Logical Fallacies
Logical fallacies are common patterns of reasoning that appear persuasive but fail under scrutiny.
They often rely on familiar intuitions, emotional shortcuts, or subtle shifts in meaning that make an argument feel convincing even when it does not logically support its conclusion. Because these patterns are easy to miss in the moment, fallacies frequently appear in everyday conversation, public debate, media, politics, and discussions about religion and science.
For skeptics, understanding fallacies serves a deeper purpose than spotting mistakes in others’ arguments. It provides a way to discipline one’s own thinking, separate evidence from expectation, and recognize when a conclusion feels right for reasons unrelated to truth. Fallacies remind us that confidence, repetition, and intuition are not substitutes for sound reasoning.
Logical fallacies are commonly divided into formal and informal types.
Formal Fallacies
Formal fallacies are errors in the logical structure of an argument.
In these cases, the conclusion does not follow from the premises, even if the premises themselves are true. The failure lies in the form of the reasoning rather than in its subject matter or language.
For skeptics, formal fallacies are especially important because they show how arguments can fail independently of evidence, intention, or persuasion. An argument may sound rigorous, use technical language, or follow familiar patterns, yet still be invalid. Learning to recognize formal fallacies helps separate arguments that merely resemble logic from those that actually obey its rules.
- Affirming the Consequent
- Bad Reason Fallacy
- Propositional Fallacies
- Quantification Fallacies
- Sunk Cost Fallacy
- Syllogistic Fallacies
Informal Fallacies
Informal fallacies are errors that arise from relevance, clarity, or unjustified assumptions rather than from logical structure.
In these cases, the reasoning may appear sound on the surface, but the argument fails because key terms shift meaning, important alternatives are ignored, or conclusions are supported by inappropriate considerations.
For skeptics, informal fallacies are often more difficult to detect because they exploit intuition, emotion, and social expectations rather than explicit logical form. Recognizing informal fallacies helps guard against persuasion that feels reasonable while quietly bypassing evidence, context, or critical scrutiny.
- Ad Hominem
- Ambiguity
- Anecdotal
- Appeal to Authority
- Appeal to Emotion
- Appeal to Nature
- Appeal to Ridicule
- Appeal to Tradition
- Argument from Repetition
- Argumentum ad Populum
- Bandwagon
- Begging the Question
- Burden of Proof
- Circular Reasoning
- Continuum Fallacy
- Equivocation
- Etymological Fallacy
- Fallacy Fallacy
- Fallacy of Composition and Division
- Fallacy of Quoting Out of Context
- False Cause & False Attribution
- False Dilemma
- Furtive Fallacy
- Gambler’s Fallacy
- Genetic Fallacy
- Ignoratio Elenchi
- Incomplete Comparison
- Inflation of Conflict
- Kettle Logic
- Loaded Question
- Middle Ground
- No True Scotsman
- Personal Incredulity
- Proof by Verbosity
- Proving Too Much
- Red Herring
- Reification
- Retrospective Determinism
- Shotgun Argumentation
- Slippery Slope
- Special Pleading
- Strawman
- Texas Sharpshooter
- Tu Quoque
More Coming
This index grows one fallacy at a time. If you’d like to suggest one to add next (or submit a real-world example for the gallery), use the submission link in the footer.