Logical fallacies
What are logical fallacies?
When someone uses points in a discussion that are flawed, we can call these ‘logical fallacies’. In other words, they are arguments where incorrect or insufficient information is used, often in order to persuade people about a certain point. For example, a person using a personal anecdote they read online to convince others that aliens have come to earth is using a committing a logical fallacy.
Why should I know about logical fallacies?
You’ll need to put your critical thinking skills to the test to detect arguments that are not based on fact — but it’s worth it — once you know what to look for, being able to identify a logical fallacy can help you to avoid misinformation. You’ll be able to evaluate arguments and decide for yourself when people are trying to mislead you or when you are being presented with information that is incorrect. In turn, this will help you become more aware of the arguments that you make, check your own biases, and realise when you might be making flawed claims.
These are great skills to have at university, in the workplace and in everyday life. At university, being able to spot flaws in logic will be crucial for your assignments. At work, you may need to provide advice, and if you base your advice on flawed ideas, this could lead to problems. In daily life, you’ll often be faced with logical fallacies.
Types of logical fallacies
Depending on who you ask, there are a varying number of logical fallacies, and they have some pretty unique names. Let’s explore some of the most common ones:
To learn more about the many types of logical fallacies, visit Thou shall not commit logical fallacies and the Learning Lab Logical Fallacies page.
Identifying logical fallacies
Jake has to write an essay on the following topic:
“There are many health benefits to eating a vegetarian diet. Discuss.”
Reflect
Can you think of any other examples of the logical fallacies explained above? Or an argument you’ve heard in real life that fits the description of a logical fallacy?
- Ad hominem
- Correlation-causation
- Anecdotal evidence
- Burden of proof
- Appeal to authority
- Appeal to emotion
Can you think of real-world examples where logical fallacies were used to manipulate opinions or deceive people?
Have you ever unintentionally used logical fallacies in your own arguments or reasoning?
How have you dealt with situations in which people have used flawed arguments in the past? Did you enter into a debate? Get frustrated? Change their mind? Agree to disagree? Or something else?
How do you think recognising logical fallacies will help you when you encounter them in the future?
Avoid committing logical fallacies – a checklist
It’s important to remember that logical fallacies are not only committed by other people, and it’s a good idea to step back and examine our own arguments from time to time.
Here’s a list of yes/no questions you can use to identify shortcomings in your own arguments:
- Have you made changes to information so that it better supports your argument?
- Have you based your opinion on information that cannot be fact checked?
- Have you deliberately hidden or ignored any information because it would weaken your argument?
- Have you represented yourself as a professional or expert, when you are not?
- Have you pretended to be certain about something, when in fact, you are not?
- Have you intentionally used misleading information or illogical reasoning?
- Have you questioned someone’s intelligence rather than responding to their point of view?
- Have you based your argument on your own personal experience or a story someone else has told you?
If you answer ‘yes’ to any of these questions, there is a strong chance that your argument could be flawed.
Countering logical fallacies
In everyday life, you’re likely to encounter people using flawed arguments to express their opinion or tell you that they don’t agree with yours. This can be a frustrating experience. Here are some suggestions on how to deal with this scenario:
When you’re writing a response to a fallacious argument and want to take a more academic or assertive approach, you can use the following pattern to name, explain, and refute someone’s argument.
Sentence one:
- Name your ‘opponent’/the source of the fallacy
- Use reporting verb structures that show you don’t believe them or doubt their logic
- Paraphrase/summarise what they said. Usually, the paraphrase/summary will be in cause-effect form (they want us to do or believe x because y). You may have to think more deeply about what their argument really is, because if someone is using a logical fallacy, they usually don’t explain their argument completely — or it would be obvious that it doesn’t make sense!
Example: The advertisers imply that if we buy their brand of jeans, we will experience the same joy and beauty as the group of young people with their puppy.
