Logical Fallacies: A Concise Guide to Common Errors in Reasoning

You may have heard of the logical fallacy and pondered over what it was and how it can be used. In this article, we are going to be looking at logical fallacies in a little more depth finding out what they are and how they function. We are also going to be looking at some examples of logical fallacies to gain a further understanding of how they work.

Logical Fallacy

What Is A Logical Fallacy?

A logical fallacy is something that is used commonly in a variety of ways on purpose such as in politics or in sales. However, when we are writing we might sometimes create a logical fallacy without realizing it and it is important to be able to avoid this.

But we must first understand what a logical fallacy is. Logical fallacies are errors in reasoning or an assumption that is false. The logical fallacy will undermine the logic within an argument, they might be seen to appear as an irrelevant point or an argument that is not legitimate. They can be easily picked out as they don’t contain evidence that will support the claim being made.

Understanding Logical Fallacies

Formal Fallacies

Formal fallacies are errors in the structure or organization of an argument. These fallacies occur when the conclusion of an argument does not logically follow from its premises. The structure of the argument, rather than its content or context, renders it invalid. For example, a common formal fallacy is the “Affirming the Consequent” fallacy:

  1. If it rains, the ground is wet.
  2. The ground is wet.
  3. Therefore, it rained.

In this example, it is possible that the ground is wet for a reason other than rain, so the conclusion does not follow logically from the premises.

Some common types of formal fallacies include:

  • Affirming the Consequent
  • Denying the Antecedent
  • Undistributed middle

Informal Fallacies

Informal fallacies, on the other hand, are errors in reasoning that occur due to the content or context of an argument. These fallacies usually involve faulty logic or misrepresentation of evidence. They are often used in rhetoric to persuade and mislead rather than to promote critical thinking.

Examples of informal fallacies include:

  • Ad hominem: Attacking the person making the argument instead of addressing the argument itself.
  • Straw man: Misrepresenting an opponent’s argument in order to rebut it more easily.
  • False cause: Assuming that a correlation between two events implies that one event caused the other.

Students should be cautious of informal fallacies, as they can create illusions of validity and exploit cognitive biases. Recognizing and avoiding these fallacies can enhance students’ understanding of effective argumentation and improve their critical thinking skills.

To summarize, understanding logical fallacies is crucial for evaluating and constructing valid arguments. Recognizing the differences between formal and informal fallacies can help identify errors in reasoning and avoid being misled by faulty logic. By honing their critical thinking skills, students can become better communicators and make more informed decisions.

Types of Logical Fallacies

The logical fallacy does not simply come in one form, there are many different types of logical fallacy and in order to be able to spot them, it is important that we understand the difference between each one. We are now going to take a look at the different types of logical fallacies and some examples to demonstrate their use.

The Slippery Slope

The slippery slope is a common type of logical fallacy whereby the author or speaker will equate A to Z. For example, they will tell you that if you wish to prevent Z from happening then A must never occur, despite these two things being completely unrelated in most cases. The writer assumes that if situation A were to occur, then B and C and D, and so on would naturally follow. Let’s take a look at an example of this.

If we are to ban air travel because of its negative effect on the environment then eventually the authorities would ban every type of motorized travel. Therefore we should not ban air travel.

You can see that the argument is not at all logical and just because one extreme thing is occurring in the argument, it cannot be automatically presumed that this will create a snowball effect.

Hasty Generalization

In this type of logical fallacy – hasty generalization, the writer or speaker will jump to a conclusion before they understand all the facts which are relevant to it. In the following example, we see that the writer is making an evaluation of his new job based on the first morning spent there which is not a clear indication of the truth of the situation.

Despite it being only noon on the morning of my first day at my new job, I can sense that this is going to be too much hard work.

Post Hoc Ergo Propter Hoc

In this form of logical fallacy, the speaker or writer will assume that A is a result of B owing to the fact that A took place after B. An example of this might look as follows:

I ate lunch at that new cafe and this evening I am ill, that cafe must not be clean.

