Logical Fallacies
Is Appeal to Authority Always a Fallacy? Examples and Rules
No. Citing a real expert on their own subject is fair evidence. It becomes a fallacy when the source is unqualified, untrustworthy, or experts disagree.
Think it through.
Plain-English guides to spotting bad arguments, catching your own biases and weighing evidence, each one built on research and university sources.
Premise Premise
Conclusion Browse by topic
- Reasoning & Arguments What critical thinking is, how arguments work and how to reason more carefully. 3 guides
- Logical Fallacies The common errors in reasoning, with examples and how to answer them. 6 guides
- Cognitive Biases The mental shortcuts that skew judgment, and what research says about reducing them. 4 guides
- Evaluating Information How to check sources, claims and evidence before you trust or share them. 1 guide
- Learning How to Learn Study and learning methods that research shows actually work. 1 guide
Latest guides
All guidesLogical Fallacies
False Dilemma Fallacy: Definition and Examples
A false dilemma presents too few options, often just two, as the only choices when others exist. See its other names, examples, and how to respond to one.
Cognitive Biases
What Is Groupthink? Symptoms and Prevention
Groupthink is when a close-knit group's drive for agreement overrides careful judgment. Janis's causes, eight symptoms, famous cases and how to prevent it.
Cognitive Biases
Sunk Cost Fallacy: What It Is, How to Avoid It
The sunk cost fallacy is sticking with something because of what you've already spent on it. What the research shows, why it happens and how to avoid it.
Logical Fallacies
Slippery Slope Fallacy: Meaning and Examples
The slippery slope fallacy claims one step will set off a chain ending in disaster, without evidence for each link. See examples, types, and when it's valid.
Logical Fallacies
Ad Hominem Fallacy: Types and Examples
The ad hominem fallacy attacks the person making an argument instead of the argument. Learn its main types, see examples, and find out when it isn't a fallacy.