Critical Thinking: Chapter 4

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Critical Thinking Chapter 4

• Credibility

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Credibility

• Are you gullible?

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Credibility

• Are you gullible?
• Do you get taken advantaged of?

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Credibility

• Are you gullible?
• Do you get taken advantaged of?
• Do people think you are naïve?

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Credibility

• Are you gullible?
• Do you get taken advantaged of?
• Do people think you are naïve?
• Are you trusting? Is there anything wrong with
  being trusting?

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Credibility

• Are you gullible?
• Do you get taken advantaged of?
• Do people think you are naïve?
• Are you trusting? Is there anything wrong with
  being trusting?
• Are you a skeptic?

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Credibility

• Are you gullible?
• Do you get taken advantaged of?
• Do people think you are naïve?
• Are you trusting? Is there anything wrong with
  being trusting?
• Are you a skeptic?
• These are the type of questions we are going to
  look at in this chapter.

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Credibility

• Is a claim credible or not?
• Basically credibility comes in degrees.

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Credibility

• It is very difficult to judge the credibility of
  a person just by looking at them.

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Credibility

• 1st general principle It is reasonable to be
  suspicious if a claim either lacks credibility
  inherently or comes from a source that lacks
  credibility.
• So there are two issues here When does a claim
  lack credibility and when does a source lack
  credibility?

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Credibility

• 2nd general principle A claim lacks inherent
  credibility to the extent it conflicts with what
  we have observed or what we think we know (our
  background information), or with other credible
  claims.

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Assessing the Contents of the Claim

• Does the claim conflict with our personal
  observations?

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Four Issues with observations

• The problem is that we are aware that observation
  is a trick business. There are four issues with
  observations
• 1. Observations depend on the conditions under
  which they are made.

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Four Issues with observations

• 1. Observations depend on the conditions under
  which they are made.
• For Example Perhaps the lighting is poor or the
  room is noisy perhaps we are distracted,
  emotionally upset, or mentally fatigued.

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Four Issues with observations

• 2. The power of observation can differ with
  peoples expertise and experience.
• For Example Some people have special training or
  experience that makes them better observers.

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Four Issues with observations

• 3. Expectations often influence observation.
• For Example We overlook many of the mean and
  selfish actions of the people we love. By
  contrast, people we detest can hardly do anything
  that we dont perceive as mean and selfish.

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Four Issues with observations

• 4. An observation made in the past suffers from
  the same dangers of unreliability as memory in
  general.
• Critical thinkers are always alert to the
  possibility that what they remember having
  observed may not be what they did observe!

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Does the claim conflict with our background
information?

• Background information includes all the general
  and specific facts we have learned through our
  lives. Three points to remember

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Does the claim conflict with our background
information?

• Background information includes all the general
  and specific facts we have learned through our
  lives. Three points to remember
• 1. Together with direct observation, background
  information forms the ground against which to
  pose any new claim.

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Does the claim conflict with our background
information?

• Background information is that immense body of
  justified beliefs that consists of facts we learn
  from our own direct observation and facts we
  learn from others.

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Background information

• Much of our background information is well
  confirmed by a variety of sources. Factual claims
  that conflict with this store of information are
  usually quite properly dismissed.

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Background information

• For Example We immediately reject the claim
  Palm trees grow in abundance near the North
  Pole, even though we are not in a position to
  confirm or disprove the statement by direct
  observation.

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Does the claim conflict with our background
information?

• Three points to remember
• 1. Together with direct observation, background
  information forms the ground against which to
  pose any new claim.

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Does the claim conflict with our background
information?

• Three points to remember
• 2. When two claims conflict, the burden of proof
  lies on the one with less initial plausibility.
  We have reason to be more skeptical.
• Example A claim that two people swam a mile in
  cold water, one person is 21 and the other person
  is 91.

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Does the claim conflict with our background
information?

