Lesson 1: Ad Hominem

Spot the Faulty Logic #

During a class discussion about school uniforms, Jake says, “I think uniforms would save families money.” Emma responds, “That’s silly, Jake always wears the same shirt anyway. He doesn’t know anything about fashion.”

Discussion: Talk with your teacher about this example. What seems wrong with Emma’s response?

How/Why It’s Often Used #

People use Ad Hominem when they can’t think of a good response to someone’s argument, or when they want to distract from the real issue. It’s easier to criticize a person than to think through complicated ideas. Ad Hominem arguments can be found anywhere emotions run high and patience wears thin. It’s one of the most common fallacies around because it’s an easy way to get around having to deal with a real argument. This kind of bad logic attacks the person and is often successful at deflecting from the point entirely. However, if you catch it and maintain your cool in the face of a personal attack, it is easily refuted as nothing more than irrelevant unkindness.

Ad Hominem in Action #

Did you spot the faulty logic? #

Jake offered a real argument for why school uniforms might be a good idea. Emma ignored his logic and attacked him instead. However, Jake’s fashion sense and preference of clothing has nothing to do with whether he is right or wrong about uniforms saving families money.

Second Example #

Two siblings are cleaning the kitchen. Valerie: “You shouldn’t put the cast iron pan in the dishwasher; it ruins the seasoning.” Jackson: “Why should I listen to you? You don’t know anything about cleaning, your bedroom is a total disaster zone.”

The Flaw #

Whether Valerie’s bedroom is spotless or a disaster zone is completely irrelevant to the chemistry of what a dishwasher does to a cast iron pan. She could be the messiest person on Earth and still be correct about the pan. Jackson is trying to discredit the messenger to avoid having to deal with the message.

Lesson 2: False Dilemma

Spot the Faulty Logic #

A student receives his math work back and has gotten almost all the questions wrong. He says to his mom, “Ugh, I did so badly! I’m just terrible at math.”

Discussion: Talk with your teacher about this example. What seems wrong with his response?

How/Why It’s Often Used #

False dilemmas can appear in a variety of use cases. People often use this fallacy to make decisions seem urgent or simple, or to pressure others into choosing the option they prefer. It’s used unintentionally when someone hasn’t thought carefully about all the possibilities. You might encounter it in social settings when others want to create a “with us or against us” situation. You might even hear it in motivational speeches when someone is being overly simplistic in order to push toward a goal. Framing an argument in this way can be used to manipulate others into beliefs or actions they would not have chosen if they had been aware of other options.

False Dilemma in Action #

Did you spot the faulty logic? #

The student frames his relationship with math as if there’s only two options. Because he did poorly, he must be terrible at math. This ignores the reality of so many other possible options though. He can be good at math but didn’t study enough this time, or perhaps he just had a bad day, or maybe he’s good at other parts of math but struggles with this specific topic.

Second Example #

A coach is talking to his athletes before a big tournament. He’s trying to get them pumped up and ready to give it their all. Pushing for intensity, he says, “If you aren’t first, you’re last.”

The Flaw #

This bad thinking missing the middle entirely. Coming in 2nd, 3rd, or even beating your own personal best are all distinct achievements. Being 1st place is certainly not the only form of success to be had. The coach’s phrase erases all measure of success but one.

Lesson 3: Bandwagon Appeal

Spot the Faulty Logic #

Jordan is telling her mother about this new brand of water bottle, she says, “it’s so cool, practically everyone has one! I have to get one too!”

Discussion: Talk with your teacher about this example. What seems wrong with Jordan’s argument?

How/Why It’s Often Used #

People use this fallacy because it feels safe to do what everyone else is doing, and it can be persuasive to point out that “everyone” agrees. It’s also used in advertising to make products seem more appealing. This type of bad thinking can be very compelling because as humans we are driven to seek belonging and avoid social isolation. We should ask ourselves “why is this a good idea,” and require a better reason than “because everybody says so.”

Bandwagon Appeal in Action #

Did you spot the faulty logic? #

Does the fact that a lot of kids have this particular brand of water bottle really mean it’s the best choice for you? It would be helpful to consider whether it’s within your budget, or if there are better things you could spend your money on. Do you actually need a new water bottle or are you just looking to fit in with your friends?

Second Example #

During a group project discussion, someone says, “Everyone thinks we should do our presentation on video games, so that’s obviously the best topic.”

The Flaw #

The group’s preference doesn’t automatically make video games the best topic for their specific assignment. They should consider factors like available research, assignment requirements, and their own expertise.

Lesson 4: Appeal to Authority

Spot the Faulty Logic #

I found this cool dinosaur encyclopedia in my grandpa’s attic from 1980. It has a drawing of a T-Rex standing straight up like a kangaroo with its tail dragging on the ground. My teacher says T-Rexes leaned forward and walked with their tails in the air, but I believe the book because it’s a real encyclopedia.

Discussion: Talk with your teacher about this example. What seems wrong with this line of thinking?

How/Why It’s Often Used #

People use this fallacy often unconsciously because we’re taught to respect authority figures, and it’s often easier to quote someone famous than to research the actual evidence. It can make arguments sound more convincing. TV commercial advertisers pay famous athletes or movie stars to hold a product because they know you are more likely to trust a familiar, cool face than you are to research the actual quality of the item. People also unknowingly fall prey to the appeal to authority fallacy when reading or listening to their favorite authors or speakers. If we’re not careful we can blindly believe everything said by this person based solely on who they are and not on the claim itself.

Appeal to Authority in Action #

Did you spot the faulty logic? #

The student believed the book not on the basis of real evidence but because it was a published book. This appeal to authority caused him to believe a particular source he didn’t think could be wrong. However, scientists are always learning and new technology helps refine what we believe to be true all the time. Just because the encyclopedia says something doesn’t mean that information hasn’t been proved to be inaccurate. Truth can come from any source and any source can be mistaken.

