Logical fallacies, or errors in reasoning that invalidate our arguments, play a role in most political debates, in the media, and in our everyday discussions. Although they are frequently committed unintentionally, they may be used effectively as a rhetorical technique to gain an advantage in a debate. And, more often than not, they appear to us as completely valid arguments and fly undetected under our radar.
As such, understanding how the most common logical fallacies work and knowing how to spot them is a useful skill for almost anyone. In this article, we’ll take a look at 12 logical fallacies (in no particular order) that often appear in various types of discussion.
Appeal to Popularity
Appeal to popularity, or the bandwagon fallacy, is based on the false assumption that when something is popular, it must be true or good. It is a fallacy because it uses an appeal to the popular ideas, values, or tastes in place of a valid argument; even though many popular beliefs are undoubtedly true, it is the factual evidence supporting the beliefs that make them so, not simply the fact that they are popular.
Appeal to popularity can be seen as a type of emotional appeal as it’s often designed to rouse the feelings and enthusiasm of the multitude rather than making a convincing argument that is backed by relevant evidence.
There was a time when everyone believed the world was flat and a more recent time when the majority condoned slavery. As we gather new information and our cultural values change, so too does the majority opinion. Therefore, even though the majority is often right, the fluctuation of the majority opinion implies that a logically valid conclusion cannot be based on the majority alone.
Robert J. Sternberg, Henry L. Roediger, and Diane F. Halpern, Critical Thinking in Psychology, 2007.
Bandwagon reasoning is extremely common everywhere due to our built-in biases, such as the bias of social proof; we have a natural tendency to behave the same way as others, and the more people believe in a particular idea, the more correct we deem it to be.
Examples
- “McDonald’s has served 100 billion people in the world. It must be the best fast food restaurant in the world.”
- “Officer, I think I don’t deserve a ticket. Everyone is going this speed, and if I went slower, I wouldn’t be going with the stream of traffic.”
- Sony. Ask anyone. (Sony’s trademark in the 1970s)
Appeal to False Authority
The fallacy of appeal to false authority occurs when someone uses a statement from an irrelevant or poor authority as evidence for a particular claim. In other words, the authority is not a real expert on the issue under consideration, and thus their testimony doesn’t provide reliable evidence to support a claim regarding the issue. For example, citing Einstein when making a claim on religion would be an appeal to false authority since his expertise lied in physics, not in religious matters.
Appeal to false authority is the most common form of the appeal to authority fallacy and appears frequently in media, politics, and in advertisements.
Examples
- “Richard Dawkins, a brilliant evolutionary biologist, said that God doesn’t exist. Therefore, God does not exist.”
- “Three out of four yoga teachers say that stretching makes your life meaningful.”
Appeal to Celebrity
Appeal to celebrity is a specific type of appeal to false authority which occurs when someone accepts a claim from a famous person simply due to the fact that they are famous, rather than judging the claim based on its logic and the evidence supporting it. As such, its logical form is as follows:
- Famous person X supports Y.
- Therefore, Y is true.
Appeal to celebrity is the meat and potatoes of many marketing campaigns as companies hire celebrities to endorse their products to build a stronger brand image and rank up the sales. However, since most celebrities are actors, singers, or sports stars, they are rarely experts on the subjects they talk about.
The celebrity status of the person supporting a certain idea or brand is the pillar the whole claim rests on. This is an error in reasoning because, in reality, popularity is irrelevant to the truth.
Examples
- A commercial claiming that a specific brand of cereal is the best way to start the day because Tiger Woods eats it for breakfast every morning
- Celebrity X, who is a famous actor, says that global warming is real and we have to start paying more attention to it.
Appeal to Emotion
Appeal to emotion fallacy occurs when someone appeals to the feelings of the listeners in order to convince them that something is true, instead of using relevant facts and valid logic. For example, in a debate, someone may attempt to convince the audience to dismiss their opponent’s conclusion by arousing the feeling of disgust in the audience towards the outcome of the claim.