The assumption that eating at the cafe was a cause of illness is not logical since there could be a huge variety of reasons that the writer is sick. Just because one event happened after another, it does not mean there is an automatic connection between the two.

Learn more: Post Hoc Ergo Propter Hoc

Genetic Fallacy

Someone using genetic fallacy will assume that the background of an idea, person, place, etc determines its nature or worth. An example of this might be as follows:

All German people are bad because the leader of that country started the second world war.

One cannot link the entire population of Germany with being bad simply because of one person’s behavior in history.

Begging the Question

Begging the question – This is a form of logical fallacy where the claim that is being made is backed up within itself. Let’s take a look at an example of this.

Dirty and bacteria-ridden water should not be ingested.

Circular Reasoning

The circular argument does not prove the argument but rather restates its. This is done by using two claims which mean the same thing but by not giving any specific evidence to back this up. Here is an example of what this might sound like.

Van Gogh was an excellent artist because he painted well.

Both of the claims in this sentence mean the same thing but neither give us any real evidence to back them up. Both of them require further data to be proven to be correct.


This type of logical fallacy brings the argument down to one of two choices making it overly simple. A good example of this might be as follows.

We either have the choice of stopping the use of motor vehicles or ruining the planet.

This sentence tells us that there are only two options however there is no mention to the wealth of other choices that could be considered such as reducing the use of motor vehicles or using cleaner versions of these.

Ad Hominem

A form of logical fallacy that is used to attack someone’s character instead of their argument or opinion. Let’s take a look at an example of this.

The strategies of Greenpeace are not effective since they are just a bunch of lazy, unclean tree huggers.

The writer here does not describe which strategies he is referring to nor does he try to look at the positive points, rather he simply makes a personal attack on the character of those within the group.

Discover more: Ad Hominem

Bandwagon Appeal

This type of logical fallacy is also known as the ‘ad populum’ and will use an opinion of the masses as a way to convince one person to believe the same thing. Let’s take a look at an example of this.

If you were a true Brit, you would back the views of the Queen.

The writer here makes the reader feel as though they want to be ‘a true Brit’ however being a true Brit does not necessarily mean that one should have the same views as the monarch, as the author of this sentence would suggest. There is no logical connection between the two ideas.

Red Herring

This type of logical fallacy, red herring, is used in order to evade the issue at heart, it is used as a way of steering clear of the opposing argument instead of addressing it. An example of this might be as follows.

The rising levels of mercury within sea food is not safe, but what are fishermen going to do to provide for their loved ones?

The writer of this sentence does not tackle the issue at the heart of the problem but rather turns his attention to another point.

Straw Man

The straw man is used as a way of making the opponent’s view overly simple and then attacking the argument which now appears hollow. Let’s look at an example of this.

Those who do not support the minimum wage rise which has been proposed clearly dislike the poor.

The writer is implying that the opposition has a view which is not necessarily true and creating an emotional response within the audience. Just because the opposition does not agree with the wage rise, this has no bearing on his feelings towards a certain group of people.

Reductio Ad Absurdum

Reductio ad absurdum shows an opposite of the claim that has being made and how it would draw nothing but an absurd conclusion, therefore, disproving the theory.

I am taking my driver’s test tomorrow, so please do pray for me. If a lot of people pray about this then God will allow me to pass the test with ease.

False Equivalence

The false equivalence fallacy is one which shows up regularly in day-to-day conversation as well as in written pieces such as newspaper articles and other media.

Moral Equivalence

The final type of logical fallacy that we will look at is one where the writer or speaker will compare a minor misdeed against something much more major. This gives the impression that both are as bad as one another. Let’s take a look at an example of this.

The person who took my seat on the bus is as bad as Satan.

The author is making a comparison between a very mild thing and something completely evil, making such a comparison is neither fair nor accurate.

