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Title: Reasoning and Argument Analysis


1
Reasoning and Argument Analysis
Clark Wolf Director of Bioethics Iowa State
University jwcwolf_at_iastate.edu
2
  • OBJECTIVES On completion of this unit, students
    should be able
  • 1.1 to recognize when they are presented with an
    argument,
  • 1.2 to analyze arguments by identifying the
    conclusion and distinguishing conclusions from
    premises.
  • 1.3 to evaluate arguments by considering the
    plausibility of the premises and the extent to
    which the premises support the conclusion.
  • 1.4 to distinguish deductive and inductive
    arguments,
  • 1.5 to distinguish an arguments content from
    its form.
  • 1.5 to define key concepts argument, premise,
    conclusion, evidence, rationally persuasive
    argument, fallacy, valid argument, invalid
    argument, inductive argument, abductive argument.
  • 1.6 to evaluate arguments, by (i)
    distinguishing premises from conclusion, (ii)
    putting the argument in standard form, (iii)
    critically examining the premises, and (iv)
    evaluating the inference from premises to
    conclusion.
  • 1.7 to be self-reflectively critical of their
    own arguments and those of others.

3
What is an Argument?
  • Argument A set of statements, some of which
    serve as premises, one of which serves as a
    conclusion, such that the premises purport to
    give evidence for the conclusion.
  • Premise A premise is a statement that purports
    to give evidence for the conclusion.
  • Evidence To say that a statement A is evidence
    for another statement B is to say that if A were
    true, this would provide some reason to believe
    that B is true.
  • Conclusion The statement in an argument that is
    supposedly supported by the evidence.

4
When do we encounter arguments?
  • Any time anyone tries to persuade you of
    something, or to make you change your mind.
  • Rational persuasion uses reasons, but even
    irrational persuasion employs reasons (bad
    reasons). In evaluating arguments, we need to be
    able to evaluate reasons and patterns of
    reasoning.

5
  • Nick OK, lets say youre defending chocolate
    and Im defending vanilla. Now if I were to say
    to you vanilla is the best flavor ice cream,
    youd say?
  • Joey No, Chocolate is.
  • Nick Exactly. But you cant win that argument.
    So, Ill ask you, So you think chocolate is the
    end all and be all of ice cream, do you?
  • Joey Its the best ice cream. I wouldnt order
    any other.
  • Nick Oh, so its all chocolate for you, is it?
  • Joey Yes, chocolate is all I need.
  • Nick Well, I need more than chocolate. And for
    that matter, I need more than vanilla. I believe
    that we need freedom, and choice when it comes to
    our ice cream, and that, Joey Naylor, that is the
    definition of liberty.
  • Joey But thats not what were talking about.
  • Nick Ah, but thats what Im talking about.
  • -from Thank you for Smoking (Film)

6
  • Joey But thats not what were talking about.
  • Nick Ah, but thats what Im talking about.
  • Joey But you didnt prove that vanilla is the
    best.
  • Nick I didnt have to. I proved that you are
    wrong, and if youre wrong, Im right.
  • Joey But you didnt convince me.
  • Nick Im not after you, Im after them.
    (pointing to the crowd around them)
  • -from Thank you for Smoking (Film)

7
Rational Argument v. Persuasive Rhetoric
  • Sometimes people are persuasive not because they
    are offering well-reasoned arguments, but because
    they are good at bamboozling other people.
  • Good philosophical arguments should be rationally
    persuasive.

8
Indicator Words
  • Indicator words Sometimes writers use language
    that indicates the structure of the argument they
    are giving. The following words and phrases
    indicate that what follows is probably the
    conclusion of an argument
  • Therefore
  • thus
  • for that reason
  • hence
  • it follows that

9
Conclusion Indicators
  • Because
  • Since
  • For
  • For the reason that

10
Example
  • Because animals are conscious, capable of
    experiencing pain and pleasure, they are like
    people in significant respects. Since they are
    also intelligentoften far more intelligent than
    newborn babies for example, it follows that they
    deserve kind treatment from human beings and that
    it is wrong to treat them with cruelty.