Appeal to emotion is a common and highly effective technique in persuading and manipulating people’s opinions, beliefs, and actions; due to human nature and our cognitive biases, people often rely on their emotional responses to things when making decisions, instead of reviewing facts and thinking strategically. Furthermore, emotional appeals frequently utilize loaded language – meaning language that is intended to produce an emotional response and to directly affect the listener’s views – as well as concepts such as religion, country, crime, and drugs to make an appeal to the audience’s enthusiasms and prejudices.
Although the appeal to emotion fallacy can involve any emotion that we humans may experience, there are a number of emotional appeals that are categorized as individual logical fallacies due to their widespread use. These sub-fallacies include:
- Appeal to popularity
- Appeal to fear
- Appeal to envy
- Appeal to hatred
- appeal to pity
- appeal to nature
Examples
- Daughter: “Mom I’m too full, I can’t eat anymore.”
- Mother: “You have to eat everything on your plate, just think of all the starving children in Africa.”
- A grocery store commercial displaying a happy family sitting around the table at Thanksgiving dinner.
Appeal to Ignorance
This fallacy occurs when it’s assumed that if something cannot be proven false, it must be true, or if something cannot be proven true, it must be false. In other words, it’s based on the assumption that if there is no contrary evidence for a certain claim, we must accept it as correct.
In reality, appeal to ignorance only shows that we don’t know something (“absence of evidence is not evidence of absence”). This type of argument could be applied to support two opposing arguments, which is an obvious clue that it is based on flawed reasoning: for example, “you cannot prove that ghosts don’t exist, therefore they must exist” or “you cannot prove that ghosts exist, therefore they don’t exist”.
Examples
- “You cannot prove that God does not exist; therefore God exists.”
- “No one has ever proven that UFOs haven’t visited earth yet, so I believe that they have.”
- “You can’t prove that you are innocent, therefore you are guilty to me.”
Appeal to Tradition
This is a common logical fallacy in which one claims that because a certain action or a belief is traditional, it must be good or true. More specifically, it states that if something has been done a certain way for a long time (that is, traditionally) it is necessarily the right way of doing it. For example, if someone says that “we’ve always been smokers in our family, therefore I should be a smoker too”, they are guilty of committing the appeal to tradition fallacy.
Such reasoning is fallacious because it makes a conclusion simply on the basis of historical preferences. The fact alone that something is a tradition does not prove it is necessarily better or the right way of behaving.
This fallacy is also known as “appeal to antiquity”, “appeal to common practice”, and “appeal to age”.
Examples
- “Gays have never had the legal right to marry, therefore it must be wrong and we shouldn’t legalize it now.”
- “Our family has a long tradition of men becoming lawyers; my great-grandfather, grandfather, and father were all lawyers. Thus, It’s the right and only option for
me to become a lawyer too.” - “People have believed in God for thousands of years, so it seems obvious to me that God exists.”
Appeal to Fear
Appeal to fear, or argumentum ad metum in Latin, is a sub-fallacy of appeal to emotion and occurs when fear is used in place of relevant evidence and valid reasoning to get the listeners to accept something as true. For instance, it is often employed to get people’s support for a particular view by making them fear the alternative option.
Appealing to fear, like all emotional appeals, is effective in influencing other’s attitudes and behaviors. As such, this fallacy occurs frequently in the political arena, as well as in the advertising industry.
Note that, even though fear appeals may sometimes be used unethically for personal gain, they can also be used productively to reduce or eliminate various harmful behaviors; for example, campaigns addressing safe driving may show us car accidents that happened due to texting while driving in order to instill fear in us and change our behavior for the better.
This fallacy is sometimes confused with the fallacy of appeal to force. The difference between them is that the appeal to fear is a warning, pointing out the supposed dangers of accepting a certain view as true (or buying a competitor’s product), but the appeal to force is a direct threat towards the audience or opponent.
Examples
- “If you don’t believe in God, you will burn in hell for eternity.”
- “If we let any more immigrants into our country, they will take our jobs and destroy the culture of our beautiful country.”
Appeal to Nature
Appeal to nature is based on the assumption that if something is “natural” it must be good, or inversely, if something is “unnatural” it must be bad. This kind of reasoning is fallacious because it is not fact-based; something being “natural” doesn’t mean it’s necessarily better or good.
There are three usual logical forms for this type of argument:
- That which is natural is good (or right).
- X is natural.
- Therefore, X is good (or right).
