order to determine what caused the malfunction. For example, if the match doesn't light, we can check to see whether the matches are wet. If we find that the matches are wet then we can explain the lack of the flame by saying something like, "dropping the matches in the water caused the matches not to light". In contrast, a sufficient condition is one which, if present, will always bring about the effect. For example, a person being fed through an operating wood chipper is sufficient for causing that person's death (as was the fate of Steve Buscemi's character in the movie Fargo).
Because the natural world functions in accordance with natural laws (such as the laws of physics), causes can be generalized. For example, any object near the surface of the earth will fall towards the earth at 9.8 m/s2 unless impeded by some contrary force (such as the propulsion of a rocket). This generalization applies to apples, rocks, people, wood chippers and every other object. Such causal generalizations are often parts of explanations. For example, we can explain why the airplane crashed to the ground by citing the causal generalization that all unsupported objects fall to the ground and by noting that the airplane had lost any method of propelling itself because the engines had died. So we invoke the causal generalization in explaining why the airplane crashed. Causal generalizations have a particular form:
For any x, if x has the feature(s) F , then x has the feature G
For example:
For any human, if that human has been fed through an operating wood chipper , then that human is dead .
For any engine, if that engine has no fuel , then that engine will not operate .
For any object near the surface of the earth, if that object is unsupported and not impeded by some contrary force , then that object will fall towards the earth at 9.8 m/s 2 .
Being able to determine when causal generalizations are true is an important part of becoming a critical thinker. Since in both scientific and every day contexts we rely on causal generalizations in explaining and understanding our world, the ability to assess when a causal generalization is true is an important skill. For example, suppose that we are trying to figure out what causes our dog, Charlie, to have seizures. To simplify, let's suppose that we have a set of potential candidates for what causes his seizures. It could be either:
or some combination of these things. Suppose we keep a log of when these things occur each day and when his seizures (S) occur. In the table below, I will represent the absence of the feature by a negation. So in the table below, "~A" represents that Charlie did not eat human food on that day; "~B" represents that he did not get a bath and shampoo that day; "~S" represents that he did not have a seizure that day. In contrast, "B" represents that he did have a bath and shampoo, whereas "C" represents that he was given a flea treatment that day. Here is how the log looks:
Day 1 | ~A | B | C | D | S |
---|---|---|---|---|---|
Day 2 | A | ~B | C | D | ~S |
Day 3 | A | B | ~C | D | ~S |
Day 4 | A | B | C | ~D | S |
Day 5 | A | B | ~C | D | ~S |
Day 6 | A | ~B | C | D | ~S |
How can we use this information to determine what might be causing Charlie to have seizures? The first thing we'd want to know is what feature is present every time he has a seizure. This would be a necessary (but not sufficient) condition. And that can tell us something important about the cause. The necessary condition test says that any candidate feature (here A, B, C, or D) that is absent when the target feature (S) is present is eliminated as a possible necessary condition of S.3 In the table above, A is absent when S is present, so A can't be a necessary condition (i.e., day 1). D is also absent when S is present (day 4) so D can't be a necessary condition either. In contrast, B is never absent when S is present—that is every time S is present, B is also present. That means B is a necessary condition, based on the data that we have gathered so far. The same applies to C since it is never absent when S is present. Notice that there are times when both B and C are absent, but on those days the target feature (S) is absent as well, so it doesn't matter.
The next thing we'd want to know is which feature is such that every time it is present, Charlie has a seizure. The test that is relevant to determining this is called the sufficient condition test. The sufficient condition test says that any candidate that is present when the target feature (S) is absent is eliminated as a possible sufficient condition of S. In the table above, we can see that no one candidate feature is a sufficient condition for causing the seizures since for each candidate (A, B, C, D) there is a case (i.e. day) where it is present but that no seizure occurred. Although no one feature is sufficient for causing the seizures (according to the data we have gathered so far), it is still possible that certain features are jointly sufficient . Two candidate features are jointly sufficient for a target feature if and only if there is no case in which both candidates are present and yet the target is absent. Applying this test, we can see that B and C are jointly sufficient for the target feature since any time both are present, the target feature is always present. Thus, from the data we have gathered so far, we can say that the likely cause of Charlie's seizures are when we both give him a bath and then follow that bath up with a flea treatment. Every time those two things occur, he has a seizure (sufficient condition); and every time he has a seizure, those two things occur (necessary condition). Thus, the data gathered so far supports the following causal conditional:
Any time Charlie is given a shampoo bath and a flea treatment, he has a seizure.
