Common logical fallacies to avoid

1. Common logical fallacies to avoid Statements that weaken arguments...

2. Argument An argument can be supported by... • logic (logos) - an appeal to reasoning such as deductive and inductive; • ethics (ethos) - an appeal to one's sense of right and wrong or good sense, or to • emotions(pathos) - an appeal to one’s patriotism, fears, or sympathies.

3. Weak Arguments • Weak arguments rely on illogical statements called fallacies.

4. Definition Logical fallacies are flaws in reasoning that lead to faulty, illogical statements. They are unreasonable argumentative tactics named for what has gone wrong during the reasoning process.

5. Most logical fallacies masquerade as reasonable statements, but they are in fact attempts to manipulate readers by reaching their emotions instead of their intellects.

6. The following slides contain examples of logical fallacies...

7. Hasty generalization • a conclusion based on insufficient evidence or one that ignores exceptions. These can sometimes be made acceptable by using qualifying words such as many, most, generally, and some. Taco Bell Examples: Three members of Congress have had affairs. Therefore, members of Congress are adulterers. Five UK players left for the draft after their freshman year. Therefore, no UK players complete their 4 year degree.

8. Attacking the Person/Ad Hominem (to the man) AKA: Name calling- avoids the real issue and attacks people in support of the issue. Examples: • Sam is divorced, so how can he make sound financial decisions for the city? • Mr. Spock is not an effective second-in- command because he has ugly pointed ears. MSNBC Commentators’ Ad Hominem Attack on NRA Hillary Clinton’s Ad Hominem Attack on Obama

9. False Authority Citing someone’s name and position even though they have no expertise in the subject of the article. Rather than focusing on the merits of an argument, the arguer will try to attach their argument to a person of authority in an attempt to give credence to their argument. Expert testimony is only valuable when it comes from someone knowledgeable about the topic in question. • Examples: • 3 out of 4 dentists prefer Crest. (Did Crest pick the dentists?) • I surveyed 100 people and they all agreed with me. (I chose my friends). • Dr. X says this is the fastest and safest way to lose weight. (Did he/she get paid? Where do they practice?) Fix the examples above by analyzing the evidence. Think: From where did the support come? Is there self interest involved? Did you get the whole picture?

10. Circular Reasoning • When an argument takes its proof from a factor within the argument itself, rather than from an external one. In other words, the reason offered for an opinion is simply the opinion stated in different words. Examples: • Martha is a good supervisor because she supervises the company's personnel office effectively. • I believe that Frosted Flakes are good for you because it says on the box that they are a nutritious start to your day.

11. Either –Or Reasoning • ...assumes that every issue has only two possible sides. Usually, there are many different choices or positions that fall between the extremes. Examples: • Either you are with America's fight against terrorism or you are America's enemy. • We can either stop using cars or destroy the earth. • Either you go to college or you will become a minimum wage worker barely making ends meet.

12. Non-sequitur- ("it does not follow") • “Non-SECK-quit-er” Statements or ideas are presented as logically connected but in fact are not. One is not a logical consequence of the other. Examples: • The President graduated from Harvard. He can't make mistakes. • I dated a man who was an accountant and all he talked about was work. Accountants are boring people. • I got into a car accident on a rainy day. I don't think anyone should drive in the rain.

13. Red Herring • ...named after a strong-smelling fish, the scent of which throws hounds off the scent of a trail. The Red Herring occurs when one draws attention away from the main issue by focusing on a side issue or on something irrelevant.  • Examples: • I know your car isn't working right. But, if you had gone to the store one day earlier, you'd not be having problems. • Example: I know I forgot to deposit the check into the bank yesterday. But, nothing I do pleases you.

14. Red Herring Example Both Obama and Mitt Romney use Red Herring to answer the same debate question—neither addresses the AK-47 issue—neither even says the word “AK-47.”

15. Bandwagon • relying on the emotional passion of the crowd in making an argument; playing on a group's fears or prejudices. Appeal that say, “Everyone’s doing it, so you should do it, too.” Examples: • We will all go broke if we don't put a stop to welfare fraud. • All I can say is that if enjoying junk food is unhealthy, then the majority of us are unhealthy! • Just ask anyone in Mr. Burton‘s class’s if the latest test was extremely unfair.

16. Bandwagon example Coke Commercial

17. Card Stacking • Providing favorable information for only one side of the argument; sometimes, important details are purposely left out. Example: • Telling your parents that you’re going to a party but neglecting to tell them there will be alcohol there. Nutella

18. Logical Fallacies: Slippery Slope Slippery Slope: Claiming that if A happens, eventually, through a series of small steps, Z will happen too. **If we don’t want Z to happen, then we should not allow A to happen. “If we ban Hummers because they are bad for the environment, then soon the government will ban all of our cars and we will lose our right to drive at all. • Direct TV