A logical fallacy occurs when someone tries to persuade you with a faulty argument. Sometimes, logical fallacies are innocuous: the writer has a good argument to make, it was just set up through faulty logic. However, logical fallacies run rampant among less-than-sincere writers, and if you want to write well and read well, then knowing our list of logical fallacies will help arm you against faulty arguments.
Because people are constantly trying to persuade you of something—politicians, advertisers, social media posts, etc.—logical fallacies occur all the time. Good persuasive writers will know how to avoid these common logical fallacies, and good readers will know how to identify them without being persuaded.
So, what is a logical fallacy? And why do they matter for my writing? Understanding the arguments in this list of logical fallacies will help strengthen your writing and ability to write effective arguments. But before we look at some examples of logical fallacies, let’s get clear on these persuasive and invasive mistakes in rhetoric.
- Logical Fallacy Definition: What is a Logical Fallacy?
- Common Types of Logical Fallacies
- A Note on Good Persuasive Writing
- Logical Fallacies Examples: Fallacies of Relevance
- Logical Fallacies Examples: Fallacies of Unacceptable Premises
- Logical Fallacies Examples: Formal Fallacies
- Other Logical Fallacies Examples
Logical Fallacy Definition: What is a Logical Fallacy?
Simply put, a logical fallacy is an error in reasoning that undermines the logic of an argument. It does not necessarily undermine the persuasiveness of that argument, however; unless you are well-versed in the different types of logical fallacies, you can certainly be persuaded by one yourself.
A logical fallacy is an error in reasoning that undermines the logic, but not necessarily the persuasiveness, of an argument.
A common logical fallacy example is a red herring. A red herring is an attempt to divert the audience’s attention from the argument itself. It might look something like this:
Some people criticize the SAT for measuring test taking skills, not college readiness. Nonetheless, a high SAT score will get you into better colleges.
This statement isn’t actually addressing the issue of the SAT’s validity, it’s distracting you by bringing up the importance of a high test score, going so far as dismissing the original claim entirely.
All logical fallacies have one thing in common: they don’t hold up to scrutiny. But there are different ways in which writers might present less-than-foolproof arguments. Let’s examine the common types of logical fallacies.
All logical fallacies have one thing in common: they don’t hold up to scrutiny.
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Common Types of Logical Fallacies
Most logical fallacies can be sorted into one of three categories:
- Fallacies of Relevance: arguments that do not apply to the central claim.
- For example: You had a bad day because Mercury is in retrograde.
- Fallacies of Unacceptable Premises: arguments that are relevant to the central claim but do not support it.
- For example: You had a bad day because you always have bad days when it rains before noon.
- Formal Fallacies: one or more arguments are simply incorrect, bringing the listener to an invalid conclusion.
- For example: Because rain symbolizes sadness, and because you are having a bad day, the rain is causing your bad day.
- In a formal fallacy, the flaw is in the logic and conclusion. Most other fallacies are informal fallacies, in which the flaw is simply the logic.
We’ll examine these three categories shortly. But before we examine some examples of logical fallacies, let’s talk about good persuasive writing.
A Note on Good Persuasive Writing
By now, you’re probably familiar with the basic structure of an argumentative essay. Most essays, including those at the higher academic level, generally follow a thesis statement, followed by supporting claims, evidence, and a conclusion. Most essays also address potential counterclaims and offer rebuttal arguments.
The structure is the easy part. Aside from side-stepping all logical fallacies, how do you write a persuasive essay that’s actually, well, persuasive?
Here are a few tips:
- Speak to your reader. Knowing your audience is crucial to making an effective argument. What ideas are they likely to resonate with? What vocabulary and word choice will they most likely understand? Even if you don’t know your exact audience, speaking to them will help you make a genuine connection with your readers.
- Be concrete. Tie your thesis and arguments to the real world, even if your writing isn’t about real world issues. For example, an essay about the values of optimism can demonstrate those values through concrete examples: anecdotes, case studies, and psychological research, as well as moral and philosophical reasoning.
