Logical Fallacies and Critical Thinking

The History’s Mysteries project is about more than just giving students topics to write about. It also teaches students the critical thinking tools they need to evaluate information and find good sources. That includes distinguishing between fact and opinion, recognizing bias, finding authoritative sources and citing those sources correctly. Critical thinking skills also includes avoiding logical fallacies in texts, as well as students’ own writing.

Our worksheet (fill out the form below to download it) identifies some of the most common logical fallacies. The worksheet discusses the fallacies, why they are illogical, and gives students practice identifying fallacies in the wild, while also picking out good logical arguments.

Here are some logical fallacies that I think are really important to understand in today’s world, and how they are often seen in the wild.


You counterattack your opponent calling them a hypocrite rather than defending your argument. The fact  that someone else did something wrong or that your opponent is not perfect does not actually make you right, however.

  • You say that I broke the law? Well, were you angry when another person broke the law?
  • You say you have a solution to climate change, but you drive a car which produces a lot of air pollution.

Sometimes, you’ll see a comment on an article discussing a completely unrelated topic. This draws the writer’s attention and that of future commentators away from the article and onto a topic of the commenter’s choosing.

  • You’ve raised some interesting points about why the candidate I support is not perfect. But have you heard about this guy who appears to share the same beliefs as you? He’s a criminal and yet you say nothing about him in this article.

Ad Hominem

You attack the person instead of the argument, often with insults or accusations of bad behavior. However, people can have personal flaws and still produce logical arguments. Often, these days this argument takes the form of accusing the other person of bias or suggesting they have personal reasons to attack you. Neither method addresses the logic of an argument though.

  • Of course, you would say I’m wrong. You subscribe to a newspaper that often disagrees with me, so you’re obviously brainwashed to hate me.
  • Sure, students say they have too much homework. But they also don’t keep the bathrooms clean so I don’t see why we should believe them!

Begging the Question

You support your argument with logic that is only true if your argument is true. Notice that this isn’t the same thing as “raising a question”.

  • According to my autobiography, I’m very intelligent, so it must be true. Why else would I write that?
  • Exercise is the best way to stay healthy because the healthiest thing you can do is exercise.
  • This movie is very popular, probably because a lot of people like it.

Slippery Slope

Arguing that something is wrong because it can lead to some extreme case or example.

  • If we let these immigrants fleeing a natural disaster into our country, we have to let anyone in and soon we’ll be flooded with millions of new people, and we won’t have done background checks on any of them, and we won’t have the resources to feed and house and employ all 7 billion people on Earth!
  • I have to punish you for this. Otherwise you’ll do more and more bad things and eventually end up in jail!


You oversimplify or distort your opponents’ argument to make it easier to attack. Sometimes this is done by linking your opponent to another group. This is very common in political debates and it often overlaps with slippery slope fallacies. One of the easiest ways to make your opponent look bad is to pretend they want some kind of extreme measures.

  • My opponent says he wants to increase funding for police departments. Sounds like he wants the police to be standing on every corner watching our every move.”
  • The teachers want limits on how many hours they can be forced to work. But last year, university professors in the neighboring state agreed to give up overtime. So what exactly do these teachers and professors even want?”
  • You say you want to buy a cat? But many people are allergic to cats, so basically you want me to stop having friends over after school!”

Don’t forget that logical fallacies often come from misguided, but sincere, attempts to discuss an issue rationally. Who among us hasn’t inadvertently cherrypicked data to support our opinions or delighted in a ad hominem attack about a public figure we don’t like? We don’t mean to, but it happens. When our flaws in logic are pointed out, we take them back and create better arguments.

A man has two wastebaskets, one marked yes. The other is marked no. The man  is tossing papers at the wastebaskets and saying "Ultimately, my decisions are based on logic."

Rhetorical Techniques That Use Logical Fallacies

However, sometimes it feels as if trolls and partisan actors are working to create flawed rhetorical techniques deliberately. These techniques often disguise the fallacies by cloaking them in emotional language or merging a few fallacies together. And they play on common sense intuitions that are all too human, but do not represent the best of human reason. Here are a few that I think deserve special attention, particularly when students read about “hot” topics such as gun control, voter rights, immigration, COVID-19 measures, and claims by political figures.

Magician’s Force

You could also call this “damned if you do, damned if you don’t” but magician’s force sounds classier and is more classroom friendly. The name comes from a method used by stage magicians to control a magic trick while giving you the illusion of choice (well-known enough that I don’t think I’m spoiling anything. Good magicians use it without you even realizing it anyway).

Imagine that there are two cards on a table. The magician wants you to choose the card on the right. So they tell you to pick any card you want. However, if you choose the card on the left, the magician says to discard it. If you choose the card on the right, the magician says to flip it over. So you control your choice, but the magician controls the reaction.

In the rhetorical world, this fallacy works by finding fault no matter what. The criticism is often crafted into talking points and spread by partisan organizations. It’s particularly blatant when employed inconsistently.