Second Example #

Someone says, “Climate change isn’t real because my uncle, who’s a successful businessman, says it’s just a hoax.”

The Flaw #

Being successful in business doesn’t make someone an expert on climate science. The uncle’s opinion carries no more weight than any other non-expert’s.

Lesson 5: Hasty Generalization

Spot the Faulty Logic #

After meeting two unfriendly kids at a park in a new town, Noah concludes, “Wow, all the kids in this town are mean.”

Discussion: Talk with your teacher about this example. What seems wrong with Noah’s response?

How/Why It’s Often Used #

People use this fallacy as a mental shortcut because it is much easier to make a quick judgment than to take the time to learn the truth. It happens when someone takes a tiny amount of evidence, like one or two bad experiences, and assumes it applies to everyone or everything in that group. It is often used to create stereotypes or to justify being angry at a whole group of people based on the actions of just one person. It creates a simple (but usually wrong) conclusion so people don’t have to think too hard.

Hasty Generalization in Action #

Did you spot the faulty logic? #

Noah had a bad experience with two kids in a new town. However, there might be thousands of kids in that town. To assume that the whole town is full of mean kids based on one experience with such a small number of kids is quite a hasty generalization.

Second Example #

Sarah tries three different math problems and gets them all wrong. She says, “I’m terrible at math and will never understand it.”

The Flaw #

Sarah’s logic is faulty because she is judging her entire potential based on a tiny sample size of just three failed attempts. The biggest mistake she is making is treating “Math” like it is one single skill, when it is actually a huge umbrella covering many different areas. She might be great at fractions, but struggle with multi-digit multiplication. Or perhaps with practice or different teaching methods, Sarah might actually be quite good at math. Three failed problems is insufficient evidence to make such a grand statement about her math ability.

Lesson 6: Loaded Question

Spot the Faulty Logic #

You are playing a pickup game of basketball or soccer at the park. Your team loses, and a frustrated teammate looks at you and says, “do you hog the ball because you think you’re better than everyone else?”

Discussion: Talk with your teacher about this example. What might be the problem with the teammate’s question?

How/Why It’s Often Used #

People use the Loaded Question fallacy as a verbal trap. It is a way of sneaking an accusation or an insult into a conversation without saying it directly. The goal is to force you to admit to something you didn’t do, or to make you look guilty no matter how you answer. It is often used by someone who wants to control the argument. By asking a question with a “built-in” lie, they force you to defend yourself against the lie instead of answering the actual question. It puts you on the defensive immediately.

Loaded Question in Action #

Did you spot the faulty logic? #

The teammate isn’t actually asking if you hogged the ball; they are stating it as a fact. They are only giving you the ability to refute the reason for your supposed bad behavior. Answering the question whether you think you’re better than everyone or not traps you into accepting that you did in fact hog the ball.

Second Example #

A group of kids is planning a prank that you think is mean and dangerous. You say you don’t want to go. The leader of the group turns on you and says, “why are you scared of a little fun?”

The Flaw #

Are you scared of fun? Or is this bad thinking trying to force you into justifying yourself while deflecting from the real issue? The leader of this group should’ve asked why you didn’t want to go, giving you an opportunity to explain that you think the prank might be too mean or possibly dangerous. Instead, the reason is assumed and loaded into the question as fact.

Lesson 7: Appeal to Emotion

Spot the Faulty Logic #

“We absolutely have to adopt this puppy today. If we leave him at the shelter, he will be all alone in a cold cage and think that nobody loves him.”

Discussion: Talk with your teacher about this example. What might be the problem with the child’s statement?

How/Why It’s Often Used #

People use this fallacy because emotions are powerful and can be more persuasive than facts. It’s also easier to make people feel something than to do the critical thinking needed for a logical argument.

Appeal to Emotion in Action #

Did you spot the faulty logic? #

This argument tries to manipulate the listener into making a major commitment based purely on pity and guilt, rather than practical logic. It completely ignores important questions - like whether the family has the time, money, or space to care for a pet - and focuses entirely on the emotional sadness of the puppy’s situation to force a “yes.”

Second Example #

“You absolutely must finish everything on your plate, even if you are full. Think of the poor, starving children around the world who have nothing to eat; it is just too heartbreaking to let this food go to waste.”

The Flaw #

This argument relies on guilt and sadness to force compliance rather than logic. Whether or not you finish your meal has no physical effect on the starving children; eating past the point of fullness does not feed them, but the speaker uses the tragedy of their hunger to make you feel too guilty to say “no.”

Lesson 8: Red Herring

Spot the Faulty Logic #

“I know I forgot to take out the trash like you asked, but look at this A on my math test! I studied really hard for it.”

Discussion: Talk with your teacher about this example. What might be the problem with the child’s statement?

How/Why It’s Often Used #

The term comes from an old practice used to train hunting dogs. Herring (a type of fish) turns red and smells very pungent when it is smoked. Trainers would drag this smelly fish across a fox’s scent trail to test the dogs. If the dogs were disciplined, they would stay on the fox’s trail. However, if they were easily distracted, they would follow the strong smell of the fish instead. In logic, a “Red Herring” is that smelly fish, a strong distraction thrown in to lead you away from the real issue.

People use this fallacy when they can’t defend their position on the actual topic, or when they want to avoid discussing something uncomfortable. It’s also used to confuse the audience by introducing a flashy, shocking, or emotionally positive topic to draw attention away from the original issue. The goal is to send the argument off on a “false trail” so the original point is abandoned.

Red Herring in Action #

Did you spot the faulty logic? #

The student uses their success in math to distract from their failure to do the requested chore. The math grade is great, but it is irrelevant to the trash issue. The child is using this statement to distract attention away from the core issue.

Second Example #

"During a discussion about whether the school should have a dress code, someone says, “Instead of worrying about clothes, we should be concerned about the bullying problem!”

