Flaw

Causal Confusion

Assumes that because A and B are correlated, A causes B.

Reverse Causation

Assumes A causes B when B may actually cause A.

Causal Alternative

Assumes A causes B while ignoring another possible cause of B.

Causation from Temporal Sequence

Assumes that because A happened before B, A caused B.

Causal Necessity

Assumes A is necessary for B just because A causes or contributes to B.

Causal Sufficiency

Assumes A alone is enough to cause B when other factors may be required.

Sampling Bias

Draws a conclusion about a whole population from an unrepresentative sample.

Unrepresentative Sample

Uses evidence from a group that does not accurately represent the group being generalized about.

Small Sample

Generalizes from too few examples to support a broad conclusion.

Hasty Generalization

Makes a broad claim based on insufficient evidence.

Overgeneralization

Extends a limited finding beyond the group or situation actually supported.

Part-to-Whole

Assumes that what is true of each part must be true of the whole.

Whole-to-Part

Assumes that what is true of the whole must be true of each part.

False Analogy

Treats two things as sufficiently similar when the relevant similarities have not been established.

Irrelevant Comparison

Compares things that differ in a way that matters to the conclusion.

Circular Reasoning

Uses the conclusion itself as support for the conclusion.

Begging the Question

Assumes what the argument is supposed to prove.

Equivocation

Uses the same word or phrase with two different meanings.

Straw Man

Misrepresents an opposing position and attacks the weaker version instead.

Ad Hominem

Attacks the person instead of addressing the person’s argument.

Appeal to Authority

Treats an authority’s claim as true without adequate support.

Appeal to Popularity

Treats something as true because many people believe it.

Appeal to Tradition

Treats something as correct because it has traditionally been done.

Appeal to Ignorance

Treats lack of evidence against a claim as evidence that the claim is true.

False Dichotomy

Presents an either/or choice when the alternatives are not exhaustive.

Quantifier Shift

Illegitimately changes the scope of words like “some,” “all,” or “most.”

Scope Shift

Moves from a narrower claim to a broader one without justification.

Unwarranted Assumption

Relies on a premise that the argument never establishes.

Percentage vs. Number

Confuses a percentage change with an absolute numerical change.

Correlation vs. Causation

Treats a statistical relationship as proof of a causal relationship.

Possibility vs. Probability

Treats something that could happen as though it is likely to happen.

Could Be True vs. Must Be True

Treats the possibility of something as proof that it must be true.

Counterexample Ignored

Makes a universal claim despite evidence of an exception.

Exception as Rule

Uses an unusual or exceptional case to support a general rule.

Condition vs. Guarantee

Treats a condition that helps produce an outcome as guaranteeing that outcome.

Condition vs. Requirement

Treats something that can produce an outcome as something required for that outcome.

Past-to-Future Assumption

Assumes that a past pattern will necessarily continue into the future.

Unrepresentative Evidence

Uses evidence that is atypical of the situation being discussed.

Irrelevant Evidence

Provides evidence that does not actually bear on the conclusion.

Failure to Consider Consequences

Recommends an action without considering an important consequence.

Failure to Consider Costs

Supports an option without considering relevant costs or disadvantages.

Failure to Consider Benefits

Criticizes an option without considering relevant benefits or advantages.

Premise Does Not Entail Conclusion

The premises could all be true while the conclusion is false.