Logical fallacys

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. 

Katherine is a bad choice for mayor because she didn’t grow up in this town. 

Red herring

A red herring is an attempt to shift focus from the debate at hand by introducing an irrelevant point. 

Having cavities in your teeth can be scary, but have you heard about the Tooth Fairy?

Strawman

A straw man argument is one that misrepresents an opponent’s argument to make it easier to attack.  Often, strawman arguments are hyperbolic, inaccurate versions of the opposition’s claims.

Erin thinks we need to stop using all plastics, right now, to save the planet from climate change. 

Equivocation

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.  This is different from lying in that a lie as an intentionally false utterance; equivocation is technically true but uses vague language deceptively

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. 

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. 

If we allow students to retake one test, next they’ll expect to retake every test, and soon there won’t be any accountability in this school at all.

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. 

I felt nauseated both times I ate pizza from Vito’s, so I must be allergic to something in pizza. 

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. 

If you don’t support my decision, you were never really my friend. 

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. 

If you want to be healthy, you need to stop drinking coffee. I read it on a fitness blog. 

Bandwagon fallacy

With the bandwagon fallacy, the arguer claims that a certain action is the right thing to do because it’s popular. 

All of my friends are skipping class today, so it must be okay to do it.

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. 

There’s no evidence that ghosts aren’t real, so they must be haunting us.

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. 

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. 

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.

Causal fallacy

A causal fallacy is one that implies a relationship between two things where one can’t actually be proven. 

When ice cream sales are up, so are shark attacks. Therefore, buying ice cream increases your risk of being bitten by a shark. 

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. 

“You don’t have enough experience to be the new leader.” “Neither do you!”