Critical Thinking

1. Don’t Be Fooled by Bad Arguments Critical Thinking

2. First, what are arguments? Distinguish arguments from explanations: Arguments are the assertion of a conclusion from reasons that are better known than the conclusion. Explanations are the assertion of reasons for a conclusion that is better known than those reasons.

3. Ad Hominem Argumentum ad Hominem (Argument to the Person): Attacking the arguer instead of their argument. Famous response to an ad hominem attack: “I may be the devil’s brother, sir, but you still haven’t answered my argument.” 3 Kinds of ad Hominem arguments: Abusive ad Hominem: “I believe murderers should die for the sake of their victim’s family.” “Only a total jerk would want anyone to die!” …does the speaker being a jerk have anything to do with whether capital punishment is justified based on concern for the victim’s family?

4. Ad Hominem Circumstantial ad Hominem: “I believe murderers should die for the sake of the victim’s family.” “Well, since your cousin was murdered, it isn’t hard to see why you feel that way.” Tu Quoque (you too): “I believe murderers should die for the sake of the victim’s family.” “Well, I recall you defending your Uncle when he was convicted … you weren’t suggesting he die for the family of the guy he shot!”

5. Appeal to Ignorance Appeal to Ignorance (ad Ignorantiam): Arguing from a lack of knowledge: No one has proven X true, (or false) X is false (or true) “God does not exist.” “Says who?” “Well, no one has proven God exists, so he doesn’t.” “God exists.” “Says who?” “Well, no one as proven God doesn’t exist, so he does.”

6. Appeal to Ignorance, cont. Exceptions (below are good arguments (pretty good)): “Guy’s innocent.” “Says who?” “Well, he hasn’t been proven guilty, so he is innocent.” “There is no crocodile in the hall.” “Says who?” “Well, no one has proven there’s a crocodile in the hall, so there isn’t.”

7. Appeal to the Majority / Tradition Appeal to the Majority: The fallacy has the form: X is popular X is true Direct Approach: appeal directly to the crowd of people … use emotive language to create mob mentality support for a conclusion. Political speeches often good examples? Indirect Approach: appeal indirectly to the crowd by appealing directly to individuals and their relationship to the crowd … also called a “Bandwagon Argument”: “Come on … everyone in this class smokes crack ... you should take a hit!” Individual crowd

8. Appeal to the Majority / Tradition Appeal to the People (Argumentum ad Populum): Ad Populum has the form: X is popular X is true When the majority’s opinion becomes enshrined over time it becomes a tradition. Think of Appeal to Tradition as an instance of Indirect Appeal to the Majority If your school had a tradition of crack smoking, the example below would be appeal to tradition. “Come on … everyone in this class smokes crack ... you should take a hit!” Individual crowd

9. Appeal to Feelings: Fear Appeal to Force or Fear: Supporting or avoiding a conclusion by threats Worst case: when debates get derailed by jeering or “shouting down” an arguer so that the argument can’t be heard. More subtle case: “I think we should choose xBox over Playstation because its online multiplayer stuff is better.” “How about I stomp your guts out? How would that be?” Committing Appeal to Fear is less an error in reasoning, more a bullying tactic. Either way, the response is irrelevant to the quality of the argument.

10. Appeal to Feelings: Pity Appeal to Pity (Argumentum ad Misericordiam): “I’m afraid going 70 in a 25mph zone means you deserve this ticket, Ms. Garcia.” “No, Judge, I have three kids, late bills, and work two jobs … I can’t deserve this speeding ticket!” Is the sorry state of the arguer logically relevant to deserving the ticket? Might the judge considering it in sentencing?

11. Absolutizing Rules Absolutizing Rules (Misapplying a Rule) “Yes I told the axe murderer where the little girl was! … if you check your bible, you’ll find Thou Shalt Not Lie”

12. Double Standards To have a double standard is to apply two different rules or judgments to one and the same thing or kind of thing. What a jerk! She totally shouldn’t be sitting with that guy when she has a boyfriend! Yeah, but you sit with Betty sometimes and you have a girlfriend! Yeah, but that’s different. I’m a guy!