• 3. It is important to remember that we dont have
  all the background information we need and some
  of our information may be false.
• The single most effective means of increasing
  your ability as a critical thinker, regardless of
  the subject, is to increase what you know.

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Assessing the credibility of sources

• The guiding principle in evaluating claims
  requires that they come from credible sources.
  The credibility of people is usually a matter of
  their knowledge on one hand, and their
  truthfulness, accuracy, and objectivity on the
  other. Seven points

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Sharpening and Leveling

• The reports people give one another are very
  frequently subject to innocent sharpening and
  leveling--exaggerating what the speaker thinks is
  the main point and dropping out or de-emphasizing
  details that seem unimportant. The result can be
  a distortion of the story.

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Assessing the credibility of sources 3 points

• 1. Be wary of eyewitness accounts. Untrained
  observers are more likely to exaggerate their
  observations.
• Example Several people seeing the same event
  will often describe it differently!

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Assessing the credibility of sources 3 points

• 2. How we feel about an experience colors our
  ability to discern objectively.
• Example if we really like a band, it may be
  difficult to give an objective review of their
  latest album.

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Assessing the credibility of sources 3 points

• 3. Look for expert knowledge.
• Example Look for education, training,
  experience, accomplishments, reputation, and
  titles.
• Cautions about experts Just because someone is
  an expert in one thing does not make them an
  expert in all things!

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The news media and the internet

• Our abundance of sources of information is a good
  thing, but it can be complicated when trying to
  figure out what we can trust and believe. Five
  points

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The news media and the internet 5 points

• 1. Most talk shows have a specific political
  agenda.
• Look for documentation of sources.

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The news media and the internet 5 points

• 2. The traditional news media has to be watched
  for both length and depth of coverage.
• The accessibility of reliable reports also
  restricts coverage because governments,
  corporations, and individuals often withhold
  information.

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The news media and the internet 5 points

• 3. Reporters are, for the most part, given the
  news.
• Be careful over having too romantic a view of
  the investigative reporter. Time and money
  often limit the ability of a reporter to
  investigate.

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The news media and the internet 5 points

• 4. The media is a business.
• Follow the money! Good and bad sides to this.
  Good side independent of government. Bad side
  the need to make a profit.

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The news media and the internet 5 points

• 5. The internet has to be treated like the
  media Anyone can put up a web page saying
  anything, so check for credibility. Sites that
  represent institutions and universities tend to
  be more objective and reliable than a site with
  no backing organization, but it is always a good
  idea to use your critical thinking skills!

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Advertising

• Advertising is the science of arresting human
  intelligence long enough to get money from it.
• Stephen Leacock

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Advertising

• Advertising does not only sell consumer goods.
  Advertising is used to sell candidates, ideas,
  and as we have seen recently, wars.

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Advertising

• How does advertising work?
• It acts by creating desires, and it uses every
  persuasive technique available to excite those
  desires.

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Advertising

• The usual reasons found in an advertisement are
  vague, ambiguous, misleading, or exaggerated. In
  doing this we often find ourselves needing
  something we might not have known existed before!

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Advertising

• So what is a good advertisement?
• Basically a good ad simply lets you know that
  something you already want is available somewhere
  at a price you can afford.

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• In the early 1800s, bears were a nuisance to
  settlers in upstate New York.
• Smithsonian

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• In the early 1800s, bears were a nuisance to
  settlers in upstate New York.
• Smithsonian
• Probably true

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• NO CHOLESTEROL!
• Label on Crisco Corn Oil

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• NO CHOLESTEROL!
• Label on Crisco Corn Oil
• Probably true. Vegetable oils do not contain
  cholesterol, and even if you didnt know that,
  such claims made by national brands are usually
  true (despite several famous exceptions).