Although in the above case, the necessary and sufficient conditions were the same, this needn't always be the case. Sometimes sufficient conditions are not necessary conditions. For example, being fed through a wood chipper is a sufficient condition for death, but it certainly isn't necessary! (Lot's of people die without being fed through a wood chipper, so it can't be a necessary condition of dying). In any case, determining necessary and sufficient conditions is a key part of determining a cause.
When analyzing data to find a cause it is important that we rigorously test each candidate. Here is an example to illustrate rigorous testing. Suppose that on every day we collected data about Charlie he ate human food but that on none of the days was he given a bath and shampoo, as the table below indicates.
Day 1 | A | ~B | C | D | ~S |
---|---|---|---|---|---|
Day 2 | A | ~B | C | D | ~S |
Day 3 | A | ~B | ~C | D | ~S |
Day 4 | A | ~B | C | ~D | S |
Day 5 | A | ~B | ~C | D | ~S |
Day 6 | A | ~B | C | D | S |
Given this data, A trivially passes the necessary condition test since it is always present (thus, there can never be a case where A is absent when S is present). However, in order to rigorously test A as a necessary condition, we have to look for cases in which A is not present and then see if our target condition S is present. We have rigorously tested A as a necessary condition only if we have collected data in which A was not present. Otherwise, we don't really know whether A is a necessary condition. Similarly, B trivially passes the sufficient condition test since it is never present (thus, there can never be a case where B is present but S is absent). However, in order to rigorously test B as a sufficient condition, we have to look for cases in which B is present and then see if our target condition S is absent. We have rigorously tested B as a sufficient condition only if we have collected data in which B is present. Otherwise, we don't really know whether B is a sufficient condition or not.
In rigorous testing , we are actively looking for (or trying to create) situations in which a candidate feature fails one of the tests. That is why when rigorously testing a candidate for the necessary condition test, we must seek out cases in which the candidate is not present, whereas when rigorously testing a candidate for the sufficient condition test, we must seek out cases in which the candidate is present. In the example above, A is not rigorously tested as a necessary condition and B is not rigorously tested as a sufficient condition. If we are interested in finding a cause, we should always rigorously test each candidate. This means that we should always have a mix of different situations where the candidates and targets are sometimes present and sometimes absent.
The necessary and sufficient conditions tests can be applied when features of the environment are wholly present or wholly absent. However, in situations where features of the environment are always present in some degree, these tests will not work (since there will never be cases where the features are absent and so rigorous testing cannot be applied). For example, suppose we are trying to figure out whether CO 2 is a contributing cause to higher global temperatures. In this case, we can't very well look for cases in which CO 2 is present but high global temperatures aren't (sufficient condition test), since CO 2 and high temperatures are always present to some degree. Nor can we look for cases in which CO 2 is absent when high global temperatures are present (necessary condition test), since, again, CO 2 and high global temperatures are always present to some degree. Rather, we must use a different method, the method that J.S. Mill called the method of concomitant variation . In concomitant variation we look for how things vary vis-à-vis each other. For example, if we see that as CO 2 levels rise, global temperatures also rise, then this is evidence that CO 2 and higher temperatures are positively correlated. When two things are positively correlated , as one increases, the other also increases at a similar rate (or as one decreases, the other decreases at a similar rate). In contrast, when two things are negatively correlated , as one increases, the other decreases at similar rate (or vice versa). For example, if as a police department increased the number of police officers on the street, the number of crimes reported decreases, then number of police on the street and number of crimes reported would be negatively correlated. In each of these examples, we may think we can directly infer the cause from the correlation - the rising CO2 levels are causing the rising global temperatures and the increasing number of police on the street is causing the crime rate to drop. However, we cannot directly infer causation from correlation. Correlation is not causation. If A and B are positively correlated, then there are four distinct possibilities regarding what the cause is:
