Claims and Critical Thinking

1
Claims and Critical Thinking

• Claims are either true or false.
• Some sentences (even some nondeclarative ones)
  make claims, but some (even some declarative
  ones) do other things.
• CRITICAL THINKING The careful, deliberate
  determination of whether to accept, reject, or
  suspend judgment about a claim and the degree
  of confidence with which we accept or reject it.

2
Skills Beneficial to Everyone

• Critical thinking is not about attacking and
  defeating others its about helping them and
  you.
• Critical thinking is more a set of skills than a
  set of facts.

3
Skills Involved in Critical Thinking

• Careful listening and reasoning
• Finding hidden assumptions
• Tracing the consequences of claims
• Determining the credibility of sources
• Recognizing and avoiding various sorts of
  rhetoric and pseudoreasoning
• Analyzing and evaluating arguments

4
Issues

• Issue a matter of controversy or uncertainty.
• Issues may be internal (between self and self) or
  external (between self and others.)
• Topics of conversation arent issues unless there
  is controversy or uncertainty that the parties
  are trying to resolve.
• Critical thinking requires identifying the issue,
  separating it from others and focusing on it.
• Issues should be kept straight and dealt with in
  proper order (efficiently.)

5
Arguments

• Arguments are one of the ways used to settle
  issues.
• Arguments attempt to support a claim (the
  conclusion) by giving reasons for believing it
  (the premises.)
• The issue is Whether or not the conclusion is
  acceptable given the premises.

6
Facts and Opinions

• Fact indicates that a claim is true.
• Opinion indicates that a claim is believed.
• Clearly, some opinions are factual and some
  arent.

7
Objectivity and Subjectivity

• An issue is factual or (objective) if there are
  accepted means for settling it.
• An issue is a matter of pure opinion (subjective)
  if both sides could be correct.
• Objective claims are true or false regardless of
  our inner states while subjective claims are
  usually just expressions of inner states.
• Controversy alone does not make an issue
  subjective equality of persons doesnt mean
  equality of opinions.
• Disputes may arise over whether certain types of
  claims (e.g., moral ones) are objective or
  subjective.

8
Organizing an Argumentative Essay

• Make the focus clear at the beginning.
• Stick to the issue.
• Arrange the elements in a logical order.
• Be complete (easier with limited topics.)

9
Good Writing Habits

• Outline after the first draft.
• Revise, revise, revise!
• Let others read and criticize.
• Read it out loud.
• When satisfied, put it aside for a while then
  revise again!

10
Essays to Avoid

• Windy preamble essays.
• Rambling stream-of-consciousness essays.
• Knee-jerk reaction essays.
• Glancing-blow essays.
• Let-the-reader-do-the-work essays.

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Clarity I Definitions

• A definition can serve different purposes to
  stipulate, to explain, to precise and to
  persuade.
• Definitions can be by example, by synonym or
  analytical (genus-species).
• Abstract terms may not be completely definable.
• The literal meaning of a term is distinct from
  its emotive force (the denotation is distinct
  from the connotation.)

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Clarity II Ambiguity

• Ambiguous claims have more than one meaning in
  the context.
• In semantical ambiguity, specific words or
  phrases have multiple meanings.
• In syntactical ambiguity, the entire structure of
  the sentence is at fault.
• In grouping ambiguity, it isnt clear whether we
  are talking about the members of a group
  collectively or individually.

13
Composition and Division Fallacies

• A composition fallacy occurs when we argue that
  what holds true individually must hold true
  collectively.
• A division fallacy occurs when we argue that what
  holds true collectively must hold true
  individually.

14
Clarity III Vagueness

• A claim is vague if it doesnt have a precise
  enough meaning in the context.
• Vagueness is a matter of degree.
• Fuzzy words (old, bald, rich) can produce
  vagueness, but you can be vague even without them.

15
Clarity IV Comparative Claims

• Is important information missing?
• Is the standard of comparison clear?
• Is the same standard being used?
• Are the same reporting and recording practices
  being used?
• Are the items really comparable?
• Is the comparison an average and, if so, what
  kind (mean, median or mode)?

16
When Should We Accept an Unsupported Claim?

• If it does not conflict with our observations,
  our background knowledge or other credible
  claims.
• If it comes from a credible, unbiased source.

17
Even Personal Observation Can Be Unreliable

• If the observing conditions are bad
• If the observer is distracted or impaired
• If the instruments used are faulty

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Other Factors Affecting Personal Observation

• Individual powers of observation
• Training and experience
• Beliefs, hopes, fears, expectations, bias
• Memory
• Even so, personal observation is usually the best
  source of information we have we should accept
  it unless we have a specific reason to challenge
  it.

