Logical fallacies: what they are and how to recognize them
Are you sure that your beliefs are based on logic and not on erroneous conclusions? Our brain often looks for shortcuts, which leads to logical failures. These errors are one of the favorite tools of manipulators and the source of our wrong decisions. We will analyze in detail how they work, and most importantly — how to stop making them.
Logical fallacies are flaws or failures in reasoning that make an argument invalid, leading to incorrect conclusions and decisions. Such errors can occur both at the level of the structure of the argument and at the level of content. They are often confused with cognitive biases, which are systematic errors in thinking. Simply put, biases affect how we perceive facts, while logical fallacies affect how we connect them and use them in argumentation.
All logical errors can be divided into two groups: formal and informal.
1. Formal logical errors are violations of the structure of inferences.
- A consequent statement is a logical fallacy that occurs when the truth of an antecedent (condition) is incorrectly inferred from the truth of a consequent (consequence). Formally, this is a fallacy in conditional reasoning of the form: “If A, then B. B is true. Therefore, A is true.”
Examples:
– If I eat the whole bowl of soup (A), I will be full (B). I am full now, therefore I ate the whole bowl of soup. What is the mistake: being full (B) can be for other reasons, not necessarily because of the bowl of soup eaten (A).
– “Scientists say: “If you wear a mask (A), it reduces the risk of getting coronavirus (B)” But I know people who always wore masks and still got sick! So masks don’t work, and it’s all a hoax!” What is the mistake: The mask does not eliminate the risk 100%, but significantly reduces it. However, it is possible to get sick while wearing a mask if, for example, the mask was put on incorrectly or the infection occurred through the mucous membrane of the eye. The effectiveness of masks is proven not by individual cases, but by large studies and statistics that show that in groups where masks are worn, the infection rate is lower than in groups where they are not worn.
How to fix: It is important to understand that the truth of consequence B does not guarantee the truth of condition A, since B can be caused by other factors. To test the hypothesis, you need to look for additional evidence of the truth of A, and not rely only on the fact of the truth of B.
- Denial of the antecedent is a logical fallacy in which an incorrect conclusion is drawn based on the fact that a condition (the antecedent) is not met. Formally, this is a fallacy in conditional reasoning of the form: “If A, then B. A is not true. Therefore, B is not true.”
Examples:
– If a driver falls asleep at the wheel (A), he will have an accident (B). The driver is not asleep. Therefore, he will not have an accident. What is wrong: an accident (B) can happen for other reasons, not necessarily because the driver fell asleep (A).
– If politician N is at a rally (A), then he supports it (B). Politician N was not at the rally. Therefore, he does not support it. What is wrong: politician N could have supported the rally financially, made a post on social media, or instructed his assistant to speak. Absence from the rally does not prove lack of support.
How to fix: You need to look for additional information and consider all possible causes that could lead to the result. Instead of jumping to conclusions based on the absence of one condition, you should consider whether the result could arise for other reasons.
- The fallacy of composition is a logical error in which the whole is mistakenly inferred to have a certain property because its parts have that same property. That is, the characteristics of the parts are mistakenly transferred to the whole.
Examples:
– Living cells are invisible to the naked eye. People are made up of cells. Therefore, people are invisible to the naked eye. What’s wrong is that people as a whole have other properties that are not limited to the properties of individual cells.
– “Look at ordinary American families! They are deeply in debt, taking out loans for cars and equipment, barely making ends meet. It is obvious that the country’s economy is in complete decline and is about to collapse!” What is wrong: the economy is not a simple sum of family budgets, but a complex system that includes GDP, unemployment, the stock market, corporate profits, inflation, government debt and much more.
How to fix: do not automatically transfer the properties or characteristics of parts to the whole without additional justification. When analyzing a situation, consider the entire system as a separate object, with its own characteristics and context.
- A false dilemma is a logical error in which only two possible options or solutions are considered, excluding all other possibilities. This error is common in disputes, since it simplifies the situation and forces you to choose between “black” and “white”, ignoring all alternative options.
Examples:
– Those who are not with us are against us.
– “Either we completely ban anonymity on the Internet, or we accept the fact that criminals will freely operate on the Internet.” What’s wrong: in reality, there is a range of more balanced and targeted solutions that do not require sacrificing the privacy of all users for the sake of security.