- A is the cause of B
- B is the cause of A
- Some third thing, C, is the cause of both A and B increasing
- The correlation is accidental
In order to infer what causes what in a correlation, we must rely on our general background knowledge (i.e., things we know to be true about the world), our scientific knowledge, and possibly further scientific testing. For example, in the global warming case, there is no scientific theory that explains how rising global temperatures could cause rising levels of CO 2 but there is a scientific theory that enables us to understand how rising levels of CO 2 could increase average global temperatures. This knowledge makes it plausible to infer that the rising CO 2 levels are causing the rising average global temperatures. In the police/crime case, drawing on our background knowledge we can easily come up with an inference to the best explanation argument for why increased police presence on the streets would lower the crime rate - the more police on the street, the harder it is for criminals to get away with crimes because there are fewer places where those crimes could take place without the criminal being caught. Since criminals don't want to risk getting caught when they commit a crime, seeing more police around will make them less likely to commit a crime. In contrast, there is no good explanation for why decreased crime would cause there to be more police on the street. In fact, it would seem to be just the opposite: if the crime rate is low, the city should cut back, or at least remain stable, on the number of police officers and put those resources somewhere else. This makes it plausible to infer that it is the increased police officers on the street that is causing the decrease in crime.
Sometimes two things can be correlated without either one causing the other. Rather, some third thing is causing them both. For example, suppose that Bob discovers a correlation between waking up with all his clothes on and waking up with a headache. Bob might try to infer that sleeping with all his clothes on causes headaches, but there is probably a better explanation than that. It is more likely that Bob's drinking too much the night before caused him to pass out in his bed with all his clothes on, as well as his headache. In this scenario, Bob's inebriation is the common cause of both his headache and his clothes being on in bed.
Sometimes correlations are merely accidental, meaning that there is no causal relationship between them at all. For example, Tyler Vigen4 reports that the per capita consumption of cheese in the U.S. correlates with the number of people who die by becoming entangled in their bedsheets:
![causal fallacy critical thinking ...](https://learn.saylor.org/pluginfile.php/5689196/mod_book/chapter/57506/Screenshot_12.png)
And the number of Mexican lemons imported to the U.S. correlates with the number of traffic fatalities:
![causal fallacy critical thinking ...](https://learn.saylor.org/pluginfile.php/5689196/mod_book/chapter/57506/Screenshot_13.png)
Clearly neither of these correlations are causally related at all - they are accidental correlations . What makes them accidental is that we have no theory that would make sense of how they could be causally related. This just goes to show that it isn't simply the correlation that allows us to infer a cause, but, rather, some additional background theory, scientific theory, or other evidence that establishes one thing as causing another. We can explain the relationship between correlation and causation using the concepts of necessary and sufficient conditions (first introduced in chapter 2): correlation is a necessary condition for causation, but it is not a sufficient condition for causation.
Our discussion of causes has shown that we cannot say that just because A precedes B or is correlated with B, that A caused B. To claim that since A precedes or correlates with B, A must therefore be the cause of B is to commit what is called the false cause fallacy . The false cause fallacy is sometimes called the "post hoc" fallacy. "Post hoc" is short for the Latin phrase, "post hoc ergo propter hoc," which means "after this therefore because of this". As we've seen, false cause fallacies occur any time someone assumes that two events that are correlated must be in a causal relationship, or that since one event precedes another, it must cause the other. To avoid the false cause fallacy, one must look more carefully into the relationship between A and B to determine whether there is a true cause or just a common cause or accidental correlation. Common causes and accidental correlations are more common than one might think.
![causal fallacy critical thinking Creative Commons License](https://i.creativecommons.org/l/by/4.0/80x15.png)
Academia.edu no longer supports Internet Explorer.
