Logical Fallacies: How Reasoning Goes Wrong: quick revision, 17 bites

A Fallacy Is a Broken Step in Reasoning

Bad logic can still sound convincing.

A **logical fallacy** is an error in reasoning that makes an argument look stronger than it really is. The conclusion may even be true — but the *reasoning* used to get there is flawed.

Takeaway. A true conclusion reached through faulty reasoning is still a fallacious argument.

Formal vs Informal Fallacies

Two families of bad reasoning.

Formal fallacies break the rules of logic itself; informal fallacies persuade through tricks of language, emotion, or relevance.

Takeaway. Formal = wrong shape. Informal = wrong substance or tactic.

Valid vs Fallacious Reasoning

Same topic, very different logic.

Takeaway. Ask whether the conclusion actually follows from the premises — not whether it feels right.

Ad Hominem: Attack the Person, Not the Point

Insult the speaker, dodge the argument.

Takeaway. Who says it is irrelevant; what they say and how they support it is what matters.

Straw Man: Attack a Weaker Version

Twist their words, then knock them down.

Takeaway. Always restate the opponent's view fairly before responding.

False Dilemma: Only Two Choices?

Forced into a fake either-or.

Takeaway. Real life rarely fits into two boxes — demand the full set of options.

Appeal to Authority: Famous ≠ Correct

A celebrity said it, so it's true?

Takeaway. Authority is only as good as the evidence behind the claim.

Bandwagon: Everyone Does It

Popularity is not proof.

Takeaway. Ask for evidence, not a crowd count.

Slippery Slope: One Step to Disaster

One small step, a chain of doom.

Takeaway. A chain of 'will lead to' claims needs proof at every link.

Circular Reasoning: Assuming the Conclusion

The proof is the claim itself.

Takeaway. Real proof must come from outside the claim being defended.

Post Hoc: Correlation Isn't Cause

After it, therefore because of it?

Takeaway. Sequence in time is not proof of cause.

Red Herring: Change the Subject

Dodge the question with a distraction.

Takeaway. Notice when the topic quietly shifts — and pull it back.

Spotting a Fallacy ≠ Winning the Argument

Naming a fallacy isn't a rebuttal.

The **fallacy fallacy** is assuming that because an argument is flawed, its conclusion must be wrong.

Takeaway. Fallacies expose weak reasoning — they don't automatically disprove the conclusion.

A 4-Step Fallacy Check

Run every argument through this filter.

Takeaway. A repeatable checklist beats memorizing dozens of fallacy names.

Exam Strategy: Name + Explain + Fix

Three moves earn full marks.

Examiners reward precise identification plus reasoning — not just the label.

Takeaway. Label + reason + correction = full-marks answer.

Remember the Big Five by Their Targets

Five fallacies, five targets.

Takeaway. Grouping fallacies by what they attack makes recall far easier.

Fallacies in Ads and Headlines

You're targeted daily.

Recognizing these patterns makes you a harder target for manipulation.

Takeaway. Everyday media is full of fallacies — spotting them is a life skill, not just an exam skill.