Philosophy 1100
Title:
Critical Reasoning
Instructor:
Paul Dickey
E-mail Address: pdickey2@mccneb.edu
Website:http://mockingbird.creighton.edu/NCW/dickey.htm
Today: Editorial Essay #1 Due.
Next class (6/24/13):
New Portfolio Assignment & Submit your
Portfolio for review by Instructor
Reading Assignment: Chapters Six and Seven
1
Student Portfolios:
Assignment #3
How do I know an argument when I see it?
How do I evaluate it? How does Relevance
play in this? Collect from your daily
experience 2-3 “artifacts” that describe your
identification of an argument in your daily
life, either one you made yourself or one you
observed from someone else.
·
For each, write a description or
explanation of the artifact selected and how
you evaluate the argument for yourself. (1
paragraph)
·
Write a brief assessment of the
relevance of your anecdotes chosen in
Section Two of your portfolio to that topic.
·
Chapter Two
Review
Two Kinds of Reasoning
The Fundamental Principle of Critical
Thinking is The Nature of an Argument
•
Making a claim is stating a belief or opinion
-- the conclusion
•
An argument is presented when you give a
reason or reasons that the claim is true. -the premise(s)
•
Thus, an argument consists of two parts,
and one part (the premise or premises)
is/are the reason(s) for thinking that the
conclusion is true.
What is a Factual Claim?
• A claim is sometimes called an assertion,
an opinion, a belief, a “view”, a thought, a
conviction, or perhaps, an idea.
• A claim must be expressed as a statement
or a complete, declarative sentence. It
cannot be a question.
• In its clearest form, a claim asserts that
something is true or false. That is, it
asserts a fact. This kind of claim is
known as a “factual claim” or a
“descriptive claim.”
What is a Normative Claim?
• Value statements can also be claims
though. In such claims, a fact is not
asserted in the same sense that it was in
factual claims.
• For example, the claim “You should come to
class” is not true or false (at least in the
same way that the claim “P1100 class is
held in Room 218” is).
• Thus, some claims are “normative claims”
or “prescriptive claims.” They express
values and how one should act based on
values. A value statement is a claim that
asserts something is good or bad.
Now, Critical Thinking is Absolutely
Relevant to Both Sets of Claims
• As we shall see in this class, it is
necessary that we identify very
clearly which kind of a claim we
have before we can properly
evaluate any argument for it!
• Thus, please note we are taking a
position against the subjectivist and
saying that even moral judgments
can be analyzed by the principles
of critical thinking.
Arguments & Subjectivism
•
The view that “one opinion is as good as
another,” “it’s true for me though it might not
be true for you” or “whatever is true is only
what you think is true” is known as
subjectivism.
•
For some things, this makes sense, e.g.
Miller taste great.
My grandson is cute.
The waiter at the restaurant was nice.
•
Your text refers to these as “subjective
claims” and says that “some people” (but
presumably not critical thinkers may call
these “opinions.”)
Two Kinds of Good Arguments
•
A good deductive argument is one in which if
the premises are true, then the conclusion
necessarily (that is, has to be) true.
•
Such an argument is called “valid” and
“proves” the conclusion.
•
For example – Lebron James lives in the United
States because he lives in Nebraska.
All men are mortal.
Socrates is a man.
____
Socrates is mortal.
•
A sound argument is a valid, deductive
argument in which the premises are in fact true.
How Do Premises Support Conclusions?
For an Deductive argument, premises prove or
demonstrate a conclusion based on if the premises
make the conclusion certainly true.
Consider the argument:
(P1) If it’s raining outside, the grass near the
house gets wet.
(P2) It’s raining outside.
_________________________
The grass near the house is wet.
In a Deductive argument, premises prove a
conclusion based on the logical form of the
statement or based on definitions. It would be a
contradiction to suggest that the conclusion is
false but the premises are true.
Two Kinds of Good Arguments
•
A good inductive argument is one in
which if the premises are true, then the
conclusion is probably true, but not
always. The truth of the premises do not
guarantee the truth of the conclusion.
•
Such an argument is called “strong”
and supports the conclusion.
•
For example: Dan lives in Nebraska
and he loves football, so he is a
Nebraska Cornhusker fan.
If offered to me before class tonight, I would
have made a bet with my wife that each of you would
sit in the same seat in class that you did last week.
If she would have taken the bet, would I
have won more money than I would have lost?
What is “Beyond a Reasonable Doubt” vs “Proof?