To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser .
Enter the email address you signed up with and we'll email you a reset link.
- We're Hiring!
- Help Center
![causal fallacy critical thinking paper cover thumbnail](https://0.academia-photos.com/attachment_thumbnails/115863425/mini_magick20240802-1-fb0jbg.png?1722564625)
Logical Fallacies: How They Undermine Critical Thinking and How to Avoid Them
![causal fallacy critical thinking Profile image of Hershey H Friedman](https://0.academia-photos.com/93329/13659542/14799502/s65_hershey.friedman.jpg)
This paper explains how to recognize and steer clear of numerous common logical fallacies, ranging from ad hominem arguments to wishful thinking, that can damage an argument. Critical thinking is essential in the digital age, where we must question false or flawed claims. It helps us base our decisions on facts and evidence, not feelings or fallacious reasoning. Unfortunately, many employers struggle to find workers with this skill. To develop it, one must learn how to understand and evaluate the essence of an argument.
Related Papers
claudia cuadro
![causal fallacy critical thinking causal fallacy critical thinking](https://a.academia-assets.com/images/loswp/related-pdf-icon.png)
rohmani indah
Critical thinking skill has been a crucial issue in the context of higher education as the benchmark of qualified graduates. It is integrated in all aspects and involved in all of the courses as elaborated in the syllabus. Assessing the critical thinking becomes prominent to make sure that its quality is maintained. The real reflection of critical thinking can be traced through students’ ability to express their thought in the form of arguments. Good arguments must be supported not only by convincing claims and careful choice of supporting details but also on the rhetorical pattern which is free from fallacious statements. Identifying the fallacious statement which include recognizing the fallacy varieties assures the quality of their critical thinking. This study investigates the fallacious statements in the argumentative writing of the students of UIN Maulana Malik Ibrahim Malang who argue on global issues. The faulty reasoning is found in terms of the the discussion on the topics...
Charlene Tan
This chapter introduces key concepts in critical thinking using films and music videos. It focuses on the critical thinking skills needed for the identification, analysis and evaluation of arguments. Based on 12 key questions, readers are introduced to core features of an argument such as “premise”, “conclusion” and “assumption”. The main types of arguments and the criteria for evaluating these arguments are also discussed. Throughout the chapter, films such as A Beautiful Mind, Bowling for Columbine and CSI: Miami, and music videos of John Lennon’s “Imagine”, Britney Spears’ “Toxic”, Michael Jackson’s “Billie Jean” and others are used to illustrate the concepts.
Abdulvahit Çakır
The aim of this study was to explore the impact of raising awareness about reasoning fallacies on the development of critical reading skills of the first grade students in the ELT department, Gazi Faculty of Education. It was evaluated via a 56-question reasoning fallacies test confining seven questions to each fallacy studied in this research. Although there are numerous kinds of fallacies, between 14 and 191 to be more precise, the common ones were chosen in accordance with the reasoning fallacies test for practical reasons. In addition to this, during the literature review, some other common fallacies were determined and included in this dissertation. This study compared the students trained explicitly about questioning the arguments and argumentative texts on the one side and the students in the ordinary reading classes following the regular syllabus in terms of awareness about reasoning fallacies. A true experimental design was used to collect data through pre- and post-tests. ...
Robert Gass
The ability to think, reason, and argue well depends, among other things, on students’ ability to identify and avoid informal fallacies. This exercise enhances students’ understanding of fallacies through an experiential activity in which they construct fallacies on their own and identify fallacies created by other students. In the process, they consider the ethical and practical considerations of encountering fallacies in "real life." The exercise can be used in a variety of college courses, including public speaking, logic, debate, argumentation, critical thinking, writing, rhetoric, and others.