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• Mezzo-soprano Frederica von Stades two little
  girls always tried to keep her from singing in
  church because, they said, every time she did,
  everyone would turn around and stare at her.
• Joseph McLellan, in the Washington Post

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• Mezzo-soprano Frederica von Stades two little
  girls always tried to keep her from singing in
  church because, they said, every time she did,
  everyone would turn around and stare at her.
• Joseph McLellan, in the Washington Post
• Probably true

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• In the near future look for floods in Britain
  which will culminate in the flooding of
  Parliament.
• A prediction made by Maitreya Swami, The World
  Teacher, in the News Release of the Tara Center,
  N. Hollywood, Calif.

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• In the near future look for floods in Britain
  which will culminate in the flooding of
  Parliament.
• A prediction made by Maitreya Swami, The World
  Teacher, in the News Release of the Tara Center,
  N. Hollywood, Calif.
• Probably false. I wont get into the
  philosophical difficulties involved in attaching
  truth values to future contingent events.

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• Smoking more than triples the likelihood of
  premature facial wrinkling.
• Dr. Donald Kadunce, lead author of a group of
  University of Utah scientists, reporting in
  Annals of Internal Medicine

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• Smoking more than triples the likelihood of
  premature facial wrinkling.
• Dr. Donald Kadunce, lead author of a group of
  University of Utah scientists, reporting in
  Annals of Internal Medicine
• Probably true, but youd probably want to have a
  look at the study to see, among other things, how
  the degree of wrinkling is ascertained.

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• University student to professor Im sorry I
  missed the test on Thursday, Dr. Aarsack. My
  grandmother unexpectedly died, and I had to go
  home.

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• University student to professor Im sorry I
  missed the test on Thursday, Dr. Aarsack. My
  grandmother unexpectedly died, and I had to go
  home.
• Requires further documentation.

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Exercises

• Assess each of the following claims as probably
  true, probably false, as requiring further
  documentation before judgment, or as a claim that
  cannot properly be evaluated. Consider both the
  nature of the claim and the source.
• A few years ago ATT did two surveys showing
  that technically trained persons did not achieve
  as many top managerial jobs in the company as
  liberal arts graduates did.
• New York Times

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Exercises

• A few years ago ATT did two surveys showing
  that technically trained persons did not achieve
  as many top managerial jobs in the company as
  liberal arts graduates did.
• New York Times
• Probably true. It is often risky to accept what
  secondhand reports say about what surveys show,
  but the New York Times is a credible source. This
  claim is probably true. Note, however, the
  vagueness of did not achieve and top
  managerial jobs.

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Exercises

• Q Did Marilyn Monroe keep a diary about her
  relationships with John and Robert Kennedy?
• A No.
• Walter Scotts Personality Parade, Parade

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Exercises

• Q Did Marilyn Monroe keep a diary about her
  relationships with John and Robert Kennedy?
• A No.
• Walter Scotts Personality Parade, Parade
• Requires further documentation. Scotts
  question-and-answer column is probably a
  reasonably reliable source of information about
  the questions asked. Secret diaries are always a
  possibility, of course.

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Exercises

• Comment from an acquaintance I saw Bigfoot with
  my own eyes! It was huge!

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Exercises

• Comment from an acquaintance I saw Bigfoot with
  my own eyes! It was huge!
• Probably false observational error is more
  likely than incorrect background information.

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Exercises

• Every day 5,000 Americans try cocaine for the
  first timea total of 22 million so faraccording
  to estimates by the National Institute on Drug
  Abuse. About five million people are believed to
  be using the drug at least once a month, and they
  are administering it to themselves in
  increasingly destructive ways.
• James Lieber, in the Atlantic

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Exercises

• Every day 5,000 Americans try cocaine for the
  first timea total of 22 million so faraccording
  to estimates by the National Institute on Drug
  Abuse. About five million people are believed to
  be using the drug at least once a month, and they
  are administering it to themselves in
  increasingly destructive ways.
• James Lieber, in the Atlantic
• Requires further documentation. I dont know
  much about the National Institute on Drug Abuse,
  but I have found the Atlantic to be pretty
  reliable in factual matters. Notice that no exact
  figures are claimed the first is explicitly said
  to be an estimate, and the phrases about and
  believed to be qualify the second. I would
  expect these claims to be close to the truth.

