1 PHIL102 SUM2014, M-F12:00-1:00, SAV 264 Instructor: Benjamin HoleOffice Hours: M-F1-1:15

2 Reading Arguments PhilosophicallyToday’s Agenda Clicker Quiz How to do the readings Basics of philosophical argumentation Classic argumentative forms and fallacies Practice argument reconstructions

3 Please set your Turning Technology Clicker to channel 41QUIZ Please set your Turning Technology Clicker to channel 41 Press “Ch”, then “41”, then “Ch”

4 Is the following argument validIs the following argument valid? “If Lincoln was killed in an automobile accident, then Lincoln is dead. Lincoln was killed in an automobile accident. Therefore, Lincoln is dead.” Yes No

5 Modus ponens (affirming the antecedent) What is the form if this argument? “If Lincoln was killed in an automobile accident, then Lincoln is dead. Lincoln was killed in an automobile accident. Therefore, Lincoln is dead.” Modus ponens (affirming the antecedent) Modus tollens (denying to consequent) Affirming the consequent Denying the antecedent None of the above

6 Is the following argument validIs the following argument valid? “If Lincoln was killed in an automobile accident, then Lincoln is dead. Lincoln was not killed in an automobile accident. Therefore, Lincoln is not dead.” Yes No

7 how should you read? Your goal is to:understand the arguments, and then critically evaluate the arguments.

8 how should you read? Jim Pryor’s three-pass method:Find the text’s conclusion(s) and get a sense of its argumentative structure Go back and read it carefully Evaluate the author's arguments

9 What is an argument? An argument is a pattern of reasoning in which premises are offered as reasons to believe in the truth of a conclusion. conclusions.

10 What is an argument? An argument is a pattern of reasoning in which premises are offered as reasons to believe in the truth of a conclusion. f conclusions. Premises: reasons (propositions) offered to support the conclusion.

11 What is an argument? An argument is a pattern of reasoning in which premises are offered as reasons to believe in the truth of a conclusion f conclusions. Premises: reasons (propositions) offered to support the conclusion. Conclusion: what the premises are supposed to provide reason to believe.

12 Deductive argument. The premises intend to guarantee the conclusion.Inductive argument. The truth of the premises gives us probabilistic reason to believe in the truth of the conclusions. Two Kinds of Argument

13 Two Kinds of Argument: Deductive argument. The premises intend to guarantee the conclusion. Example: 1. Socrates is a man 2. All men are mortal 3. Therefore, Socrates is mortal This is a good deductive argument; if you grant premises, you can’t avoid the conclusion.

14 Two Kinds of Argument: Inductive argument. The truth of the premises gives us probabilistic reason to believe in the truth of the conclusions. Example: 1. Every January I’ve seen in Seattle has been rainy. 2. This January in Seattle will probably be rainy. This is a good inductive argument. It’s evidence for the conclusion, but not a certain proof.

15 Form & Content Deductive argumentsWhat makes a deductive argument a good one? Form & Content

16 Form & Content Deductive argumentsWhat makes a deductive argument a good one? Form. Is it impossible for the premises to be true while the conclusion is false? If so, this is a valid argument. An argument is valid if and only if the truth of the premises guarantees the truth of the conclusion. Form & Content

17 Form & Content Deductive argumentsWhat makes a deductive argument a good one? Is it impossible for the premises to be true while the conclusion is false? If so, this is a valid argument. Example: 1. If Socrates is a Martian, then Socrates has green skin. 2. Socrates is a Martian. 3. Therefore, Socrates has green skin. What’s wrong with this argument? It’s valid, but the premises aren’t true. Form & Content

18 Form & Content Deductive argumentsWhat makes a deductive argument a good one? Content. The second requirement is that the argument be valid and the premises true. That makes the argument sound. An argument is sound if and only if it is valid and has all true premises. Form & Content

19 Form & Content Deductive argumentsWhat makes a deductive argument a good one? So the second requirement is that the argument be valid and the premises true. That makes the argument sound. Example (once again): 1. If Socrates is a man, then Socrates is mortal 2. Socrates is a man 3. Therefore, Socrates is mortal Form & Content

20 When you read philosophy:Evaluate the argument’s form. Reconstruct the argument. Are the premises and conclusion connected in the right way? Evaluate the argument’s content. Are the premises true? And, similarly, when we criticize arguments, we’re going to try to show that they aren’t sound. Form & Content