Sandra Dwyer
Hal Campbell
Critical thinking by definition can be explained as the determination of whether we should accept, reject, or suspend judgment about a claim and the degree of confidence with which we should accept or reject it. Critical thinking helps us to formulate a judgment as to whether a position, theory, or idea is incomplete or unclear, insufficiently supported by the contentions made in its behalf, or whether the argument is unconvincing, or simply wrong. One of the principle tenants of critical thinking is that the ideas, arguments, and conclusions being offered are critiqued and not the person making them. As you can tell from the dogma and discourse going on in the media these days, this isn’t a widely embraced approach amongst politicians, pundits, reporters, and the general public. It is perfectly acceptable to come to a conclusion about the person making the argument, but that comes much later and is based upon the position they took on the issue and the rationale they used to argue their point. It is also a measure of how often they are perceived as inaccurate, uninformed, or simply incorrect about an issue that they postulate, and what strategies they use routinely to manipulate the people they are endeavoring to persuade to their point of view.
Inquiry: Critical Thinking Across the Disciplines
Sharon Bailin , Mark Battersby
Sabina Saldanha
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.
RELATED PAPERS
Cherie K. Miller
ANIMA Indonesian Psychological Journal
Ide Bagus Siaputra
Khánh Linh Nguyễn
Mark Battersby
Maarten Boudry
Rupkatha Journal on Interdisciplinary Studies in Humanities
Galina Jasečková
Carolyn Hartz
Ricardo Arieira
Lissa Schneider
Davy Budiono, M.Hum.
Dr Jason J Braithwaite
International Journal of Linguistics, Literature and Translation
brahim khartite
Educational Theory
Sophie Haroutunian-Gordon
In S. Oswald & T. Herman (Eds.) Rhetoric and Cognition, Bern, Peter Lang, p. 89-110.
Vasco Correia
John Stamper
Informal Logic
Jeffrey Maynes
Argumentation and Advocacy, Vol. 28, 1991. pp. 1-22.
Douglas Walton
Logic and Logical Philosophy
Katarzyna Budzynska
Proceedings 4th International Conference on Argumentation, Rhetoric, Debate and the Pedagogy of Empowerment, Sellami A. S. (Ed.), pp. 199-214.
Manuele De Conti
Robert Ricco
Philosophy and Rhetoric
Eugen Octav Popa
Effective Executive
Michael Walton
Mark Weinstein
RELATED TOPICS
- We're Hiring!
- Help Center
- Find new research papers in:
- Health Sciences
- Earth Sciences
- Cognitive Science
- Mathematics
- Computer Science
- Academia ©2024
Logical Fallacies: How They Undermine Critical Thinking and How to Avoid Them
29 Pages Posted: 24 Apr 2024
Hershey H. Friedman
City University of New York (CUNY) - Koppelman School of Business
Leon Kaganovskiy
Touro College - Department of Mathematics
Date Written: June 10, 2024
This paper explains how to recognize and steer clear of numerous common logical fallacies, ranging from ad hominem arguments to wishful thinking, that can damage an argument. Critical thinking is essential in the digital age, where we must question false or flawed claims. It helps us base our decisions on facts and evidence, not feelings or fallacious reasoning. Unfortunately, many employers struggle to find workers with this skill. To develop it, one must learn how to understand and evaluate the essence of an argument.
Keywords: critical thinking, cognitive bias, logical fallacy, Aristotle, causal arguments, straw
JEL Classification: A20, C44, D70, D81, G11
Suggested Citation: Suggested Citation
Hershey H. Friedman (Contact Author)
City university of new york (cuny) - koppelman school of business ( email ).
Management, Marketing & Entrepreneurship Dept. 2900 Bedford Avenue BROOKLYN, NY 11210 United States 7189515000 (Phone)
Touro College - Department of Mathematics ( email )
Do you have a job opening that you would like to promote on ssrn, paper statistics, related ejournals, microeconomics: decision-making under risk & uncertainty ejournal.
Subscribe to this fee journal for more curated articles on this topic
Cognitive Psychology eJournal
Decision-making in operations research ejournal, logic ejournal.