11
Examples
  • Since private business is the most effective
    instrument of economic change, the government
    should utilize the resources of private business
    in its economic planning and decision making.
  • Women work just as hard as men and are just as
    productive. Therefore they should be compensated
    the same.

12
Standard Form
  • Standard Form Usually we find arguments
    expressed in ordinary prose. But as noted, when
    we are evaluating arguments it is a good idea to
    separate the premises from the conclusion, and to
    put the argument into standard form. We say
    that an argument is in standard form when the
    premises are numbered and listed separately, and
    when the conclusion is clearly written underneath
    them.

13
Standard Form Version
  • (1) Animals are conscious.
  • (2) Animals are capable of experiencing pain and
    pleasure.
  • (3) Animals are intelligent.
  • (4) Animals are like people in significant
    respects.
  • Conclusion
  • (5) Therefore (i) animals deserve kind treatment
    from humans and (ii) it is wrong to treat animals
    with cruelty.

14
A Reservation
  • Whenever we put an argument in standard form, we
    have given an interpretation of that argument.
    Ideally, an interpretation should accurately
    capture the meaning of the original, but it is
    always possible to challenge the accuracy of an
    interpretation.

15
Evaluating an Argument
  • By splicing genes into crop plants, scientists
    have changed these crops in ways that never could
    have come about through the natural process of
    selective breeding. These changes in our food
    crops threaten the health of everyone in the
    world, and impose a great danger of massive
    environmental damage. Genetically modified crops
    are unnatural and dangerous. We should avoid
    using them and growing them, and should do
    whatever it takes to eliminate them from Iowa
    farms.

16
Questions
  • What is the author of this passage trying to
    persuade you to believe? (Whats the
    conclusion?)
  • What reasons are being offered? (What are the
    premises?)
  • In this argument there are few indicator words
    used, but it is not hard to figure out what the
    author would like us to believe.

17
Whats the Conclusion?
  • Conclusion Often the conclusion of an argument
    is stated either in the first sentence of a
    paragraph, or in the last sentence of the
    paragraph. In this case, the conclusionthe
    claim the author intends to persuade us to
    acceptis a complex claim. The author urges
    that
  • (1) We should avoid using and growing genetically
    modified crops, and
  • (2) We should do whatever it takes to eliminate
    these crops from Iowa farms.

18
Whats evidence or reasons are given?
  • Premises
  • P1) Gene splicing changes crops in ways that
    could never have come about through selective
    breeding.
  • P2) Changes in food crops due to gene splicing
    threaten everyones health.
  • P3) Changes in food crops pose a threat of
    massive environmental damage.
  • P4) Genetic modification of crops is unnatural.
  • P5) Genetic modification of crops is dangerous.

19
Step One Are the premises true?
  • Premise 1 Gene splicing changes crops in ways
    that never could have come about through
    selective breeding.
  • Evaluation Is this true? Some of the properties
    that have been induced through genetic
    engineering might have been produced through
    selective breeding. But it is unlikely that the
    genetic alterations that have been effected in
    the production of genetically modified crops
    would have been produced in any other way.
    Perhaps this premise should be somewhat
    qualified, but it contains a kernel of truth.

20
Step One Are the premises true?
  • Premise 2 Changes in food crops due to gene
    splicing threaten everyones health.
  • Evaluation This claim requires additional
    support and evidence. Many people are concerned
    about the health effects of genetically modified
    food crops, but no one has shown that these crops
    are dangerous. The author of the paragraph
    provides no evidence that genetically modified
    crops are dangerous.

21
Step One Are the premises true?
  • Premise 3 Changes in food crops pose a threat of
    massive environmental damage.
  • Evaluation Once again, this claim requires
    support. There may indeed be reasons for concern
    about the environmental effects of genetically
    modified crops, but the author has not given us
    any evidence. Without more evidence, we may not
    be in a position to evaluate this premise.

22
Step One Are the premises true?
  • Premise 4 Genetic modification of crops is
    unnatural.
  • Evaluation The term natural can be slippery,
    and we may need to know more about what the
    author has in mind. In context, it seems that
    the author regards things that are unnatural as
    bad. But in an important sense, bridges,
    computers, vaccines and artworks are unnatural.

