Logic and Contemporary Rhetoric

Logic and Contemporary Rhetoric

LOGIC AND CONTEMPORARY RHETORIC:

THE USE OF REASON IN EVERYDAY LIFE

STUDY GUIDE

CHAPTER 1

GOOD AND BAD REASONING

  1. Brief Chapter Outline
  1. Reasoning and Arguments

Exercise 1-1

  1. Exposition and Argument

Exercise 1-2

  1. Cogent Reasoning

Believable Premises

No Relevant Information Passed Over

Valid Reasoning

  1. Two Basic Kinds of Valid Arguments

Deductive Validity

Inductive Validity

Exercise 1-3

  1. Some Wrong Ideas about Cogent Reasoning
  2. Background Beliefs
  3. Kinds of Background Beliefs
  4. Worldviews or Philosophies
  5. Insufficiently Grounded Beliefs

Exercise 1-4

Exercise 1-5

Exercise 1-6

Exercise 1-7

Exercise 1-8

  1. Two Vital Kinds of Background Beliefs

The Nature of Human Nature

The Reliability of Information Sources

  1. Science to the Rescue

Exercise 1-9

Summary of Chapter 1

  1. List of Key Terms

Argument

Background beliefs

Claim

Conclusion

Correct

Deductively valid

Exposition

Fallacious

Form

Induction

Inductively valid

Modus ponens

Philosophies

Premises

Reasoning

Valid

Warranted

Worldviews

  1. Chapter Summary

In this Chapter the authors note that reasoning is the essential ingredient in problem solving, and that since this is so we need to know how to distinguish good, cogent, reasoning from bad, fallacious, reasoning. They begin their discussion of this by outlining the structure of an argument, noting that all arguments have premises and a conclusion, and distinguishing arguments from exposition.

They then distinguish between cogent and fallacious reasoning, noting that we reason cogently when our premises are believable, we consider all likely relevant information, and our reasoning is valid. Here, they distinguish between two basic kinds of valid arguments; those that are deductively valid, and those that are inductively valid. They then outline some common mistakes about cogent reasoning, such that what counts as good reasoning is “culturally relative,” or “individually relative”.

Returning to their discussion of cogent reasoning the authors note that whether one’s premises are believable, and whether one is using all relevant information, will depend upon one’s background beliefs. These beliefs can pertain to matters of fact, and beliefs about values. They can also be divided into those that are true and those that are false; they also differ in how firmly they should be held. The most deeply ingrained of a person’s background beliefs tend to be those that constitute her worldview or her philosophy. We need to make sure that these beliefs are well-grounded, and so we need to examine them, as well as our other background beliefs. Of these, two kinds are especially important; those that concern the nature of human nature, and those that concern the reliability of information sources. We should recognize that the most accurate information that we have comes from the well-established sciences of physics, chemistry, and biology, as well as to a lesser extent psychology.