- Sound like yourself. Using a lofty vocabulary or purple prose will not win over any of your readers. Part of building effective ethos is sounding like a reasonable voice, one which the reader can trust and rely on, and that comes through employing smart writing style strategies.
- Know your rhetorical devices. A good balance of ethos, pathos, logos, and kairos will go a long way towards persuasiveness. And, knowing different types of argumentative and rhetorical structures will certainly come in handy. Similes, metaphors, and analogies are also great ways of demonstrating an argument.
Of course, these strategies alone don’t make for great persuasive writing. Having solid logic behind your reasoning and carefully crafted arguments will make your essays shine. As such, let’s look at some common logical fallacies and discuss how you can avoid them.
Logical Fallacies Examples
A good persuasive essay requires good thinking, writing, researching, and revising. Nonetheless, even the best thinkers are prone to these common logical fallacies. Understanding the errors of logic in this list, how they happen, and how to avoid them will strengthen your ability to argue and to identify faulty arguments.
We’ve sectioned this list by the different types of logical fallacies. Let’s examine them below!
Logical Fallacies Examples: Fallacies of Relevance
Fallacies of Relevance are any number of informal logical fallacies in which an irrelevant argument is presented as relevant, distorting the conclusion or misdirecting the audience. You may have heard of the red herring logical fallacy before; most fallacies of relevance are, in some way, red herrings.
Fallacies of Relevance are logical fallacies in which an irrelevant argument is presented as relevant, distorting the conclusion or misdirecting the audience.
Let’s look closer at each one.
Ad Hominem Logical Fallacy
An Ad Hominem (Latin: “against the person”) attack is a logical fallacy in which the person is argued against, rather than the argument the person is making. In other words, it attacks the source but not the credibility of the argument.
Here are a few examples:
- The car salesman is lying about the quality of the car because it’s his job to sell cars.
- “You have no reason to raise the minimum wage if you’ve never run a business before.”
- “I just saw my boss do a hit and run. Clearly, this means he’s a bad boss.”
None of these examples actually engage with logic. Accusing someone of lying or ignorance is a lazy way of avoiding the argument. And, while someone who commits a hit and run has questionable ethics, there isn’t a clear relationship between bad driving and bad leadership.
If any of these attacks sound familiar, it’s because Ad Hominem is a prominent feature of our cultural and political landscape. Now, there is something to be said about questioning the ethos of the person making an argument. There are plenty of people, politicians and otherwise, who do have ulterior motives and hidden agendas behind their logic and reasoning.
However, in good argumentation, you cannot simply question the ethos of the person. You must engage with the arguments themselves; an Ad Hominem attack is simply a distraction, meant to make the audience angry or distracted from the issues at hand.
In good argumentation, you must engage with the arguments themselves.
Appeal to Consequences Logical Fallacy
The Appeal to Consequences argues that a premise is correct or incorrect based on whether the outcome is positive or negative. In other words, if a certain hypothesis leads to an undesirable consequence, the hypothesis “must” be wrong; if the consequence is positive, it “must” be right.
- Rent prices are bound to decrease because more people will be able to afford housing.
- It’s impossible to spend all your money gambling because then you couldn’t afford to eat.
Of course, valid hypotheses can result in negative outcomes, because an argument is valid irrespective of its outcome. And invalid hypotheses can suggest positive outcomes because “wishful thinking” is inherently a logical fallacy.
Appeal to Emotion Logical Fallacy
An Appeal to Emotion occurs when an argument tries to evoke an emotional response, rather than a logical one. For example:
- “You should eat your food because a poor, starving child in Africa doesn’t have any.”
- (Appealing to your sense of guilt.)
- “If you pass this law, thousands of your constituents will ransack your office.” (Appealing to your sense of fear.)
- “You can’t raise the minimum wage; your childhood enemy might make more money.” (Appealing to your sense of hatred.)
