Understanding Common Logical Fallacies

Ambiguity

Using a word, phrase, or claim that gives rise to more than one possible interpretation.

Division

Assuming that all members of a set share characteristics of the set as a whole.

Composition

Assuming that a set shares characteristics with a given member of a set.

Equivocation

Making two words or phasing equivalent in meaning while ignoring contextual differences.

Non sequitur

'It does not follow.' Drawing conclusions that are unrelated or do not follow logically from the premises.

Distorting the Facts

misrepresenting information to make an argument appear stronger than it is

Post Hoc

Assuming that sequence equals consequence.

Many Questions

Presupposing facts that are assumed in the question itself.

Hasty Generalizations

Jumping to conclusions based on insufficient evidence or biases.

Slippery Slope

Arguing that an idea or action will lead inevitably to unrealistically steeper and steeper consequences.

False Analogy

Comparing two things that may be similar in some ways but remain different in other ways.

Straw Man

Misrepresenting an argument so that you can attack the misrepresentation rather than the actual argument.

Special Pleading

Making an unwarranted claim by misapplying or misusing rules and standards.

Begging the Question

Making an argument in which the premises are based on the truth of the conclusion.

False Dichotomy

Establishing only two opposing positions or points when more might be available or when the opposing positions are not mutually exclusive.

Oversimplification

Reducing a complex thing to a simple cause or consequence.

Red Herring

Presenting a question or issue intended to divert and distract from the central or most relevant question or issue.

Tu Quoque

Literally, 'you also.' Discrediting an argument by attacking the speaker's failure to adhere to their conclusion.

Genetic Fallacy

Arguing a position based on the real or imagined origin, history, or source of the idea.

Appeal to Ignorance

Saying that something is true because there is no evidence against it.

Poisoning the Well

Creating negative associations preemptively to discredit another person or position.

Ad Hominem

Literally, 'against the man [person].' Attacking the character of a person by providing irrelevant negative information.

Appeal to Authority

Asserting that a claim is true by citing someone thought to be an authority, regardless of the merits of the position or the relevance of the authority's expertise.

Appeal to Fear

Supporting a position by instilling irrational fear of the alternatives.

Fallacy of Appeal to Fear

Supporting a position by instilling irrational fear of the alternatives.

Death by a Thousand Qualifications

Justifying a weak idea or position by changing (or qualifying) it each time it is challenged.

Protecting the Hypothesis

Distorting evidence to support a pre-existing belief or idea.