  1. Practice Questions
  1. Objective Multiple Choice
  1. The essential ingredient in problem-solving is
  1. Information
  2. Reasoning
  3. Values
  4. Knowledge
  1. The claim made by an argument is its
  1. Form
  2. Conclusion
  3. Premise
  4. Value
  1. An argument
  1. Will only have two premises
  2. Will always stand alone
  3. Will always have a conclusion
  4. Will always be correct
  1. We reason cogently only when
  1. Our premises are warranted, we consider all likely information, and our reasoning is valid
  2. Our premises are warranted, we consider all likely information, and our reasoning is deductive
  3. Our premises are warranted, we consider some likely information, and our reasoning is valid
  4. Our premises are warranted, we consider all likely information, and our reasoning is inductive
  1. A bad argument is a
  1. Fallacious one
  2. Valid one
  3. Inductive one
  4. Deductive one
  1. The first condition of cogent reasoning requires
  1. That we use our background beliefs to assess the premises of the argument we are evaluating
  2. That we assess the logical form of the argument that we are evaluating
  3. That we reject our background beliefs prior to assessing the premises of the argument we are evaluating
  4. That we use background beliefs to assess the conclusion of the argument we are evaluating
  1. The second criterion of cogent reasoning requires that we
  1. Do not pass over any relevant information
  2. Ignore relevant information
  3. Assess the form of the argument
  4. Assess the conclusion of the argument
  1. The third criterion of cogent reasoning requires that
  1. The premises of the argument in question are all true
  2. The premises of the argument in question fit with our background beliefs
  3. The premises of the argument in question have the correct form
  4. The premises of the argument in question genuinely support its conclusion
  1. Validity concerns
  1. The connection between the premises and the reader’s background beliefs
  2. The connection between the premises and the conclusion of the argument
  3. The truth of the premises
  4. The truth of the conclusion
  1. The fundamental property of a deductively valid argument is
  1. That if all of its premises are true, then its conclusion must be true also
  2. That if its conclusion is true, then its premises must be true
  3. That if all of its premises are true, then its conclusion is likely to be true
  4. That if all of its premises are false, then its conclusion is likely to be false
  1. The idea behind valid induction is that of
  1. Learning from mistakes
  2. Learning from logic
  3. Learning from experience
  4. Learning from books
  1. Good reasoning is
  1. Culturally relative
  2. Gender relative
  3. Individually relative
  4. Not relative
  1. Ignorance is
  1. Bliss
  2. Not bliss
  3. Necessary to evaluate arguments
  4. Included in our background beliefs
  1. Background beliefs
  1. Are always true
  2. Are always false
  3. Can be true or false
  4. Are neither true nor false
  1. Background beliefs
  1. Can be about matters of fact and matters of value
  2. Are always about matters of fact
  3. Are always about matters of value
  4. Cannot be about both matters of facts and matters of value
  1. The beliefs that are most deeply ingrained in us are an important part of our
  1. Worldview, or philosophy
  2. Worldview, but not philosophy
  3. Philosophy, but not worldview
  4. Value system
  1. Two kinds of background beliefs that are extremely important concern
  1. Personal preferences and religious views
  2. Personal preferences and the nature of human nature
  3. The nature of human nature and the reliability of information sources
  4. The nature of human nature and religious views
  1. We cannot assume
  1. That a source is reliable without some reason for thinking this
  2. That science is any better than intuition in giving accurate information
  3. That logic works in all cases
  4. That science is gender-neutral
  1. The most reliable information we have comes from
  1. Well-established religion
  2. Well-established science
  3. Personal intuition
  4. Personal judgments
  1. Common everyday sayings
  1. Contain some wisdom
  2. Are fallacious
  3. Are completely correct
  4. Should be rejected
  1. True/False
  1. Bad reasoning is fallacious reasoning
  1. Valid deductive arguments always have true conclusions
  1. Invalid deductive arguments can have true conclusions
  1. Masculine logic is different from feminine logic
  1. Science is a very reliable source of information
  1. Our background beliefs are immune from criticism
  1. Freud was right about everything
  1. Psychology is not as well-established a science as physics
  1. Cogent reasoning involves warranted premises
  1. Inductive arguments ignore experience
  1. How the world works depends on the sex of the person evaluating it
  1. Philosophers all agree that there are objective moral truths
  1. We have no background beliefs concerning the nature of human nature
  1. All information sources are equally reliable
  1. Expositions sometimes contain implicit arguments
  1. Fill-in-the-Blanks
  1. The purpose of Logic and Contemporary Rhetoric is not to ______.
  1. The statements in an argument that give reasons for accepting the conclusion are called _____.
  1. Conclusions are sometimes signaled by words such as ____ [thus], _____ [therefore], or ______.
  1. Expressions such as “It has been observed that…” are used to indicate _____ .
  1. According to the authors, it would be a mistake to think that talk was generally _____.
  1. It is important to understand the difference between rhetoric that is primarily argumentative and that which is mainly ______.
  1. It is the ____ of an argument that makes it deductively valid
  1. Background beliefs can be divided up ______.
  1. We need to examine our background beliefs for ______and ______.
  1. ______plays a central place in modern life.
  1. Essay Questions
  1. Identify one of your most basic background beliefs. Under what circumstances do you think you could be moved to reject this belief? Could you be argued out of holding it? Would you be moved to reject it if certain evidence was presented to you? If you did reject this belief, how would this effect your other beliefs about the world?
  1. Outline the main differences between inductive reasoning and deductive reasoning. Are there any areas of life in which one form of reasoning might be more useful than the other? Explain your view.
  1. Is science based upon inductive reasoning, or deductive reasoning, or a combination of both? Drawing from the Chapter’s discussion of these two types of reasoning, do you think that science can give us absolutely certain knowledge? Why, or why not?
  1. Is reasoning relative to the sex, race, or personality of the person who uses it? Explain your view fully.
  1. How can reasoning be misused, either deliberately or unintentionally? Provide examples of each type of misuse, making it clear why the reasoning in question is bad.
  1. Additional Sources for Study and Research
  1. InfoTrac Search Terms

