A Gentle Introduction to Logical Fallacies
12 min read

A Gentle Introduction to Logical Fallacies

A Gentle Introduction to Logical Fallacies

Logical Fallacies are common errors in reasoning that break the logic of your argument. When your argument has Logical Fallacies it will appear to be deceptive in that it looks better to you than it really is.

Logical Fallacies are common because they are so easy to overlook, often being a result of our subconscious human psychology. You can see them take form in a number of ways:

  • Illegitimate arguments
  • Irrelevant points and data
  • Weak connections between points
  • Exaggerations and jumping to conclusions

All of these forms lack evidence and are fundamentally broken. Still, they are easy to overlook as they are so natural to make. We only recognize them when we step back and take a deeper, more rational look at the points.

Today, you'll learn about the most common Logical Fallacies, with examples to make things clear.

1. Slippery Slope Fallacy

The Slippery Slope Fallacy is an argument where one asserts that a relatively small step, action, or event will set off a chain reaction of related events. Importantly, the chain reaction of events is more extreme than the initial one.

People fall into the Slippery Slope when they are trying to emphasize their point. They know that connecting multiple events or points together will make their overall argument seem stronger. Thus, even if there is only a tiny relationship between two things, they connect them together anyways.

Of course, even if two things are related it doesn't necessarily mean that they are connected and that one will lead to the other. Connecting them leads to unecessary and overly extreme conclusions. Be careful to only connect things that are 100% reliant on each other, where there is causality.

Examples

  • "If I don't get this job, I'm screwed. I'll never increase my salary and my partner will leave me"
  • "You can never eat chocolate if you want to be healthy. First it's one peice a day, then two, then three – next thing you know you're eating a whole box and becoming obese!"

2. Hasty Generalization Fallacy

The Hasty Generalization Fallacy occurs when one forms a general conclusion about something based on only a small amount of evidence or information.

Personal experiences have a strong influence on us. Seeing or feeling something first hand makes you remember it more clearly, both in your mind and emotionally. It's then easy to generalize and apply your opinion of it to everything because it's so clear in your mind.

But just because one small thing has occurred in your life does not mean it applies everywhere else, even if it's important to you. Your personal experience is unique. It's better to gather more data before forming any strong opinions.

Examples

  • "The first day of class was so slow, we only went over the outline! The rest of the year is going to be boring"
  • "I ordered from Pizza Hut last week and the delivery guy gave me the wrong pizza on his first day! Definetely not ordering from there again"

3. Genetic Fallacy

The Genetic Fallacy is an assumption of judgement where one assumes that something or someone is the same as their history. It disregards the current context and any changes that may have happended since the history.

This fallacy happens because history is often the clearest evidence that one has available. The more easily we can recall information, the more strongly it influences our judgement of the subject in question. Thus, our brains ignore the need for any complex thinking and go for the simple answer: the future will be the same as the past.

Yet changes over time and indeed the current context have a strong effect on things. People, situations, and entire societies are dynamic. It's more practical to consider history as an extra data point in your calculations, but not the only one.

Examples

  • "He started his career working at an ice cream shop; even though he's worked his way up the chain, I don't think we can give someone like that the CEO position"
  • "Volkswagen is an evil car company because their cars were designed by Hitler's army during World War II"

4. Begging the Claim Fallacy

The Begging the Claim Fallacy happens when the points of an argument already assume that a particular conclusion is true. It is in effect a commitment to the conclusion without honest consideration of the evidence.

This is an incentivised fallacy in the sense that one typically falls into it when they are incentivised to make the conclusion. You might really want a particular conclusion to be true because it feels good or benefits you in some way. Thus, you make points that already support the conclusion by default.

But we shouldn't be jumping to conclusions just because they make us feel good; that's no argument! An argument should be based on facts, data, and logical reasoning. Be sure to take your emotions and any personal incentives out of the equation when making an argument.

Examples

  • "The Macbook Pro is the best laptop computer because no one makes better laptops than Apple"
  • "This cereal is really healthy, it's made of all natural ingredients"

5. Circular Argument Fallacy

The Circular Argument Fallacy occurs when one restates their argument in a different way rather than actually proving it. Instead of doing the hard work required to find and present evidence, the arguing person tries to force their point by restating it.

Technically speaking, the Circular Argument is logically valid. If you say the original statement that you're trying to prove in a different way, then your statements effectively act as supporting points for each other. Point (A) supports point (B) and point (B) supports point (A). Any time someone challenges your conclusion, you have an endless loop of support to back it up.

The problem is that you're never have any real evidence. So while your argument might sound smooth, it isn't based on any solid information or rationale.

Examples

  • "The United States is the best place to live because it’s better than all the other countries"
  • "Joe is an excellent communicator because he speaks really well"

6. Either/or Fallacy

The Either/or Fallacy happens when one considers only two options, even though the situation has multiple options. The two options are usually the most extreme of those available.

People fall into the Either/or Fallacy when they attempt to simplify their problem. With multiple options to choose from, it's easier to reduce the problem down to just the two most extreme options. This isn't ideal, but looks "good enough", especially when the other options are completely forgotten.