The Flaw #

Bullying is a serious issue, but bringing it up doesn’t address the question about dress codes, it simply distracts away from it. Both topics can be important and should be addressed separately.

Lesson 9: Straw Man

Spot the Faulty Logic #

Maya says, “I think we should have 30 minutes of quiet reading time each day at school.” Her classmate responds, “So you think we should just read books all day and never do math or science? That’s ridiculous!”

Discussion: Talk with your teacher about this example. What seems wrong with the classmate’s response?

How/Why It’s Often Used #

People use this fallacy because it’s much easier to argue against a weak, distorted version of someone’s position than their actual argument. Instead of addressing what the person really said, they create a “straw man” - a flimsy version of the argument that can be easily knocked down, just like a scarecrow made of straw.

This happens when someone either doesn’t understand the original argument, doesn’t want to deal with it honestly, or wants to make their opponent look foolish. It’s common in debates, arguments between friends, and in media coverage of controversial topics.

Straw Man in Action #

Did you spot the faulty logic? #

Maya suggested 30 minutes of reading time, not replacing the entire school day with reading. Her classmate twisted her reasonable suggestion into an extreme position that Maya never actually held, making it easy to dismiss.

Second Example #

Dad: “I think you should limit your video game time to one hour on school nights.” Child: “So you want me to never have any fun and just do homework until I go to bed? You want me to be miserable!”

The Flaw #

Dad suggested limiting video games to one hour, not eliminating all fun. The child exaggerated the position to something extreme that Dad never said, making it easier to argue against.

Lesson 10: Slippery Slope

Spot the Faulty Logic #

A student asks if they can have their phone during lunch to text their mom. The teacher responds, “If I let you use your phone, then everyone will want to use their phones, and soon no one will be talking to each other, and our whole school community will fall apart!”

Discussion: Talk with your teacher about this example. What seems wrong with the teacher’s reasoning?

How/Why It’s Often Used #

People use this fallacy to create fear about a decision by imagining the worst possible outcome. It’s often used to resist change or to argue against something relatively small by connecting it to something much larger and scarier. The argument suggests that once you take one step, you’ll slide all the way down a “slippery slope” to disaster.

It’s commonly used in discussions about rules, policies, and permissions. Parents, teachers, and politicians often use this type of reasoning when they want to prevent something from happening.

Slippery Slope in Action #

Did you spot the faulty logic? #

The teacher jumped from one student texting their mom to the complete breakdown of school community. There are many steps in between, and none of them are inevitable. The school could set reasonable limits, and most students would probably still talk to each other even if some used phones.

Second Example #

“If we allow students to choose their own reading books, next they’ll want to choose whether to do homework at all, then they’ll refuse to come to school, and eventually they’ll never learn anything!”

The Flaw #

Choosing reading books doesn’t automatically lead to refusing all homework or abandoning school entirely. Each of these would be a separate decision with its own considerations.

Lesson 11: Post Hoc Ergo Propter Hoc

Spot the Faulty Logic #

“I wore my lucky socks to the game and we won! My socks must have caused us to win.”

Discussion: Talk with your teacher about this example. What seems wrong with this reasoning?

How/Why It’s Often Used #

Our brains are wired to look for patterns and causes. When two things happen close together in time, it’s natural to assume they’re connected. This is actually useful sometimes - it helps us learn that touching a hot stove causes burns! But it can lead us astray when we see connections that aren’t really there.

People often use this reasoning to support superstitions, lucky charms, and rituals. It’s also common in advertising (“I used this product and then got better grades!”) and in everyday explanations of events.

Post Hoc in Action #

Did you spot the faulty logic? #

The team won for many possible reasons: good plays, team effort, the other team’s mistakes, or just luck. The socks happened to be worn on the same day, but there’s no logical connection between sock choice and game outcomes.

Second Example #

“I started taking this vitamin last week and my cold went away. The vitamin cured my cold!”

The Flaw #

Colds naturally go away on their own after about a week. The timing of the vitamin coincided with the natural end of the cold, but that doesn’t mean the vitamin caused the recovery.

Lesson 12: Circular Reasoning

Spot the Faulty Logic #

“This book is the best book ever written because it says so right here on the cover: ‘The Best Book Ever Written!’”

Discussion: Talk with your teacher about this example. What seems wrong with this argument?

How/Why It’s Often Used #

Sometimes circular reasoning happens because the person hasn’t thought carefully about their argument. Other times, it’s used intentionally to sound convincing without actually proving anything. The argument can sound complete because it seems to have a reason, but when you look closely, the reason is just a restatement of the claim.

This fallacy is also called “begging the question” in its traditional philosophical sense. It’s common in discussions about beliefs, rules, and traditions where people might not question the underlying assumptions.

Circular Reasoning in Action #

Did you spot the faulty logic? #

The claim is that the book is the best. The evidence is that the book says it’s the best. But a book claiming to be the best doesn’t make it the best - that’s just the claim repeated, not evidence for the claim.

Second Example #

“Why do you have to go to bed at 9pm?” “Because that’s your bedtime.” “But why is that my bedtime?” “Because that’s when you have to go to bed.”

The Flaw #

This answer just restates the rule without explaining the reason behind it. The bedtime is the bedtime because it’s the bedtime - that’s circular. A real reason might be: “Because growing kids need 10 hours of sleep and you need to wake up at 7am.”

Lesson 13: False Cause

Spot the Faulty Logic #

“Studies show that students who eat breakfast get better grades. So if you want better grades, just eat breakfast!”

Discussion: Talk with your teacher about this example. What might be missing from this reasoning?

How/Why It’s Often Used #

Humans naturally want to understand why things happen. When we see two things occurring together, our brains quickly assume one must cause the other. This mental shortcut usually helps us navigate the world, but it can lead to faulty conclusions.

