Title: Reasoning and Argument Analysis
1Reasoning 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.
3What 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.
4When 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)
7Rational 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.
8Indicator 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
9Conclusion Indicators
- Because
- Since
- For
- For the reason that
10Example
- 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.
11Examples
- 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.
12Standard 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.
13Standard 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.
14A 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.
15Evaluating 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.
16Questions
- 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.
17Whats 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.
18Whats 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.
19Step 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.
20Step 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.
21Step 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.
22Step 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.
23Step 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?
26Argument 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.
27In 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.
28Thoughts 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?
29Fallacies
- Fallacy An argument that provides the illusion
of support, but no real support, for its
conclusion.
30Evaluating 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.
31Next 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.
32Deductively 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.
33Comments
- 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?
34Comments 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
35Comments 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.
36Soundness
- An argument is sound iff it is deductively
valid, and its premises are true.
37Some 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.
-
38Some 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.
-
39Some 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.
-
40Some 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.
41Some 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?)
42Quiz 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.
43Quiz 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.
44Aristotelian 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!
45An 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.
46Testing 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. -
47Testing 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.
48Testing 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.(?)
49Another 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.
50Testing 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.
51Nondeductive 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.
52Dick should not drink the coffee.
53Inductive 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.
54Inductive 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.
55Facts 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.
56Weak 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.
57Weak 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.
58Abductive 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.
59Evaluating 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.
60Evaluating 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.
61Evaluating 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.
62Evaluating 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.
63Argument 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.
64READING 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.
65READING 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.
66READING 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.
67READING 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.
68READING 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.
69READING 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."
70READING 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.
71READING 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.
72READING PLATO REPUBLIC Book I