Now, this logical fallacy is similar to the rhetorical device “pathos.” The difference is that, in good rhetoric, pathos is not the central argument. Pathos is a feature of good argumentation, because a good rhetorician knows which emotions to evoke from the audience and how those emotions inspire action or belief. But, when that emotional response is the desired outcome of the argument, without credible logic to back it up, then the speaker is trying to twist your feelings without good reasoning.
- Pathos-inspired logic: Martin Luther King, Jr.’s “I Have a Dream” speech included many examples of racial inequality, including how “one hundred years [after slavery], the Negro lives on a lonely island of poverty in the midst of a vast ocean of material prosperity”. Calling attention to something ostensibly unfair inspired action; elsewhere in the speech, King uses ethos and logos to demand a better life for Black Americans—which, for the skeptical member of King’s audience, will also improve the lives of all Americans.
- Appeal to Emotion fallacy: Let’s say King’s entire speech was just pathos. Or, let’s say King started arguing “if we don’t achieve racial equality, America will burn and everyone will die.” Then, the purpose of the speech would have been simply to make people angry and afraid, rather than to push for a more equitable society. The difference, here, lies in the purpose of the speech, and in the facts and logic played out on the national stage.
Appeal to Force Logical Fallacy
An Appeal to Force argues that physical or emotional harm is a consequence of certain arguments. It is related to the Appeal to Emotion in that it inspires fear.
- “If you don’t work extra hours without pay, you’ll be fired without severance.”
- “Maybe you’ll agree with me after I break a few of your ribs.”
- “If you don’t vote for me, your rent will skyrocket, the streets will be riddled with crime, and your children will have no future to speak of.”
Obviously, these arguments aren’t arguments at all: they’re trying to coerce you into agreeing with something that has no logical backing.
Appeal to Ignorance Logical Fallacy
The Appeal to Ignorance is a logical fallacy in which something must be true because there is no evidence against it. In other words, the fallacy is that the absence of counterevidence means there is no counterevidence. However, the absence of something is not an argument for its own absence: “absence of evidence is not evidence of absence.”
- Aliens do not exist because we have not come into contact with them.
- We haven’t come into contact with the core of a black hole, so you cannot assume that the core of a black hole is not made up of bird’s feathers.
The Appeal to Ignorance is especially consequential in the courtroom. For example, if you don’t have an alibi, that means you must have killed the victim. The logic isn’t sound, but the wrong jury, or a jury with strong prejudices, might buy it.
Appeal to Improper Authority Logical Fallacy
The Appeal to Improper Authority argues that an argument must be true because it came from an authority figure. This is misplaced ethos, because the logical fallacy assumes one’s authority automatically grants ethos on a position, instead of that ethos being earned through argumentation.
- “She has bipolar disorder. Trust me, I’m a psychology major.”
- “My high school gym teacher told me never to use ice on a sprained ankle.”
Sometimes, the Appeal to Improper Authority is an appeal to the wrong kind of authority. Being a psychology major isn’t justification for diagnosing someone; you should have an advanced degree and research experience. You should also have conducted a psych evaluation on the person in question. Other times, this Appeal isn’t enough justification; you still need to back your arguments with logic. What knowledge does your degree as a psych major give you to make a certain conclusion?
However, this is not license to assume something is incorrect just because it comes from an authority figure. For example, many people assume that the advice from a doctor must be wrong. While doctors do make mistakes, attacking the credibility of a doctor, rather than the science behind the decisions they make, is just an Ad Hominem.
Appeal to Tradition Logical Fallacy
The Appeal to Tradition logical fallacy says “we’ve always done it this way.” Rather than interrogate the logic behind a certain action, the argument assumes the action is logically sound because it’s been done for a certain amount of time.
- “Our family has always voted this way. Grandpa would kill me if I voted any other way!” (This neglects that a party’s positions change over time, as well as the political needs of a city/state/nation.)