But simplifying the problem may lead to a non-optimal or outright bad solution. Extreme options often overlook critical details that more moderate options take into account. Better to look at all the options equally and eliminate them based on facts and logical reasoning.

Examples

  • "Look, either we stop driving cars right now or the earth is going to be destroyed"
  • "If you eat that one peice of chocolate, your diet will be ruined"

7. Ad Hominem Fallacy

The Ad hominem Fallacy happens when one attacks the character of a person, rather than their opinions or arguments. The attacks are often petty and totally irrelevant to the discussion at hand.

This is the cheapest and most cowardly of the Logical Fallacies. It takes a lot less thought, and less courage, to attack a person than it does to form an actual argument. Luckily, it's pretty easy to spot – whenever someone switches from logical arguing to irrelevant insults, you know that it's Ad Hominem at work.  

If you find people falling into this fallacy when arguing with you, just ignore their insults and bring the conversation back to the facts. If you find yourself falling into it then slow things down, take the time to think of a more concrete and logical argument.

Examples

  • "Mike's idea for this project isn't going to work, he never graduated from Harvard like I did"
  • "You could never understand how hard I work at the office, you're just fat"

8. Bandwagon Appeal Fallacy

The Bandwagon Appeal Fallacy is when one presents what most people think in order to convince someone else to have the same belief. They are telling that new person to "hop on the bandwagon" because everyone else is doing it.

The pressure of the crowd is incredibly powerful when it comes to persuasion. From a social perspective, people want to fit in. From a logical perspective, it's seems smart to follow the crowd. If everyone else came to a certain conclusion, perhaps there's a good chance that it's correct – or so we think.

But that's not the way life works. The same social constructs that worked for others might not be the right fit for your unique situation. Also, just because 10 or 1000 or even millions of people came to a particular conclusion doesn't make it right. Just ask Galileo about the people who thought the earth was the center of the universe.

Examples

  • "200,000 people have already voted for me, can I count on you?"
  • "C'mon dude, everyone goes out on Friday night! Why would you workout today of all days?"

9. Red Herring Fallacy

The Red Herring Fallacy consists of avoiding the real issue by diverting to a  tangentinal point. This is done to avoid having the argument and instead bring up a point that's easier to make and defend.

Coming up with a strong argument that directly addresses the key issue is difficult, especially when it has to be done on the spot like in an interview or debate. This difficulty is magnified when the issue in question is something important or sensitive. Thus, people fall back to a Red Herring Fallacy to make an easier and still perfectly valid point. It doesn't address the real issue, but often passes through simply because it still makes sense.

Although Red Herrings might make logical sense, they are unproductive since they do not address the key issue. The most productive argument is one that deliberatly focuses on the real target.

Examples

  • "Climate change may be bad, but the current industry for fossil fuels creates over 2 million jobs"
  • "The layoffs of all non-citizens last quarter did not effect the release of our new line of smartphones; customers are loving it!"

10. Straw Man Fallacy

The Straw Man Fallacy is a simplification of an opponent's viewpoint followed by an attack on the simplified version. The simplified viewpoint overlooks contextual details that are important for a clear understanding.

The Straw Man Fallacy is all about assumptions. Instead of digging in to understand the true meaning of the opposing side's argument, one assumes the worst motive and least intelligence. This jumping to conclusion makes attacking the opposing viewpiont easy – it's been so over-simplified that it sounds absurb and even offensive.

Jumping to conclusions so rashly is never a good thing. From a social perspective, it's disrespectual to the opponent as their viewpoint is not given fair thought. From a logical perspective, it's dangerous as critical details are easily missed.

Examples

  • "If you don't support raising the minimum wage then you must hate all poor people"
  • "Mike: 'If we're going to get a pet, I'd rather have a dog'.
    Kathy: 'What makes you hate cats so much?'"

11. Moral Equivalence Fallacy

The Moral Equivalence Fallacy compares minor actions to much more serious ones, suggesting that they are equivalent. This suggesstion is made regardless of the nature or magnitude of the actions.

This Logical Fallacy can be thought of more simply as exaggerating. A person experiences an action or event that affects them emotionally. They then exagerate it way out of proportion due to those emotions. The emotions are so strongly felt that they drive the judgement of moral equivalance.

But different actions or situations should never be judged in the same way. Each one has a different context and affects people differently. They should be judged based on their own specific context and application to ensure fair consideration.

Examples

  • "Taxes are basically the same as theft because the government takes your money with the threat of violence if you don't comply"
  • "Kitchen knives and guns can both kill people – therefore we should allow both to be sold in department stores"

12. Appeal to Authority Fallacy

The Appeal to Authority Fallacy is a type of argument in which the opinion of an authority figure is used as evidence to support the argument. This figure of authority is usually a well-known person, like a deep expert or social figure.

This fallacy attempts to defer the burden of proof to an authority figure. People trust authority figures by default even if they don't know them personally. Saying that "this well-known person agrees with my opinion" looks like a strong defence to most people.

The problem is that authority figures are not always right. The opinion of one person may not apply to your specific situation, even if they're really smart. Better to consider authority opinion as a regular data point, at most perhaps with extra weight. But it shouldn't be the only point in your argument or decision making process.