•
Although standard English usage is often
lax about this, technically speaking,
PROOF requires a valid deductive
argument.
•
“Beyond a reasonable doubt” requires a
level of evidence in an inductive
argument such that if someone were to
believe it were not true, they might still
possibly be right, but that probability is
so remote that reasonable, critical
thinking, people will be satisfied to act
and claim to know without a proof.
How Do Premises Support Conclusions?
For an Inductive argument, premises support
(never prove) a conclusion based on how strongly
the premises provide evidence for the conclusion.
Consider the argument (Variation One):
(P1) When it rains outside, the grass near the house
only gets wet when the wind is blowing strongly
from the North.
(P2) The wind usually blows from the South in
Omaha.
________________________
Even though it is raining, the grass near the house is
not wet.
How Do Premises Support Conclusions?
For an Inductive argument, premises support
(never prove) a conclusion based on how strongly
the premises provide evidence for the conclusion.
Consider the argument (Variation Two):
(P1) When it rains outside, the grass near the house
always gets wet when the wind is blowing strongly
from the North.
(P2) In Omaha, the wind usually blows from the
South.
(P3) Today the wind is blowing from the North.
________________________
The grass near the house is wet.
How Do Premises Support
Factual vs. Normative Conclusions?
In regard to evaluating Inductive support for Factual
vs. Normative Conclusions, I would suggest the
following two tips to keep in mind
1) Only Factual Premises support Factual
Conclusions. That is, if the conclusion is factual (or
descriptive), ALL premises must be factual.
2) A Normative Premise is always needed to
support a Normative Conclusion. That is, if the
conclusion is normative (or prescriptive), there must
be at least one normative premise. Of course, there
may or may not be factual premises!
Chapter Three:
Vagueness
& Ambiguity
16
Vagueness
•
A vague statement is one whose meaning is
imprecise or lacks appropriate or relevant detail.
“Your instructor wants everyone to be
successful in this class.”
“Your instructor is bald.”
•
Vagueness is often evident when there are
borderline cases. Problem is not so much what the
concept is but what is the scope of the concept.
(e.g. baldness)
•
Some assertions may be so vague that they are
essentially meaningless (e.g. “This country is
morally bankrupt,” but most concepts though
vague can still be useful.
17
Vagueness
•
A critical thinker will first want to clarify what is
being asserted, even before asking about what are
the reasons to believe or what is the evidence.
•
The more precise or less vague a statement is the
more relevant information it gives us.
a. Rooney served the church his entire life.
b. Rooney has taught Sunday School in the
church for thirty years.
a. The glass is half full with soda pop.
b. I poured half of a 12 oz can of soda pop into the
empty glass.
18
Vagueness
•
What detail is appropriate depends on audience
or the issue. It can be difficult to determine.
Compare your friend calling you after reading an
article in the paper about mortgage rates and
telling you that you should expect to pay higher
rates vs. your bank calling you and telling you
that your mortgage rate is going up.
You are at your neighbor’s for a BBQ and you
ask him, “So how big is your yard? How far does
the property line go to? “ He says “Oh, right
behind the trees.” This is probably a good
answer. But now you are thinking about buying
his home and you ask the real estate agent the
same question. You will not be satisfied with his
“vague” answer.
19
Vagueness
•
Vagueness at times is intentional and useful.
1) Precise information is unavailable and any
information is valuable.
“This word just in. There has been a shooting at the
Westroads Mall and there may be fatalities. More
information will be forthcoming as soon as
available.”
2) Precise information will serve no useful function in
the context (yes, even in a logical argument!)
Rarely, if ever, at a funeral, does a minister remind the
grieving family that their father only attended church
infrequently and showed no interest in his family
attending. Ministers who would do such a thing would
probably be considered jerks.
20
Vagueness in a Logical Argument
•
The bottom line in the context of analyzing or
proposing a logical argument, a claim is vague
when additional information is required to
determine whether or not a premise is relevant.
•
Such vagueness is always a weakness and
effort must be taken to avoid it. It is generally
considered to be “hiding the evidence” when it
is done intentionally.
•
You remove vagueness by adding the relevant
detail.
21
Ambiguity
•
A statement which can have multiple
interpretations or meanings is
ambiguous.
•
Examples:
“Lindsay Lohan is not pleased with our textbook.”
“The average student at Metro is under 35.”
“Jessica rents her house.”
“Alice cashed the check.”
“The boys chased the girls. They were giggling.”
22
Ambiguity
•
Of course, ambiguities can be obvious
(and perhaps rather silly)
“The Raider tackle threw a block at the
Giants linebacker.”
