Chapter 3 continued

1
Chapter 3 (continued)

• Evaluating Moral Arguments

2
Review

• Moral reasoning is ordinary critical reasoning
  applied to moral arguments.
• A statement (or claim) is the assertion that
  something is either true or false.
• an argument is a group of statements, one of
  which is supposed to be supported by the rest.
• The statement that is being supported by the
  others is the conclusion.
• The supporting statements are called premises.

3
Review

• Deductive Argument

• Inductive Argument

• Is supposed to give logically conclusive support
  for its conclusion
• Is valid on the condition that if its premises
  are true, then its conclusion must be true
• A valid argument with true premises is sound

• Is supposed to give probable support for its
  conclusion
• Is strong on the condition that if its premises
  are true, then its conclusion is probable
• A strong argument with true premises is cogent

4
Review

• VALID FORMS
• Affirming the antecedent
• Denying the consequent
• The hypothetical syllogism
• INVALID FORMS
• Denying the antecedent
• Affirming the consequent

5
Implied Premises

• When you evaluate an argument, you should try to
  explicitly state any implied premise whenever the
  following applies
• There seems to be a logical gap between premises.
• The missing material is not a commonsense
  assumption.

6
Implied Premises

• The premise that you provide in place of an
  implied premise should
• make the argument valid (when the argument is
  meant to be deductive) or strong (when its meant
  to be inductive)
• be plausible (as close to the truth as possible)
• be fitting (coincide with the authors intent)

7
Moral and Non-moral Statements

• A moral statement is a statement affirming that
  an action is right or wrong
• Capital punishment is wrong.
• Jena should not have lied.

8
Moral and Non-moral Statements

• A non-moral statement is a statement affirming
  that something is true or false, without
  assigning a moral value to it
• Many people think that capital punishment is
  wrong.
• Jena did not lie.

9
Moral Statements in Moral Arguments

• Every moral argument should offer at least one
  premise that is a moral statement.
• Without a moral premise, we cannot make a moral
  argument. We cannot establish what ought or
  should be based solely on what is.

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Non-moral Statements in Moral Arguments

• Every moral argument should also offer at least
  one premise that is a non-moral statement.
• We cannot infer a moral conclusion from a moral
  premise unless we have a non-moral premise that
  links the two.

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Testing Moral Premises

• To test a moral premise, look for counterexamples.

12
Testing Moral Premises

• Consider this premise
• Causing a persons death is wrong.

13
Testing Moral Premises

• Causing a persons death is wrong.
• To test this premise, consider all the possible
  circumstances under which it may be morally
  acceptable to cause a persons death
• --in self-defense
• --in war
• --to save thousands of other people

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Assessing Non-moral Premises

• Ensuring that non-moral premises are supported by
  good reasons is always worth the effort.

15
Assessing Non-moral Premises

• As you assess a non-moral statement, keep the
  following in mind
• Use reliable sources
• Beware when evidence conflicts
• Let reason rule

16
Avoiding Bad Arguments

• Bad arguments come in many shapes and sizes, but
  they all share in common one of the following two
  problems
• At least one false premise
• A conclusion that doesnt follow from its premises

17
Fallacies

• These very common types of bad argument can be
  persuasive, and are frequently used to mislead
  the unwary.

18
Fallacies

• Begging the Question
• Trying to use a statement as both a premise in an
  argument and the conclusion of that argument.

19
Fallacies

• Begging the Question (example)
• Women in Muslim countries are entitled to certain
  rights, including but not limited to suffrage.
  Therefore, all women in Muslim countries have the
  right to vote.

20
Fallacies

• Equivocation
• Assigning two different meanings to the same term
  in an argument.

21
Fallacies

• Equivocation (example)
• A fetus is an individual that is indisputably
  human. A human is endowed with rights that
  cannot be invalidated, including the right to
  life. Therefore, a fetus has a right to life.
• The equivocation hinges on the two different
  meanings of human asserted here.

22
Fallacies

• Appeal to Authority
• Citing as an expert someone who is either not an
  expert in the relevant field or is a non-expert

23
Fallacies

• Appeal to Authority (example)
• As Katie Couric noted in a recent interview, the
  likelihood of being killed by a gun in the United
  States is ten times greater than the likelihood
  of being killed by any violent means in Germany,
  where gun-control regulations are very strict.

24
Fallacies

• Slippery Slope
• Arguing that a particular action will inevitably
  lead to other actions that are disastrous

25
Fallacies

• Slippery Slope (example)
• Rampant proliferation of pornography on the
  Internet leads to an obsession with pornographic
  materials. Obsession with pornographic materials
  disrupts relationships, leads to divorce, and
  ultimately destroys society. Therefore, we should
  ban pornography.

26
Fallacies

• Faulty Analogy
• Arguing that because two things are alike in one
  way, they must be alike in some additional way

27
Fallacies

• Faulty Analogy (example)
• Humans feel pain, care for their young, live in
  social groups, and can use complex language.
  Apes also feel pain, care for their young and
  live in social groups. Therefore, apes must also
  be able to use complex language.

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Fallacies

• Appeal to ignorance
• Arguing that we can believe a claim because of a
  lack of evidence for its contrary

29
Fallacies

• Appeal to ignorance (example)
• It is obviously false that a fetus is a person,
  because science has not proven that it is a
  person.

30
Fallacies

• Straw Man
• Misrepresenting someones claim or argument so it
  can be more easily refuted

31
Fallacies

• Straw Man (example)
• Actual statement
• We should adopt a code of ethics for our
  professional society that is essentially secular,
  so that it can be used by all of our members,
  regardless of their religious beliefs.
• Straw-man characterization
• Clearly, our colleague wants to strip religious
  faith away from every member of our profession
  and to banish religion entirely from the realm of
  ethics.

32
Fallacies

• Appeal to the person (ad hominem)
• Arguing that a claim should be rejected solely
  because of the characteristics of the person who
  makes it

33
Fallacies

• Appeal to the person (example)
• Why should we listen to anything Bill Clinton has
  to say about ethical issues? Hes a rotten
  philanderer!

34
Fallacies

• Hasty generalization
• Drawing a conclusion about an entire group of
  people or things based on an undersized sample of
  the group

35
Fallacies

• Hasty generalization (example)
• In the past thirty years, at least two people on
  death row in this state have been executed and
  later found to be innocent by DNA evidence. Why
  is the state constantly executing innocent people?

36
Quiz 1 Answers

• 1. Ethics, or moral philosophy, is
• c. The philosophical study of morality
• 2. Things that are valuable because they are a
  means to something else are said to be
• b. Instrumentally valuable
• 3. The principle of universalizability demands
  that a moral statement that applies in one
  situation must apply in
• d. All other situations that are relevantly
  similar
•  
• 4. The idea that something is right only if God
  wills it to be so is known as...
• c. Divine command theory
•  
• 5. In the Euthyphro, Socrates argues that
• b. Piety cannot be properly defined as that
  which is dear to the gods

37
Quiz 1 Answers

• 6. The doctrine that some moral norms are valid
  for everyone (in other words, universal) is...
• c. Ethical objectivism
•  
•  7. Subjective relativism
• c. Implies that moral disagreements cannot
  happen
•  
•  8. The view that moral statements are neither
  true nor false, but are instead expressions of
  feelings or sentiments is called...
• b. Emotivism
•  9. Cultural relativism is the view that an
  action is morally right if
• b. Ones culture approves of it
•  
• 10.Ruth Benedict argues that
• d. Normality is, within a very wide range,
  culturally
• defined