Last week, I shared ​the story​ of the Donkey and the Tiger, who argued over the color of the grass.

The Donkey insisted it was blue, while the Tiger maintained it was green. To settle the argument, they brought their case to the Lion, who agreed with the Donkey and sentenced the Tiger to a year of silence. Before walking away, the Tiger asked why he was punished, when the Lion knew the grass was green.

"Because someone as wise as you should never waste time proving anything to a fool."

The lesson of the story is simple: Never argue with a fool. Because if you argue with a fool, you become one yourself.

Well, today's piece is the natural expansion of that lesson.

I'll walk through 20 common logical fallacies—errors in reasoning that destroy the quality of an argument. If you spot any of these in a debate, online or in person, that may be your cue to politely find the exit.

Think of this as your field guide to avoiding arguments with fools...

Ad Hominem

Attack the person.

It's one of the oldest tricks in the book: Attempt to discredit the messenger so you don't have to face the message.

"You can't trust his opinion on this policy, he's a high school dropout."

An all-too-common "strategy" in political discourse.

The Straw Man

Distort to destroy.

The person distorts your argument into a weaker version so they can easily tear it down. Instead of engaging with your actual point, they invent a flimsy one and proudly defeat it.

"So, you really think we should just let criminals run wild in the streets?"

A classic move for anyone more interested in winning than understanding.

False Dilemma

You only have two choices.

They present two extreme options as if they're the only possibilities. Oversimplification to avoid confronting the fact that reality is almost always in some shade of grey.

"If you don't believe in pure personal liberty, you believe in pure government oppression."

This thrives in political and social media echo chambers.

Appeal to Authority

Trust me, they said so.

The person uses an expert's opinion as proof, without any supporting evidence. Experts can inform your thinking, but they generally shouldn't replace it.

Gibson's Law is a tongue-in-cheek observation that, "For every PhD, there's an equal and opposite PhD." In simple terms, you can find an expert on both sides of any given argument, so we cannot default to using them as proof.

"All the leading officials say it's the right strategy, so it must be right."

People often hide behind credentials when logic runs out.

Bandwagon Fallacy

Everyone's doing it.

Assuming something is true simply because everyone believes it. Popularity isn't evidence. The crowd has been confidently wrong many times before.

"All of the biggest investors are putting in money, so you should too."

The herd may be loudest right before walking off the cliff.

Sunk Cost Fallacy

Can't quit now.

The person argues to continue on the path simply because of what has already been invested to date. In truth, past effort has no bearing on whether continuing makes sense.

"We've spent four years on this project, we can't quit now."

Smart people cut losses when they no longer make sense. Fools double down to avoid accepting the loss.

Red Herring

Hey, look over there!

Hunting dog trainers would often use a kippered herring as a distracting scent to test whether the dogs were able to stay on track.

The red herring is a distraction masquerading as relevant. Someone shifts the topic to something tangential to avoid addressing the issue at hand.

"You're mad about pay cuts? But you still have such strong benefits!"

A masterclass in misdirection.

Tu Quoque

"And you too."

Instead of addressing a criticism, the person points out your flaws to avoid accountability.

"Don't lecture me on honesty, you lied at your hearing that one time."

Alleged hypocrisy doesn't invalidate truth.

Hasty Generalization

Small sample, big claim.

Someone draws a sweeping conclusion from very limited evidence. Anecdotes are not data. One case does not make a real pattern.

"My friend lost it all in crypto, so it's clearly a scam."

Humans love shortcuts, but sound logic requires a larger sample size.

The Fallacy Fallacy

Bad argument ≠ bad idea.

The person assumes a claim is false simply because it was argued poorly. Bad reasoning doesn't automatically make an idea wrong, just unproven.

"Your argument for aliens is weak, so aliens aren't real."

Don't confuse a poor advocate with a poor idea.

The Texas Sharpshooter

Cherry-pick the data.

A marksman fires bullets at a wall, then paints a target around the tightest cluster of bullet holes. The person chooses the story first, then pulls the evidence to confirm it.

"All of our successful test launches have been safe and effective."

Avoid the conflicting evidence by only choosing the good.

Post Hoc Ergo Propter Hoc

False cause.

A Latin phrase meaning, "After this, therefore because of this." The person assumes that just because B followed A, A must have caused B.

"The rooster crowed, then the sun rose. The rooster must make the sun rise."

Correlation doesn't equal causation.

Slippery Slope

The domino effect.

Someone insists that one small step will inevitably lead to a catastrophe. Each individual step may sound plausible, but the chain connecting them rarely holds up.

"If we allow them to redo the test, pretty soon, they'll skip the class altogether and drop out of school."

Think of this like a parlay bet (a bet that links together multiple bets or events into one). The more bets linked together, the lower the odds of the parlay hitting (and the higher the payout).

Any one of the events may have a reasonable probability of occurring, but all of them occurring, and in the correct order, is often nearly impossible.

Burden of Proof

Ok, then prove me wrong.

The person claims something is true simply because it can't be proven false. In truth, the responsibility to prove the claim lies with the person making it.

"You can't prove ghosts aren't real, so they must be real."

The absence of evidence to the contrary isn't evidence in support.

Personal Incredulity

I don't get it, so it's wrong.

The person rejects the idea because they can't understand or imagine how it could be true. A personal lack of understanding doesn't make something impossible.

"I can't see how we'd ever live on Mars, so it's impossible."

Complex ideas often look absurd before they're real. Real innovation is everyone agreeing with you, later.

Loaded Question

The trap question.

Someone raises a Trojan Horse question that smuggles in an accusation or assumption. The question is pre-loaded with a presumption of guilt. No matter how you answer, you lose.

"Have you ever stopped lying to your customers?"

A classic rigged game used by politicians in debates.

No True Scotsman

Moving the goalposts.

The person redefines a group to protect their claim from counterexamples. They shift the rules mid-argument to stay in the right.

"A Scotsman never drinks scotch with soda."

"I am a Scotsman and I drink scotch with soda."

"Then you must not be a true Scotsman!"

Rather than acknowledge the counter-argument and evidence, the terms of the argument are changed to simply exclude the counter-argument.

Equivocation

Word games.

The same word is used in two different ways to mislead the opponent. It sounds consistent on the surface, but the meaning quietly shifts.

“A feather is light. What is light can’t be dark. Therefore, a feather can’t be dark.”

Imprecise language leads to imprecise argument.

Non-Sequitur

That doesn't follow.

The conclusion doesn't logically follow from the premise. It's random reasoning masquerading as thoughtful insight.

"He drives a fancy car, so he must be smart and trustworthy."

Beware the conclusion out of thin air.

Begging the Question

Circular reasoning.

The person creates a circular argument where the conclusion they seek is assumed in the premise itself. It vaguely sounds like logic, but it collapses on itself.

"Ghosts are real because I once saw and heard something that was a ghost."

A logical dog chasing its own tail.

Never Wrestle a Pig in Mud

There's an old saying I love:

“Never wrestle a pig in the mud. You both get dirty—but the pig will enjoy it.”

The next time you find yourself pulled into an argument, remember these logical fallacies.

Use them to distinguish between those engaging in good faith and those who just want to wrestle you in the mud.

I recommend you bookmark this field guide and come back to it as needed. It will leave you well-equipped for life in the modern era.