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Exercises

• Reported after a debate between Al Gore and Bill
  Bradley, who were running for the Democratic
  nomination for the presidency in 2000 Lt. Gov.
  of California Cruz Bustamante, a Gore
  supporter, declared his candidate the winner in
  the debate, saying hed made his case more
  strongly.

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Exercises

• Reported after a debate between Al Gore and Bill
  Bradley, who were running for the Democratic
  nomination for the presidency in 2000 Lt. Gov.
  of California Cruz Bustamante, a Gore
  supporter, declared his candidate the winner in
  the debate, saying hed made his case more
  strongly.
• Cannot properly be evaluated. Absolutely
  unreliable for reasons of bias. Wed reserve
  judgment.

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Exercises

• Do you feel insecure? Or are you confident about
  your position in life? According to Dr. Ian
  Cameron, how and where you stand in an elevator
  will reveal the answers to these questions.
• Reported in the National Examiner. Dr. Cameron
  is described in the article as a noted scientist
  and researcher.

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Exercises

• Do you feel insecure? Or are you confident about
  your position in life? According to Dr. Ian
  Cameron, how and where you stand in an elevator
  will reveal the answers to these questions.
• Reported in the National Examiner. Dr. Cameron
  is described in the article as a noted scientist
  and researcher.
• Cannot properly be evaluated. Is this remark the
  conclusion of a study? A speculation on the part
  of Dr. Cameron? Who is Dr. Cameron, anyway? I am
  suspicious because so little information is given
  about him. More important, the claim runs counter
  to my background information.

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Exercises

• Atmospheric nuclear tests do not seriously
  endanger either present or future generations.
• Edward Teller, physicist, one of the fathers
  of the atomic bomb, 1958

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Exercises

• Atmospheric nuclear tests do not seriously
  endanger either present or future generations.
• Edward Teller, physicist, one of the fathers
  of the atomic bomb, 1958
• Requires further documentation. Id expect this
  kind of claim, coming from such a source, to be
  trustworthy. That it turned out to be false
  probably shows either that Teller was biased or
  that there was not enough information on the
  effects of atmospheric tests in 1958, or both.

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Exercises

• For the following, discuss which source youd
  trust more, and give at least one reason why.
• Discuss whose opinion on the foreign policy of
  the current administration is more credible.
• a. A former U.S. president of the same political
  party as the current president
• b. A former U.S. president not of the same
  political party as the current president

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Exercises

• For the following, discuss which source youd
  trust more, and give at least one reason why.
• Discuss whose opinion on the foreign policy of
  the current administration is more credible.
• a. A Ph.D. in political science whose speciality
  is U.S. foreign policy
• b. The chairman of the U.S. Senate Foreign
  Relations Committee

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Exercises

• Discuss whose opinion on the condition of the
  tires on your car is more credible.
• a. A salesperson at Goodyear
• b. A mechanic at a garage certified by the
  American Automobile Association

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Exercises

• Issue A proposal for legislation regarding
  automobile insurance rates is on the ballot.
  Discuss whose opinion on the benefits for
  consumers is more credible.
• a. A spokesperson for the insurance industry
• b. Ralph Nader

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Exercises

• Did life evolve, or was it created? Discuss whose
  opinion is the more credible.
• a. A biologist
• b. A minister

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Exercises

• What percentage of American high school students
  have smoked marijuana?
• a. USA Today
• b. Americans for Legalized Marijuana (ALM)

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Exercises

• How many homicides involve the use of a stolen
  firearm?
• a. A Democratic U.S. senator
• b. A Republican U.S. senator

75
Exercises

• Which of two current movies you would be more apt
  to like?
• a. One recommended by a movie critic whose
  opinions you enjoy listening to
• b. One recommended by a friend