21 Important Forms of Argument1. Modus Ponens 2. Modus Tollens 3. Syllogism 4. Disjunctive Syllogism Important Forms of Argument

22 MoPo Important forms of argumentIf Socrates is a man, then Socrates is mortal Socrates is a man Therefore, Socrates is mortal We can formalize this, to show the structure: A => B A Therefore B This is called modus ponens. It doesn’t matter what we put into A or B. MoPo

23 MoTo Important forms of argumentIf Socrates is a Martian, then Socrates has green skin. Socrates does not have green skin. Therefore, Socrates is not a Martian We can formalize this, to show the structure: A => B Not B Therefore not A This is called modus tollens. It doesn’t matter what we put into A or B. MoTo

24 Syllogism Important forms of argumentAll men are mortal. Socrates is a man. Therefore, Socrates is mortal. We can formalize this, to show the structure: All As are Bs C is an A Therefore C is a B This is called a syllogism. It doesn’t matter what we put into A or B. Syllogism

25 DS Important forms of argumentEither Socrates is dead, or he has mystic powers of survival. Socrates does not have mystic powers of survival. Therefore, Socrates is dead. A or B Not B Therefore A This is called the disjunctive syllogism. It doesn’t matter what we put into A or B. DS

26 Fallacies Affirming the consequent Denying the antecedentBegging the question Fallacies

27 These are the first two fallacies we’re looking at:Affirming the consequent Denying the antecedent

28 AtC Affirming the ConsequentIf Socrates is a man, then Socrates is mortal Socrates is mortal Therefore, Socrates is a man A => B B Therefore A This is called affirming the consequent. AtC

29 “I’ve just read about a disease that has absolutely no symptoms, and kills you within the day. I feel fine, so I’m going to be dead by this evening.” AtC

30 DtA Denying the AntecedentIf Socrates is an American citizen, then Socrates is a human. Socrates is not an American citizen. Therefore, Socrates is not a human A => B Not A Therefore not B This is called denying the antecedent. DtA

31 “People who eat broken glass get sick and die“People who eat broken glass get sick and die. I don’t eat broken glass, so I guess I’m immortal.” DtA

32 What’s wrong with this? “Of course the Bible is God’s word. The Bible says so, and God wouldn’t lie.”

33 What’s wrong with this:“Of course the Bible is God’s word. The Bible says so, and God wouldn’t lie.” This is the fallacy known as begging the question. It means to assume as a premise what is being argued for in the conclusion.

34 * Note that begging the question isn’t the same as asking for a question, in philosophical terms - despite the use of the phrase in ordinary language. Begging the question means that you’ve used what you’re trying to argue for as a premise in your argument. Further Example: “Why should we give criminals the right to a fair trial? When they committed crimes, they showed us that they don’t care about our rights!”

35 Is this argument is valid:Is this argument is valid:? “If utilitarianism is true, then sometimes it is morally permissible to murder innocent people (to serve the greater good). Utilitarianism is true. Therefore, sometimes it is morally permissible to murder innocent people. ” True False

36 reconstructing arguments

37 Reconstructing argumentsRead the passage carefully (more than once) Identify the conclusion Identify the premises. (Consider the conclusion and ask yourself what the author needs to do to prove it. ) Sketch out a formal reconstruction of the argument as a series of steps.

38 It is morally wrong to steal a loaf of bread to feed your starving family and loved ones.Strongly Agree Agree Somewhat Agree Neutral Somewhat Disagree Disagree Strongly Disagree

39 The rightness or wrongness of an action does not depend on its consequences.Strongly Agree Agree Somewhat Agree Neutral Somewhat Disagree Disagree Strongly Disagree

40 It is morally wrong to make yourself an exception to a rule (e. gIt is morally wrong to make yourself an exception to a rule (e.g., cutting in line). Strongly Agree Agree Somewhat Agree Neutral Somewhat Disagree Disagree Strongly Disagree

41 Theorizing about ethics can help provide practical guidance.Strongly Agree Agree Somewhat Agree Neutral Somewhat Disagree Disagree Strongly Disagree

42 I am skeptical about ethical theory.Strongly Agree Agree Somewhat Agree Neutral Somewhat Disagree Disagree Strongly Disagree