logical fallacies

Argument

A conclusion together with the premises that support it.

Premise

A reason offered as support for another claim.

Conclusion

A claim supported by a premise.

Valid

An argument whose premises genuinely support its conclusion.

Unsound

An argument that has at least one false premise.

Fallacy

An argument that relies upon faulty reasoning.

Booby-trap

An argument that, while not a fallacy itself, might lead an inattentive reader to commit an error.

Red Herring

A fallacy that introduces an irrelevant issue to divert attention from the subject under discussion.

Ad Hominem

A fallacy that attacks the person rather than dealing with the real issue in dispute.

Either – Or

A fallacy that forces listeners to choose between two alternatives when more than two options exist. It is usually a false dilemma.

Band Wagon

A fallacy that assumes that because something is popular, it is therefore good, correct, or desirable.

Slippery Slope

A fallacy that assumes that taking the first step will lead to subsequent steps that cannot be prevented.

Non Sequitur

A fallacy that occurs when one claim doesn’t follow from the other.

The argument from Dubious Authority

A fallacy that occurs when a speaker supports an argument with an authority whose expertise lies outside the issue.

Post Hoc Ergo Propter Hoc

A fallacy that assumes a cause and effect relationship exists just because one event follows or coincides with another.

Begging the Question

A fallacy that occurs when the conclusion’s truth is assumed in the premise.

Genetic Fallacy

Rejecting an argument based on its origins rather than on its own merits.

Straw Man

A fallacy that occurs when a speaker attacks an argument, which is different from and usually weaker than the opponent’s best argument.

Vagueness (booby-trap not fallacy)

A lack of clarity or precision in language.

Equivocation

Using a term or expression in an argument in one sense in one place and another sense in another.