23
Step One Are the premises true?
  • Premise 5 Genetic modification of crops is
    dangerous.
  • Evaluation Once again we need evidence for such
    a claim before we can place our trust in it. In
    what sense is genetic modification dangerous, and
    what are the specific dangers the author has in
    mind? Without more evidence, we may simply find
    that we are not yet in a position to evaluate the
    argument.

24
  • Step Two
  • If the premises were true, would they provide
    good evidence for the conclusions?
  • Are there implicit premises that should be
    included in the evaluation of the argument?

25
  • A Strategy for Evaluating Arguments Of course,
    for the purposes of this course, your views about
    GM crops are not what matter. What does matter
    is the strategy used here for evaluating the
    argument under consideration
  • First, identify the arguments premises, and
    restate them clearly.
  • Second, evaluate each premise individually is it
    true or false? What evidence, what information
    would you need to know in order to determine
    whether the premises are true?
  • If you discover that the premises of the argument
    are simply false, you may need to go no further.
    But if the premises seem true, there is a third
    important step to take in evaluating the
    argument
  • Third, consider the relationship between the
    premises and the conclusion. What kind of
    argument is it? Is it a good argument of its
    kind?

26
Argument for Analysis
  • Different cultures have different moral values
    For example, some cultures hold that its
    morally right to ethnically cleanse the nation by
    killing those who are not members of the dominant
    group. Some cultures hold that terrorism is
    morally praiseworthy, while others believe that
    its wrong to harm innocent people. But no one
    is in a position to say that their values are
    better than the cultural values of any other
    group. Because of this, it is inappropriate for
    us to impose our arbitrary cultural values on
    terrorists or ethnic cleansers whose values are
    different from ours.

27
In Standard Form
  • 1) Different cultures have different moral
    values.
  • For example, some cultures hold that its
    morally right to ethnically cleanse the nation by
    killing those who are not members of the dominant
    group. Some cultures hold that terrorism is
    morally praiseworthy, while others believe that
    its wrong to harm innocent people.
  • 2) No one is in a position to say that their
    values are better than the cultural values of any
    other group.
  • 3) Our own values are arbitrary, and we are
    unjustified in giving them special weight.
  • (Implied premise?)
  • 4) Conclusion It is inappropriate for us to
    impose our arbitrary values on terrorists or
    ethnic cleansers whose values are different.

28
Thoughts on this Argument
  • If this argument goes wrong, where does it go
    wrong? Is it intolerant to prevent people from
    harming one another?
  • Is harmfulness an intercultural value that
    allows us to make judgments about the value
    systems of different cultural groups?
  • The argument concludes with a plea for tolerance
    Should we be tolerant of all differences? Is it
    intolerant to prohibit theft and assault, since
    thieves and assailants clearly dont share the
    values that motivate our legal system. What are
    the limits of tolerance, and how can we justify
    these limits?
  • What is the relationship between relativism and
    toleration? If one is a relativist, would one
    be tolerant of others? What if tolerance is
    not one of the values ones own culture
    recommends? Are we tolerant when we permit
    others to harm and oppress?

29
Fallacies
  • Fallacy An argument that provides the illusion
    of support, but no real support, for its
    conclusion.

30
Evaluating Philosophical Arguments
  • Fair-Mindedness and the State of Suspended
    Judgment When evaluating arguments, we should
    strive to be impartial and fair-minded. We
    should try to follow where the best reasons lead
    instead of pre-judging the conclusion.

31
Next Deductive Arguments
  • Deductive Argument An argument that has the
    property that if the premises are true, then the
    conclusion cannot be false.
  • Example
  • All vertibrates have hip bones.
  • Snakes are vertibrates.
  • Therefore, snakes have hipbones.

32
Deductively Valid Arguments
  • Df An argument is (df) deductively valid iff it
    has the property that if the premises are true,
    then the conclusion cannot be false.
  • Example (From Aristotles Logic)
  • All men are mortal.
  • Socrates is a man.
  • Therefore, Socrates is mortal.