13. Double Standards Notice the relationship with Tu Quoque, the “You too!” fallacy: • Having a double standard doesn’t make the claim “she’s a jerk” false. It still might be true. It simply means that if it’s true, “he’s a jerk” is true as well. • On the flip side, perhaps it’s false that “she’s a jerk” for sitting with a boy. It will follow that “he’s a jerk” for sitting with a girl is false.

14. Bifurcation (False) False Bifurcation: • False Dichotomy • Faulty Dilemma • Black and White Thinking • Either/Or fallacy • False Choice Either ice cream or tantrum … you choose! (from kid) Either exercise or heart attack … you choose! (from Doc) *Ultimatums are rarely False Bifurcations, but can be

15. Bifurcation (False) Note how premises are red, just like the conclusions. Bifurcation is a fallacy of presumption. With multiplication, 12 is either 6x2 or 4x3 … so, which is it, kid? When cooking chicken, it’s either frying or baking. So, what do you want to do? Note also there are many genuine bifurcations, trifurcations, tetrafurcations, etc.: Either the universe was created by an intelligent being or it is eternal or it had a natural origin. It’s either chocolate or vanilla … that’s all we have.

16. Hasty Judgment Missing the Point: “So, you say Bill punched Bob in the nose? All right, better get Bob straight to the emergency room!” Sometimes MtP is jumping to a distant conclusion. Sometimes MtP is just missing the point. “That’s a priceless Steinway! Not anymore.” “If you’re not out of here … in 5 seconds! ... Ah, I could easily be out of here in three!”

17. Hasty Generalization Hasty Generalization (Converse Accident): Taking a small sample, and inferring from it all or most of that kind are the same. “My cabbie in New York City was surly, so, all cabbies in NYC are surly.” Exceptions: • “This Root Beer, Roundy’s, is blah, so all Roundy’s Root Beer is blah.” • “This Pit Bull (Rottweiler, Tarantula, Python, etc.) is dangerous, so, all Pit Bulls (Rottweilers, Tarantulas, Pythons, etc.) are dangerous.”

18. Hasty Generalization Two more things regarding the logic of danger (#2): • When people say Pit Bulls, for instance, are dangerous, they plainly don’t mean to include dead ones, very old ones, very young ones. Their statement is perhaps elliptical for, “these healthy adult dogs can kill you and animals are unpredictable. Be on guard!” You must decide if a statement is straight-forward or elliptical based on context, knowledge of the speaker, or by asking, if possible. • Risk assessment logic: Risk assessments have 2 parts: • probability and, • severity. Some things have very low probabilities of harm, but are dangerous because of high severity. Commonly believed dangerous things: • your weird looking neighbor, • flying in a commercial jet, • driving a car without a seatbelt, • playing just one round of Russian Roulette, • hitchhiking. All have very low probabilities of harm. How then are they dangerous?

19. Quick Quiz: We should give that new position to Frank Thompson. Frank has six hungry kids to feed, and his wife needs an operation to save her eyesight.

20. Quick Quiz: Professor Pearson’s arguments in favor of the theory of evolution should be discounted. Pearson is a cocaine-snorting sex pervert and, according to some reports, a member of the communist party.

21. Quick Quiz: Some of you oppose the appointment of David Cole as new sales manager. Upon further consideration, I am sure you will find him suitable for the job. If not confirmed, it may be necessary to make severe personnel cutbacks in your department.

22. Quick Quiz: You should read Irving Stone’s latest novel right away. It has sold over a million copies, and nearly everyone in the Manhattan cocktail circuit is talking about it.

23. Quick Quiz: Actress Andie MacDowell says that it’s healthy to drink milk. But the dairy industry pays MacDowell thousands of dollars to make these ads. Therefore, we shouldn’t take her testimonials too seriously.

24. Quick Quiz: Dr. Morrison has argued that smoking is responsible for the majority of health problems in this country and that every smoker concerned about his or her health should quit. Unfortunately, however, we must consign Dr. Morrison’s argument to the trash bin. Only yesterday I saw none other than Dr. Morrison himself smoking a cigar.

25. Quick Quiz: If you give Jane a cookie, she’ll want a glass of milk. Then, she won’t be hungry for her supper!

26. Quick Quiz: Ellen is a mean drunk. I wouldn’t invite her to your kegger, if I were you.

27. Quick Quiz: Probably no life exists on Venus. Teams of scientists have conducted exhaustive studies on the planet’s surface and atmosphere, and no living organisms have been found.