Analogy, Aristotelian (Logic), Claims, Contingency, Fallacies, Logic, Critical Thinking, Syllogism, Hypothetical Syllogism, Induction, Informal Logic, Probability, Thesis, Valid.

  1. Internet Sites

Stanford Encyclopedia of Philosophy

http://plato.stanford.edu/

Internet Encyclopedia of Philosophy

http://www.iep.utm.edu/

Wikipedia; Logic entry

Factasia Logic

  1. Answer Key
  1. Objective Multiple Choice

1. b

2. b

3. c

4. a

5. a

6. a

7. a

8. d

9. b

10. a

11. c

12. d

13. b

14. c

15. a

16. a

17. c

18. a

19. b

20. a

  1. True/False

1. F

2. F

3. T

4. F

5. T

6. F

7. F

8. T

9. T

10. F

11. F

12. F

13. F

14. F

15. T

  1. Fill-in-the-Blanks

1. alter student’s political views

2. premises

3. thus, therefore, consequently

4. premises

5. aimless

6. expository

7. form

8. in many different ways

9. consistency, believability

10. science

CHAPTER 2

MORE ON DEDUCTION AND INDUCTION

  1. Brief Chapter Outline
  1. Deductive Validity

Exercise 2-1

  1. Deductive Invalidity

Exercise 2-2

  1. Syllogisms

Exercise 2-3

  1. Indirect Proofs
  2. Tautologies, Contradictions, and Contingent Statements

Exercise 2-4

  1. Inductive Validity (Correctness) and Invalidity (Incorrectness)

Reasoning by Analogy

Statistical induction

Higher-level Inductions

Reasoning to Causal Connections

Concatenated inductions

Exercise 2-5

  1. A Misconception About Deduction and Induction
  2. Reasoning Cogently Versus Being Right in Fact

Summary of Chapter 2

  1. List of Key Terms

Affirming the consequent

Analogy

Categorical proposition

Causes

Concatenated

Contingent

Contradiction

Denying the antecedent

Disjunctive syllogism

Higher-level induction

Hypothetical syllogism

Indirect proof

Induction by enumeration

Major term

Middle term

Minor term

Modus ponens

Modus tollens

Mood

Particular affirmative

Particular negative

Predicate class

Proof

Reductio ad absurdum

Statistical induction

Structure

Subject class

Syllogisms

Tautology

Thesis

Universal affirmative

Universal negative

  1. Chapter Summary

In this Chapter the authors outline various different forms of argument, including modus tollens, modus ponens, hypothetical syllogism, and disjunctive syllogism. They then outline the concepts of validity and invalidity, and outline the fallacies of denying the antecedent and affirming the consequent. They then discuss further traditional syllogistic logic, noting that categorical propositions assert or deny relationships between a subject class and a predicate class; these assertions or denials give rise to four kinds of categorical propositions. Having discussed syllogistic logic the authors then discuss indirect reasoning, and then the definitions of tautologies, contradictions, and contingent statements, offering examples of each.

