Presentation: "Arguments"
Please turn off
all cell phones!
Room Change:
Sec 009
CB 346
Fall 2010
PHI 120
Raise your hand
to get a syllabus,
if you don't already have one.
Homework for Next Lecture
• Read J/H, Introductory Logic
– Chapter 2, pp. 25-48.
• Answer "review questions,"
p. 47: 1-3, 6, 9-10
– may be collected by your recitation instructor
• Homework assigned last class:
– Read Chapter 1
– p. 22 Answer “review questions," p.22: 1, 4 – 8, 10
Class Web Site
http://sweb.uky.edu/~rsand1/phi120/
tilde – rsand -- onephi -- 120
• Important documents
Available Sunday Before Class
• Presentations
Daily schedule (Including Exams)
Grading
• 3 exams
= 60%
– 20% each of total grade
– Administered in the lecture classroom
• Quizzes/Homeworks
= 40%
– Administered in recitation sections
• 20% - quizzes
• 20% - homework
Total =100%
Grading
• Attendance/Participation: mandatory
– +3% for perfect attendance
– no penalty for only one unexcused absence
– -2% for every subsequent unexcused, up to 10%
– 7 unexcused absences = 50% deduction
Read the lecture and recitation syllabi carefully!
Introduction
Logic and Argument
PHI 120 Introductory Logic
Introductory Logic, PHI 120
What is an argument?
Does abuse play any role in rational argumentation?
Is contradiction an argument?
Is mere contradiction bad argumentation?
What is a good argument?
What sort of intellectual process is argumentation?
Definitions
• Argument
– a set of statements connected together in such a
way that the truth of one statement is claimed to
follow from at least one (other) statement
– Properties of a Statement
1. Subject-predicate
form
What is a phone?
Turn true
off your
phones!
2. Either
or false
vs.
Statements
either
ordimensions.
false.
A phone
is a woodenare
object
having true
only two
or
The phone rang in the classroom.
Logical Arguments
• “Arguments”
that
are
not
logical
An argument is a collected series of
– Mr Barnard: WHAT DO YOU WANT?
– Man: Well, I was told outside that...
– Mr Barnard: Don't give me that, you snotty-faced heap of parrot
droppings!
Man:abuse
What?
•– not
Barnard:
Shut yourisfestering
gob, you
Your type really
•– aMrgood
argument
more than
justtit!contradiction?
makes me puke, you vacuous, coffee-nosed, maloderous,
pervert!!!
– Man: Look, I CAME HERE FOR AN ARGUMENT, I'm not going to
just stand...!!
– Mr Barnard: OH, oh I'm sorry, but this is abuse.
next lecture
statements to establish a definite
proposition.
What is a good argument?
Statements in an Argument
• Every argument contains one conclusion and
at least one premise
Statements in an Argument
“If argument
you are a UK
student,
must and
• Every
contains
oneyou
conclusion
fulfillone
thepremise
logic-inference USP
at least
requirement.
You are a whose
UK student.
– Conclusion:
the statement
truth is So
claimed
must
fulfill
the
requirement.”
toyou
follow
from
some
evidence
• More than a one conclusion, more than one argument
– Premise(s): provide evidence in support of a
conclusion being true
Argument Analysis
The Argumentative Passage
• Non-argumentative elements
a) Explanatory passages
b) Opinion unsubstantiated by any reference to
evidence for it being true
c) Warnings
d) Etc.
"Freedom of religion might provide the right to build the mosque in
the shadow of Ground Zero, but common sense and respect for
those who lost their lives and loved ones gives sensible reason to
build the mosque someplace else."
Democratic U.S. Senate candidate Jeff Greene of Florida
http://news.yahoo.com/s/ap/20100814/ap_on_go_pr_wh/us_ground_zero_mosque_obama
Our aim: argument analysis
• Identify main conclusion
• Lay out premises (evidence) in
support of that conclusion
The heart of an argument is its
conclusion
First step in argument analysis:
Identify the conclusion
Clue Words
Identifying the conclusion
and premises
Clues to Argument Form
If you don’t study, you’ll do poorly in this class.
Congratulations. You got an A. Since you did well,
I conclude you must have studied.
• Common indicator words
– Conclusion: therefore, thus, hence, consequently,
so
– Premise: because, since, for, given
Clues to Argument Form
If you don’t study, you’ll do poorly in this class.
Congratulations. You got an A. Since you did well,
I conclude you must have studied.
• Common indicator words
– Conclusion: therefore, thus, hence, consequently,
so
– Premise: because, since, for, given
Argument Form
If you don’t study, you’ll do poorly in this class.
Congratulations. You got an A. Since you did well,
I conclude you must have studied.
• Note: "Congratulations" is an interjection and not part of
the argument.
• Note: "You got an A" is the same as "you did well."
The Form of this Argument
Premises:
(1) If you don't study, you'll do poorly in this class
(2) You did well.
Conclusion:
(3) You must have studied.
Argument Analysis
Diagramming
Diagramming
1. Representation of argument form
– Structure of support
• Independent
• Joint
– Extended arguments
2. Technique of analysis
– A useful device for making sense of complicated
pieces of reasoning
(1) If you don’t study, then you will do poorly
in this class. (2) However, you got an A which
is excellent. (3) Hence you must have studied.
Joint Support Structure
Another Example
(1) Since apes don’t have language, (2) they
can’t reason.
(1) Since apes don’t have language, (2) they
can’t reason.
Independent Support Structure
More Complicated Example
One last example
An extended argument
1) Since apes don’t have language, and (2)
language is necessary to be able to reason, (3)
it follows that apes can’t reason. (4) For their
speech pathways are too underdeveloped in
their brains.
1) Since apes don’t have language, and (2)
language is necessary to be able to reason, (3)
it follows that apes can’t reason. (4) For their
speech pathways are too underdeveloped in
their brains.
Summary
1. Any argument is composed of statements
– one conclusion
– a number of premises
2. Argument Analysis
i. Identify the (main) conclusion
ii. Diagram
3. Diagramming
A. Structures:
1) Independent
2) Joint
B. Extended arguments
Homework for Next Lecture
• Read J/H, Introductory Logic
– Chapter 2, pp. 25-48.
• Answer "review questions,"
p. 47: 1-3, 6, 9-10
– may be collected by your recitation instructor
• Homework assigned last class:
– Read Chapter 1
– p. 22 Answer “review questions," p.22: 1, 4 – 8, 10