Logical Fallacies — Convergence Protocol
Errors in reasoning that undermine the logic of an argument
What is a Logical Fallacy?
A logical fallacy is a flaw in reasoning that makes an argument invalid, unsound, or weak. Unlike cognitive biases (which are unconscious patterns), fallacies are often deliberate or structural errors in how we construct and present arguments.
“A fallacy is the use of invalid or otherwise faulty reasoning in the construction of an argument.”
Categories of Fallacies
Formal Fallacies
Errors in the logical structure itself.
Informal Fallacies
Errors in the content or context of the argument.
Common Fallacies to Document
Appeal to Emotion
- Appeal to Fear (Argumentum ad Metum)
- Appeal to Pity (Argumentum ad Misericordiam)
- Appeal to Ridicule
- Appeal to Spite
Appeal to Authority / Popularity
- Appeal to Authority (Argumentum ad Verecundiam)
- Appeal to Anonymous Authority
- Appeal to Common Practice
- Bandwagon Fallacy (Argumentum ad Populum)
- Appeal to Tradition
Causation Errors
- Post Hoc Ergo Propter Hoc (After this, therefore because of this)
- Cum Hoc Ergo Propter Hoc (With this, therefore because of this)
- Slippery Slope
False Dilemmas
- False Dichotomy (Either/Or Fallacy)
- Perfect Solution Fallacy (Nirvana Fallacy)
Relevance Errors
- Ad Hominem (Attack the person)
- Appeal to Ignorance (Argumentum ad Ignorantiam)
- Red Herring (Ignoratio Elenchi)
- Straw Man
- Tu Quoque (You too)
Evidence Errors
- Cherry Picking
- Confirmation Bias (overlap with biases)
- Hasty Generalization
- Anecdotal Evidence
- Appeal to Probability
Semantic / Linguistic Errors
- Equivocation
- Amphiboly
- Accent Fallacy
- Quoting Out of Context
Statistical Fallacies
- Base Rate Fallacy (overlap with biases)
- Gambler’s Fallacy
- Regression Fallacy
- Prosecutor’s Fallacy
Relationship to Cognitive Biases
| Bias | Related Fallacy |
|---|---|
| Confirmation Bias | Cherry Picking |
| Availability Heuristic | Hasty Generalization |
| Anchoring Bias | Appeal to Tradition |
| Authority Bias | Appeal to Authority |
| Ingroup Bias | Genetic Fallacy |
Template for Each Fallacy
# [Fallacy Name]
**Type:** [Formal / Informal — Category]
**Also Known As:** [Alternative names]
## Definition
[Clear, concise definition]
## Form
[Logical structure showing the error]
## Examples
### Example 1
[Simple example]
### Example 2
[Real-world example]
### Example 3
[Political/media example]
## Why It Persuades
[Why does this fallacy work psychologically?]
## How to Counter
[How to identify and respond to this fallacy]
## Related Concepts
- [[Cognitive Bias Name]]
- [[Other Fallacy]]
- [[Mental Model]]
## References
- [Source material]Index
- Ad Hominem
- Appeal to Authority
- Appeal to Emotion
- Appeal to Ignorance
- Bandwagon Fallacy
- Cherry Picking
- False Dichotomy
- Hasty Generalization
- Post Hoc
- Red Herring
- Slippery Slope
- Straw Man
- Tu Quoque
Part of the Convergence Protocol — Clear thinking for complex times.