The authors then move from deductive logic to discuss inductive validity and invalidity. Here, they outline various types of induction, including induction by enumeration, reasoning by analogy, statistical induction, higher-level inductions, reasoning to causal connections, and concatenated inductions. They then note that it is not true that in deductive reasoning we go from the general to the particular, while in inductive reasoning we go from the particular to the general. They then discuss the difference between reasoning cogently and being right in fact.

  1. Practice Questions
  1. Objective Multiple Choice
  1. “If A, then B. A. Therefore B” is an example of the argument form
  1. Modus ponens
  2. Modus tollens
  3. Hypothetical syllogism
  4. Disjunctive syllogism
  1. “If A, then B. Not B. Therefore, Not A” is an example of the argument form
  1. Modus ponens
  2. Modus tollens
  3. Hypothetical syllogism
  4. Disjunctive syllogism
  1. “If A then B. If B then C. Therefore, if A, then C” is an example of the argument form
  1. Modus ponens
  2. Modus tollens
  3. Hypothetical syllogism
  4. Disjunctive syllogism
  1. “A or B. Not A. Therefore, B” is an example of the argument form
  1. Modus ponens
  2. Modus tollens
  3. Hypothetical syllogism
  4. Disjunctive syllogism
  1. “If A then B. Not A. Not B” is an example of the fallacy of
  1. Denying the antecedent
  2. Affirming the consequent
  3. Hypothetical syllogism
  4. Disjunctive syllogism
  1. “If A then B. B. Therefore, A” is an example of the fallacy of
  1. Denying the antecedent
  2. Affirming the consequent
  3. Hypothetical syllogism
  4. Disjunctive syllogism
  1. A categorical proposition is
  1. An unconditional offer
  2. A subject-predicate proposition
  3. A syllogistic proposition
  4. A conditional offer
  1. The predicate of the conclusion in a syllogism is the syllogism’s
  1. Major term
  2. Minor term
  3. Middle term
  4. Propositional term
  1. The subject of the conclusion in a syllogism is the syllogism’s
  1. Major term
  2. Minor term
  3. Middle term
  4. Propositional term
  1. The term that occurs in each premise but not in the conclusion is the syllogism’s
  1. Major term
  2. Minor term
  3. Middle term
  4. Propositional term
  1. “Some S are P” is a
  1. Universal affirmative proposition
  2. Universal negative proposition
  3. Particular affirmative proposition
  4. Particular negative proposition
  1. “No S are P” is a
  1. Universal affirmative proposition
  2. Universal negative proposition
  3. Particular affirmative proposition
  4. Particular negative proposition
  1. “All S are P” is a
  1. Universal affirmative proposition
  2. Universal negative proposition
  3. Particular affirmative proposition
  4. Particular negative proposition
  1. A particular negative proposition is an
  1. A proposition
  2. E proposition
  3. I proposition
  4. O proposition
  1. A universal affirmative proposition is an
  1. A proposition
  2. E proposition
  3. I proposition
  4. O proposition
  1. A universal negative proposition is an
  1. A proposition
  2. E proposition
  3. I proposition
  4. O proposition
  1. “No dogs are smart” is an example of a
  1. Universal affirmative proposition
  2. Universal negative proposition
  3. Particular affirmative proposition
  4. Particular negative proposition
  1. “Some parrots are not linguists” is an example of an
  1. A proposition
  2. E proposition
  3. I proposition
  4. O proposition
  1. A contradiction is a statement
  1. That is necessarily true
  2. That can be true or false
  3. That is neither true nor false
  4. That is necessarily false
  1. “Either you will pass this class or you won’t pass this class” is an example of
  1. A tautology
  2. A contradiction
  3. A contingent statement
  4. A false statement
  1. True/False