False cause reasoning is common in advertising, health claims, and everyday explanations. It’s also closely related to the Post Hoc fallacy, but broader - it includes any time someone mistakenly identifies a cause, not just when events happen in sequence.

False Cause in Action #

Did you spot the faulty logic? #

The real cause might be different. Perhaps families who have time to provide breakfast also have more time for homework help, or more resources for education. Breakfast might be correlated with good grades without being the actual cause. Simply adding breakfast won’t necessarily improve grades if the real causes are different.

Second Example #

“Cities with more ice cream sales have more drowning deaths. Ice cream must be dangerous!”

The Flaw #

Both ice cream sales and swimming (which leads to drowning risk) increase in summer due to hot weather. The weather is the common cause - ice cream doesn’t cause drowning at all.

Lesson 14: Sunk Cost Fallacy

Spot the Faulty Logic #

“I’ve already read 200 pages of this book and it’s terrible, but I have to finish it because I’ve invested so much time already.”

Discussion: Talk with your teacher about this example. What seems wrong with this reasoning?

How/Why It’s Often Used #

We hate to feel like our past efforts were wasted. It’s psychologically painful to admit that time or money we’ve already spent is gone and can’t be recovered. So we keep going, hoping to somehow “redeem” our investment, even when quitting would actually be the smarter choice.

This fallacy affects all kinds of decisions: finishing bad movies, staying in activities we don’t enjoy, or continuing projects that aren’t working. Businesses fall into this trap too, pouring more money into failing projects because they’ve already invested so much.

Sunk Cost in Action #

Did you spot the faulty logic? #

Those 200 pages are already read - that time is gone. The real question is: “Would I rather spend my next few hours finishing a book I don’t enjoy, or doing something else?” The past investment doesn’t change what the best future choice is.

Second Example #

“I know this movie is boring, but we already paid for the tickets, so we have to stay until the end.”

The Flaw #

The ticket money is spent either way - you don’t get it back by staying. The question is whether the next two hours are better spent watching something you don’t enjoy or leaving to do something else. The past purchase shouldn’t trap you into future misery.

Lesson 15: Cherry Picking

Spot the Faulty Logic #

A student claims, “Our school’s basketball team is amazing! They won their last three games!” (But they don’t mention that the team lost their first twelve games of the season.)

Discussion: Talk with your teacher about this example. What important information is being left out?

How/Why It’s Often Used #

When we want to prove a point, it’s tempting to focus only on evidence that supports us. Cherry picking makes an argument seem stronger than it actually is by hiding the full picture. Sometimes people do this intentionally to deceive others, but often they do it unconsciously because of their own biases.

This fallacy is extremely common in advertising (“4 out of 5 dentists recommend…” - but what about the 5th dentist?), in arguments between people, and in how we sometimes think about ourselves (remembering our successes more than our failures).

Cherry Picking in Action #

Did you spot the faulty logic? #

By mentioning only the recent wins and ignoring the twelve losses, the student creates a false impression of the team’s performance. The full record (3-12) tells a very different story than “won their last three games.”

Second Example #

“This diet is scientifically proven! Here are five studies that show it works.” (But they don’t mention the fifteen studies that showed it didn’t work.)

The Flaw #

Selecting only the supportive studies while ignoring the contradicting ones doesn’t prove the diet works - it just shows the person is only presenting part of the picture.

Lesson 16: Appeal to Tradition

Spot the Faulty Logic #

“We’ve always done the science fair in March. We can’t move it to April just because it would work better with the schedule. That’s not how we do things here!”

Discussion: Talk with your teacher about this example. What seems wrong with this reasoning?

How/Why It’s Often Used #

Traditions can provide comfort, connection, and a sense of identity. When something has worked in the past, it’s natural to assume it will continue to work. Change can feel risky and uncertain, while tradition feels safe and proven.

People use this reasoning to resist changes they don’t want to make, or when they haven’t thought critically about why something is done a certain way. It’s common in families, organizations, and societies when facing decisions about whether to keep doing things the old way or try something new.

Appeal to Tradition in Action #

Did you spot the faulty logic? #

The length of time the science fair has been in March doesn’t prove March is the best month. If April works better with the current schedule, that’s a logical reason to consider changing. “We’ve always done it this way” isn’t a reason - it’s just a statement of history.

Second Example #

“My grandfather used this method to train dogs, and his father before him. It’s the traditional way, so it must be the right way.”

The Flaw #

Dog training methods have evolved significantly as we’ve learned more about animal behavior. Just because a method is old doesn’t mean it’s effective or humane. Each practice should be evaluated on its own merits, not its age.

Lesson 17: Appeal to Novelty

Spot the Faulty Logic #

“You should switch to this new study method - it’s the latest technique that was just developed this year! The old ways of studying are outdated.”

Discussion: Talk with your teacher about this example. What seems wrong with this reasoning?

How/Why It’s Often Used #

Our culture often celebrates newness. “New and improved” is a powerful marketing phrase. There’s an excitement about trying the latest thing, and sometimes newer really is better. But the assumption that new automatically equals better is a logical shortcut that doesn’t always hold true.

This fallacy is heavily used in advertising (for products, apps, technologies) and in discussions about methods, ideas, or practices. It’s the opposite of Appeal to Tradition - both make the mistake of judging something based on its age rather than its actual merits.

Appeal to Novelty in Action #

Did you spot the faulty logic? #

The argument gives no evidence that the new study method actually works better - just that it’s new. Proven study techniques that have helped students for decades might actually be more effective than an untested new approach.

Second Example #

“Why are you still reading physical books? E-readers are newer technology. You should switch!”

The Flaw #

The newness of e-readers doesn’t make them better for everyone. Physical books and e-readers each have advantages and disadvantages. The right choice depends on personal preferences and circumstances, not just which is newer.

Lesson 18: Anecdotal Evidence

Spot the Faulty Logic #

“My grandpa smoked his whole life and lived to be 95, so smoking can’t be that dangerous.”