Logical Fallacies for Testers I: The Causal Fallacy
- Post author By kristinjackvony
- Post date January 7, 2023
- 1 Comment on Logical Fallacies for Testers I: The Causal Fallacy
Lately I’ve been thinking about thinking ; specifically, critical thinking skills and how important they are for everyone, especially testers. When testers can’t think critically, they aren’t able to diagnose software problems quickly or find good solutions to testing challenges. In light of this, I’ve decided to focus on critical thinking in my blog posts this year!
Each month, I’ll be writing about a different logical fallacy . A logical fallacy is a common reasoning error that most of us make when thinking about a problem. Logical fallacies are often made when people are arguing for a specific side in a debate, but they are also found when trying to get at the root cause of a problem. In each of my blog posts, I’ll describe the logical fallacy of the month, give a typical example, and then describe how it can be found in software testing. Then I’ll invite you to look for ways you have used that fallacy in your own testing. This month, we begin with the Causal Fallacy .
![causal fallacy critical thinking](https://thinkingtester.com/wp-content/uploads/2023/01/ice-cream-6993656_640.png)
The Causal Fallacy happens when someone takes two separate events and determines that one causes the other because they correlate. For example, let’s say that researchers on Amity Island are investigating why there have been so many shark attacks that summer. They take a look at other data they have for the island, and they discover that ice cream sales are up that summer as well. They come to the conclusion that all that ice cream consumption must be causing the increase in shark attacks.
Obviously this is ridiculous! A correlation between two data points does not mean that one causes the other. (For some really funny examples of data correlation, see Tyler Vigen’s website, Spurious Correlations .)
Let’s take a look at a software testing example. Imagine there is a social media site, Cute Kitten Photos, where users can create an account and share photos of their kittens. Every Friday, the data collection team at Cute Kitten Photos runs a series of reports where they determine the weekly usage of the platform and the most liked photos for the week. Also every Friday, the IT team has discovered that the CPU usage on the servers has spiked to dangerous levels, so much so that some users are getting 500 errors when they try to go to the site.
It’s pretty clear that these data collection reports are causing the CPU spikes, right? That’s what the IT team thinks! But the data collection team is sure that they are not causing the problem. They point to data that shows that their reports cause very little load on the system.
Finally, a deeper investigation discovers that one user of the platform has been sharing TIFF images of their kittens. The software is not handling this image type well, which is causing several retries, and retries of the retries, putting the heavy load on the servers.
From this example, it’s easy to see that correlation does not mean causation, and that the first and most obvious cause of a problem is not always the right one.
In the next few weeks, when you encounter an odd bug that seems to have an obvious cause, ask yourself, “What else could this mean?”
1 thought on “ Logical Fallacies for Testers I: The Causal Fallacy ”
Looking forward to seeing more test examples on this matter. But thanks a lot for the link to Spurious Correlations page – it is hilarious 🙂
Comments are closed.
The Gambler’s Fallacy: What It Is And How To Overcome It
The gambler’s fallacy is a common cognitive error that can have profound implications for decision making. Understanding the gambler’s fallacy, recognizing how it can influence decisions, and learning how to mitigate its effects is crucial for leaders who wish to make rational, informed choices.
Also known as the Monte Carlo fallacy , the gambler’s fallacy is based on the mistaken belief that if something happens more frequently than normal during a given period, it will happen less frequently in the future, or vice versa. Because it is based on our inherent misunderstanding of randomness, this fallacy often manifests in situations involving random events, such as gambling, where individuals wrongly assume that past outcomes influence future probabilities.
The gambler’s fallacy is a common cognitive error that can have profound implications for decision ... [+] making.
A famous example of this occurred on August 18, 1913, at the Casino de Monte-Carlo when black came up 26 times in a row on a roulette wheel. As word of this amazing streak spread through the casino, gamblers flocked to that table. They lost millions of francs betting on red in the mistaken belief that the streak must end. In reality, the odds of each spin coming up black remained the same each time, just as the odds of a tossed coin coming up “heads” are still 50:50, even if the last one hundred tosses came up “tails” (scientists have actually determined that the odds are 51:49 in favor of whichever side of the coin was facing up if it was flipped by a human; if tossed by a machine, the odds are indeed 50:50).