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Does the Claim Conflict with Background Knowledge

• The less conflict, the higher the initial
  plausibility of the claim.
• If there is conflict we can rightfully reject the
  claim even without evidence from personal
  observation.
• Remember Some of your background beliefs are
  surely wrong but you dont know which.
• The broader your background knowledge the better!

20
Assessing the Credibility of a Source Expertise

• Education
• Experience
• Accomplishments
• Reputation (especially among other experts)
• Position
• All, of course, in fields relevant to the issue.

21
Why Experts Can Be Wrong

• Expertise can be bought
• The experts may disagree
• The subject may be such that none can claim
  expertise.

22
News Media

• Print provides broader coverage than electronic
• Newspapers may feel pressure from advertisers and
  the local public
• Headlines are sometimes misleading
• Size and location of the story may be
  disproportionate to its importance
• Opinion sometimes gets blended with facts

23
Slanters

• These are the various linguistic devices commonly
  used to attempt to persuade without argument.
• They rely on
• the emotive force of words and phrases and/or
• linguistic manipulations that suggest hidden
  meanings

24
Words of Caution on Slanters

• Slanters are only bad when they are used to
  mislead.
• Slanters can be combined with perfectly good
  reasoning (so dont throw the baby out with the
  bath.)
• Sometimes its wise and good to slant.

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Slanters I Emotive Force

• Euphemisms and Dysphemisms Its all in how you
  describe it
• Persuasive comparisons, definitions and
  explanations or how you compare, define or
  explain it.
• Stereotypes Just read the label.

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Slanters II Linguistic Manipulation

• Innuendo I never said he was drunk
• Loaded questions These have unjustified hidden
  assumptions (innuendo in interrogative dress)
• Weaslers Watering down a claim
• Downplayers The verbal brush-off
• Hyperbole Extravagant overstatement
• Proof Surrogates Evidence that isnt

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Manipulating the Information I The News

• Most stories are given, not dug up sources must
  not be offended.
• Since the news media are private businesses, they
  mustnt offend either advertisers or audiences.
• The result is bias, oversimplification, passivity
  and an overindulgence in entertainment.
• We will get the news we want and pay for.

28
Advertising

• General Question Does this ad give me a good
  reason to buy the product?
• General Answer Only if it establishes that I
  will be better off with the product than without
  it (or than with the money it will cost).
• Keep in mind
• Wants should be distinct from needs
• Ads purposefully try to instill desires and fears
  we previously lacked

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Three Ways Ads Lacking Reasons Can Persuade

• By associating the product with pleasurable
  feelings
• By associating the product with people we admire
  or wish to be like
• By associating the product with desirable
  situations
• Unless availability is all you need to know,
  buying a product based on a reasonless ad is
  never justified.

30
What About Promise Ads that Supply Reasons?

• Claims in ads often come with no guarantees and
  are notoriously vague, ambiguous, misleading,
  exaggerated and wrong.
• We only get the information the seller wants us
  to have!
• Our suspicions about ads in general justifies
  suspicions about particular ads.
• So even ads with reasons dont in themselves
  justify a purchase.

31
What Pseudoreasoning Is

• No grounds for accepting a claim are given even
  though something approximating an argument may be
  there.
• Emotional appeals, factual irrelevancies and
  persuasive devices are used to induce acceptance
  of a claim.

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Types of Psedoreasoning

• Smokescreen/Red Herring
• Subjectivist Fallacy
• Common Belief
• Common Practice
• Peer Pressure/Bandwagon
• Wishful Thinking
• Scare Tactics

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More Pseudoreasoning

• Appeal to Pity
• Apple Polishing
• Horse Laugh/Ridicule/Sarcasm
• Appeal to Anger or Indignation
• Two Wrongs Make a Right

34
Even More Pseudoreasoning

• Ad Hominem
• Personal Attack
• Circumstantial ad Hominem
• Pseudorefutation
• Poisoning the Well
• Genetic Fallacy
• Burden of Proof

35
Some Oldies but Goodies

• Straw Man
• False Dilemma
• Perfectionist Fallacy
• Line-Drawing Fallacy
• Slippery Slope
• Begging the Question

36
Arguments and Explanations

• We give an argument to try to settle whether some
  claim is true.
• We give an explanation to try to explain why some
  claim is true.

37
Argument or Explanation?

• Sometimes the writer doesnt know
• They use the same words and phrases (reason,
  thats why, etc.)
• The word explanation and its derivatives can
  appear in arguments.
• Explanations can be used in arguments.
• Sometimes it depends on the context and the
  interests of those concerned.

