Logical Fallacies

Logical Fallacies How are we persuaded by the media?

Logical Fallacies A Logical Fallacy is… A mistake in reasoning.

Types of Logical Fallacies • Ad Hominem • False Causality • Red Herring • Overgeneralization • Bandwagon Effect

Ad Hominem • Using a personal attack to disprove an argument. • Types: name calling; irrelevant character issue; guilt by association; false analogy. • Example: • You can't tell me I should quit smoking. You've never done cancer research, so what would you know about it?

False Causality • Because one thing follows another, it has caused the other • The cause identified is only part of the entire cause • Example: The only reason that Katy missed school was because she is hanging out with the wrong crowd.

Red Herring • Reasons have little relevance to the argument at hand. • Desperate arguers often try to change the ground of the argument by changing the subject. • Example: • "I think there is great merit in making the requirements stricter for the graduate students. I recommend that you support it, too. After all, we are in a budget crisis and we do not want our salaries affected."

Overgeneralization • The argument draws a conclusion from a sample that is too small and is made up of too few cases • Example: • In both of the murder mysteries I have read, the District Attorney was the culprit. All mystery writers like to make lawyers out to be villains."

Bandwagon Effect • The main argument is that everyone is doing it and everyone should join. • Example: • Fifty million Elvis fans can’t be wrong, I have to buy the CD!

Which Fallacy is being used? • "Affirmative action proponents accuse me of opposing equal opportunity in the work force. I think my positions on military expenditures, education and public health speak for themselves.“ 2. "Despite the women's movement in the ‘70s, women still do not receive equal pay for equal work. Obviously, all such attempts to change the status quo are doomed to failure."

Which Fallacy is it? • "Since Harvard, Stanford, and Berkeley have all added a multicultural component to their graduations requirements, Notre Dame should get with the program. • Traditional historians appeal to the public's feeling of nationalism just as the Nazis did.“ • We must have a poltergeist in the house. When the dog ran under the table the vase just seemed to jump off the shelf all by itself.

Put this quote in your own words and explain what it might mean to you. • The most perfidious (deceitful) manner of injuring a cause is to vindicate (justify) it intentionally with fallacious arguments. -Friedrich Nietzsche

Logical Fallacies