Argument Fallacies *Adapted from FactCheckEd.org “Monty Python and the Quest for the Perfect Fallacy”

Key Terms Argument: a conclusion together with the premises that support it Premise: a reason offered as support for another claim Conclusion: a claim that is supported by a premise Valid: an argument whose premises genuinely support its conclusion

Key Terms Unsound: an argument that has at least one false premise Invalid: an argument whose premises are true but whose conclusion is still false Fallacy: an argument that relies upon faulty reasoning Booby-trap: an argument that, while not fallacious itself, might lead an inattentive reader to commit a fallacy

A valid argument: Whichever basketball team scores the most points will win the game. Virginia scored more points than UNC. Therefore, Virginia won the game.

A valid argument? Whichever candidate receives the greatest share of the popular vote will be elected President of the United States. Al Gore received more votes than George W. Bush. Therefore, Al Gore was elected President of the United States.

Examples: If Burger King sells Big Macs, then McDonald’s will go out of business. Burger King does sell Big Macs. Therefore, McDonald’s will go out of business.

Examples: Baptists are often politically conservative. Republicans are often politically conservative. Therefore, Baptists are often Republicans. John Elway is a great quarterback. Michael Vick is a great quarterback. Therefore, Michael Vick is really John Elway.

Examples: Dr. Roy Spencer, who is a prominent climate scientist at the University of Alabama at Huntsville and winner of NASA’s Medal for Exceptional Scientific Achievement, doesn’t think that humans are causing global warming. So humans are probably not causing global warming.

The Basic Fallacies Genetic Fallacy Red Herring Straw Man False Cause Undistributed Middle Ad Hominem Slippery Slope Tu Quoque Appeal to Authority Circular Argument Vagueness Equivocation Suppressed Evidence Questionable Statistics Appeal to History Appeal to Popularity Inconsistency Generalization Restricting the Options Weak Analogy

Exercise: Identifying Fallacies After going over the [limited] list of basic fallacies, ask any clarifying questions that you might have. Form groups of 3 or 4. Look at the “Sample Fallacies” handout. Each argument contains a fallacy (or “booby-trap”). Identify the fallacy (or fallacies) in each argument. Report back to the class on your findings.