- “Women have always tended to the hearth and raised the kids. It’s easier this way!”
Sometimes, tradition is rooted in logic. But a good argument will illuminate that logic, and that logic’s relevance to the modern day, rather than assume the logic exists.
Argument From Incredulity Logical Fallacy
An argument from incredulity occurs when you argue that something can’t be true solely because it’s difficult to imagine, hard to understand, or else doesn’t conform to your particular worldview.
- Not believing we landed men on the moon.
- “I don’t understand your argument, therefore it isn’t logical.”
- “Your argument doesn’t align with my spiritual or political beliefs. Therefore, it’s wrong.”
This logical fallacy is often at play among conspiracy theorists, but it’s just another easy way to avoid the hard work of understanding and responding to logically sound arguments.
Argumentum ad Populum Logical Fallacy
The Argumentum ad Populum (Argument to the People, or “to Popularity”) is based on the premise that, if a certain number of people believe in the argument, it must be correct. This logical fallacy has a few different manifestations, including:
- The Bandwagon Argument: “Most people believe that the iPhone is superior, so you should buy an iPhone.”
- The Patriotic Argument (Jingoism): “You must buy an iPhone, because you’re supporting an American company with American values. Any other phone is tantamount to treason!”
- The Snob Argument: “Anyone who’s rich and important has an iPhone. So, you should have one if you want to be rich and important.”
This argument can be difficult to respond to, because if the argument is wrong, you might be implying that the masses have poor logic. Well, sometimes they do. Argumentum ad Populum is simply peer pressure, not sound logic.
The Genetic Fallacy occurs when you base the validity, or invalidity, of an argument solely on its source. Ad Hominem can be a type of Genetic Fallacy, but you can also attack an argument’s validity by saying it came from Wikipedia, YouTube, or a certain publisher or newspaper.
- “My parents told me not to trust dentists, so I don’t trust dentists.” (This is also an Appeal to Improper Authority.)
- “Your information comes from Wikipedia. Clearly, your argument isn’t grounded on reliable data.”
You should certainly interrogate the source of information. However, good critical arguments will examine the research and methodologies behind that data, instead of just assuming invalidity.
Irrelevant Conclusion Logical Fallacy
The logical fallacy Irrelevant Conclusion, also known as ignoratio elenchi, describes a conclusion that is irrelevant to the premises allegedly supporting it.
- “Fire can’t be dangerous to humans because it keeps us warm in the winter.”
- “Cane sugar is good for you because it’s white, which is a pure color.”
Most logical fallacies of relevance are, in some way, fallacies of Irrelevant Conclusion.
Straw Man Argument Logical Fallacy
The Straw Man Argument occurs when you refute someone’s argument by responding to a completely different, utterly warped argument that the original person did not make. In other words, you distort an argument to make it easier to attack. The Straw Man is often a kind of Ad Hominem. It might look something like this:
Person 1: Investing money in your happiness today helps keep you motivated for longer term goals.
Person 2: What are you, some kind of hedonist?
This logical fallacy also occurs when you quote someone out of context. Think Fred Jones saying “I think Coolsville sucks!” in Scooby-Doo 2: Monsters Unleashed.
Tu Quoque Logical Fallacy
Tu Quoque is another form of Ad Hominem, in which a person’s behavior or past beliefs are called into question to discredit their current argument.
- “Doctors tell you not to smoke, but doctors smoke all the time.”
- “You cheated on your girlfriend, so why can’t I?”
Tu Quoque is sometimes called the Appeal to Hypocrisy. The importance of hypocrisy is not to be understated, but when it comes to logic and reasoning, someone being a hypocrite doesn’t necessarily discredit the argument at hand.
Logical Fallacies Examples: Fallacies of Unacceptable Premises
Fallacies of Unacceptable Premises attempt to introduce premises that, though possibly true, do not ultimately support the argument’s conclusions. This is different from fallacies of relevance because the premises are relevant, they just don’t support the conclusions.