How to fix: it is necessary to broaden the view of the situation and see possible alternatives. When analyzing a situation, it is important to ask yourself questions: “Are there other options?” or “Why are these two options considered the only possible ones?”
- A vicious circle is a circular reasoning in which a statement is proven by itself through a chain of arguments. The proof uses what still needs to be proven, and thus the proof does not go beyond the initial assumption.
Example: I know he is honest because he tells the truth, and I believe him because he is honest.
What is wrong is that the proof is closed in a circle without receiving new confirmation.
How to fix: You need to use independent arguments to support your thesis, without relying on the statement being proven itself.
- An illogical conclusion is a logical error when the conclusion drawn does not follow from the existing premises, that is, there is no logical connection between the conclusion and the premises.
Examples:
– We should require all students to study a foreign language because it is important to provide them with a quality education. What is wrong: there is no connection between language learning and the quality of education.
– The mayor’s wife recently bought a new luxury car. At the same time, the city budget allocated a large contract for road repairs to company N. It is known from open sources that the mayor’s wife’s brother is a shareholder of N. This proves that the mayor personally received a bribe for this contract. What is wrong: even true premises can be deliberately combined to create a false conclusion, and the accusation is based only on hints and assumptions, not on evidence.
How to fix: it is necessary to check that the conclusion follows from the arguments and is not arbitrary or unrelated to them.
2. Informal logical errors are errors in content and argumentation associated with the use of incorrect arguments, manipulations, and incomplete evidence.
- Appeal to authority is a logical fallacy in which a statement is assumed to be true simply because it was made or supported by someone with authority or influence. In this case, the opinion of the authority is used as the only correct argument without checking the facts.
Example: This diet works because a famous blogger recommends it. What’s wrong: the blogger is not a nutritionist.
How to fix: It is necessary to check the competence and professionalism of the author of the authoritative opinion in the topic under discussion. Do not accept the opinion of the authority as the only absolute truth, but use it only as one of the arguments, supplementing it with other evidence and facts.
- Appeal to the majority is a logical fallacy in which a statement is considered true simply because a majority of people support it. The assumption is that if many people think or do something, it must be right.
Examples:
– Everyone crosses the street on a red light, so I will do the same.
– This phone is the best on the market because millions of people bought it.
How to fix: It is important to avoid relying on the majority opinion as the only argument in favor of the truth of a statement. It is necessary to seek and rely on objective evidence and facts.
- False causality is a logical fallacy in which a cause-and-effect relationship is mistakenly assumed between two events or variables when in fact there is no such relationship.
There are two main types of false causality:
– Post hoc ergo propter hoc (“after this, therefore because of this”) is a fallacy in which event B is considered the cause of event A only because B occurred after A. For example, if a person’s condition improves after taking a medicine, the medicine is automatically considered to have caused the recovery, without taking other factors into account.
– Cum hoc ergo propter hoc (“in common with this, therefore because of this”) is a fallacy when a causal relationship is assumed between two events or phenomena that simply occur simultaneously, but do not influence each other. Example: Ice cream sales and sunglasses sales grow at the same time, which means ice cream sales cause sunglasses sales to grow. What’s wrong: the reason here is the heat, not their effect on each other.
How to fix: Critically evaluate cause-and-effect relationships, trying not to draw conclusions based solely on the sequence of events.
- An appeal to emotion is a logical fallacy in which beliefs and conclusions are formed not based on facts and logic, but by manipulating the emotions of the audience. Instead of objectively discussing a topic, emotions such as fear, pity, anger, joy, or shame are used to elicit agreement without critical reflection.
Example: “If you don’t agree with me, you will ruin my entire life (an appeal to pity).”
How to fix: To control one’s emotions and be able to distinguish between them; to critically evaluate arguments by asking the question: “Do they have a rational basis, or is this an attempt to manipulate emotions?”
- Personal attack is a logical fallacy in which an opponent’s argument is refuted or weakened by attacking his or her personal qualities rather than by refuting his or her arguments and facts.
The main types of appeal to personality:
– ad hominem personam — direct criticism of a person or insult (“Don’t listen to his opinion about health, he himself leads an unhealthy lifestyle”).