For example:

  • I like this linguist’s talks on TikTok but why does she wear so much makeup? It really detracts from her credibility. That other account is great too, but it’s hard to watch her because she always wears an old T-shirt. If you want people to take you seriously, you need to dress up a bit!
  • You need to spend more time on self-care. Relax and enjoy yourself. But you also need to figure out how to be more productive so that you don’t become lazy!
  • We shouldn’t get involved in this conflict. The government is wrong to send our soldiers into danger all the time. And remember I’m not a dove. I have always said we need to get involved in this other conflict. Our government is too slow to use military action to stop these dangerous forces!

Rhetorical Ignorance

Another classic logical fallacy is the appeal to ignorance, the belief that if there’s little or no evidence against you, it must be true! In the age of the Internet, appeal to ignorance is becoming not just a logical fallacy, but a sign that the person is arguing in bad faith.  I’m not saying Googling is the same as researching, weighing evidence, and coming to a well-founded conclusion. But it’s hard to say “I’ve never seen an elephant swim” or “I don’t remember your newspaper writing stories about this event” when you can look up “elephants swimming” or search the newspaper archives for stories.

And yet, you’ll often find people making false assertions, often disguised as rhetorical questions, without any acknowledgement that the truth can easily be discovered. Because the person rarely acknowledges the truth, it’s a very effective way of spreading falsehoods quickly. Note that the person often uses hedges like “I don’t think” or “I doubt” or “It’s hard to believe” so they can claim that they didn’t actually accuse anybody of anything. It’s appeal to ignorance on steroids. I haven’t seen it and I’m certainly not going to look for it!

For example:

  • My opponent says he cares about veterans. But has he ever sponsored any programs or laws to help them? I doubt it.
  • If this issue is so important, why hasn’t the mayor ever mentioned it in a speech? I don’t remember them every saying a word about it!

This technique works well in combination with whataboutism, calling someone a hypocrite for not doing something even if they may well have done that very thing.

  • Your newspaper talks about these kinds of incidents but I’ve never seen you mention this other event, not even once!

In many cases, you see statements that the person admits are totally fictional:

  • The administrators have cut the school budget again. But I’ll bet they have plenty of money for their own offices! They probably have brand new computers and leather chairs and all sort of things!

Casting Doubt

This fallacy (some call it the fallacy fallacy) says that if any part of an idea is questionable, the whole idea is wrong. It ignores the fact that no idea is beyond criticism or doubt and no action will be 100% effective. It’s an easy one to use to target large concepts and widescale policies.

For example,

  • If evolution is real, why aren’t there talking apes?
  • God can’t be real because there are so many different religions that disagree.
  • This new program to boost test scores isn’t working because some kids are still getting low scores.

The trick is that these kinds of questions are not necessarily bad questions. People of faith have questions and doubts. Lawmakers are always looking to evaluate and improve programs they create and scientists are supposed to be asking questions and clarifying points. The fallacy is in assuming the existence of any doubt means the whole concept is invalid. Furthermore, proponents of the idea in question have usually thought of these questions before and can address them, even if they can’t solve them to everyone’s satisfaction!

Nitpicking Sealions

You may have heard of sealioning, where someone, often a troll on social media, insists on asking question after question. They allege that they are simply trying to understand your position but in fact they are trying to annoy you so that you lash out. They will then claim (ad hominem style) that because you said something mean, your position is wrong. It’s also a great way to find questions to cast doubt. Eventually, they dig down to some level where you aren’t sure of the answer or you can’t account for all the nuances.

For example,

A: You say that yoga reduces your stress?

B: Yes. I always feel more relaxed after doing yoga.

A: But how exactly does stretching your body lower stress levels?

B: Well, I don’t know exactly what the connection is.

A: Your ignorance of anatomy and organic chemistry proves that yoga doesn’t make you healthier!

Teaching Logical Fallacies

These are only a few of the logical fallacies and bad-faith rhetorical techniques used out there. I’ll consider talking about some more in the future. Regardless of the method used, we can give students skills to help them spot faulty thinking and create arguments that are valid. To bring logical fallacies into the classroom, you can:

  • Download the Logical Fallacies worksheet below which identifies common logical fallacies
  • Have them find real world examples of arguments and analyze them for fallacies and deceptive rhetorical devices. Examples can include: advertisements, speeches by politicians, opinion essays newspapers, even social media posts.
  • Controversial takes on historical events are another great source of potential logical fallacies. Check out History’s Mysteries for examples!
  • Students can peer edit each other’s essays and look for fallacies, then suggest how to fix them.
  • Have students write logically fallacious statements or paragraphs and then fix them.
  • Check out more resources including flashcards and classroom posters at https://yourlogicalfallacyis.com/.
  • Enjoy these logical fallacy referee memes to employ on social media or use as flash cards: https://imgur.com/a/QDbyt/all.


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