Fallacies of Unacceptable Premises attempt to introduce premises that, though possibly true, do not ultimately support the argument’s conclusions.
Let’s look closer at each one.
Begging the Question Logical Fallacy
Begging the Question is a logical fallacy in which the validity of the conclusion is buried in the premise of the argument. In other words, the logic undergirding an argument makes assumptions that, when questioned, reveal the argument’s lack of reasoning. It is a premise restating the conclusion without supporting the conclusion.
- “I’m the boss (conclusion) because I get to make the final decision on everything (premise).”
- This is just saying “I’m the boss” in two different ways. It doesn’t actually explain why the boss gets to make those decisions.
- “The apple turnover is our bestseller (conclusion) because we sell it the most (premise).”
- Well, yes. That’s the definition of a bestseller. But this doesn’t explain why the apple turnover sells so well.
- “We should raise the minimum wage (conclusion) because low-income earners will make more money (premise).”
- The premise is saying the same thing as the conclusion, perhaps with a moral appeal attached. Take it a step further: what benefits do we get from raising the minimum wage? The argument hasn’t been made yet.
Begging the Question happens a lot more often than you might think. By knowing this logical fallacy and noticing it, you’ll be able to question a person’s logic (or lack thereof) much more directly.
The division fallacy occurs when you assume that something true for a whole entity is also true for each individual component of that entity. For example:
- There is a lot of money in the technology sector.
- You work in the technology sector.
- You make a lot of money.
Plenty of people make a lot of money in tech, but this assumption is riddled with errors. There are some low-paying positions in tech, and this argument does not take into account how money is distributed in tech.
False Dilemma Logical Fallacy
A False Dilemma occurs when an argument presents the audience a limited number of sides to an issue, when many more sides exist. By doing this, the argument hopes to make you choose its side over the other, when the situation is actually much more nuanced.
- “You either support the war or you hate your country.”
- “In high school, you’re either a nerd, a jock, or a prep.”
- “Anything that doesn’t support a free market Capitalist economy is clearly part of an authoritarian Communist agenda.”
Binary thinking is a prominent—and dangerous—way of thinking. Good, honest rhetoricians will recognize that one issue can have many sides, and that good thinking acknowledges gray spaces and ambiguities, rather than trying to paint a black and white picture of the world. Rhetoricians should be confident in their arguments, but if someone presents themselves as knowing everything, especially if they present a limited number of sides to an issue, be skeptical.
Slippery Slope Logical Fallacy
The Slippery Slope fallacy argues that a small first step will result in a later, usually catastrophic major event. It amplifies the stakes of an argument without providing clear justification that the catastrophe will occur.
- “Failing this one test means you might fail the class, which all but guarantees you won’t obtain your Master’s Degree.”
- “Weed is a gateway drug. Within a few years, you’ll be a jobless, homeless addict craving your next fix.”
- If you give this person a pass for being late, you’ll have to give everyone a pass, and then the rules won’t matter anymore.
- Lowering the voting age to 16 will encourage 12 year olds to try and vote. Eventually, this country will be run by children.
This isn’t to say that all catastrophizing is automatically a Slippery Slope. Rather, it’s to note that small decisions can lead to a variety of outcomes; if a catastrophic outcome is predicted, that prediction must be underscored with clear, structurally sound logic.
Hasty Generalization Logical Fallacy
A Hasty Generalization is a logical fallacy where a conclusion is drawn from a limited amount of information. The argument simply does not have enough data to support the conclusion it arrives at.
- “My neighbor has tanned every day for the past 20 years and has flawless skin. Therefore, sun exposure doesn’t cause skin cancer.”
- “Someone on the South Side flipped me off today. Everyone who lives there is so mean.”
- “1000 people committed food stamp fraud last year. All 3 million of them must be gaming the system.”
As you can see, Hasty Generalizations are really useful tools for assigning blame and turning the audience against a certain group of people. If you want to claim something about a group or an outcome, a good argument uses robust, clearly organized data to support that claim.