Discussion: Talk with your teacher about this example. What’s the problem with using this one story as proof?

How/Why It’s Often Used #

Stories are powerful and memorable. We naturally relate to personal experiences more than statistics or studies. When someone tells a vivid story about their own experience, it feels more real and convincing than abstract data.

This fallacy often appears in discussions about health, success, products, and practices. It’s easy to find one person whose experience supports almost any claim. People use anecdotes to argue for miracle cures, get-rich-quick schemes, and all kinds of beliefs.

Anecdotal Evidence in Action #

Did you spot the faulty logic? #

One person living long despite smoking doesn’t disprove the well-documented health risks. This grandfather might have had unusual genes, or other factors in his favor. The scientific evidence from millions of cases clearly shows smoking is dangerous, even if some individuals are exceptions.

Second Example #

“My friend dropped out of college and now she’s a millionaire. You don’t need an education to be successful!”

The Flaw #

One friend’s success doesn’t prove that dropping out is a good strategy in general. For every dropout who succeeds, many others struggle. We need to look at outcomes for many people, not just one memorable story.

Lesson 19: Special Pleading

Spot the Faulty Logic #

“I know the rule says no phones in class, but my situation is different. I really need to check my messages because I’m expecting something important.”

Discussion: Talk with your teacher about this example. What’s wrong with claiming to be a special exception?

How/Why It’s Often Used #

We naturally see our own situations as unique. It’s easy to believe that the rules should apply to everyone else, but our circumstances are special. This kind of reasoning often happens when we want something we know we shouldn’t have, or when we want to avoid following a rule we find inconvenient.

People use special pleading to justify their own behavior while holding others to different standards. It’s common in discussions about rules, fairness, and responsibility.

Special Pleading in Action #

Did you spot the faulty logic? #

Everyone in class might have something they consider “important.” Without a truly compelling reason why this person’s situation is different (like a family emergency), they’re just asking to be exempt from a rule they want everyone else to follow.

Second Example #

“Yes, I know I said people shouldn’t leave dishes in the sink, but when I do it, it’s different because I’m really busy.”

The Flaw #

Being busy isn’t a unique condition - everyone is busy sometimes. If the rule against leaving dishes is reasonable, it should apply equally. Claiming a special exemption without a genuinely special reason is unfair.

Lesson 20: Appeal to Pity

Spot the Faulty Logic #

“You have to give me an A on this project. I worked so hard on it and I’ve been having a really tough week. My dog is sick and I’ve been so stressed. Please?”

Discussion: Talk with your teacher about this example. What’s wrong with using these reasons to argue for a better grade?

How/Why It’s Often Used #

Sympathy is a powerful emotion. When we feel sorry for someone, we want to help them feel better. This natural compassion can be manipulated to bypass logical evaluation. Someone might use their difficulties or sad circumstances to get what they want, even when those circumstances aren’t relevant to the decision.

This fallacy often appears in requests for grades, favors, exceptions to rules, or special treatment. While compassion is important, it shouldn’t replace logical evaluation of whether something is deserved or appropriate.

Appeal to Pity in Action #

Did you spot the faulty logic? #

The grade should be based on the quality of the project, not on how stressed the student was or whether their dog is sick. Those are reasons to offer emotional support, but they don’t change what grade the work deserves.

Second Example #

“You should let me borrow your bike. I really want to go to the park and I’ll be so sad if I can’t go!”

The Flaw #

The desire to go to the park and potential sadness don’t create an obligation for someone to lend their bike. A logical argument would address why lending the bike is reasonable - not just that the person will be sad without it.

Lesson 21: Tu Quoque

Spot the Faulty Logic #

Parent: “You really should read more instead of watching so much TV.” Child: “But you watch TV every night after dinner! You’re being hypocritical!”

Discussion: Talk with your teacher about this example. Does the parent’s TV watching change whether the advice is good?

How/Why It’s Often Used #

When we’re criticized, it’s uncomfortable. A quick way to shift attention away from ourselves is to point out that the person criticizing us isn’t perfect either. It feels satisfying to call someone a hypocrite, and it can derail the conversation away from our own behavior.

Tu Quoque is extremely common in arguments between siblings, friends, and in public debates. It’s essentially saying, “You can’t criticize me because you’re not perfect!”

Tu Quoque in Action #

Did you spot the faulty logic? #

The parent watching TV doesn’t change whether reading is valuable. The child is avoiding the actual question (should they read more?) by attacking the messenger instead of addressing the message.

Second Example #

“You can’t tell me to eat healthier - I’ve seen you eat pizza!”

The Flaw #

Someone eating pizza occasionally doesn’t invalidate good nutritional advice. The focus should be on whether eating healthier is good advice, not on whether the advisor is perfect.

Lesson 22: No True Scotsman

Spot the Faulty Logic #

Person A: “All real gamers prefer PC over console.” Person B: “But my friend loves console gaming and he’s been gaming for 20 years.” Person A: “Well, then he’s not a REAL gamer.”

Discussion: Talk with your teacher about this example. What’s wrong with how Person A responds to the counterexample?

How/Why It’s Often Used #

When someone makes a broad claim about a group (“All X are Y”) and is presented with a counterexample, they might try to save their claim by excluding the counterexample from the group. Instead of admitting their original claim was too broad, they change what counts as being part of the group.

The name comes from a famous example: “No Scotsman puts sugar in his porridge.” “But my uncle Angus is Scottish and he puts sugar in his.” “Well, no TRUE Scotsman puts sugar in his porridge.”

No True Scotsman in Action #

Did you spot the faulty logic? #

When presented with a long-time gamer who prefers console, Person A simply excluded them from the category of “real gamers” rather than admitting their original claim was too broad. The definition of “real gamer” is being manipulated to protect a false generalization.