Impact on Business Decision Making
The gambler's fallacy can impair decision making, particularly in situations where outcomes are influenced by random chance. This bias can lead to overconfidence in predicting future events based on past occurrences, which may not have any bearing on what will happen next.
In business, this can manifest in several ways.
Investors may fall prey to the gambler’s fallacy by believing that a stock that has performed poorly for an extended period is "due" for a rebound. Conversely, they may assume that a consistently successful stock is bound to decline. Either assumption can lead to misguided investment strategies and significant financial losses.
Sales teams might misinterpret patterns in customer behavior, assuming that a period of low sales will be followed by a surge, or that a streak of high sales will inevitably end. This can lead to inappropriate allocation of resources or missed opportunities.
The gambler’s fallacy can also affect risk management decisions. Leaders may underestimate risks after a series of positive outcomes, assuming that “bad luck” is less likely to occur or that positive trends will continue indefinitely. This can result in inadequate preparation for potential setbacks or crises.
6 Ways to Overcome the Gambler’s Fallacy
Recognizing and overcoming the gambler’s fallacy is essential for making sound decisions, especially in environments characterized by uncertainty and risk. Here are some strategies that you can use to avoid falling into this cognitive trap:
- Education and Awareness: The first step in overcoming the gambler’s fallacy is understanding the concept and acknowledging its potential influence on decision making. Educating oneself and others about the fallacy can raise awareness and reduce the likelihood of falling prey to it.
- Embrace Probabilistic Thinking : Decision-makers should focus on the actual probabilities of events rather than relying on perceived patterns. This involves understanding that independent events do not influence each other and that the odds remain constant regardless of past outcomes. Embracing probabilistic thinking can help leaders make more rational, data-driven decisions.
- Use Decision-Making Frameworks: Implementing structured decision-making frameworks can help counteract cognitive biases like the gambler’s fallacy. Techniques such as red teaming, scenario planning, and pre-mortem analysis encourage a comprehensive examination of potential outcomes and risks, reducing the influence of faulty assumptions.
- Consult Diverse Perspectives: Seeking input from a diverse group of stakeholders can also mitigate the effects of the gambler’s fallacy. Different perspectives can challenge erroneous beliefs and provide a more balanced view of potential outcomes, leading to better-informed decisions.
- Leverage Technology and Data Analytics: Modern technology and data analytics tools can assist in making more accurate predictions and decisions by analyzing large datasets and identifying genuine patterns. By relying on data rather than intuition, leaders can avoid the pitfalls of the gambler’s fallacy.
- Mindfulness and Self-reflection: Practicing mindfulness and regularly reflecting on past decisions can help individuals recognize when they are falling into the trap of the gambler’s fallacy. By critically assessing their thought processes, leaders can identify and correct biased thinking before it leads to poor decisions.
The gambler’s fallacy is a powerful cognitive bias that can significantly distort decision making, particularly in uncertain environments. By understanding this fallacy, recognizing its impact, and employing strategies to overcome it, leaders can improve their decision-making processes and avoid costly mistakes.
![](http://writinghelp.online/777/templates/cheerup/res/banner1.gif)
IMAGES
VIDEO
COMMENTS
What the False Cause Fallacy is: The False Cause fallacy occurs when someone assumes that because two events occur together, one causes the other, without sufficient evidence to establish a causal relationship. When does it occur: This fallacy arises when correlation is mistaken for causation, leading.
The false dilemma (or false dichotomy) is a logical fallacy where a situation is presented as being an either/or option when, in reality, there are more possible options available than just the chosen two. Here's an example: Rebecca rings the doorbell but Ethan doesn't answer. She then thinks, "Oh, Ethan must not be home."
Revised on July 24, 2023. A false cause fallacy occurs when someone incorrectly assumes that a causal relation exists between two things or events. This is an improper conclusion because either such a relationship does not exist or the evidence in support of it is insufficient. False cause fallacy example. "Every time I bring my umbrella with ...