Faulty Analogy Logical Fallacy
A Faulty Analogy is the use of an analogy to compare two things that do not merit a direct comparison. (In brief, an analogy is a literary device in which two or more discrete things are compared as equals.) Using a Faulty Analogy misrepresents the topic at hand.
- “Computer programmers can create entire worlds using only code. God created the entire world in 7 days. Programmers are as powerful as God.”
- There’s a false equivalence of those different “worlds” here.
- “More people die from driving related incidents than from opiates. Therefore, we should put all our energy into making the roads safer.”
- Part of the reason for this difference is that more people drive than take opiates. In any case, this is also presenting a False Dilemma: why can’t we improve both situations?
- “Winning the lottery and meeting Lady Gaga are both unlikely. If you meet Lady Gaga, you should buy a lottery ticket right away!”
- This assumes that the two chance happenings are related to one another. But luck does not operate in any logical or meaningful way. The two simply can’t be compared.
When someone makes an argument using an analogy, ask yourself whether the items being compared exist on the same playing field. If they don’t, a logical fallacy is likely at play.
The Fallacy Fallacy
The Fallacy Fallacy occurs when you assume that an argument is incorrect because it contains a logical fallacy.
Now, that might seem ironic, or even completely contradictory. Isn’t that the entire point of this article?
What this means is, an argument can have the correct conclusion even if it uses a logical fallacy. The argument itself is incorrect, but the conclusion can still be true, it just needs to be reached using a different logic or set of data.
- “Horses can’t swim, and sharks aren’t horses, so sharks can swim.”
- Obviously, sharks can swim, but not because they’re not horses.
- “It rains a lot in Seattle. We’re in Seattle, which means it must be raining right now.”
- It could very well be raining in Seattle right now. But the reason it’s raining has nothing to do with the existence of Seattle, it has to do with the weather conditions Seattle finds itself in.
Don’t disregard the existence of this common logical fallacy. If a conclusion seems accurate, or even just intriguing, approach it with a sense of curiosity. Sure, the argument you’re given might be wrong, but under what conditions might it be right? And why is that?
Good logical thinking doesn’t just call out bad arguments, it also creates opportunities to discover more about the world.
Logical Fallacies Examples: Formal Fallacies
Formal fallacies are logical fallacies involving an error in deductive reasoning. As a refresher, deductive reasoning is the use of existing information (premises) to create new information (conclusions).
Formal fallacies are logical fallacies involving an error in deductive reasoning.
- A bird has wings, feathers, and claws.
- A cardinal has wings, feathers, and claws.
- A cardinal is a bird.
Formal fallacies include the following:
- Affirming the consequent
- Denying the antecedent
- Affirming a disjunct
- Denying a conjunct
- Fallacy of the undistributed middle
- Fallacy of four terms
You may have heard of the term non sequitur before. All formal fallacies are non sequiturs, because their conclusions do not follow the claims associated with them.
Let’s look closer at each one.
Affirming the Consequent Logical Fallacy
Affirming the Consequent occurs when the premise and the conclusion are switched in a formal argument. Let’s say you argue the following:
- If it is raining, then it is cloudy.
- It is rainy, thus
- It is cloudy.
Affirming the Consequent means switching the order of the latter two bullets. So, the logical fallacy would be:
- If it is raining, then it is cloudy.
- It is cloudy, thus
- It is raining.
This isn’t true, because it can be cloudy without it raining. The “if” and “then” statements have been reversed, resulting in a conclusion that can’t be supported.
Denying the Antecedent Logical Fallacy
Denying the Antecedent occurs when you take a standard argument, put it in the negative, and then argue that the negative is just as true. In other words, you argue that the opposite of a true argument is just as true.
Let’s take the above example. This argument is correct:
- If it is raining, then it is cloudy.
- It is rainy, thus
- It is cloudy.