  1. In induction by enumeration, we reason from the fact that all As observed so far have been Bs to the conclusion that all are Bs.
  1. In induction by enumeration, a greater sample size yields lower probability.
  1. More than one counterexample is needed to shoot down induction by enumeration.
  1. Higher-level inductions are used to evaluate those that are more general.
  1. Statistical induction is a weak form of induction.
  1. Concatenated reasoning joins together inductions and deductions to find a pattern.
  1. If you reason correctly you will always get a true conclusion.
  1. If you have a true conclusion you will have reasoned correctly.
  1. Deductively valid reasoning progresses from the general to the particular.
  1. It is not the case that inductively valid reasoning goes from the particular to the general.
  1. “No As are Bs” is a universal negative statement.
  1. “Some Ps are Qs” is a universal affirmative statement.
  1. Denying the antecedent is a fallacy.
  1. “If A, then B. B. Therefore, A” is an example of modus tollens.
  1. When we reason inductively we are often looking for causes.
  1. Fill-in-the-Blanks
  1. An argument that doesn’t have a deductively valid form is said to be _____.
  1. The fallacy of affirming the consequent is of the form _____ .
  1. A hypothetical syllogism is not a true ____ .
  1. A categorical proposition expresses a relationship between a _____ class and a ____ class.
  1. “No men are mortal” is a ______proposition.
  1. Every syllogism has _____ terms.
  1. Indirect proofs are sometimes called ______proofs.
  1. “Barry Bonds didn’t take steroids” is a ______statement.
  1. Only _____ resemblances count in drawing correct analogies.
  1. Unfortunately, we can reason correctly and get a ______conclusion.
  1. Essay Questions
  1. Why were hypothethical syllogisms not considered to be syllogism by Aristotle? In answering this question you should explain Aristotle’s reasoning, and not merely state his view. Does this affect their potential validity in any way?
  1. Provide an example of concatenated reasoning that draws on at least four different types of reasoning process, and evaluate it for correctness.
  1. It is often claimed that deductive reasoning moves from the general to the particular, while inductive reasoning moves from the particular to the general. Do you agree with this view? Explain your answer, taking care to explain why some people might be persuaded by this account of deductive and inductive reasoning.
  1. If it is possible for us to reason correctly and yet be wrong in fact, what is the use of reasoning at all? Explain your answer, and provide examples to illustrate it.
  1. Provide an example of two different deductively invalid arguments, and explain where they go wrong.
  1. Additional Sources for Study and Research
  1. InfoTrac Search Terms

Analogy, Antecedent, Causality, Claims, Disjunctive Syllogism, Fallacies, Hypothetical Syllogism, Induction, Inductive Reasoning, Necessity, predicate, Premise, Probability, Medieval Logic, Reasoning, Syllogism, Tautology, True, Valid.

  1. Internet sites

Wikipedia; inductive reasoning

Wikipedia; deductive reasoning

Sparknotes: inductive and deductive reasoning

Informal fallacies

http://www.drury.edu/ess/Logic/Informal/Overview.html

  1. Answer Key
  1. Objective Multiple Choice

1. a

2. b

3. c

4. d

5. a

6. b

7. b

8. a

9. b

10. c

11. c

12. b

13. a

14. d

15. a

16. b

17. b

18. d

19. d

20. a

  1. True/False

1.T

2. F

3. F

4. F

5. F

6. T

7. F

8. F

9. F

10. T

11. T

12. F

13. T

14. F

15. T

  1. Fill-in-the-Blanks

1. Deductively invalid

2. If A, then B, B, therefore A

3. syllogism

4. subject/predicate

5. universal negative

6. three

7. reductio ad absurdum

8. contingent

9. relevant

10. false

CHAPTER 3

FALLACIOUS REASONING—1

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