Second Example #

“All serious athletes wake up early to train.” “Michael is a serious athlete who competes nationally, and he trains in the evenings.” “Then he’s not a TRULY serious athlete.”

The Flaw #

Michael’s competitive status is evidence he IS a serious athlete. Redefining “serious athlete” to exclude him just protects a claim that was too broad to begin with.

Lesson 23: Texas Sharpshooter

Spot the Faulty Logic #

“Look at these sports statistics! I correctly predicted the winner in 8 out of 10 games last month!” (But they actually made predictions for 100 games and are only showing the ones they got right.)

Discussion: Talk with your teacher about this example. What’s being hidden here?

How/Why It’s Often Used #

The name comes from a joke about a person who shoots randomly at a barn wall, then paints a target around the bullet holes and claims to be a sharpshooter. They’re finding a “pattern” after the fact, not actually demonstrating skill.

Our brains naturally look for patterns - it’s how we make sense of the world. But this can lead us astray when we focus only on the “hits” (data that fits) and ignore all the “misses” (data that doesn’t). It’s closely related to cherry picking, but specifically involves finding patterns in randomness.

Texas Sharpshooter in Action #

Did you spot the faulty logic? #

If you make 100 predictions, you’d expect to get many right just by chance. Highlighting only the 8 out of 10 correct ones (while hiding the other 92 predictions) creates a false impression of predictive ability.

Second Example #

“This psychic is amazing! She predicted that something significant would happen to me this month, and look - my car broke down!”

The Flaw #

“Something significant” is so vague that almost anything could count as fulfilling the prediction. The prediction wasn’t specific enough to be meaningful, and the “pattern” is being found after the fact.

Lesson 24: Middle Ground Fallacy

Spot the Faulty Logic #

“My friend says we should study for 4 hours, and my other friend says we shouldn’t study at all. The truth must be in the middle - let’s study for 2 hours.”

Discussion: Talk with your teacher about this example. Is the middle ground always the right answer?

How/Why It’s Often Used #

Compromise feels fair and reasonable. We’re taught to find middle ground and avoid extremes. This is often wise in negotiations and relationships. But when it comes to determining truth or making optimal decisions, the “middle” position isn’t automatically correct just because it’s in the middle.

This fallacy is common in debates where people want to appear balanced and fair. It can also be exploited - if someone takes an extreme position, they can make a less extreme (but still unreasonable) position seem moderate by comparison.

Middle Ground in Action #

Did you spot the faulty logic? #

How much to study should depend on what the material requires and the person’s goals - not on finding a middle point between two friends’ opinions. If 4 hours is actually needed, studying only 2 hours because that’s the “middle” would be inadequate.

Second Example #

“Scientists say the Earth is about 4.5 billion years old. Some people say it’s only 6,000 years old. The truth is probably somewhere in the middle.”

The Flaw #

Scientific evidence strongly supports the 4.5 billion year estimate. The existence of a different opinion doesn’t mean truth lies in the middle. Evidence determines what’s true, not averaging different claims.

Lesson 25: Genetic Fallacy

Spot the Faulty Logic #

“You can’t trust that scientific theory - it was originally developed by someone who lived 200 years ago. What could they possibly know?”

Discussion: Talk with your teacher about this example. Does where an idea comes from determine if it’s true?

How/Why It’s Often Used #

We sometimes make shortcuts by judging ideas based on where they come from rather than examining them directly. If an idea comes from a source we like, we accept it. If it comes from a source we dislike or distrust, we reject it. This saves time but can lead us to wrong conclusions.

This fallacy works in both directions - rejecting good ideas because of their origin, or accepting bad ideas because they come from a favored source. It’s related to Ad Hominem, but focuses more broadly on origin rather than just the person arguing.

Genetic Fallacy in Action #

Did you spot the faulty logic? #

The age of a theory doesn’t determine its validity. Many scientific principles developed centuries ago are still accurate. What matters is whether the theory is supported by evidence and testing, not when or by whom it was first proposed.

Second Example #

“That peace agreement idea came from our rival country, so it must be a trick.”

The Flaw #

Even rivals can propose genuinely good ideas. The proposal should be evaluated on its actual terms - is it fair? Does it address the issues? - not dismissed simply because of who suggested it.

Lesson 26: Equivocation

Spot the Faulty Logic #

“The sign says ‘fine for parking here.’ So I parked here. What’s wrong with parking somewhere that’s fine to park?”

Discussion: Talk with your teacher about this example. What’s tricky about the word “fine” here?

How/Why It’s Often Used #

Many words in English have multiple meanings. Arguments that switch between these meanings can seem logical on the surface while actually being nonsense. Sometimes this is done deliberately to trick people; other times it happens accidentally when people aren’t precise with their language.

Equivocation is common in jokes and puns (which deliberately play with multiple meanings), but it becomes a problem when used in serious arguments. It can make illogical arguments sound convincing.

Equivocation in Action #

Did you spot the faulty logic? #

The word “fine” has two completely different meanings: “fine” as in “acceptable/okay” and “fine” as in “a penalty fee.” The sign means there’s a penalty for parking there, not that it’s acceptable to park there!

Second Example #

“All men are created equal. Since I’m a man and you’re a woman, I was created your equal. Therefore, you weren’t created equal.”

The Flaw #

The word “men” in “all men are created equal” means “all people” or “mankind,” not specifically male humans. The argument switches between these meanings to reach an absurd conclusion.

Lesson 27: Appeal to Nature

Spot the Faulty Logic #

“I only use natural remedies for headaches because natural things are always safer than artificial medicines.”

Discussion: Talk with your teacher about this example. Is everything natural automatically safe?

How/Why It’s Often Used #

There’s a romantic idea that nature is pure and good, while human-made things are artificial and potentially harmful. This feeling has some basis - processed foods and synthetic chemicals have sometimes caused problems. But the conclusion that “natural = good” and “unnatural = bad” is far too simple.

