Logical fallacies
A logical fallacy is an argument that sounds convincing but does not support its conclusion. These are the ones people ask about most, each in a sentence, with everyday examples and a fair way to answer it.
Relevance
- Ad hominem fallacyAn ad hominem fallacy is rejecting an argument by attacking the person who made it, whether their character, motives or circumstances, instead of the reasons they gave.
- Appeal to authority fallacyAn appeal to authority fallacy is treating someone’s status or reputation as proof of a claim, especially when they are not expert in the subject or experts broadly disagree.
- Red herring fallacyA red herring is an irrelevant point brought into a discussion that draws attention away from the real issue.
- Straw man fallacyA straw man fallacy is replacing someone’s actual argument with a weaker or exaggerated version, then refuting that version as if it were theirs.
Definition & framing
- False dilemma fallacyA false dilemma presents two options as the only possibilities when others exist, so that rejecting one seems to force acceptance of the other.
- No true Scotsman fallacyThe no true Scotsman fallacy is shielding a generalisation from a counter-example by redefining the group so that the counter-example no longer counts.
Causal reasoning
- Post hoc fallacy (post hoc ergo propter hoc)The post hoc fallacy is assuming that because one event followed another, the first must have caused the second.
- Slippery slope fallacyThe slippery slope fallacy is claiming that one modest step will inevitably trigger a chain of further steps ending in disaster, without showing why each link in that chain is actually likely.
Fallacies are mistakes in an argument. Mistakes in the mind that makes the argument are cognitive biases, and the tools for thinking well are mental models.