A logical fallacy is an argument that can be disproven through reasoning. This is different from a subjective argument or one that can be disproven with facts; for a position to be a logical fallacy, it must be logically flawed or deceptive in some way.
You’ll find logical fallacies just about anywhere you find people debating and using rhetoric, especially in spaces that aren’t academic or professional in nature. In fact, we can almost guarantee that you’ve encountered logical fallacies on social media, especially in the comments under divisive posts. But remember that they can and often do appear in academic writing, especially in the kinds of writing where the author has to defend a position, like argumentative essays and persuasive writing. They can even show up in expository writing.
The best way to avoid making logical fallacies in your own writing is to familiarize yourself with them and learn how to recognize them. That way, they’ll stick out to you when you’re reading your first draft, and you’ll see exactly where your writing needs thoughtful revision.
What are 15 common types of logical fallacies?
As you’ll see below, there are a lot of ways an argument can be flawed. Take a look at fifteen of the most commonly used logical fallacies.
1 Ad hominem
An ad hominem fallacy is one that attempts to invalidate an opponent’s position based on a personal trait or fact about the opponent rather than through logic.
Example: Katherine is a bad choice for mayor because she didn’t grow up in this town.
2 Red herring
A red herring is an attempt to shift focus from the debate at hand by introducing an irrelevant point.
Example: Losing a tooth can be scary, but have you heard about the Tooth Fairy?
3 Straw man
A straw man argument is one that argues against a hyperbolic, inaccurate version of the opposition rather than their actual argument.
Example: Erin thinks we need to stop using all plastics, right now, to save the planet from climate change.
An equivocation is a statement crafted to mislead or confuse readers or listeners by using multiple meanings or interpretations of a word or simply through unclear phrasing.
Example: While I have a clear plan for the campus budget that accounts for every dollar spent, my opponent simply wants to throw money at special interest projects.
5 Slippery slope
With a slippery slope fallacy, the arguer claims a specific series of events will follow one starting point, typically with no supporting evidence for this chain of events.
Example: If we make an exception for Bijal’s service dog, then other people will want to bring their dogs. Then everybody will bring their dog, and before you know it, our restaurant will be overrun with dogs, their slobber, their hair, and all the noise they make, and nobody will want to eat here anymore.
6 Hasty generalization
A hasty generalization is a statement made after considering just one or a few examples rather than relying on more extensive research to back up the claim. It’s important to keep in mind that what constitutes sufficient research depends on the issue at hand and the statement being made about it.
Example: I felt nauseated both times I ate pizza from Georgio’s, so I must be allergic to something in pizza.
7 Appeal to authority
In an appeal to authority, the arguer claims an authority figure’s expertise to support a claim despite this expertise being irrelevant or overstated.
Example: If you want to be healthy, you need to stop drinking coffee. I read it on a fitness blog.
8 False dilemma
A false dilemma, also known as a false dichotomy, claims there are only two options in a given situation. Often, these two options are extreme opposites of each other, failing to acknowledge that other, more reasonable, options exist.
Example: If you don’t support my decision, you were never really my friend.
9 Bandwagon fallacy
With the bandwagon fallacy, the arguer claims that a certain action is the right thing to do because it’s popular.
Example: It’s fine to wait until the last minute to write your paper. Everybody does it!
10 Appeal to ignorance
An appeal to ignorance is a claim that something must be true because it hasn’t been proven false. It can also be a claim that something must be false because it hasn’t been proven true. This is also known as the burden of proof fallacy.
Example: There must be fairies living in our attic because nobody’s ever proven that there aren’t fairies living in our attic.
11 Circular argument
A circular argument is one that uses the same statement as both the premise and the conclusion. No new information or justification is introduced.
Example: Peppers are the easiest vegetable to grow because I think peppers are the easiest vegetable to grow.
12 Sunk cost fallacy
With the sunk cost fallacy, the arguer justifies their decision to continue a specific course of action by the amount of time or money they’ve already spent on it.
Example: I’m not enjoying this book, but I bought it, so I have to finish reading it.
13 Appeal to pity
An appeal to pity attempts to sway a reader’s or listener’s opinion by provoking them emotionally.
Example: I know I should have been on time for the interview, but I woke up late and felt really bad about it, then the stress of being late made it hard to concentrate on driving here.
14 Causal Fallacy
A causal fallacy is one that implies a relationship between two things where one can’t actually be proven.
Example: When ice cream sales are up, so are shark attacks. Therefore, buying ice cream increases your risk of being bitten by a shark.
15 Appeal to hypocrisy
An appeal to hypocrisy, also known as a tu quoque fallacy, is a rebuttal that responds to one claim with reactive criticism rather than with a response to the claim itself.
Example: “You don’t have enough experience to be the new leader.” “Neither do you!”
Although this list covers the most commonly seen logical fallacies, it’s not exhaustive. Other logical fallacies include the no true Scotsman fallacy (“New Yorkers fold their pizza, so you must not really be from New York if you eat yours with utensils.”) and the Texas sharpshooter fallacy (cherry-picking data to support a claim rather than drawing a logical conclusion from a broad body of evidence).