- That which is unnatural is bad (or wrong).
- X is unnatural.
- Therefore, X is bad (or wrong).
- X is natural.
- Y is unnatural.
- Therefore, X is better than Y.
Appeal to nature, like the appeal to tradition fallacy, appears quite frequently in alternative medicine: someone claims that a particular herbal medicine is necessarily a better or healthier option for treatment than a “synthetic” medicine (that is, caused by human intervention) solely by its virtue of being natural.
Examples
- “Marijuana is a natural drug, so it can’t be bad for you.”
- “Humans have always been meat-eaters, therefore it is natural to us and must be good for our health.”
- “We shouldn’t vaccinate our children because vaccines are unnatural.”
Appeal to coincidence
Appeal to coincidence is a fallacy in which a person claims that some event was due to a coincidence despite strong evidence to the contrary.
It is easy to show why this argument is fallacious; if we have evidence to show that a particular event was not, in fact, due to chance, it’s irrational to dismiss it. However, this fallacy may be committed in a situation where someone can’t find a proper counter-argument and, out of desperation, attempts to put the blame on their bad luck.
As such, this fallacy is also known as appeal to luck and appeal to bad luck, and it’s a form of slothful induction fallacy.
Examples
- Brian has had 10 car accidents in the last twelve months. He insists that it is just a coincidence and not his fault, even though the evidence overwhelmingly suggests otherwise.
- “The view that smoking causes specific diseases remains an opinion or a judgment, and not an established scientific fact.” (Agin, Junk Science, p. 89)
Appeal to Pity
Appeal to pity (or ad misericordiam) is a fallacy in which someone attempts to persuade or distract from the truth by arousing the feeling of pity in the listener. Or, something must be true because it would be sad if it wasn’t.
This is a common and effective type of emotional appeal, however fallacious and unreasonable from a logical perspective; the fact that something is sad doesn’t make it any more true or any less wrong.
Its opposite fallacy is the appeal to hate, which is an attempt to win support for an argument by exploiting the feeling of hate.
Examples
- “We should find the defendant innocent since it would break his poor mother’s heart if we were to send him to jail.”
- “Just think of all the starving children in Africa.”
- “I think I deserve a raise because I really need the extra money to support my family.”
Appeal to Consequences
Argumentum ad consequentiam occurs when someone concludes that a proposition is either true or false based on whether its consequences are desirable or undesirable. In other words, someone determines the truthfulness of a proposition based on what it would cause or imply.
This is a fallacious assumption because, in reality, the truthfulness of an idea is not related to how desirable the consequences of it being true or false would be.
As such, the positive form of this fallacy is:
- If A is true, it will cause B.
- B is desirable.
- Therefore, A is true.
And conversely, its negative form is:
- If X is true, it will cause Y.
- Y is undesirable.
- Therefore, X is false.
Appeal to consequences is related to wishful thinking, which refers to making decisions based on what would be a pleasing outcome to imagine, rather than choosing the best course of action based on facts and rationality.
Examples
- “X is not a terrible president. The citizens of this country chose him/her, and if he/she really were that bad, what would that tell about us?”
- “I want to believe that all people are good deep down because it would be really sad if it wasn’t true.”
- “If you don’t believe in God, you will go to hell. Therefore, you should believe in God.”
Appeal to Novelty
This is a fallacy in which someone claims that something must be good or true simply because it is new. Typically, it falsely assumes that there is something inherently good about novel ideas or products. For example, if someone claims that a certain idea is better than its alternative, that has been around for a long time, solely on the basis that it is newer, they are guilty of committing the appeal to novelty fallacy. The most common form of this type of argument is:
- X is novel (new).
- Y has been around for a relatively long time.
- Therefore, X is better.
Appeal to novelty either overestimate things that are new or underestimate things that are considered as old. Also, it frequently manifests itself in situations where people are required to make a choice between a newer and an older option; the option that is new may naturally feel to us like a better, more desirable option when compared to its older alternative.
Examples
- “If you want to lose weight, you should always follow the latest diet.”
- “This new strategy will make our company better and more profitable in no time.”
- “You have to buy the new iPhone as soon as it comes out; it must be so much better than the previous one.”
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