“Charles drew his gun.”
•
In these cases, we are not likely to be
confused. The context tells us more or
less what is meant. However, it should
be understood that it is often not good to
assume our audience will always have
the same knowledge, orientation, and
background that we do.
23
Ambiguity
•
Carmen's Swimsuit Switcheroo
Frequently a logical argument is
sabotaged by a person switching
meanings in the middle of an
argument. This is known as
equivocation.
We all know what we mean by
“subjective” in this class, but we need
to be sure that the term is used
consistently and not switch to one of
the other meanings in the middle of a
a discussion.
24
Ambiguity
•
•
Ambiguities can also be quite subtle, e.g. “We heard
that he informed you of what he said in his letter.”
•
One ambiguity here is whether the person (the
“you” in question) received a letter at all. Did “he”
inform “you” of what he said but only we saw a
letter to that affect, thus “we heard in his letter (to
us),” or did “we hear” that within a letter “you”
were informed and we heard that you were
informed by means of a letter to “you”?
•
Such a point might seem tedious, but could in
fact legally be very significant.
Actually, Bill Clinton had a point when he said “It
depends on what the meaning of is is.” e.g. Are you
having a fight with your husband?
25
Ambiguity
•
Keep in mind that ambiguity, like
vagueness, is at times intentional and
often is useful.
1) Clever uses of “double meaning” can
catch our attention and entertain us or
provoke us to consider the claim more
carefully.
“Tuxedos cut ridiculously.”
“You can’t pick a better juice than
Tropicana.”’
“Don’t freeze your can at the game.”
“We promise nothing.”
26
Ambiguity in a Logical Argument
•
The bottom line is that in the context of
analyzing or proposing a logical argument,
ambiguity is always a weakness and effort
should be taken to avoid it.
•
If you use it for “effect,” you should be
absolutely sure that the claim and your
premises are clear to your audience.
27
Ambiguity
•
Please note that while with the case of
vagueness, we resolved it by adding
information that clarified meaning, with the
case of ambiguity what we are interested in
is to eliminate the suggestion of the potential
alternate meaning that we do not desire.
•
“The Raider tackle threw a block at the
Giants linebacker.”
We want to eliminate the possibility that one
could think that one is “throwing a block (of
wood?)” Thus, we can say “ The Raider
tackle blocked the Giant’s linebacker.”
28
Ambiguity
•
Let’s discuss three kinds of ambiguity.
1. Semantic ambiguity is where there is an
ambiguous word or phrase, e.g. “average” price.
-- When Barry Goldwater ran for president, his
slogan was, "In your heart, you know he's right."
In what way is this ambiguous?
2. Syntactic ambiguity is where there is ambiguity
because of grammar or sentence structure, e.g.
--“Players with beginners’ skills only may use
Court #1.”
3. Grouping ambiguity is ambiguous in that the
claim could be about an individual in the group or
the group entirely,
-- Baseball players make more money that
computer programmers.” (fallacy of division)
29
Defining Your Terms
•
Defining terms helps one avoid vagueness
and ambiguity.
Video
•
Sometimes you need to use a stipulating
definition if perhaps you are using a word in
an argument in a different way than it is
usually understood or it is a word in which
there is itself some controversy.
•
It is frequently quite reasonable in a logical
argument to accept a stipulating definition that
you would not yourself have chosen, but does
not pre-judge the issue and allows the
discussion to precede without distractions.
30
Defining Your Terms
•
Most definitions are one of three kinds:
1.
2.
3.
Definition by example.
Definition by synonym.
Analytical definition.
•
Any of these might be appropriate.
•
Be careful of “rhetorical” definitions that use
emotionally tinged words to pre-judge an
issue.
•
Do not allow someone in an argument to
use a “rhetorical definition” as a stipulative
definition. If you do, the argument will likely
be pointless and subjective.
31
Chapter Five:
Persuasion Through
Rhetoric
•
Rhetoric tries to persuade through
use of the emotional power of
language and is an art in itself.
•
Though it can be psychologically
influential, rhetoric has no logical
strength.
•
Rhetoric does not make your
argument any better, even if it
convinces everyone.
•
Can you recognize rhetoric?
Euphemisms and Dysphemisms
•
A euphemism attempts to mute the
disagreeable aspects of something.
•
If I say a car is “pre-owned,” does that
sound better and a person would be more
likely to buy it than if I said the car was
“used?” There is no logical difference. it
is the same car.
