Logical Fallacies

• ELA
• 8th Grade

Logical Fallacies

Based on the previous slide and meme, what do you THINK a logical fallacy might be?

Why Thinking Critically Matters (and How We Mess It Up All the Time)

Most of the stuff you learn in school or college? Let’s be real—it’s not always super useful for your future. That’s not because your teachers are bad or the lessons are pointless. It’s just that some things you study don’t end up connecting to your life much.

But every now and then, you take a class that sticks with you and changes how you think. That happened to me during my second year in college when I signed up for a philosophy class called Logic and Reasoning. I thought it sounded better than sitting through something like Romantic Poetry of the 1800s, so I gave it a shot. Turns out, it was the best decision I ever made.

The Train Question

From the first day, the class was full of mind-twisting questions. For example, one day, the professor wrote this on the board:

"Every time a train comes to the station, there are a lot of people waiting. Today, there are a lot of people waiting at the station. Does that mean a train is definitely about to arrive?"

 

What do you think? Does that mean a train is definitely about to arrive? Why or why not?

The Train Question

Most of us said, “Yes!” But the professor told us the answer was no. Just because trains usually show up when people are there doesn’t mean the people waiting caused the train to come. It’s a coincidence, not a guarantee.

The room would explode with frustration every time we tackled questions like this, but I loved it. The professor was showing us that the way we think isn’t always as logical as we believe.

Logical Fallacies: How We Mess Up Our Thinking

We all make mistakes in reasoning—big ones, small ones, and everything in between. These mistakes are called logical fallacies, and they’re everywhere: in the news, on social media, in arguments with your friends. Let’s break down a few common ones.  Knowing some of the commonly used logical fallacies will help us avoid them, and give us some tools for critical thinking.

1. Correlation Is Not Causation

Just because two things happen at the same time doesn’t mean one causes the other. 

For example:

Let’s pretend for a second that today, I ate some ice cream and you lost your job. And what’s crazier is that the last time I ate ice cream, somebody else lost their job. Would you then say that me eating ice cream causes people to lose jobs? (If so, this would be one strange superpower.)

Or would you simply say these are two common occurrences that happen to be occurring together for a short period of time?

1. The author eating ice cream definitely causes people to lose their jobs
2. The author eating ice cream might be the cause of people losing their jobs.
3. The author eating ice cream does not have anything to do with people losing their jobs. It's just a coincidence.
4. People losing their jobs causes the author to eat ice cream.

People often confuse coincidences for causes. For example, you might hear, “Social media causes depression.” Just because people who use social media sometimes feel depressed doesn’t mean one causes the other. Maybe depressed people use social media more, or maybe there’s another reason for both.

Let’s look at some examples:

According to the bar graph, the number of people who died in a swimming pool accident each year and the number of Nicholas Cage movies are closely related.

Amount of cheese eaten and the number of people who died becoming tangled in their bedsheets is closely aligned as the bar graph shows. 

The two previous slides suggest that there is a correlation between two unrelated events. Does this mean that one thing causes the other to happen? Explain why or why not.

2. Slippery Slope Fallacy

This happens when someone argues that one small thing will lead to a massive disaster.

 For example:

"If we let kids have phones, they’ll spend all their time on TikTok. Then they won’t study, fail school, and never get a job!”

One thing doesn’t always lead to the next. Sometimes, people jump to extreme conclusions out of fear.

The Slippery Slope Fallacy causes a lot of unnecessary fear and anxiety. We mess up an assignment at work. The boss gets mad. You start thinking, “Well if the boss is mad, then she’s going to hate me. And if the boss hates me, then I’m going to get fired. And if I get fired, then I’m going to be homeless. OMG I DON’T WANT TO BE HOMELESS!!!”

Create your own slippery slope argument below.

3. False Dichotomy

This is when someone acts like there are only two choices, but in reality, there are more. 

For example:

"You’re either my friend, or you’re my enemy."

That’s not true—you could just be neutral or not care! False dichotomies try to oversimplify things to make you pick a side.

Sometimes, there really are only two options in a situation. For example, I could say, “There are two types of people: people named Ron and people not named Ron.” This is a true dichotomy because everyone either has the name Ron or doesn’t.

But a false dichotomy happens when someone acts like there are only two choices when, in reality, there are more. 

For example, if I said, “There are only two types of people: people named Ron and idiots,” that would be a false dichotomy. Why? Because not being named Ron doesn’t automatically make someone an idiot. Plus, let’s be real—there are definitely some people named Ron who aren’t exactly the smartest!

Which is an example of false dichotomy?

1. Cats or dogs are pets
2. Choice of pizza toppings
3. It's raining or it's sunny
4. You are either with us or against us

Why is false dichotomy misleading?

1. It encourages healthy debate
2. It promotes critical thinking
3. It clarifies all options clearly
4. It oversimplifies complex issues

4. Red Herring

A red herring is a distraction from the real issue. 

For example:

You: “You stole my bike!”

Friend: “Why are you so angry? Millions of bikes get stolen every year!”

Instead of addressing the fact they took your bike, they’re trying to distract you with irrelevant information.

