informal-fallacies
Catalog of informal fallacies with definitions, canonical examples, and detection heuristics. Covers relevance fallacies (ad hominem, straw man, red herring, appeal to authority, appeal to emotion), presumption fallacies (false dichotomy, complex question, begging the question), ambiguity fallacies (equivocation, amphiboly, accent), causal fallacies (post hoc, slippery slope, correlation-causation), and statistical fallacies (hasty generalization, cherry-picking). Use when evaluating arguments for rhetorical or informal reasoning errors.
npx skills add majiayu000/claude-skill-registry --skill informal-fallacies --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Informal Fallacies An informal fallacy is a pattern of reasoning that can look persuasive but fails to actually support its conclusion. Unlike formal fallacies (which are detectable by structure alone), informal fallacies depend on context, content, or rhetorical framing. They are the failure modes of everyday argument, the traps in political discourse, and the stock repertoire of bad faith. This skill catalogs the most common informal fallacies, grouped by family, with canonical examples and detection heuristics. It is not a complete taxonomy -- the literature catalogs over a hundred named fallacies -- but it covers the ones that actually appear in ordinary discourse. **Agent affinity:** russell (critical analysis), quine (linguistic precision), langer (pedagogical framing) **Concept IDs:** log-informal-fallacies, log-argument-evaluation, log-cognitive-biases, log-propaganda-techniques ## Using Fallacy Labels Responsibly Before the catalog, a warning: **fallacy labels are tools, not weapons**. Calling an argument a fallacy is not the same as refuting it. A flawed argument may still have a correct conclusion; a fallacy label is a reason to ask for a better argument, not to dismis
- Using Fallacy Labels Responsibly
- Family 1: Relevance Fallacies
- Ad Hominem (Against the Person)
- Straw Man
- Red Herring
- Appeal to Authority (Argumentum ad Verecundiam)
- Appeal to Emotion (Argumentum ad Passiones)
- Appeal to Ignorance (Argumentum ad Ignorantiam)
- Family 2: Presumption Fallacies
- False Dichotomy (False Dilemma)
- Begging the Question (Petitio Principii)
- Complex Question (Loaded Question)
- Slippery Slope
- Family 3: Ambiguity Fallacies
What does the informal-fallacies skill do?
Catalog of informal fallacies with definitions, canonical examples, and detection heuristics. Covers relevance fallacies (ad hominem, straw man, red herring, appeal to authority, appeal to emotion), presumption fallacies (false dichotomy, complex question, begging the question), ambiguity fallacies (equivocation, amphiboly, accent), causal fallacies (post hoc, slippery slope, correlation-causation), and statistical fallacies (hasty generalization, cherry-picking). Use when evaluating arguments for rhetorical or informal reasoning errors.
How do I install it?
Run `npx skills add majiayu000/claude-skill-registry --skill informal-fallacies --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From majiayu000/claude-skill-registry, a repository with 534 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.