Examples

  • "This is the best sandwhich shop in LA, Brad Pitt said so in his interview last week"
  • "How do I know this stock will go up? Well, Elon Musk tweeted about it just yesterday and he's rich"

13. Slothful Induction Fallacy

The Slothful Induction Fallacy happens when an argument's conclusion is denied, even when there is strong and clear evidence. The denial is coupled with the denying person pointing to luck and coincidence.

When someone is passionate about a certain belief they'll do anything they can to stick to it, even if it means avoiding clear evidence against it. You may present a solid argument, but the other person falls back to Slothful Induction saying that your information is based on luck or coincidence. It's an easy defence to make and very hard for you to prove otherwise – even something that's 99.99% sure can be argued.  

The problem of course is that anything can be considered lucky or coincidental if a person believes that it is. When making an argument or decision, there has to be some point where we draw a line and say "good enough evidence."

Examples

  • "I don't believe in climate change, the evidence that scientists collected is probably just the coincidence of the position of the sun and earth"
  • "Jacky has been in 5 car accidents in the past 4 months, yet she insists that she's a good driver because the traffic and weather were bad on all 5 accidents"

14. Correlation/Causation Fallacy

The Correlation/Causation Fallacy refers to a situation where a conclusion of causation is made, when in fact there is only correlation. Causation means that one action or event has directly influenced another. Correlation means that there is a relationship between two things.

Correlation by its definition is weaker than causation. A correlation implies a weak relationship; causation implies a direct connection. Assuming a causation when there is only a correlation is a mistake in interpretation. That is, a similarity is being interpretted as an equivalence.

Be careful when making such interpretations. Even if two things are highly correlated, that does not necessarily mean that there is causation. For causation to occur, there must be a direct connection, 100% reliance between the two events or actions.

Examples

  • "The students enrolled in private tutoring have worse grades than those who aren't; therefore, student who get tutored do worse in school"
  • "Since the 1950s, the number of driving-related deaths has gone down by 50% while global warming has also increased. Therefore, global warming reduces deaths on the road"

15. Anecdotal Evidence Fallacy

The Anecdotal Evidence Fallacy arises when one forms their argument based on points from their own personal experiences. This induces bias in the argument, drastically increasing the chances of making a mistake.

The most relatable form of evidence you can ever get is from yourself. The things you see, the experiences you have, and the memories you imagine. It's a lot easier make those points into an argument than it is to gather robust evidence. It also makes a lot more sense in your head as you remember those things more clearly.

But personal experiences are too biased to count as evidence. A strong argument should be objective, taking biases out of the equation. This requires a well-trained mind to think in a more general and systematic manner.

Examples

  • "I eat bacon everyday and I'm skinny. Trust me, bacon is good for losing weight"
  • "The past 10 stocks I bought at 11 AM went up by at least 3% before I sold then at 3 PM. 11 AM is the best time to buy stocks"

16. Middle Ground Fallacy

The Middle Ground Fallacy is when one argues for the middle point between two options. The two options are opposing each other, on opposite sides of the topic in question.

When there's a heated argument between two extreme options, it's easier to just select the middle point as a default. It's "fair" because it's in the middle, giving half and half to each side. This is usually done to avoid conflict by making a decision that is "good enough" for both arguing groups.

This fallacy is a total cop-out. The middle might not be the best solution. By defaulting to the middle ground, you are deliberately avoidng the task of working through the problem to find out what the real best answer is.

Examples

  • "My friend Bob says it's OK to skip class, but my other friend Mike said I should never skip. Therefore, I'll only skip half of my classes"
  • "I did some research and figured our house is worth $1,000,000. But Kathy just offered us $800,000. We'll settle for the middle price of $900,000"

Summary

Logical Fallacies are common errors in reasoning that can break your argument. They're quite hard to detect as they often result from your built-in human psychology.

The good news is that by being aware of them, you can learn how to deal with them effectively and make your arguments stronger. Here are the 16 most common Logical Fallacies, explained in simple words:

  1. Slippery Slope – Assuming that there will be a big chain reaction
  2. Hasty Generalization – Generalizing small things to apply to everything
  3. Genetic – The present is the same as the past
  4. Begging the Claim – Making points that assume your conclusion is already true
  5. Circular Argument – Point (A) supports point (B) and point (B) supports point (A)
  6. Either/or – Reducing a situation down to only two options even when more exist
  7. Ad Hominem – Attacking the person instead of the argument
  8. Bandwagon Appeal – If everyone else is doing it then it must be good
  9. Red Herring – Diveriting to a tangentinal point to avoid the real issue
  10. Straw Man – Assuming the other person has a bad motive or is unintelligent
  11. Moral Equivalence – Exaggerating the seriousness of things based on how they made you feel
  12. Appeal to Authority – Taking the opinion of authority figures as gospel
  13. Slothful Induction – Denying a conclusion by assuming luck or coincidence
  14. Correlation/Causation – Concluding that two things are directly connected when they are in fact only highly correlated
  15. Anecdotal Evidence – Making an argument based on biased personal experiences
  16. Middle Ground – Picking the middle of the options as a default because it's "fair"