Identifying and Avoiding Fallacies

Critical Thinking Skills

To identify and avoid logical fallacies, one needs to develop strong critical thinking skills. Critical thinking involves the ability to recognize problems in arguments, evaluate the strengths and weaknesses of premises and conclusions, and identify patterns of faulty reasoning. Some techniques to enhance critical thinking include:

  • Challenge assumptions and biases
  • Evaluate the credibility of sources
  • Consider alternative explanations for observed phenomena
  • Assess the strength of relationships between premises and conclusions

Evaluating Arguments

When evaluating an argument, there are several important factors to consider:

  • Premises: Ensure that the facts and evidence provided are accurate, relevant, and reliable. Insufficient or false evidence leads to weak arguments and fallacious reasoning.
  • Logic: Check whether the argument’s reasoning is sound and follows logically from the premises. Logical fallacies often arise from faulty logic or unstated assumptions.
  • Emotions: While persuasive, an argument based on emotions rather than logical reasoning can be misleading, either intentionally or unintentionally.
  • Credibility: Evaluate the credibility of the argument’s source, and ensure that their claims are supported by appropriate justification and evidence.
Fallacy TypeExampleExplanation
Hasty GeneralizationI got sick after eating at that restaurant, so their food must always be bad.Drawing conclusions based on limited or insufficient evidence.
Slippery SlopeIf we allow one exception, everyone will want special treatment.Assuming that an action will inevitably lead to a series of undesirable consequences.
Non-SequiturHe's a great athlete, so he must make a great coach.Drawing a conclusion that is not logically derived from the premises provided.

Types of Evidence

In order to avoid fallacies in your arguments, it is crucial to provide various types of solid evidence:

  1. Facts: Objective, verifiable data that can be independently confirmed
  2. Statistics: Quantitative data that can help establish trends or patterns
  3. Expert testimony: Opinions or interpretations provided by someone with authority on a subject
  4. Personal anecdotes: Relevant experience that can provide specific, illustrative examples
  5. Test results: Empirical findings from studies or experiments that support an argument

By incorporating a range of evidence types and carefully evaluating arguments, one can avoid both intentional and unintentional fallacies, ultimately strengthening their reasoning and credibility.

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Different Types of Logical Fallacies

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FAQs on Logical Fallacies

What is a logical fallacy?

A logical fallacy is an argument that may sound convincing or true but is actually flawed. They often occur due to poor reasoning or can be intentionally made to manipulate others. Logical fallacies lead to unsupported conclusions.

Why are logical fallacies important to recognize?

Identifying logical fallacies in arguments is crucial for effective communication and decision-making. Being aware of them helps to avoid being misled and enables a better examination of arguments.

What are some common logical fallacies?

  • Ad hominem: Attacking an opponent’s character instead of addressing their argument.
  • Straw man: Misrepresenting someone’s argument to make it easier to attack.
  • Appeal to authority: Asserting that an argument is true because an expert or authority supports it.
  • False dilemma: Presenting two alternatives as the only options when more possibilities exist.
  • Slippery slope: Claiming that one event will inevitably lead to a series of negative consequences.

How can someone avoid making logical fallacies while constructing an argument?

To reduce logical fallacies in arguments:

  1. Develop critical thinking skills and a strong understanding of the topic.
  2. Be aware of common fallacies to identify and correct them.
  3. Focus on addressing the premise and evidence rather than using personal attacks or distractions.

How to effectively counter a fallacious argument?

To counter a fallacious argument:

  • Identify the specific fallacy being used.
  • Point out the inconsistencies or lack of evidence within the argument.
  • Offer a counterargument based on logic and reliable evidence.

Last Updated on May 15, 2023

1 thought on “Logical Fallacies: A Concise Guide to Common Errors in Reasoning”

  1. I have made a logical fallacy or error ; I am not sure how to categorise it. If you can help, it will be great! in my undergraduate thesis, there are four different enzymes binding same substrate with good binding affinities and involved in chemical reactions. I was trying to find out compounds that would be competitive inhibitors based on scientific literature. I reasoned out that if the family of compounds of competitive inhibitors, which were phyto-chemicals can bind in one enzyme binding site, it has potential to bind in other enzymes as well. But I realised my reasoning is wrong, as the substrate enzyme binding mechanism depended on far more complex reactions than the obvious. I like to know, under what category of fallacy my mistake falls under?


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