33
Comments
  • Deductive validity is a property of the form of
    an argument. The following arguments have the
    same form
  • All fish are cold blooded.
  • Whales are fish.
  • Therefore whales are cold-blooded.
  • All goats are quadrupeds.
  • Abedna is a goat.
  • Abedna is a quadruped.
  • All philosophers are geniuses.
  • Clark is a philosopher.
  • Clark is a genius.
  • These arguments exemplify a valid form, so they
    are all valid. But note that some of these
    arguments contain false statements. How can an
    argument be valid if it has false premises?

34
Comments about Validity
  • Consider the definition
  • Df An argument is (df) deductively valid iff it
    has the property that if the premises are true,
    then the conclusion cannot be false.
  • A valid argument can have false premises.
  • A valid argument can have a false conclusion.
  • A valid argument can have false premises and a
    false conclusion.
  • A valid argument can have false premises and a
    true conclusion.
  • A valid argument cannot have true premises and a
    false conclusion.
  • Examples

35
Comments about Validity
  • Two Examples of Valid (but faulty) Arguments
  • False premises and false conclusion
  • 1) All horses are reptiles.
  • 2) All reptiles have wings.
  • 3) Therefore all horses have wings.
  • False Premises, True Conclusion
  • 1) All horses are reptiles.
  • 2) All reptiles have fur.
  • 3) All horses have fur.
  • These are both valid arguments. Since their
    premises are false, they do not provide good
    evidence for their conclusions.

36
Soundness
  • An argument is sound iff it is deductively
    valid, and its premises are true.

37
Some Valid Argument Forms
  • Modus Ponens If X then Y.
  • X.
  • Therefore, Y.
  • Example
  • 1) If Jon swam in the Skunk river, then hell
    stink.
  • 2) Jon swam in the skunk river.
  • 3) Jon stinks.

38
Some Valid Argument Forms
  • Modus Tollens If X then Y.
  • not Y.
  • Therefore, not X.
  • Example
  • 1) If Jon swam in the Skunk river, then hell
    stink.
  • 2) Jon doesnt stink.
  • 3) Jon didnt go swimming in the Skunk.

39
Some Related Invalid Forms
  • Affirming the Consequent If X then Y.
  • Y.
  • Therefore, X.
  • Example
  • 1) If Jon swam in the Skunk river, then hell
    stink.
  • 2) Jon stinks.
  • 3) Jon went swimming in the Skunk.

40
Some Related Invalid Forms
  • Affirming the Consequent If X then Y.
  • Y.
  • Therefore, X.
  • Counter-example
  • 1) If Jon throws water on the streets, then the
    streets will be wet.
  • 2) The streets are wet.
  • 3) Jon must have thrown water on them.
  • Obviously this is a bad argument If you find
    that the streets are wet, its more likely that
    its rained than that someone has been out
    dumping water around.

41
Some Related Invalid Forms
  • Denying the Antecedent
  • If X then Y.
  • Not X.
  • Therefore, not X.
  • Example
  • 1) If Jon swam in the Skunk river, then hell
    stink.
  • 2) Jon didnt swim in the Skunk.
  • 3) Jon wont stink.
  • (What if hes been out shoveling manure?)

42
Quiz Which are valid? Whats the Form?
  • If he eats that fish, hell die!
  • Ah! He didnt eat the fish.
  • He must still be alive.
  • If you ride your bike, youll get strong.
  • Youre strong!
  • You must be a bike rider.1
  • If you had taken logic, you would know how to
    distinguish valid from invalid arguments.
  • You cant tell which are valid and which are not!
  • You didnt take logic.
  • If you find a penny, youll have luck all day.
  • You found a penny!
  • Youll have a lucky day.

43
Quiz Which are valid? Whats the Form?
  • If he eats that fish, hell die!
  • Ah! He didnt eat the fish.
  • He must still be alive.
  • Invalid.
  • Form Denying the Antecedent.
  • If you ride your bike, youll get strong.
  • Youre strong!
  • You must be a bike rider.
  • Invalid!
  • Form Affirming the Consequent.
  • If you had taken logic, you would know how to
    distinguish valid from invalid arguments.
  • You cant tell which are valid and which are not!
  • You didnt take logic.
  • Valid.
  • Modus Tollens.
  • If you find a penny, youll have luck all day.
  • You found a penny!
  • Youll have a lucky day.
  • Valid.
  • Form Modus ponens.