Sentence two:
- Transition to your rebuttal with connecting words
- Rename your opponent/the source of the fallacy
- Use a special verb phrase
- Name the logical fallacy (or if there isn’t a clear label for it, you can just say that their logic is flawed)
Example: On closer inspection, this marketing campaign is engaging in a manipulative appeal to emotion.
Sentence three:
- Explain the error.
Example: They provide no evidence that their product is actually higher quality than any other brand.
Example paragraph:
One critic of further smoking restrictions wants to convince us that tobacco use is not actually unhealthy, based on the fact that his grandmother smoked for 80 years and did not get cancer. Clearly, this author is engaging in the anecdotal evidence fallacy. Just because this one smoker escaped the harms of tobacco use doesn’t mean that statistically, smoking is a safe practice.
Here is some language you can use to respond to logical fallacies:
| Part of your sentence | Suggested language patterns |
|---|---|
| Sentence one: source of the fallacy |
- The author/researchers etc. - The advertisers - Marketers of X - Some people - Those who agree with X - Those who disagree with X - People who think X - Proponents/advocates of X - Opponents/critics of X - Author's name |
| Sentence one: reporting verb phrase |
- imply(ies) that - seem(s) to imply that - seem(s) to think that - would have us believe that - want(s) us to believe that - wrongly suppose(s) that - claim(s) that - try(ies) to show that - want(s) to convince us that - insist(s) that |
| Sentence one: paraphrase/summary of their argument |
- X caused Y. - Y because X. - because X, Y. - X, therefore Y. - X proves Y. - we must choose between X and Y. - we should/shouldn’t X, because Y might result. - X will lead to Y. - if we X, Y will happen. |
| Sentence two: transition to your rebuttal |
- Clearly, - However, - When we examine his/her/their logic, however, - The problem with this argument is that… - On closer inspection, |
| Sentence two: rename the source (opponent) |
- he/she/they - the author/politician/advertiser etc. |
| Sentence two: special verb |
- is/are using - is/are engaging in - falls into the trap of - is/are trying to trick us with - is/are misleading their audience by |
| Sentence two: name the fallacy or error |
- the __ fallacy - a manipulative appeal to __ - faulty/flawed reasoning/logic |
| Sentence three: explain the error |
- Just because X doesn’t mean Y. - There might be another factor that caused Y. - It might be true that X means Y, but this doesn’t prove it. - There is probably another explanation: Y. - X might indeed cause Y, but this evidence doesn’t prove it because… - There is no solid proof that if X, Y. - We need to show/prove/see more evidence that/substantiate the claim that Y. - In fact, there might be a better way to Y. - Of course, it may be true that X, but that doesn’t necessarily mean Y. - Although X and Y are correlated, this doesn’t necessarily mean that X causes Y. - He/she/they fail(s) to consider that… - He/she/they is/are exaggerating the effect/impact/significance of X. - While the individual example is compelling, it alone doesn’t prove Y. |
Keep learning
Developing the ability to recognise flaws in arguments is a fundamental life skill. Being able to recognise deficiencies in reasoning can help you to write more factually accurate assignments at university and make more effective decisions in the workplace.
How will the information from this chapter help you in your day-to-day life? Well, maybe you have a friend or family member who is always making big claims they cannot prove — knowing about logical fallacies will help you to pick apart their flawed arguments!
Keep learning about logical fallacies and sharpen your critical thinking skills by checking out the following resources:
- RMIT Learning Lab: Logical Fallacies
- RMIT’s Learning Lab Contextualised Context: Recognising flawed arguments
This page includes content adapted from
- Introduction to College Composition (Lumen) by Lumen Learning licensed under CC BY-NC-SA 4.0
- Communication for Business Professionals by eCampusOntario licensed under CC BY-NC-SA 4.0
- 5.7: Finding and Refuting Logical Fallacies by Gabriel Winer, Berkeley City College & Laney College licensed under CC BY-NC 4.0