The causal fallacy is the logical fallacy of incorrectly making a conclusion about an event's cause. The causal fallacy is actually a category of fallacies rather than one specific line of faulty reasoning. All of the fallacies that fit into this category are characterized by one thing: the illogical assumption that a specific factor caused a ...
The false cause fallacy relates to causal reasoning and occurs when a speaker argues, with insufficient evidence, that one thing caused or causes another. ... Being able to identify fallacies is an important critical thinking skill. Find a letter to the editor in a paper or online and see if you can identify any of the ten fallacies discussed ...
Logical fallacies are errors in reasoning or flawed arguments that can mislead or deceive. They often appear plausible but lack sound evidence or valid reasoning, undermining the credibility of an argument. These errors can be categorized into various types, such as ad hominem attacks, strawman arguments, and false cause correlations. Impact on Critical Thinking,
Some may say that the curated images on social media lead to eating disorders—an example of the false cause fallacy where one incorrectly assumes that viewed images directly cause disordered eating. A current event example is the debate around climate change policies, where fallacies like false dilemma (presenting only two extreme solutions ...
To boost students' critical thinking, teach them how to identify and avoid making them logical fallacies in their writing and arguments. ... False cause fallacy What is the false cause fallacy? The false cause fallacy occurs when one incorrectly assumes a causal connection between two events. Take this example:
This paper explains how to recognize and steer clear of numerous common logical fallacies, ranging from ad hominem arguments to wishful thinking, that can damage an argument. Critical thinking is ...
The post hoc fallacy is part of a larger group of logical fallacies called false cause fallacies. And in this article, we will learn more about this common method of faulty logic. But first, let's look at what a false cause fallacy is. ... then follow this 7-step process to develop the critical thinking skills habit.
The study of fallacies is an application of the principles of critical thinking. Being familiar with typical fallacies can help us avoid them and help explain other people's mistakes. There are different ways of classifying fallacies. Broadly speaking, we might divide fallacies into four kinds:
This fallacy ascribes a causal relationship between two states or events on the basis of temporal succession. For example, ... The semi-logical fallacies mostly trade on ambiguous middle terms and are therefore also logical ... P., 2011, "Critical thinking and informal logic: neuropsychological perspectives," Informal Logic, 31: 152-70 ...
A logical fallacy is an argument that may sound convincing or true but is actually flawed. Logical fallacies are leaps of logic that lead us to an unsupported conclusion. People may commit a logical fallacy unintentionally, due to poor reasoning, or intentionally, in order to manipulate others. Logical fallacy example.
Causal Reasoning. Read this section to investigate the complications of causality, particularly as it relates to correlation. Sometimes, two correlated events share a common cause, and sometimes, correlation is accidental. Complete the exercises to practice determining sufficient evidence for causation and determining accidental correlation.
In this Wireless Philosophy video, Paul Henne (Duke University) explains the difference between correlation and causation.Subscribe!http://bit.ly/1vz5fK9More...
Keywords: critical thinking, cognitive bias, logical fallacy, Aristotle, causal arguments, straw man argument, moral equivalence, appeal to authority, false dilemma, tu quoque fallacy. We live in a post-factual and post-truth society where people are more influenced by their emotions and beliefs than by evidence.
This paper explains how to recognize and steer clear of numerous common logical fallacies, ranging from ad hominem arguments to wishful thinking, that can damag ... ranging from ad hominem arguments to wishful thinking, that can damage an argument. Critical thinking is essential in the digital age, where we must question false or flawed claims ...
The Causal Fallacy happens when someone takes two separate events and determines that one causes the other because they correlate. For example, let's say that researchers on Amity Island are investigating why there have been so many shark attacks that summer. They take a look at other data they have for the island, and they discover that ice ...
The hot-hand fallacy can cause individuals to overestimate their abilities to predict future success. A business leader who has made several successful strategic decisions in a row might believe ...
In business, this can manifest in several ways. Investors may fall prey to the gambler's fallacy by believing that a stock that has performed poorly for an extended period is "due" for a rebound.