Today s Tasks. 1. Argument 2. Fallacies: a. Ad Hominem b. Straw Man c. Appeal to ignorance d. Begging the Question

Transcription

1 Today s Tasks 1. Argument 2. Fallacies: a. Ad Hominem b. Straw Man c. Appeal to ignorance d. Begging the Question

2 Argument An argument is a collection of statements, some of which are intended as premises and one of which is intended as the conclusion. All humans are mortal. - premise Socrates is a human. - premise Socrates is mortal. - conclusion

3 Exercise 1 Callisto orbits Jupiter. Something must orbit a star in order to be a planet. If something orbits Jupiter, then it does not orbit a star. Therefore, Callisto is not a planet.

4 Exercise 2 The death penalty should be adopted only if it deters murder. However, it could only do this if murderers understood the consequences of their actions before acting, and since this is not so, we must reject the death penalty.

5 Argument vs. Claim 1 Situation 1 A: The death penalty should be abolished. B: The death penalty should be retained. Situation 2 A: The death penalty should be abolished because some innocent people are executed. B: The death penalty should be retained.

6 Argument vs. Claim 2 Situation 1 A: Continents move around. B: Continents don t move around. Situation 2 A: Continents move around because the coastline of eastern South America is similar to that of western Africa. B: Continents don t move around.

7 Moral 1. adjudicate, discover truths, persuade others 2. Present an argument in a debate. ex) paper, court

8 Fallacy A fallacy is an error in reasoning or a bad argument. We should try to avoid it when we are engaged in a debate.

9 Example 1 A: Plato argued that mathematical objects like circles and triangles are more real than physical objects like cups and trees. B: His theory is repugnant because he was a homosexual.

10 Example 2 Einstein: Space-time is curved near a massive object. After all, light bends near the sun. The Nazi: I reject your theory because you are a Jew.

11 Example 3 A: I believe that heat is molecular motion because if two pieces of cold metal are rubbed at high speed, they get hot. B: Your theory is objectionable because you have the greed to achieve fame with your new theory.

12 Ad Hominem(=Personal Attack) Ad hominem occurs when an attack is directed not at an argument but at an arguer.

13 Proper Response A morally bad person might have a true belief. For example, a serial killer( 유영철 ) may believe that the Earth is round. It is one thing that a scientist has a selfish motive. It is another that his theory is false.

14 Moral 1. We should separate an idea from a person in an intellectual debate. It is legitimate to criticize an idea, but not a person. 2. No personal question. ex) drug

15 Example 1 Jill: "We should clean out the closets. They are getting a bit messy." Bill: "Why? We went through those closets last year. Do we have to clean them out everyday?" Jill: "I never said anything about cleaning them out everyday."

16 Example 2 Darwin: Species have evolved by natural selection. All terrestrial organisms have descended from a common ancestor. Critic: Your theory is false because humans have not evolved from monkeys.

17 Straw Man The fallacy of straw man occurs when we attribute a problematic claim to a person which he did not make. We distorted, exaggerated, stretched, or misunderstood our opponent s position. We attacked not a real man but a straw man.

18 Morals We should analyze our opponent s position correctly and carefully before criticizing it. If our opponent s position is not clear, we should ask for a clarification. Always assume that our opponents are more reasonable and intelligent than we think.

19 Examples 1 & 2 There is no evidence that God does not exist. God exists. We don t know whether God exists or not. I ll believe that God exists.

20 Example 3 There is no evidence that you are not a communist. You are a communist.

21 Appeal to ignorance A premise states that there is no evidence, or that we don t know, but the conclusion makes a definite claim.

22 Proper Response Point out: Nothing follows from our ignorance. If you stated that there is no evidence, you should suspend your judgment as opposed to making a judgment one way or the other.

23 Moral A person who believes something bears the burden of proof. ex) prosecutor, theist I ll believe p until you prove p. (x)

24 Exercise 1 There are hostile aliens. We should be prepared for an attack by aliens. Is this argument an appeal to ignorance or not?

25 Exercise 2 God exists. We should go to church. Is this argument an appeal to ignorance or not?

26 Example 1 Theist: Whatever the bible says is true. Atheist: Why do you think so? Theist: Because the bible says whatever it says is true.

27 Example 2 Thief 1: Why do you take two gold rings? Thief 2: Because I am your boss. Thief 1: But why are you my boss? Thief 2: Because I have the two gold rings!

28 Example 3 A: How can he afford that nice car? B: Because he is rich. A: Well, why is he rich? B: Because he can afford that nice car!

29 Example 4 Women shouldn t fight bulls because a bullfighter should be a man.

30 Begging the Question To beg the question is to assume the truth of a claim in dispute in an attempt to prove it. p p p q

31 A large circle may go unnoticed. p s q r

32 Moral Don t take for granted the point under dispute. Instead, try to justify it with a different claim.

33 Question ( 김건희 ) Why should we avoid fallacies? People commit fallacies all the time in our real life.

34 Reply If you commit fallacies often, you will be ostracized from others. ( 박명곤 ) A fallacy leads us to a mistaken view. ( 이 다정 ) We are wasting our time, if we commit fallacies. ( 우승엽 )