Argument Flaw Cheat Sheet

If it's raining, the ground is wet. We know the ground is wet. So, it must be raining.

Confusing necessary and sufficient conditions

People who eat healthy diets tend to get more exercise than people who eat regular diets. Thus, one's diet can impact how much one exercises.

Assuming correlation proves causation

This new law requiring companies to reduce carbon emissions should be rejected because it will cost businesses money to implement.

Overlooking costs/benefits

Since each individual cell in my body is invisible to the naked eye, my entire body must be invisible too. Our university is ranked #1 in research, so every professor here must be a top researcher.

Confusing part v. whole

I polled people leaving a yoga studio about their exercise habits, and everyone indicated they exercise at least 5 times per week. Therefore, the average American exercises 5 times per week.

Unrepresentative samples

I got food poisoning from a sushi stall at the Cincinnati airport. So, we should generally be prepared to get food poisoning when eating sushi.

Hasty generalization

A computer and a human brain both process information using electrical signals. When a computer malfunctions, restarting it often fixes the problem. Therefore, using electroshock therapy should effectively treat many mental health conditions.

Analogies that aren't analogous enough

Since you don't support banning all guns, you must support unrestricted gun ownership.

False dichotomy

Don't listen to Dr. Smith's research on climate change - he drives a gas-guzzling SUV!

Attacking the source of the argument (ad hominem)

Tacos made up 80% of my restaurant's sales this year, whereas last year tacos made up only 50%. So, this year my restaurant sold more tacos than last year.

Percentages v. amounts

Some people say the new advertising campaign will succeed because it appeals to today's youth. But today's youth will find the campaign lame and unappealing. So, the advertising campaign will not be successful.

Lack of support vs. false conclusion

I got a higher grade in my algebra class this year than I got last year. Thus, I got a high grade in algebra this year.

Relative v. absolute

Our company needs a strong leader. Sarah has proven she's a strong person - she runs marathons and does CrossFit. Therefore, Sarah should be our next CEO.

Equivocation

Tom Brady, one of the greatest NFL quarterbacks ever, says we should invest heavily in cryptocurrency. So, let's buy some cryptocurrency.

Appealing to authority in an area outside their expertise

Everything the holy book says must be true. Why? Because the holy book can't say anything false.

Circular Reasoning

Historically, humans have always fought wars. Therefore, military conflict is an acceptable way to resolve international disputes.

Confusing "is" for "ought"

Most people believe the violent crime rate has increased this year. So, the government needs to do something about this increased violent crime rate.

Belief v. facts

The professor might dislike me, because I don't share her political opinions. So, the professor dislikes me.

Confusing possibility, probability, and certainty