Spotting Fallacies
A fallacy is a flaw in reasoning that makes an argument unreliable. Some fallacies are deliberate tricks; many are honest mistakes. Learning to spot them helps you evaluate other people's arguments and tighten your own.
Why fallacies matter
A fallacy does not automatically mean the conclusion is false. It means the argument does not establish the conclusion. A speaker can be right for the wrong reasons. The skill is to separate the truth of a claim from the quality of the reasoning offered for it.
Common fallacies
| Fallacy | What happens | Example | Why it fails |
|---|---|---|---|
| False dilemma | Two options presented as the only ones. | “Either we ban phones or we accept chaos.” | Other options exist. |
| Straw man | A weakened version of the opposing view is attacked. | “Critics want no rules at all.” | The real position is different. |
| Ad hominem | The person is attacked instead of the argument. | “You cannot trust her; she is young.” | Age does not determine truth. |
| Slippery slope | One step is said to lead inevitably to an extreme. | “If we allow this, soon nothing will be forbidden.” | The chain is asserted, not shown. |
| Appeal to popularity | Something is true because many people believe it. | “Everyone knows this works.” | Popularity is not evidence. |
| Appeal to authority | An expert's opinion is treated as proof. | “A famous scientist said it, so it must be true.” | Experts can be wrong or out of field. |
| False cause | Correlation is treated as causation. | “Test scores rose after the new uniform, so the uniform worked.” | Other factors may explain the change. |
| Cherry-picking | Only favourable evidence is presented. | “Three studies support us” (ignoring ten that do not). | The evidence is selective. |
| Loaded language | Emotive words do the work of argument. | “This dangerous scheme ...” | Emotion is not evidence. |
| Begging the question | The conclusion is assumed in the premise. | “This is the best policy because no policy is better.” | It argues in a circle. |
| Appeal to fear | Fear is used instead of reasons. | “If we do not act, everything will collapse.” | The threat is not established. |
| Tu quoque | Deflects criticism by accusing the critic. | “You did it too.” | Hypocrisy does not answer the argument. |
Fallacies in advertising
| Advertisement move | Fallacy | Question to ask |
|---|---|---|
| “Australia's favourite ...” | Appeal to popularity | Favourite according to whom? |
| “Doctors recommend ...” | Appeal to authority | Which doctors, and what evidence? |
| “Before and after” photos | False cause or selection | What else changed? |
| “Nine out of ten users ...” | Cherry-picking or vague sample | Which users? How many? |
| “If you care about your family ...” | Appeal to emotion or guilt | What is the actual evidence? |
| “Limited time only” | Appeal to urgency | Is the deadline real? |
Fallacies in speeches
Public speakers use the same moves. A politician may present a false dilemma; an activist may cherry-pick evidence; a commentator may use ad hominem. The label is less important than the question: does the argument actually support the claim?
Not every bad argument is a fallacy
People often shout “fallacy” when they mean “I disagree”. A genuine fallacy is a structural error, not just an uncomfortable conclusion. Some arguments are weak because the evidence is thin, not because the form is invalid. Say which problem you are identifying.
| Critique | What it means |
|---|---|
| “That is a false dilemma.” | The argument presents too few options. |
| “That evidence is weak.” | The study is small, old or unrepresentative. |
| “That is irrelevant.” | The point does not bear on the claim. |
| “I disagree.” | A statement of position, not a fallacy claim. |
Checking your own argument
- State your claim.
- List your reasons and evidence.
- For each, ask: does this actually support the claim, or does it just feel persuasive?
- Look for a false dilemma in your framing.
- Check whether you have represented the other side fairly.
- Look for cherry-picking: what evidence have you left out?
- Ask whether an emotion is doing the work of a reason.
Activity: fallacy hunt
- Collect five advertisements, headlines or speech extracts.
- Identify one possible fallacy in each.
- Write the claim the text is making.
- Explain why the reasoning fails.
- Rewrite one example so that it reasons rather than manipulates.
- Discuss: which examples were deliberate, and which might be honest mistakes?
Label the flaw, not the person. “That is a false dilemma” is a critique of the argument. “You are stupid” is not.
Common errors
- Fallacy spotting as a game. The goal is better reasoning, not winning points.
- Mislabeling. Not every generalisation is a fallacy.
- Ignoring the conclusion. A flawed argument can still reach a true conclusion.
- Using fallacies in your own speech. They are easier to spot in others than in yourself.
- Assuming intent. A fallacy may be a mistake, not a trick.
- Using the label to avoid the evidence. Answer the substance first.
Next, study audience and values to understand why people accept or resist an argument. The calls to action page turns persuasion into a concrete request.