5 Common Logical Fallacies

5 Common Logical Fallacies

1. Ad Hominem

2. Straw Man

3. False Dichotomy

4. Slippery Slope

5. Generalizations

Ad-Hominem

An ad hominem fallacy uses personal attacks rather than logic. This fallacy occurs when someone rejects or criticizes another point of view based on the personal characteristics, ethnic background, physical appearance, or other non-relevant traits of the person who holds it.

Ad hominem arguments are often used in politics, where they are often called "mudslinging." They are considered unethical because politicians can use them to manipulate voters' opinions against an opponent without addressing core issues.

Example: "MacDougal roots for a British football team. Clearly he's unfit to be a police chief in Ireland."

Straw Man

A straw man argument attacks a different subject rather than the topic being discussed — often a more extreme version of the counter argument. The purpose of this misdirection is to make one's position look stronger than it actually is.

The straw man argument is appropriately named after a harmless, lifeless scarecrow. Instead of contending with the actual argument, they attack the equivalent of a lifeless bundle of straw — an easily defeated puppet that the opponent was never arguing for in the first place.

Example: "The Senator thinks we can solve all our ecological problems by driving a Prius."

False Dichotomy

A false dilemma or false dichotomy presents limited options — typically by focusing on two extremes — when in fact more possibilities exist. The phrase "America: Love it or leave it" is an example of a false dilemma.

The false dilemma fallacy is a manipulative tool designed to polarize the audience, promoting one side and demonizing another. It's common in political discourse as a way of strong-arming the public into supporting controversial legislation or policies.

Example: "Either we go to war or we appear weak."

Slippery Slope

A slippery slope argument assumes that a certain course of action will necessarily lead to a chain of future events. The slippery slope fallacy takes a benign premise or starting point and suggests that it will lead to unlikely or ridiculous outcomes with no supporting evidence.

You may have used this fallacy on your parents as a teenager: "But you have to let me go to the party! If I don't go to the party, I'll be a loser with no friends. Next thing you know, I'll end up alone and jobless, living in your basement when I'm 30!"

Example: "If you miss practice, it means you were probably goofing off. People who goof off drop out of school and end up penniless."

Hasty Generalizations

A hasty generalization is a claim based on a few examples rather than substantial proof. Arguments based on hasty generalizations often don't hold up due to a lack of supporting evidence: The claim might be true in one case, but that doesn't mean it's always true.

Hasty generalizations are common in arguments because there's a wide range of what's acceptable for "sufficient" evidence. The rules for evidence can change based on the claim you're making and the environment where you are making it — whether it's rooted in philosophy, the sciences, a political debate, or discussing house rules for using the kitchen.

Example: "People nowadays only vote with their emotions instead of their brains."

Multiple Choice

John: I think we should hire someone to redesign our website.

Lola: You're saying we should throw our money away on external resources instead of building up our in-house design team? That's going to hurt our company in the long run.

• Ad-hominem

• Slippery slope

Multiple Choice

We can either agree with Barbara's plan, or just let the project fail.

• False dichotomy

• Slippery slope

Multiple Choice

We can't believe what Mr. Dahl says about climate change. I once saw him put a PET bottle in the trash.

• False dichotomy

• Ad-hominem

Multiple Choice

If we give people healthcare for free, pretty soon they'll be asking for free houses too!

• Ad-hominem

• Slippery slope

Multiple Choice

Either we cease all research into AI or let the robots enslave us.

• Hasty generalization

• False dichotomy

Multiple Choice

Person A: I think men haven't had to face some of the problems that women have had to face in their lives.

Person B: So, you think all men have had easy lives?

• Straw man

• Slippery slope

Multiple Choice

The 9th grade boys at ISZL really struggle with maturity.

• Ad-hominem

• Hasty generalization