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Exercises

• What is the best weight-lifting regimen to
  follow?
• a. Arnold Schwarzenegger
• b. Roseanne

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Exercises

• Discuss the credibility and authority of each
  individual or group listed with regard to the
  questions or issues posed. Whom would you trust
  as most reliable on each subject?
• You are thinking of insulating your attic and
  need advice relative to how much insulation you
  should install.
• a. A company that sells insulation but does not
  install it
• b. A company that sells and installs insulation
• c. An energy consultant from your local gas and
  electric company
• d. Consumer Reports
• e. A friend who has recently had his attic
  insulated

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Exercises

• a. A company that sells insulation but does not
  install it
• b. A company that sells and installs insulation
• c. An energy consultant from your local gas and
  electric company
• d. Consumer Reports
• e. A friend who has recently had his attic
  insulated
• I think you are most likely to get the best
  information from (d), with (c) a close second
  (a) and (b) are about equal in credibility, and
  (e)s ranking depends on where he got his
  information.

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Exercises

• Youve purchased a wood-burning stove. You are
  uncertain, however, what kind of wood to burn in
  it. Youve heard that some produce more smoke,
  some are more likely to contribute to chimney
  fires, some burn hotter than others, and so
  forth.
• a. The dealer from whom you purchased the stove
• b. A friend of yours who has used a wood-burning
  stove for years
• c. Another friend who sells firewood
• d. A U.S. Department of Agriculture publication,
  Comparative Properties of Fuelwood
• e. A professor of environmental horticulture at
  a state university

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Exercises

• Youve purchased a wood-burning stove. You are
  uncertain, however, what kind of wood to burn in
  it. Youve heard that some produce more smoke,
  some are more likely to contribute to chimney
  fires, some burn hotter than others, and so
  forth.
• a. The dealer from whom you purchased the stove
• b. A friend of yours who has used a wood-burning
  stove for years
• c. Another friend who sells firewood
• d. A U.S. Department of Agriculture publication,
  Comparative Properties of Fuelwood
• e. A professor of environmental horticulture at
  a state university
• All these sources are credible, but (d) should
  rank first, and, most likely, (a) should rank
  last.

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Exercises

• A number of your friends have taken up jogging,
  and you wonder whether your taking it up might
  have genuine health benefits for you.
• a. Your family physician
• b. A magazine for runners
• c. A friend who teaches physical education in
  high school
• d. The author of a best-selling book on sports
  medicine
• e. A friend who is president of a local runners
  club

82
Exercises

• a. Your family physician
• b. A magazine for runners
• c. A friend who teaches physical education in
  high school
• d. The author of a best-selling book on sports
  medicine
• e. A friend who is president of a local runners
  club
• (b), (c), and (e) might tend to be promoters of
  jogging, so Id be mildly skeptical of any
  pro-jogging claims they might make (but less
  skeptical of any liabilities of jogging that they
  might mention). Id find (a) a more credible
  source, although many general practitioners may
  not have the time to keep up on such specialized
  areas. The best potential source is probably (d),
  although Id be cautious unless I knew something
  about the author he or she might also tend to
  exaggerate either the benefitsor the risksof
  jogging.

83
Exercises

• You are looking at a sailboat that youre
  considering buying, but youve never owned one
  before and dont know whether you should buy this
  one.
• a. The boat salesman at the marina that owns the
  boat
• b. A boat salesman from another marina
• c. A friend who has owned several similar boats
• d. A buyers guide published by a sailing
  magazine
• e. Your own appraisal

84
Exercises

• For the following, discuss which source youd
  trust more, and give at least one reason why. You
  may want to add to or otherwise modify our lists
  of sources. And do keep in mind that we are glad
  our livelihoods do not depend on a general
  consensus on our rankings.
• Issue Should lawyers allow their clients to lie?
• a. The U.S. Supreme Court
• b. A law school professor
• c. A political science professor
• d. The American Bar Association
• e. A practicing defense attorney