•
Would you be more willing to support a
“revenue enhancement” or a “tax
increase”?
Euphemisms and Dysphemisms
•
Fox news put out an internal memo to its
staff to refer to U.S. servicemen in Iraq as
“sharpshooters” not “snipers.”
•
Often, we try to make something
“politically correct” by using euphemisms.
•
I would suggest perhaps a better strategy
might be to identify clearly and logically
analyze biases and thus we would likely
discard them.
•
Oppositely, a dysphemism attempts to
produce a negative association through
rhetoric.
•
How do you feel about “freedom fighters?”
How do you feel about terrorists? Often,
the difference is only based upon which
side you are on.
•
Please note that it is NOT a dysphemism
to state an objective report that just
sounds horrible, e.g. “Lizzy killed her
father with an ax.”
Analogies
•
An analogy is a form of reasoning in which one
thing is inferred to be similar to another thing in a
certain respect, on the basis of the known
similarity between the things in other respects.
•
An argument from analogy involves the drawing
of a conclusion about one object or event
because the same can obviously be said about a
similar object or event.
•
An argument from analogy can be a good
inductive argument that supports its conclusion.
•
The strength of any argument from analogy
largely depends on the strength and relevance
of the employed analogy.
Rhetorical Deceptions & Dirty Tricks
•
But a rhetorical analogy attempts to
persuade by use of a comparison (often
clever and humorous) without giving us an
argument.
Hilary’s eyes are bulgy like a
Chihuahua.
Dick Cheney has steel in his backbone.
Social Security is a Ponzi scheme.
Video
Definitions
•
An honest definition attempts to clarify
meaning. A rhetorical definition uses
emotionally tinged words to elicit an
attitude that is vague (often intentionally)
and pre-judges the issue.
Bill Maher’s defined a conservative as
“one who thinks all problems can be
solved either by more guns or more
Jesus.”
Abortion is the murder of innocent,
unborn children.
Rhetorical Explanations
•
A rhetoric explanation is similarly
deceptive and attempts to trash a person
or idea under a mask or pretense of
giving an explanation.
•
The War in Vietnam was lost because the
American people lost their nerve.”
•
Students who drop my classes do so
because they are idiots.
•
Liberals who criticize the U.S. Army’s actions
in Iraq do so only because they are disloyal to
their country.
Stereotypes
•
A stereotype is used when a speaker
groups multiple individuals together with a
name or description, suggesting that all
members of the group are the same in
some basic way.
•e.g. women are emotional, men are
insensitive, gays are effeminate,
lesbians hate men, Black men are good
at sports.
•
Stereotypes are not supported by adequate
evidence and ignore the psychological
principle of individual differences.
Stereotypes
•
People who do not think critically often
accept stereotypes because of limited
experience.
•Tiger Woods and Michael Jordan are
good at sports. Thus,….
•
Stereotypes typically originate and become
popular because of a cultural agenda (e.g.
economic privileges) and in a environment
of ignorance.
Native American tribes of the Great Plains
were generally considered noble people by
most white Americans until it became
economical advantageous to confiscate
their lands.
Most individuals of the early 20th century
who harbored biases against Native
Americans and African-Americans knew
very few personally or knew them only in
specifically defined roles.
Stereotypes are often manipulated as
propaganda to incite a nation to support a war
or actions during time of an emergency crisis.
• Hitler’s use in WWII of ethnic
propaganda not only was against Jews,
but also Blacks, gypsies, but certain
other religious groups.
• In the United States, we re-located
Japanese families on the West Coast.
• Some people believe today that the
tea-party protests against the health
care bill are manipulations for racist
agendas (based on stereotypes). But
careful, do you have GOOD PREMISES
to believe either that they are or they
are not?
Innuendo
•
An innuendo is a deceptive and veiled
suggestion or a slanting device applying
negatively to an opponent’s character or
reputation or to insert a claim though which
a direct statement of the claim is avoided
(perhaps because there is no evidence).
• e.g. “Ladies and gentlemen, I am proof
that there is at least one candidate in
this race who does not have a drinking
problem.”
•
Please note that in an innuendo the
statement given will typically be absolutely
true.
Innuendo
•
The innuendo is based on the expectation
that the reader will “read into” the
statement something more than what is
actually said, possibly thus making
unwarranted assumptions about why the
speaker may have said it.
In this case, the speaker wants the
listener to believe without giving
evidence that there is some reason to
believe that one or more of his
opponents has a drinking problem.