The “antecedent” would look like this:
- If it is raining, then it is cloudy.
- It is not raining, thus
- It is not cloudy.
Obviously, it can be cloudy without it being rainy. The premise remains true, but assuming the inverse is also true leads to poor logic.
Affirming a Disjunct Logical Fallacy
Affirming a Disjunct arises out of the ambiguity of the word “or”. In formal logic, “or” can be inclusive (meaning “and/or”), or it can be exclusive (meaning “either/or”). Because of this ambiguity, an argument can seem as though it is creating a false binary, leading to a false conclusion.
- To get rich, you must work hard or network well.
- You got rich by networking well.
- Therefore, you did not work hard.
It is possible that the conclusion is true. It is equally possible that you worked hard and networked well. Affirming a Disjunct occurs when that “or” is interpreted as “exclusive,” rather than “inclusive.”
Denying a Conjunct Logical Fallacy
Denying a Conjunct follows a similar formal fallacy as Affirming a Disjunct, in which the argument seems to be creating a binary that actually cannot be supported. In this logical fallacy, you argue that two things cannot both be true, then conclude that if one is false, the other must be true.
- You cannot be both an American and a North Korean.
- You are not North Korean, thus
- You are American.
Obviously, you can be something other than American or North Korean. The premise of the argument is true, because you can’t have dual citizenship between the two countries, but the interpretation of that premise as a binary is false.
Fallacy of the Undistributed Middle
In the Fallacy of the Undistributed Middle, the middle term, which links the premise to the conclusion, doesn’t actually have a relationship to the premise or the conclusion, leading to a faulty conclusion.
- All birds have beaks.
- An octopus has a beak, thus
- An octopus is a bird.
The conclusion is obviously incorrect. Moreover, the middle term isn’t doing any work for the argument. It tells us that octopi and birds have beaks, but it doesn’t tell us the relationship between birds and octopi, nor does the argument say that birds are the only organisms with beaks. The argument is creating a connection that doesn’t exist in the argument, leading to a conclusion it cannot support.
Fallacy of Four Terms
The Fallacy of Four Terms occurs when a standard syllogistic argument (the kind we’ve been referencing throughout this section) has four or more terms, rather than the requisite three.
By terms, we don’t mean bullet points, we mean the points of comparison in an argument. Here’s a proper syllogism:
- All books (P) are written by humans (Q).
- If this text is a book (P), then
- It was written by a human (Q).
The letters in parentheses highlight that a syllogism follows this structure:
- All Ps are Qs
- If P
- Then Q
There are variations to a proper syllogistic argument, but they always have 3 terms: a PQ term, a P term, and a Q term.
Here’s the Fallacy of Four Terms:
- Manhattan’s streets (A) have a grid pattern (B).
- A waffle (X) is made with a gridded iron (Y).
- Manhattan is a waffle.
This fallacy rests on the assumption that a grid and a gridded iron are the same term, but they’re distinct. You thus arrive at an incorrect conclusion because you’ve made a random comparison between completely unalike ideas.
Here’s another example, to further illustrate the point, as well as to show how subtle this fallacy can be:
- Nothing (A) beats a cold glass of water on a hot day (B).
- A warm glass of water (X) is better than nothing (Y).
- A warm glass of water is better than a cold glass of water.
“Nothing” is being used in multiple colloquial senses, which creates a really confusing argument here. It seems like there are only 3 terms, but “nothing” is employed in two different senses (there is nothing superior vs. something is better than nothing). As a result, you get a conclusion that, well, some people might agree with, but ultimately isn’t grounded in any meaningful logic.
Other Logical Fallacies Examples
The common logical fallacies above all rely in some way on faulty syllogistic reasoning, whether the fallacy is in the logic or in the premises themselves. The following fallacies are different errors in logic and reasoning, which can contribute to faulty arguments, but are not necessarily syllogistic.