85
Exercises

• This question is not so straightforward and
  simple as it might seem. For instance, has a
  client who is forced to tell the truth in effect
  been denied an effective defense? Can one even
  know that ones client has lied? In forming my
  opinion on the subject, Id be most influenced by
  the reasoning of the person who seemed to have
  the best grasp of the various subsidiary issues
  involved. In other words, in this case its the
  reasoning rather than the credentials of the
  reasoner that will carry the most weight. (I
  would not anticipate that any of the sources
  listed would be deficient in powers of reasoning.)

86
Exercises

• Issue In the O. J. Simpson murder case, did the
  judge rule correctly in admitting evidence that
  was obtained at Simpsons house before a search
  warrant was issued?
• a. A well-known defense attorney who heads the
  American Trial Lawyers Association
• b. The former district attorney for Los Angeles
  County
• c. A retired judge on the U.S. Court of Appeals

87
Exercises

• a. A well-known defense attorney who heads the
  American Trial Lawyers Association
• b. The former district attorney for Los Angeles
  County
• c. A retired judge on the U.S. Court of Appeals
• I put (c) way out in front, and the other two
  equally biased on opposite sides of the issue.

88
Exercises

• Issue Does violence on television contribute to
  violent behavior on the part of young viewers?
• a. The president of the National Association of
  Broadcasters
• b. The president of an organization called
  Parents Against TV Violence
• c. A university sociologist
• d. Regular panel members of a program such as
  Crossfire or The McLaughlin Group

89
Exercises

• a. The president of the National Association of
  Broadcasters
• b. The president of an organization called
  Parents Against TV Violence
• c. A university sociologist
• d. Regular panel members of a program such as
  Crossfire or The McLaughlin Group
• I rank (c) first, followed by (b), who would be
  ahead of (a). I do know what side (b) is on from
  the outset, of course, but thats somewhat
  different from having a vested interest in one
  side of the issue in the way that (a) does. I
  find most of the people like those mentioned in
  (d) to be full of hot air on most subjects.

90
Exercises

• Issue Do mountain bicycles cause ecological
  damage when ridden on hiking trails?
• a. An environmental scientist at the Harvard
  School of Public Health
• b. The chair of the Sierra Club task force for
  determining club policy on the wilderness use of
  mountain bicycles
• c. A spokesperson for a bicycle manufacturer
• d. A park ranger from a state park where
  mountain bicycles have been permitted on hiking
  trails
• e. A representative of the Washington Mountain
  Bike Riders Association

91
Exercises

• a. An environmental scientist at the Harvard
  School of Public Health
• b. The chair of the Sierra Club task force for
  determining club policy on the wilderness use of
  mountain bicycles
• c. A spokesperson for a bicycle manufacturer
• d. A park ranger from a state park where
  mountain bicycles have been permitted on hiking
  trails
• e. A representative of the Washington Mountain
  Bike Riders Association
• My ranking (d) (b) first, then (e) (c)
  (a)

92
Exercises

• Issue Are schools of business turning out too
  many ill-prepared M.B.A. graduates?
• a. The dean of the school of business at the
  University of Chicago
• b. The president of the Hewlett-Packard
  Corporation
• c. An editorial in the Wall Street Journal
• d. A recent graduate with an M.B.A.

93
Exercises

• Issue Are schools of business turning out too
  many ill-prepared M.B.A. graduates?
• a. The dean of the school of business at the
  University of Chicago
• b. The president of the Hewlett-Packard
  Corporation
• c. An editorial in the Wall Street Journal
• d. A recent graduate with an M.B.A.
• My ranking (c), (b), (a), (d)

94
Exercises

• Issue What levels of mercury and other metals in
  fish are high enough to make their consumption
  hazardous to humans?
• a. An article in a journal called Diet and
  Health, published for vegetarians
• b. A commercial fisherman
• c. A family medical doctor
• d. A spokeswoman for the National Institutes of
  Health
• e. A toxicologist who works for the Los Angeles
  coroners office