38
Explanations and Justifications

• A justification is an argument in defense of an
  action.
• Although justifications often include
  explanations, explanations can also be neutral
  regarding approval or disapproval.
• So not every attempt to explain something is an
  attempt to justify it explanations need not
  imply approval.

39
Kinds of Explanations

• Physical
• Behavioral
• Functional

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Physical Explanations

• These seek the physical background causing the
  event in question.
• The physical background consists of
• The general physical conditions (usually
  unstated)
• That link of the causal chain leading to the
  event which, based on our interests and
  knowledge, we take as the direct or immediate
  cause of the event.

41
Three Mistakes in Physical Explanations

• Tracing causal chains back too far
• Expecting reasons and motives behind all causal
  chains.
• Giving physical explanations at the wrong
  technical level for the situation and/or audience.

42
Behavioral Explanations I

• These attempt to explain behavior in terms of
  psychology, political science, sociology,
  history, economics or common-sense psychology.
• The causal background is historical.
• Which factors (political, economic, social,
  psychological) are important depends on our
  interests and knowledge there is no single
  correct explanation of any voluntary behavior.

43
Behavioral Explanations II

• Recurring patterns of behavior require
  theoretical explanations.
• Expect more exceptions to generalizations about
  behavioral regularities than to generalization
  about regularities in nature.
• These explanations can also be traced
  inappropriately far and pitched at the wrong
  technical level for the audience.
• Explanations by reasons and motives look forward,
  unlike physical explanations.
• Dont confuse a reason (argument) for the reason
  (explanation).

44
Functional Explanations

• A functional explanation by puts a thing in a
  wider context and then indicates the role it
  plays in that context.
• Actual and intended functions can differ.
• An item may have more than one function.
• Since functions usually depend on reasons and
  motives, functional explanations are often
  behavioral explanations in passive voice.

45
Spotting Weak Explanations I

• Testability Beware of rubber ad hoc
  explanations!
• Noncircularity Some explanations just describe
  the phenomena in different words.
• Relevance Does the explanation allow us to make
  predictions?
• Not Too Vague Hes rude because hes out of
  sorts.
• Reliability Does it lead to false predictions?

46
Spotting Weak Explanations II

• Explanatory Power The more it explains the
  better (especially if its a theory!)
• Freedom from Unnecessary Assumptions The fewer
  the better.
• Consistency with Well-Established Theory
• Absence of Alternative Explanations

47
Explanatory Comparisons

• Analogies arent so much true or false as either
  enlightening or unhelpful.
• The best comparisons give us the greatest number
  of close resemblances and the shortest list of
  important differences.
• The hearer must be familiar with both terms of
  the comparison to understand and evaluate it.

48
ArgumentConclusionPremises

• A claim can be the conclusion of one argument a
  premise in another.
• An argument may have an unstated premise or
  conclusion.
• Premises can support the conclusion dependently
  or independently.

49
Argument Terminology

• A good argument gives grounds for accepting the
  conclusion a better argument gives more grounds.
• A valid argument is one which, if we assume the
  premises to be true, the conclusion cannot be
  false.
• A sound argument is a valid argument with true
  premises.
• A strong argument is one which, if we assume the
  premises to be true, it is unlikely that the
  conclusion will be false.

50
Deduction and Induction

• Deductive arguments are valid or intended by
  their authors to be valid.
• Inductive arguments are neither valid nor
  intended by their authors to be valid.

51
Unstated Premises

• Is there a plausible claim that will make the
  argument valid?
• Is there a plausible claim that will make the
  argument strong?
• Be charitable in reconstructing the arguments of
  others.

52
Evaluating Arguments

• Do the premises support the conclusion?
• Are the premises reasonable?

53
Deductive Logic

• Categorical (class) logic
• Truth-functional logic

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Standard FormCategorical Claims

• A All __ are __. (quantity universal, quality
  affirmative)
• E No __ are __. (quantity universal, quality
  negative)
• I Some __ are __. (quantity particular,
  quality affirmative)
• O Some __ are not __. (quantity particular,
  quality negative)
• The terms in the blanks must be nouns or noun
  phrases (no bare adjectives)

55
The Square of Opposition

• A and O propositions are contradictories, as are
  E and I propositions (they never have the same
  truth-value).
• Assuming at least one member of the subject
  class, A and E propositions are contraries (they
  cant both be true) and I and O propositions are
  subcontraries (they cant both be false).

56
Categorical Operations

• Conversion Switch the subject and predicate
  terms (valid for E and I but not for A and O)
• Obversion Change the quality (e.g., affirmative
  to negative) and replace the predicate term with
  its complimentary term (e.g., dogs to nondogs)
• Contraposition Convert then replace both terms
  with their complimentary terms.