44
Aristotelian Syllogisms Some other Valid
Argument Forms
  • All X are Y.
  • All Y are Z.
  • Therefore, all X are Z.
  • All X are Y.
  • S is an X.
  • S is a Y.
  • No X are Y.
  • S is Y.
  • S is not X.
  • All X are Y.
  • S is not Y.
  • S is not X.

Aristotles Logic is a complicated analysis of
simple arguments like these. For almost 2000
years, this was the state of the art!
45
An Informal Method for Testing Validity
  • 1) Distinguish the arguments form from its
    substance.
  • 2) Write out an abstract version of the
    arguments form Do this by drawing a circle
    around each substantial statement and replacing
    it with a letter.
  • 3) Try to fill in the letters with alternative
    substance in such a way that you make the
    premises true, and the conclusion false. This is
    a counterexample to the argument.
  • If you can find a counterexample of this kind,
    then you know that the argument was invalid.

46
Testing validity with a counterexample
  • In order to institute a stable regime in Iraq
    and pull out, we need help from our former
    allies. But if Candidate Zero wins the election,
    then our former allies will continue to refuse to
    help us. So if Zero wins the election, we will
    not be able to institute a stable regime and pull
    out of Iraq.
  • If moral relativism were true, then we should
    expect to find that different cultures have very
    different moral values. But this is just what we
    do find different cultures do have different
    moral values. Therefore moral relativism must be
    true.

47
Testing validity with a counterexample
  • In order to institute a stable regime in Iraq
    and pull out, we need help from our former
    allies. But if Candidate Zero wins the election,
    then our former allies will continue to refuse to
    help us. So if Zero wins the election, we will
    not be able to institute a stable regime and pull
    out of Iraq.
  • Interpretation
  • If we wish to pull out of Iraq, then we need
    help from our allies.
  • If Zero is elected we wont have help.
  • If Zero is elected, then we wont be able to
    pull out.
  • Form
  • If X then Y
  • If B then Not Y.
  • If B then not X.
  • This argument is valid No counterexample will
    be forthcoming. But note that if you fail to
    find a counterexample, you dont know for sure
    that the argument is valid! Note also that my
    assurance that the argument is valid does not
    prove that the conclusion is true Perhaps one of
    the premises is false.

48
Testing validity with a counterexample
  • If moral relativism were true, then we should
    expect to find that different cultures have very
    different moral values. But this is just what we
    do find different cultures do have different
    moral values. Therefore moral relativism must be
    true.
  • If X then Y.
  • Y.
  • Therefore X.

You already know that this argument is
invalid, Since it affirms the consequent. But
for a Counterexample Counterexample If an
animal is a dog, then it must have hair. My pet
spider has hair. Therefore my pet spider is a
dog.(?)
49
Another interpretation
  • If (institute a stable regime in Iraq) and
    (pull out) then (we need help from our former
    allies.)
  • If (Zero wins) then (our allies wont help)
    Therefore if (Zero wins) then (no stable regime)
    and (wont pull out of Iraq).
  • If (X and Y) then Z. (Still valid.)
  • If B then Not Z
  • If B then Not (X and Y)
  • One more thing to notice Even though this
    argument is valid, it implies nothing about
    whether we will be able to pull out of Iraq and
    institute stability if Zero does not win. The
    argument is consistent, for example, with the
    view that we cant accomplish these things no
    matter who wins the election.

50
Testing Validity
  • If you were to take a class in formal logic, you
    would learn more reliable and technical ways to
    test for validity. When arguments are very
    complicated, you cant always simply see that
    they are valid or invalid.

51
Nondeductive Arguments Can be Good Arguments
  • Deductive arguments guarantee the truth of their
    conclusions given the truth of the premises.
  • Inductive and abductive arguments do not
    guarantee the truth of the conclusion, but when
    such arguments are strong, they provide good
    evidence that the conclusion is true. If you
    have a good non-deductive argument for a claim,
    then you have reason to believe that it is
    probably true.