95
Exercises

• a. An article in a journal called Diet and
  Health, published for vegetarians
• b. A commercial fisherman
• c. A family medical doctor
• d. A spokeswoman for the National Institutes of
  Health
• e. A toxicologist who works for the Los Angeles
  coroners office
• My ranking (d), then a substantial gap, then
  (e) and (c), another gap, then (a), (b)

96
Exercises

• Issue Were there unjustifiable cost overruns in
  the construction of ships made for the U.S. Navy
  by Lytton Industries?
• a. The chair of the Senate Armed Services
  Committee
• b. The accounting director for Lytton
• c. The Navy Chief of Staff
• d. The OMB (Office of Management and Budget)
• e. An article in The Progressive (a
  left-of-center political journal)

97
Exercises

• a. The chair of the Senate Armed Services
  Committee
• b. The accounting director for Lytton
• c. The Navy Chief of Staff
• d. The OMB (Office of Management and Budget)
• e. An article in The Progressive (a
  left-of-center political journal)
• Our ranking (d), (a), depending on the
  individuals politics, then (c) (e), (b)

98
Exercises

• State whether the following are true or false.
• You should assume that the claims made by others
  are false unless you have some specific reason to
  believe otherwise.

99
Exercises

• State whether the following are true or false.
• You should assume that the claims made by others
  are false unless you have some specific reason to
  believe otherwise.
• False

100
Exercises

• State whether the following are true or false.
• If you have reason to believe that an expert is
  biased, you should reject that experts claim as
  false.

101
Exercises

• State whether the following are true or false.
• If you have reason to believe that an expert is
  biased, you should reject that experts claim as
  false.
• False (The possibility of bias is occasion to
  question his or her claims, to suspend judgment
  on them, to give more weight to alternative
  claims from unbiased experts, and so onthis is
  different from rejecting the original experts
  claims as false.)

102
Exercises

• State whether the following are true or false.
• Except when we have the means to record our
  observations immediately, they are no better than
  our memories happen to be.

103
Exercises

• State whether the following are true or false.
• Except when we have the means to record our
  observations immediately, they are no better than
  our memories happen to be.
• True

104
Exercises

• State whether the following are true or false.
• Fallible or not, our firsthand observations are
  still the best source of information we have.

105
Exercises

• State whether the following are true or false.
• Fallible or not, our firsthand observations are
  still the best source of information we have.
• True

106
Exercises

• State whether the following are true or false.
• Reference works such as dictionaries are utterly
  reliable sources of informationotherwise they
  wouldnt be reference works.

107
Exercises

• State whether the following are true or false.
• Reference works such as dictionaries are utterly
  reliable sources of informationotherwise they
  wouldnt be reference works.
• False

108
Exercises

• State whether the following are true or false.
• A surprising claim, one that seems to conflict
  with our background knowledge, requires a more
  credible source than one that is not surprising
  in this way.

109
Exercises

• State whether the following are true or false.
• A surprising claim, one that seems to conflict
  with our background knowledge, requires a more
  credible source than one that is not surprising
  in this way.
• True

110
Exercises

• State whether the following are true or false.
• Factual claims put forth by experts about
  subjects outside their fields are not
  automatically more acceptable than claims put
  forth by nonexperts.

111
Exercises

• State whether the following are true or false.
• Factual claims put forth by experts about
  subjects outside their fields are not
  automatically more acceptable than claims put
  forth by nonexperts.
• True

112
Exercises

• State whether the following are true or false.
• You are rationally justified in accepting the
  view of the majority of experts in a given
  subject even if this view turns out later to have
  been incorrect.

113
Exercises

• State whether the following are true or false.
• You are rationally justified in accepting the
  view of the majority of experts in a given
  subject even if this view turns out later to have
  been incorrect.
• True