Red Herrings are arguments that seem relevant to an issue but actually are not.

 For example, we could be arguing about whether being vegetarian is more ethical than eating meat. Then, in the middle of a perfectly fine argument, I blurt out, “Well, Hitler was vegetarian! And he surely wasn’t ethical!”

 

This is a distraction from the real point of debate: whether eating meat is inherently unethical.

What is a red herring?

1. A type of fish
2. A literary genre
3. A style of painting
4. A misleading clue or distraction

What does a red herring do?

1. Diverts attention from the main issue
2. Supports the main thesis
3. Clarifies the main argument
4. Summarizes the findings

5. Ad Hominem

This happens when someone attacks the person instead of their argument. 

For example:

"You’re wrong because you’re dumb!"

This doesn’t prove anything except that someone’s out of good ideas.

Remember when you were a little kid and you’d get in an argument with another kid, and they’d point out how you were wrong, and at a complete loss of how to defend yourself, you’d blurt out, “Well you’re just a smelly goat-face! And I don’t listen to smelly goat-faces,” and stomp off as if that solved something?

Yeah, that’s an ad hominem fallacy, and as your teacher, I hear students using this tactic every day. You're just using stronger language.

Think of a time when you used an ad hominem attack or another person used one against you. Describe the incident below, and then tell me how you SHOULD have responded instead.

6. Straw Man

This is when someone exaggerates or misrepresents your argument to make it easier to attack. 

For example:

"Oh, you care about the environment? So, you just want us all to stop using cars and live in caves, huh?"

That’s not what you said at all, but now you’re stuck defending yourself.

Instead of arguing against what someone actually said, people sometimes twist or exaggerate their words to make them easier to attack. 

This is called the “straw man” fallacy because it’s like replacing a real person with a straw version that’s weaker and easier to knock down.

Straw man arguments happen a lot—and they’re surprisingly silly!

“You want to reduce the defense budget? You must hate the military and don’t support our soldiers.”

What is a straw man argument?

1. Misrepresenting someone's argument
2. Debating with respect
3. Presenting accurate evidence
4. Distorting an opponent's position

Why use a straw man argument?

1. To undermine an opponent's viewpoint
2. To strengthen one's own argument

Which of these is an example?

1. Claiming opponents hate freedom
2. Offering factual data
3. Discussing valid counterarguments
4. Saying they want to ban all cars

7. Begging the Question

Begging the question occurs when someone’s argument relies upon its own assumptions to make its case. 

For example:

My husband always knows what’s right for me. Why? Because he told me that he always knows what’s right for me and he’s always right, so…

Carl is a dork. Why? Because he tries to pretend he’s not a dork, so that makes him a dork.

This is often called “circular reasoning” because if you follow the logic, it leads you in a circle.

Which statement uses circular reasoning?

1. Education improves job prospects for graduates
2. Freedom is important because it matters

How to identify circular reasoning?

1. Check for statistical support in arguments
2. Look for repeated claims as evidence

8. Appealing to an outside source / Bandwagon fallacy

When in an argument, it’s tempting to skip the logic and go straight to appealing to some outside source to make your point feel more meaningful.

Well, unfortunately, logic doesn’t work that way. A bad argument is a bad argument, regardless of who agrees with you.

There are three common appeals that people make when trying to win points for their side:

• An appeal to authority: “Well, the president said it’s true, so it must be true!”
  
• An appeal to pity: “I know the data says that social media isn’t the problem, but these poor kids have so much anxiety, we should still ban social media.”
  
• An appeal to the majority: “Everyone I know says that vaccines are dangerous, so it must be true.”
  

Appealing to an outside source is also often called the Bandwagon fallacy.

Humans are super social, and we naturally care about what others think. We want to fit in, be around important people, and show that we’re kind and thoughtful.

The problem is, these things don’t have anything to do with whether something is logical or true. If something is true, it’s true no matter what anyone thinks about it.

What is the bandwagon fallacy?

1. A marketing strategy
2. A type of musical performance
3. Assuming something is true because many believe it
4. A logical argument structure

Which of these is an example of bandwagon fallacy?

1. Everyone uses this brand, so it must be good
2. This movie won many awards
3. This car model is very reliable
4. This product has great reviews

Why is bandwagon fallacy misleading?

1. It encourages logical reasoning
2. It relies on popularity, not evidence
3. It is always based on factual data
4. It supports individual opinions

What can bandwagon fallacy lead to?

1. Increased critical thinking skills
2. Clear understanding of facts
3. Poor decision-making based on trends
4. Informed and rational choices

Who is most likely to use bandwagon fallacy?

1. Advertisers and marketers
2. Scientists and researchers
3. Historians and analysts
4. Philosophers and ethicists

Why Logical Thinking Matters

It’s easy to fall into these traps, but clear thinking helps us make better decisions and avoid getting tricked. Logical reasoning isn’t about “winning” arguments; it’s about understanding the truth. So next time you’re debating, remember: focus on facts, think things through, and don’t be a Ron.

(Unless your name is Ron. Then just don’t be that guy.)

Why is it important to recognize when someone is using a logical fallacy?