This fallacy is extremely common in marketing, especially for food, medicine, and personal care products. “All natural!” is used as a selling point, implying safety and quality without proving it.

Appeal to Nature in Action #

Did you spot the faulty logic? #

Many natural substances are harmful (poison hemlock, arsenic, etc.), and many synthetic medicines are thoroughly tested and safe. “Natural” doesn’t equal “safe” - each remedy should be evaluated on its actual evidence of safety and effectiveness.

Second Example #

“Humans aren’t meant to fly - it’s unnatural. That’s why I’ll never get on an airplane.”

The Flaw #

Many things humans do are “unnatural” by some definitions - wearing clothes, cooking food, reading. The naturalness of an activity doesn’t determine whether it’s safe or good. Airplanes are extremely safe due to engineering and testing.

Lesson 28: Appeal to Fear

Spot the Faulty Logic #

“If you don’t buy our home security system, criminals will definitely target your house and your family will be in danger!”

Discussion: Talk with your teacher about this example. What’s the problem with using fear this way?

How/Why It’s Often Used #

Fear is one of our most powerful emotions - it evolved to protect us from danger. Because of this, fear-based arguments can override our rational thinking. When we’re scared, we want to act quickly to make the fear go away, often without carefully evaluating whether the threat is real or the proposed solution actually helps.

This fallacy is common in advertising (security systems, insurance, health products), politics (warnings about opponents), and everyday persuasion. It works by making you so worried about a potential bad outcome that you don’t think critically.

Appeal to Fear in Action #

Did you spot the faulty logic? #

The ad implies certain danger without evidence about actual crime rates in your area or the effectiveness of their system compared to alternatives. It uses fear to push you toward buying without rational evaluation.

Second Example #

“You have to vote for our candidate. If the other person wins, the economy will collapse and everyone will lose their jobs!”

The Flaw #

This argument relies on frightening predictions rather than evidence about policies and their likely effects. Voters should evaluate candidates on facts and track records, not be manipulated by worst-case scenarios.

Lesson 29: False Equivalence

Spot the Faulty Logic #

“My friend forgot my birthday, and you’re saying that’s not as bad as when someone robbed a store? Both are wrong, so they’re equally bad!”

Discussion: Talk with your teacher about this example. Are all wrongs really equal?

How/Why It’s Often Used #

People use this fallacy to make something seem better by comparing it to something worse, or to make something seem worse by equating it with something more serious. It’s also used in media to appear “balanced” - presenting two sides as equally valid when one has much more evidence than the other.

This reasoning can make minor problems seem as serious as major ones, or make major problems seem as minor as trivial ones. It distorts our ability to judge the relative importance of issues.

False Equivalence in Action #

Did you spot the faulty logic? #

While both forgetting a birthday and robbery are “wrong” in some sense, they’re vastly different in severity, impact, and moral weight. Lumping them together as equivalent ignores crucial differences.

Second Example #

“Some scientists doubt climate change, and other scientists support it. So we should give equal weight to both sides.”

The Flaw #

When 97% of climate scientists support human-caused climate change and 3% are skeptical, treating both positions as equally valid misrepresents the state of scientific knowledge. Numbers, evidence quality, and expert consensus matter.

Lesson 30: Composition Fallacy

Spot the Faulty Logic #

“Every player on this basketball team is excellent. Therefore, this must be the best team in the league!”

Discussion: Talk with your teacher about this example. Does having great individual players guarantee a great team?

How/Why It’s Often Used #

It seems logical that if each part has a quality, the whole should have that quality too. Sometimes this is true - if every brick in a wall is red, the wall is red. But many properties don’t transfer from parts to wholes. This fallacy happens when we don’t recognize that combining parts creates something with its own properties.

This fallacy is common in reasoning about teams, organizations, and systems. It’s used to predict group performance from individual qualities, which doesn’t always work.

Composition Fallacy in Action #

Did you spot the faulty logic? #

A team of excellent individual players might have poor teamwork, incompatible playing styles, or weak strategy. Team success requires coordination and compatibility, not just stacking talented individuals.

Second Example #

“Each ingredient in this recipe is delicious on its own. So this dish will definitely taste amazing!”

The Flaw #

Flavors interact in complex ways. Combining things that are individually delicious might result in flavors that clash. Great cooking is about how ingredients work together, not just using good ingredients.

Lesson 31: Division Fallacy

Spot the Faulty Logic #

“Our school has a really good football team. So Jake, who’s on the team, must be a really good player.”

Discussion: Talk with your teacher about this example. Does being part of a good team make every individual member good?

How/Why It’s Often Used #

Just as we might assume parts’ properties transfer to the whole (Composition Fallacy), we might also assume the whole’s properties apply to every part. This can seem reasonable - if a whole has some quality, it’s tempting to assume each component shares it.

This fallacy appears in reasoning about groups, organizations, and categories. People use it to make assumptions about individuals based on group characteristics.

Division Fallacy in Action #

Did you spot the faulty logic? #

A team’s success depends on many factors - some players might be stars, others might be average but fill important roles, and some might be substitutes who rarely play. Being on a good team doesn’t guarantee that each individual is highly skilled.

Second Example #

“Humans are visible to the naked eye. So atoms, which humans are made of, must be visible to the naked eye.”

The Flaw #

A whole can have properties its parts lack. Atoms are far too small to see, even though collections of billions of atoms (people) are visible. Size is not a property that transfers from whole to parts.

Lesson 32: Personal Incredulity

Spot the Faulty Logic #

“I just can’t imagine how billions of stars could exist in the universe. The numbers are too big to understand, so scientists must be exaggerating.”

Discussion: Talk with your teacher about this example. Does our ability to imagine something determine if it’s true?

How/Why It’s Often Used #

When we encounter information that’s hard to understand or imagine, it’s tempting to doubt it. Our brains prefer things that make intuitive sense. If something is too complex, too large, too small, or too strange to easily picture, we might reject it simply because of that difficulty.