– ad hominem circumstantiae — doubting an argument based on the opponent’s personal circumstances (“You claim that sport is good for everyone, but you are a coach, it is in your interests for people to exercise”).
– ad hominem tu quoque — indicating that the opponent does not follow his own arguments (“You are a doctor and call for quitting smoking, but you yourself smoke”).
How to fix: Focus on the substance of the argument rather than the personality of the opponent/author. Discuss facts and reasons rather than the person’s personal characteristics, motives, or behavior.
- “Straw man” fallacy is a logical fallacy in which, during an argument or discussion, an opponent’s argument is distorted, simplified, or misrepresented, and then the modified version of the argument is refuted. This creates the illusion that the opponent has been defeated, although in fact his or her real arguments remain undeniable.
Examples:
– A: It is good for children to have ice cream after school. B: It is unhealthy. A: Do you want children to starve? What’s wrong: A replaces criticism of the argument with a false thesis, allegedly B wants children to starve.
– A: “We must reduce CO2 emissions from burning fossil fuels to slow down global warming. To do this, it is important to invest in the development of renewable energy sources such as solar and wind.” B: “You want us to return to the Stone Age, give up cars, heating and electricity, leaving millions of people without work and destroying all industry and energy.” What is wrong: the original argument about a gradual transition to new energy sources is replaced with an extreme demand for a complete and immediate rejection of all modern energy, which literally means “return to the Stone Age.”
How to fix: You must not give in to attempts to distort arguments — always clarify what exactly is meant.
- Equivocation is a logical fallacy in which the same word or expression is used in different meanings in the same argument.
Example: A scientist claims that energy never disappears. This means that a person’s thoughts also do not disappear after death. In the first part of the sentence, the word “energy” is in the physical sense, and in the second — in the spiritual sense.
How to fix: It is necessary to clearly define the meanings of the words and terms used in the context of the discussion and to know that all participants in the dispute understand the terms in the same way.
- Amphiboly is a logical fallacy based on the ambiguity of linguistic expressions or grammatical construction.
Example: the phrase “To execute, not to pardon” changes its meaning depending on where the comma is placed: “To execute, not to pardon” or “To execute, not to pardon.”
How to fix: It is important to use clear, unambiguous wording, precise punctuation and correct word order, and, if necessary, explanations and clarifications of meaning.
- Survivorship bias is a logical fallacy in which attention is focused only on those objects, people, or events that “survived” or succeeded, while ignoring those that “died” or failed.
Examples:
– Stories of people who smoke a pack of cigarettes a day and live to a ripe old age are cited as evidence that smoking is not harmful, ignoring the huge number of smokers who die from disease.
– The idea that higher education is not important because many successful entrepreneurs did not graduate from university, while ignoring the fact that this is more the exception, and most people with an education have a better chance of success.
How to fix: collect complete information, considering not only successful cases, but also failures, cases of defeats. Additionally, it is necessary to analyze the reasons for the failures that have occurred.
- Gambler’s fallacy is a logical error in which a person believes that the probability of a certain random event changes depending on how often it has already happened in the past.
Example:
– After a coin has landed heads five times in a row, the player is confident that the next side will definitely be tails. The fallacy is that each coin toss is an independent event, and past results do not affect future ones.
How to fix: understand that previous outcomes do not affect future ones, and use formal knowledge of probability and statistics to realistically assess the facts.
- Selective presentation of facts is a logical fallacy in which only individual facts or data that support a specific point of view are selected from all the information, while a significant part of the information that may contradict or refute this point of view is ignored.
Example:
– Some students did not sleep all night and still passed the exam with flying colors, which means that lack of sleep does not interfere with successful studies. Here, numerous students are ignored for whom lack of sleep reduced concentration and led to poor results.
How to fix: actively seek out and consider information that is opposite or contradictory to your original point of view in order to see the full picture of an event or phenomenon, you can also try using the random sampling method.
Logical errors are real tools of manipulation that we encounter daily on the Internet and in real life. There can be a lot of variations of such errors, as well as logical chains. Therefore, the main weapon of a fact checker is a critical look and the ability to ask questions.