57
Categorical Syllogisms

• A two-premise deductive argument in which every
  claim is a standard form categorical claim (A, E,
  I, or O).
• Major term (P) The term that appears as the
  predicate term of the conclusion.
• Minor term (S) The term that occurs as the
  subject term of the conclusion.
• Middle term (M) The term that appears only in
  the premises.

58
Testing for Validity withVenn Diagrams

• Overlapping circles, minor term on left, major
  term on right, middle term lower middle.
• Shade out a section to show there is nothing
  there and put an X in a section to indicate there
  is something there.
• Always shade before Xing diagram A and E
  premises before I and O premises.
• The argument is valid if, after diagramming the
  premises you have already diagramed the
  conclusion.

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Distribution Patterns

• A claim is said to distribute a term if it says
  something about every member of the class denoted
  by the term.
• A Subject term only distributed.
• E Both terms distributed.
• I Neither term distributed.
• O Predicate term only distributed.

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The Rules Method of Testing for Validity

• The number of negative claims in the premises
  must be the same as the number of negative claims
  in the conclusion (1).
• At least one claim must distribute the middle
  term.
• Any term that is distributed in the conclusion
  must also be distributed in the premises.

61
Inductive Arguments

• Inductive arguments attempt to establish the
  likelihood (not certainty) of their conclusions
  none are deductively valid.
• They fall on a scale from very strong to very
  weak depending on the degree of support provided
  to the conclusion by the premises.
• A basic inductive idea is that the more ways some
  things are alike, the more likely it is that they
  will be alike in some further way.

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The Basic Argument Pattern

• Analogical arguments compare individuals
  inductive generalizations compare classes.
• In both cases the basic argument pattern is
• Premise X has properties a, b, and c.
• Premise Y has properties a, b, and c
• Premise X has further property p.
• Conclusion Y also has further property p

63
Terminology

• The property in question the property
  ascribed in the conclusion
• The sample the group whose members we know
  have or dont have the property in question.
• The target population the individual or group
  about which we are seeking to know whether or not
  they have the property in question (this may be a
  subset of the sample.)

64
Analogical Arguments

• The premises claim that one or more items have a
  property, and the conclusion claims that some
  similar item has that property.
• Example The two Yugos Ive previously driven
  were underpowered so this one will probably be
  underpowered too.

65
Factors Governing the Strength of Analogical
Arguments I

• As long as all the members of the sample have the
  property in question, the larger the sample the
  stronger the argument.
• The greater the percentage of the sample that has
  the property in question the stronger the
  argument.
• The greater the number of the similarities (and
  the smaller the number of dissimilarities)
  between the target and the sample the stronger
  the argument.

66
Factors Governing the Strength of Analogical
Arguments II

• With regard to a feature that, to our knowledge,
  the target may or may not have, the more diverse
  the sample the stronger the argument.
• The less narrow the conclusion the stronger the
  argument.

67
Inductive Generalizations

• These always have a class as the target.
• The sample is always drawn from the target
  population.
• Basic idea If a part of a class has the property
  in question then the class as a whole probably
  has that property too.
• The conclusion may refer to all, most, many, or
  some specified percentage of the target
  population.

68
Representativeness and Bias

• A sample is representative of a target population
  if it has all the relevant features of the target
  in the same proportions.
• A generalization not based on a representative
  sample is untrustworthy.
• An unrepresentative sample is called a biased
  sample.
• We can approximate a representative sample with a
  random sample, one in which each member of the
  target has the same chance of being in the
  sample.
• Random sampling error can occur even with an
  unbiased sample.

69
Sample Size, Error Margin, and Confidence Level

• The error margin is the range within which the
  conclusion can be expected to fall.
• The confidence level indicates the percentage of
  random samples in which the property in question
  falls within the error margin.
• As the sample size increases, the error margin
  will decrease or the confidence level will
  increase or both.

70
Criteria and Fallacies of Inductive
Generalizations

• The sample must be large enough to be
  representative of the target population (if not,
  Fallacy of Hasty Generalization.)
• The sample must be unbiased with regard to
  features relevant to the property in question (if
  not, Fallacy of Biased Generalization.)
• Basing a conclusion on a few clearly
  unrepresentative cases is an extreme form of
  hasty generalization called the Fallacy of
  Anecdotal Evidence.

71
Untrustworthy Polls

• Self-selected samples.
• Person-on-the-street interviews.
• Telephone surveys.
• Questionnaires
• Polls commissioned by advocacy groups.
• Push-polling.