52
Dick should not drink the coffee.
53
Inductive and Abductive Arguments
  • Inductive Argument (or induction)  A
    nondeductive argument in which characteristics of
    individuals not in a sample are inferred from the
    characteristics of individuals in a sample.
  • Abductive argument (or abduction) A form of
    nondeductive inference, also called inference to
    the best explanation in which a hypothesis is
    supported on the ground that it is the best
    explanation for some observed phenomenon.

54
Inductive and Abductive Arguments
  • Here is an example of an inductive argument
  • (1) 95 of all examined fish from the Otsoga
    river contained dangerous levels of mercury.
  • (2) This fish came from the Otsoga river.
  • (3) Therefore, this fish (probably) contains
    dangerous levels of mercury.

55
Facts about Inductive Arguments
  • Inductive arguments are never valid, but they
    may still be good arguments. Inductive arguments
    are said to be strong when they provide good
    evidence that the conclusion is true, and weak
    when they dont provide good evidence.
  • Inductive arguments are Strong when the sample is
    large and representative. They are weak when the
    sample is small or unrepresentative.

56
Weak Inductive Arguments
  • 1) All Bobs friends say that they plan to vote
    for Barak Obama.
  • 2) Therefore, it seems likely that Obama will
    take Iowa by a landslide.
  • Problem Unrepresentative Sample. Bobs
    friends are not likely to be a representative
    sample of Iowans as a whole. If Bob plans to
    vote for Obama, then its likely that many of his
    friends are like-minded voters.

57
Weak Inductive Arguments
  • 1) On interviewing six students at the Union, it
    was found that four of them planned to spend the
    summer in Iowa, while two of them planned to go
    abroad.
  • 2) Therefore, 33 of ISU students (probably) plan
    go abroad during the summer.
  • Problem Sample size too small. Six students
    is too small a number to make predictions about
    the whole student body.

58
Abductive Arguments
  • The world must be spherical in shape.  For the
    night sky looks different in the northern and
    southern regions, and this would be so if the
    earth were spherical.   -Aristotle, Physics.
  • To put this argument in standard form, we might
    interpret it as follows
  • (1) The night sky looks different in the
    northern and southern regions.
  • (2) The best explanation for this fact is that
    the earth is round.
  • (3) Therefore (probably) the earth is spherical
    in shape.

59
Evaluating Abductive Arguments
  • Abductive arguments are stronger if the
    explanation posited in the conclusion is the only
    explanation that will adequately account for the
    phenomenon to be explained, or if it is the most
    likely of a small set of possible explanations.
  • Abductive arguments are weaker if there are many
    other plausible explanations that would account
    for the phenomenon, or if we have independent
    reason to believe that the explanation offered is
    unlikely.

60
Evaluating Abductive Arguments
  • There is an odd and very loud banging sound
    coming from the classroom upstairs from our own.
  • If there were elephants up there, it would
    explain the sounds we hear.
  • There are elephants in the room upstairs from our
    classroom.

61
Evaluating Abductive Arguments
  • Why is the argument weak?
  • There are many alternative explanations for the
    sounds we hear.
  • We have independent reason to doubt that there
    are elephants upstairs.

62
Evaluating Abductive Arguments
  • When is an abuductive argument weak?
  • When the explanation offered is only one of many
    alternative explanations for the sounds we hear.
  • When alternative explanations are simpler,
    independently more plausible, or otherwise
    preferable to the explanation offered.
  • Where there is independent reason to doubt the
    offered explanation.

63
Argument for Analysis
  • People may seem to be kind, compassionate, or
    altruistic, but if you really search out the
    basis of their actions you will discover that
    theyre really behaving selfishly. Every
    voluntary action is motivated by the values of
    the actor herself. So in all of our voluntary
    actions, we are pursuing our own ends.
    Exclusively to pursue ones own ends is to be
    selfish. So all of our voluntary actions are
    ultimately selfish.

64
READING PLATO REPUBLIC Book I
  • I. PLATO (427-347 BCE)A. Some Background on
    Plato
  • Athens in 300BCE a place of high culture and
    intellect, in which philosophic dialogue could
    flourish (this may have been possible only
    because Athenians held slaves- the legacy is a
    mixed one). Plato lived during a time of turmoil
    in Athens.

