Common Logical Fallacies There’s no meat to your argument! Flawed Arguments

A logical fallacy… is flawed reasoning that most often leads to faulty conclusions. Learning to recognize logical fallacies will: Strengthen your own arguments Help you critique others’ arguments

Fallacies Covered: PART 1 PART 2 Slippery Slope Circular Reasoning Straw Man Bandwagon Appeal Hasty Generalization Ad Hominem Non-Sequitur Red Herring False Analogy Appeal to Fear & Force Either/Or Appeal to Celebrity / Authority Appeal to Pity

Logical Fallacies Part 1

Slippery Slope the false assumption that one thing must lead to a series of others

Slippery Slope the false assumption that one thing must lead to a series of others Example 1: If the government passes laws against assault weapons, then it won't be long before it passes laws on all weapons, and then it will begin to restrict other rights, and finally we will end up living in a communist state. Thus, we should not ban fully-automatic weapons.

Slippery Slope the false assumption that one thing must lead to a series of others Example 2: If we ban smoking, then people will start taking soft drugs and then move onto hard drugs, and the crime rate will go up and up. We should therefore prevent crime by allowing smoking.

Straw Man misrepresenting the opponent’s position

Straw Man misrepresenting the opponent’s position Example 1: Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why he wants to leave us defenseless like that.

Straw Man misrepresenting the opponent’s position Example 2: Mr. Goldberg has argued against prayer in public schools. Obviously Mr. Goldberg advocates atheism. But atheism is what they used to have in Russia. Atheism leads to the suppression of all religions and the replacement of God by an omnipotent state. Is that what we want for this country? I hardly think so. Clearly Mr. Goldberg’s argument is nonsense.

Hasty Generalization A generalization based on insufficient or unrepresented evidence

Hasty Generalization A generalization based on insufficient or unrepresented evidence Example 1: Fred, the Australian, stole my wallet. Thus, all Australians are thieves. Example 2: Deaths from drug overdoses in Metropolis have doubled over the last three years. Therefore, more Americans than ever are dying from drug abuse.

Non Sequitur (Does Not Follow) conclusion that does not follow logically from preceding statements.

Non Sequitur (Does Not Follow) conclusion that does not follow logically from preceding statements. Example 1: Mary loves children, so she will make an excellent school teacher. Example 2: Steven Johnson grew up in poverty. Therefore, he will make a fine President of the United States.

False Analogy The assumption that because two things are alike in some respects, they are alike in others.

False Analogy The assumption that because two things are alike in some respects, they are alike in others. Example 1: Employees are like nails. Just as nails must be hit in the head in order to make them work, so must employees. Example 2: If we put humans on the moon, we should be able to find a cure for the common cold.

Either/Or Fallacy (False Dilemma) The suggestion that only two alternatives exist when in fact there are more. /

Either/Or Fallacy (False Dilemma) The suggestion that only two alternatives exist when in fact there are more. Example 1: Either learn how to program a computer, or you won’t be able to get a decent job after college. /

Either/Or Fallacy (False Dilemma)

Logical Fallacies Part 2

Circular Reasoning (Begging the Question) An argument in which the writer, instead of applying evidence, simply restates the point in other language.

Circular Reasoning (Begging the Question) restating the point in other language Students should not be allowed to park in lots now reserved for faculty because those lots should be for faculty only. Mike was the best candidate for president, because he was totally better than any of the others.

Bandwagon Appeal (Ad Populum) A claim that an idea should be accepted because a large number of people favor it or believe it to be true.

Bandwagon Appeal (Ad Populum) an idea should be accepted because “everyone else does.” If you don’t have a Dodgers jersey, you’re not a true fan!

Argument to the Person (Ad Hominem) An attack on the person proposing an argument rather than on the argument itself.

Ad Hominem (Argument to the Person) An attack on the person proposing an argument rather than on the argument itself. Senator Jones was a conscientious objector during the Vietnam War, so his proposal to limit military spending has no merit. "Listen, son. Mind-altering drugs can damage your brain. You're better off avoiding them." "Who are you to talk? I know you dropped a lot of acid back in the 60's."

Red Herring An argument that focuses on an irrelevant issue to detract attention from the real issue.

Red Herring

Red Herring An argument that focuses on an irrelevant issue to detract attention from the real issue. I should not pay a fine for reckless driving. There are many other people on the street who are dangerous criminals and rapists, and the police should be chasing them, not harassing a decent tax-paying citizen like me.

Appeal to Fear/Force attempts to persuade the audience to accept the conclusion by predicting (or causing) unpleasant consequences if it is not accepted.

Appeal to Fear/Force

Appeal to Fear/Force

Appeal to Celebrity / Authority (False Authority) appeal to irrelevant authority—that is, an ‘authority’ who is not an authority in the field of question.

Appeal to Celebrity / Authority

Appeal to Celebrity / Authority

Appeal to Celebrity / Authority

Appeal to Pity Quick quiz: What other fallacy lives in the above plea? appeal to accept the truth of a conclusion out of pity for the arguer. If I don’t get at least a B in this class my GPA will drop below 2.0. If that happens I’ll lose my scholarship and have to quit school, so I ought to get a B in this course. Quick quiz: What other fallacy lives in the above plea?

Appeal to Pity

Works Consulted Annenberg Public Policy Center (2008). Monty Python and the Quest for the Perfect Fallacy. Retrieved 10-1-08 from http://www.factchecked.org/LessonPlanDetails.aspx?myId=7. Hacker, D. (1999). A Writer’s Reference, 4th ed. New York: Bedford/St. Martins. Mike, H. B. (1999). Language and Logic. Dubuque, Iowa: Kendall/Hunt Publishing, 1999. Wheeler, K. (2008). Logical fallacies handlist. Retrieved 10-1-08 from http://web.cn.edu/kwheeler/fallacies_list.html