Innuendo
•
Did President Bush in his 2003 State of the
Union address claim that Saddam Hussein
was responsible for the 9/11 terrorist attack?
•
Or did he only “say” that Saddam in general
sponsored terrorists?
http://www.youtube.com/watch?v=rgwqCdv3YQo&feature=related
The Loaded Question
•
A loaded question is a question that suggests
strongly an unwarranted and unjustified
assumption.
• e.g. Do you still hang around with petty
criminals? Have you stopped beating your
wife? Why have you not renounced your
earlier crimes? When are you going to
stop lying to us?
•
This technique is often used quite
intentionally in police interrogations to get a
suspect to confess to acts that the police
have no evidence for.
Weaseling
•
Weaseling protects you from criticism by
watering down your claim.
• e.g. What if I would have previously said,
“Probably most individuals of the early
20th century who harbored biases against
Native Americans and African-Americans
knew very few personally?”
• If so, would have my statement been a
good premise? No, not much. If you
questioned it, I have a “way out.” Thus, it
seems to lack much meaning.
Weaseling
•
Weaseling is a method of hedging a bet.
You can sometimes spot weaseling by
an inappropriate and frequent use of
qualifiers, such as “perhaps,” “possibly,”
maybe,” etc.
•
Be careful. qualifiers also are used often
to carefully say what can legitimately be
said about an issue and are not weasel
words. You need to assess the context
carefully.
Weaseling
•
Three years later, does President Bush
“weasel” on his earlier justification for the Iraq
war or does he “clarify?”
http://www.youtube.com/watch?v=ZKd71JxEYzE
Minimizing or Downplaying
•
Words and devices that add no
argument but only suggest that a
source or a claim is less significant than
what the claim or premises suggest is
called downplaying or minimizing, e.g.
Are you going to vote for a “hockey
mom?” Or “just another liberal?”
•
You can sometimes spot this by a use
of words or phrases like “so-called,”
“merely,” “mere,” or “just another.”
•
Downplayers often also make use of
stereotypes.
“That’s just Dick Cheney”
Ridicule / Sarcasm
•
Ridicule and sarcasm is a powerful
rhetorical device (often called The Old
Horse Laugh Fallacy).
•
Keep in mind that it adds absolutely
nothing to the logical force of an
argument.
•
Questioning the “intelligence” of the
person that makes a claim is logically
irrelevant to whether the claim itself is true
or false.
Video
Ridicule / Sarcasm
•
•
It is interesting after watching a spirited
debate (for example, one of political
candidates) to analyze whether the
person who came off more “humorous”
or “entertaining” and the one whom we
might have thought “won” the debate
actually took advantage of his
opponent unfairly through this method.
If so, we should re-examine ourselves
whether we were thinking critically
during the debate.
Video
Hyperbole
•
Hyperbole basically means
exaggeration or an extravagant
overstatement.
• e.g. “My boss is a fascist dictator.
He won’t let anybody do things
their own way. It is always his way
or the highway.”
•
This kind of statement, considered for
exactly what it says, is silly and lacks
credibility.
Hyperbole
•
Interestingly, hyperbole often works even
when no one believes it. In this example,
we probably don’t believe the statement
is actually true, but we would probably be
reluctant to take a job working for this guy
thinking something like “where there’s
smoke, there must be fire.”
•
Be careful: As critical thinkers, we have
no more reason to believe the claim that
the boss is a problematic one to work for
than we do to believe the hyperbole.
•
BREAKING NEWS!
Proof Surrogates
•
A proof surrogate is an expression that
suggests that there is evidence or
authority for a claim without actually
citing such evidence of authority.
• e.g. “informed sources say,” ”it is
obvious that” or “studies show” are
typical proof surrogates.
•
Proof surrogates are not substitutes for
evidence or authority.
Proof Surrogates
•
The introduction of a proof surrogate does
not support an argument.
•
They may suggest sloppy research or even
propaganda.
•
The use of proof surrogates, on the other
hand, should not be interpreted that
evidence does not exist or could not be
given. You just don’t know.
Never drive in a storm without wiper blades.
& Never go into the fierce storms of an
argument without your
WIPER SHIELD
to protect you from the evil forms of rhetoric devices:
W easeling,
I nnuendo,
P roof Surrogates
E xplanations, Analogies & Definitions
(Rhetorical)
R idicule/Sarcasm
S tereotypes
H yperbole
I mage Rhetoric
E uphemisms/Dysphemisms
L oaded Questions, and
D ownplaying/Minimizing