65
READING PLATO REPUBLIC Book I
  • Dialogue form Plato's writings are in the form
    of dialogues- careful philosophical
    conversations, in which one character (usually
    Socrates) propounds Plato's own views. Other
    characters in the dialogues usually have lots of
    lines like "Yes Socrates." "Oh of course
    Socrates" "Why of course, you've made that
    perfectly clear Socrates, you're so clever and
    wise..."
  • Others, like Thrasymachus in Republic Book I, are
    usually passionate and bullying, and are driven
    to mouth frothing fury by the inexorable reason
    of Socrates.
  • Sophists 'sophistry' Traveling teachers who
    took money for teaching. Plato looked down on
    them, and his contempt is usually reflected in
    the writings of contemporary philosophers, who
    nevertheless accept their paychecks. Plato was
    independently wealthy, and apparently despised
    those who weren't.

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READING PLATO REPUBLIC Book I
  • Sophists 'sophistry' Traveling teachers who
    took money for teaching. Plato looked down on
    them, and his contempt is usually reflected in
    the writings of contemporary philosophers, who
    nevertheless accept their paychecks. Plato was
    independently wealthy, and apparently despised
    those who weren't.

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READING PLATO REPUBLIC Book I
  • A2. Socrates and Plato
  • Socrates (469-399 BC)-neglected his work and
    family to wander streets and talk-Oracle at
    Delphi claimed that he was the wisest man alive.
    But Socrates believed that he knew nothing.
    Reasoned that if the Oracle was right, it must be
    because he at least KNEW that he was ignorant,
    while others falsely believed that they had
    knowledge.

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READING PLATO REPUBLIC Book I
  • Socratic Method- asking questions and offering
    counterexamples in a manner which ultimately
    leads the other person to reach the right (or at
    least a better) conclusion.
  • Philosopher as GADFLY (to prick at complacently
    held prejudice, and ill founded opinion) or
    MIDWIFE (to help others to give birth to truth,
    by asking the right questions to help them to
    figure out what the answer might be). Meiutic
    method...
  • Socrates condemned for being "an evil doer and a
    curious person, searching into things under the
    earth and above the heaven and making the worse
    appear the better cause, and teaching all this to
    others."
  • -Many were annoyed by Socrates' manner. (more
    people at his trial sentenced him to death than
    had earlier found him guilty- presumably because
    his defense made them mad at him.

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READING PLATO REPUBLIC Book I
  • Plato
  • -Socrates most celebrated student-had two older
    brothers (Glaucon and Adiamantus) They figure in
    the Republic. All were fortunate to come from a
    wealthy and important family. Related on fathers
    side to last king of Athens, on mothers to Solon,
    founder of Athenian Law.-Plato originally named
    Aristocles after his father Ariston, but was
    nicknamed Plato by his wrestling coach, since
    Plato is the Greek word for 'broad.' (Probably
    referred to the width of his forehead or
    shoulders.)-Founded Academy of Athens- a "great
    center of learning and wisdom."

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READING PLATO REPUBLIC Book I
  • How to Read Plato
  • 1) First, read the story line, catching the main
    subjects discussed and the main divisions marking
    change of subject or direction.
  • 2) Then Go Back and read for more specific
    content of the arguments. Tease out the structure
    of the dialogue and the patterns of reasoning,
    the claims being made, the arguments being
    offered.
  • 3) Reconstruct the argument in your own terms,
    including consideration of possible objections or
    alternatives. 4) Go back and see whether Plato
    has actually addressed your objections or
    worries.

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READING PLATO REPUBLIC Book I
  • FORM of DISCUSSIONBOOK I
  • Discussion with Cephalus Polemarchus, then...
  • Thrasymachus' challenge
  • Statement
  • Socrates objection
  • Thrasymachuss Speech
  • Socrates (unsatisfactory) response
  • BOOK II GLAUCON AND ADIAMANTUS TAKE UP
    THRASYMACHUS CASEThe rest of the book is a
    response to this strengthened case.

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READING PLATO REPUBLIC Book I
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