Correlation Vs Causation
Correlation Vs Causation occurs when you assume that a correlation implies an actual relationship between two things. For example, you might notice that people who get spray tans often wear flip flops. If you assume that getting a spray tan encourages you to wear flip flops, you’re committing this logical fallacy—there are plenty of reasons why this correlation might occur, but spray tans do not cause flip flop wearing.
Hypothesis Contrary to Fact
A Hypothesis Contrary to Fact is, simply, speculation without concrete evidence. It is an argument that, under different circumstances or historical events, the present or the future would certainly look a certain way. For example, “if you had gotten a job in finance, you’d be making loads of money right now.” This claim doesn’t take into account any number of factors: the state of the finance industry, your ability to perform finance-related work, etc.
“I’m Entitled to My Opinion”
This logical fallacy conflates opinion with fact. It is ultimately a kind of red herring. Let’s say I argue “it always rains when it’s sunny.” This is wrong; you call me out on this. I might reply saying “you can tell me I’m wrong, but I’m entitled to my opinion.” As a result, I’ve evaded the work of defending my argument or responding to yours, but the issue in question is not a matter of opinion.
A Loaded Question inserts an unfounded claim into a question in an attempt to make the audience assume something untrue. I might ask you “Are you really going to eat strawberry ice cream when artificial strawberry flavoring gives you cancer?” I’ve stated a claim as though it were true, offering no justification and ultimately coercing you into believing something false.
The Middle Ground fallacy assumes that the truth lies somewhere between two opposing sides. Let’s say two people are arguing about the color of Kirkjubøargarður, a farm in the Faroe Islands. One person argues it’s black; the other says it’s white. The person who says it’s white then argues “well, it must be somewhere in the middle. Let’s say it’s steel gray.” Yet the house is undeniably black.
This logical fallacy makes use of the existence of the False Dilemma; some things simply are black and white. Many politicians will use this argument to gain some concessions in their favor even when their position is ultimately and entirely wrong.
No True Scotsman
The No True Scotsman argument is an appeal to “purity,” in which a person argues that a true example of something doesn’t perform a certain behavior. See it played out in this conversation:
- Person 1: All New Yorkers work multiple jobs.
- Person 2: My uncle lives in New York, and only works one job.
- Person 1: Only real New Yorkers work multiple jobs.
This logical fallacy creates an arbitrary purity test, and often makes unfair arguments about a certain identity. You can imagine how this argument can be wielded much more perniciously: “only true Americans eat meat. Since you’re a vegan, you must be a Communist.”
The Single Cause fallacy assumes something occurs because of only one cause. A topical example of this is inflation in the year 2023. Some people argue inflation is because of supply chain issues; others argue it’s because of poor trade policy; others argue it’s because of corporate greed; others argue it’s because of rising wages and low unemployment. In truth, all of these are causes of inflation, as well as other causes not mentioned here.
Slothful Induction can also be called an Appeal to Coincidence. Instead of acknowledging the likely relationship between two things, you argue that something keeps happening because of coincidence. “Sure, I keep drinking while driving, but all of my DUIs are because people keep slowing their cars in front of me.” It is an abnegation of accountability.
The Texas Sharpshooter fallacy occurs when you draw a conclusion from a limited amount of data. It is a process of shooting a gun at a wall and then painting a bullseye around the bullet hole. As a result, you exclude the information that actually negates or challenges your argument.
For example, you might argue “I got into Harvard because I studied hard, did athletics and extracurriculars, and wrote a good essay.” What you failed to mention is the $5,000,000 donation your dad gave to the school.
Or, “Brian and Sally were made for each other: they both like ice cream, Russian novels, knitting, long walks on the beach, and they both dislike hypocrisy.” Perhaps you didn’t know this: Brian is also gay.
Write Without Logical Fallacies at Writers.com
Good arguments rarely happen in a vacuum: they develop out of a process of feedback, debate, and collaboration. If you’re writing for periodicals, news outlets, or any other form of CNF, our upcoming creative nonfiction classes might be for you.