This fallacy is common in discussions of science (especially quantum physics, cosmology, and evolution), technology, and other complex topics. People use their personal confusion as evidence against claims.

Personal Incredulity in Action #

Did you spot the faulty logic? #

The person’s inability to comprehend large numbers doesn’t change astronomical reality. Scientists use instruments and mathematics to study things beyond everyday human experience. Our struggle to imagine something says nothing about whether it’s true.

Second Example #

“I don’t understand how vaccines can be safe when they contain some of the disease they’re protecting against. It doesn’t make sense, so I don’t trust them.”

The Flaw #

Not understanding the science of immunology doesn’t make vaccines unsafe. The biology of how vaccines work is well-established, even if it seems counterintuitive. Personal confusion isn’t evidence against scientific findings.

Lesson 33: Begging the Question

Spot the Faulty Logic #

“We should trust this news source because they always report the truth.” “How do you know they always report the truth?” “Because they’re a trustworthy news source!”

Discussion: Talk with your teacher about this example. What’s the problem with this explanation?

How/Why It’s Often Used #

This is very similar to circular reasoning (Lesson 12), but with a subtle difference. In begging the question, the premise and conclusion might be phrased differently enough that the circularity isn’t immediately obvious. The argument smuggles the conclusion into the starting assumptions.

People often beg the question without realizing it, especially when defending beliefs they hold strongly. The conclusion seems so obviously true to them that they don’t notice they’re assuming it.

Begging the Question in Action #

Did you spot the faulty logic? #

“They report the truth because they’re trustworthy” and “they’re trustworthy because they report the truth” are the same claim in different words. Neither one provides independent evidence for the other.

Second Example #

“The law is the law. We have to follow the speed limit because it’s illegal to speed.”

The Flaw #

If someone is questioning WHY we should follow the law, saying “because it’s the law” doesn’t answer their question. They’re asking for reasons why the law is good - the existence of the law is what they’re questioning, so you can’t use it as its own justification.

Lesson 34: Burden of Proof

Spot the Faulty Logic #

“I believe there’s a dragon living under my bed. You can’t prove there isn’t, so I’m right!”

Discussion: Talk with your teacher about this example. Whose job is it to prove this claim?

How/Why It’s Often Used #

It’s often easier to ask someone to disprove your claim than to prove it yourself. This fallacy appears when someone makes a claim and, instead of providing evidence, challenges others to prove them wrong. It shifts the work of supporting an argument onto others.

This is especially common with claims that are hard or impossible to disprove (like claims about invisible things, untestable events, or vague predictions). If you can’t disprove it, they claim that means it’s true.

Burden of Proof in Action #

Did you spot the faulty logic? #

The person claiming a dragon exists should provide evidence for the dragon, not demand that others prove it doesn’t exist. We can’t disprove every possible claim - we’d spend forever disproving unicorns, fairies, and infinite other possibilities.

Second Example #

“You can’t prove that my lucky rock doesn’t give me good luck. So it does give me good luck!”

The Flaw #

The inability to disprove a claim doesn’t prove it. The person claiming the rock brings luck should show evidence of its effectiveness, not just point to the lack of disproof.

Lesson 35: Appeal to Ignorance

Spot the Faulty Logic #

“No one has ever proven that aliens DON’T visit Earth. So aliens must visit Earth!”

Discussion: Talk with your teacher about this example. Is lack of disproof the same as proof?

How/Why It’s Often Used #

This fallacy exploits the gaps in our knowledge. When we don’t know something for certain, there’s temptation to fill that gap with whatever belief we prefer. The reasoning goes: “Since we don’t know for sure, my belief is as good as any.”

It’s closely related to the Burden of Proof fallacy, but focuses specifically on using lack of knowledge as positive evidence. It appears in discussions about the paranormal, conspiracy theories, and claims that are hard to test directly.

Appeal to Ignorance in Action #

Did you spot the faulty logic? #

The fact that we haven’t disproven alien visits doesn’t prove they happen. The correct conclusion from lack of evidence is “we don’t know,” not “therefore it’s true.” We need positive evidence for a claim, not just absence of disproof.

Second Example #

“Scientists haven’t proven that this supplement works. So it must not work.”

The Flaw #

Lack of proof isn’t proof of absence. Maybe the supplement hasn’t been studied yet. The honest conclusion is “we don’t know if it works” - not “it definitely doesn’t work.” More research is needed.

Lesson 36: Moving the Goalposts

Spot the Faulty Logic #

Parent: “Clean your room and you can play video games.” (Child cleans room) Parent: “Now do the dishes too.” (Child does dishes) Parent: “Now take out the trash.” (Child takes out trash) Parent: “Now organize the garage…”

Discussion: Talk with your teacher about this example. What’s happening with the requirements?

How/Why It’s Often Used #

Sometimes people aren’t willing to accept a conclusion no matter what evidence is presented. Instead of admitting they were wrong, they keep adding new requirements. Each time the original demand is satisfied, they create a new one, making it impossible to ever “win.”

This fallacy appears in debates, negotiations, and any situation where someone has set criteria for acceptance. It’s a way of refusing to accept evidence while appearing to be reasonable.

Moving the Goalposts in Action #

Did you spot the faulty logic? #

The parent kept adding requirements after the original task was completed. If “clean your room” was supposed to be sufficient for video games, new requirements shouldn’t be added after the fact. Criteria should be clear and stable.

Second Example #

“Prove to me that exercise is good for health.” (Shows scientific studies) “Those studies are too old. Show me recent ones.” (Shows recent studies) “Those aren’t from my country. Show me local studies.” (Shows local studies) “Well, those researchers might be biased…”

The Flaw #

No matter what evidence is presented, new objections are invented. If the criteria for acceptable proof keep changing, the person isn’t genuinely open to being convinced - they’re just finding endless excuses.