Learning fallacy names has a risk: seeing fallacies everywhere. Many fallacies have a fair cousin that looks similar but reasons well, like the fair appeals to authority you have met.
Key idea
A fallacy name fits only when its faulty step is really there. Trusting real experts, following a well-supported chain of causes, and naming a real either-or are good reasoning, not fallacies.
Why it works
Each fallacy is defined by a specific failure: an irrelevant attack, a missing option, unsupported links, a biased sample. If the passage does not contain that failure, the name does not apply, however familiar the surface looks.
| Looks like… | But is fair when… |
|---|---|
| Ad hominem | the question is whether to trust a witness's report |
| Appeal to authority | the source is an expert in this field and experts agree |
| Slippery slope | each link in the chain is well supported |
| False dilemma | the two options really cover every case |
| Appeal to ignorance | a careful search would have found the thing |
| Appeal to pity | the conclusion is about kindness or help, not truth |
Worked example: Fair or fallacy?
"If we spend the trip money on snacks, we won't have enough for the bus. Without the bus, the class can't get to the museum. So we shouldn't spend it on snacks."
- It is a chain of consequences, like a slippery slope.
- But each link is a plain fact about money and travel.
Answer: Fair reasoning.
Worked example: Fair or fallacy?
"Nobody has proved the new paint is safe for the class hamster, so the paint must be poisonous."
- A lack of proof that it is safe is offered as proof that it is poisonous.
- Caution would be wise, but the conclusion claims too much.
Answer: Appeal to ignorance.
Common mistake
Fallacy hunting: shouting a fallacy name at every argument you dislike. Each name fits only when its faulty step is really there. If you cannot point to the step, withdraw the name.