Chapter 2: Lecture Notes
Pinning Down Argument Structure
Chapter 2
Before we can evaluate an argument, we need to
understand what just what the argument in question is.
We need to know what the premises and conclusion are
and how the premises are supposed to support the
conclusion.
Standardizing an argument: to standardize an argument is
to set out its premises and conclusion in clear
statements with the premises preceding the conclusion
like so:
Premise 1
Premise 2…
Premise N
Therefore,
Conclusion
Chapter 2
We number the premises and conclusions so that it makes
it easy to refer to them by a name: the number. So we
can talk about (1) or premise (1) without having to
rewrite the entire premise.
Standardizing the argument gives us a clear view of where
the arguer is going and forces us to look carefully at
what the arguer has said (22-3). Here is an argument in
standard form.
(1) If Chuck is in Atlanta, then Chuck is in Georgia.
(2) Chuck is not in Georgia.
Therefore,
(3) Chuck is not in Atlanta.
This simple argument is in a clear, standard form.
Chapter 2
Arguments often proceed in stages. Sometimes a premise
in one argument is a conclusion of another argument.
This phenomena happens in what are called
subarguments.
A subargument is a subordinate argument that is a
component of a larger argument, called the whole
argument. Figure 2.2 shows the logical relationship of
this kind of case.
From page 25.
Chapter 2
In figure 2.2, statement (2) represented by the circled ‘2’ is
the conclusion of a subargument and may be called the
subconclusion. But (2) is also a premise in the main
argument.
The main argument is (2) and (3) to (4), and when we add
the main argument with the subargument we get what
we call the whole argument.
Subarguments are necessary and useful, because
sometimes you need to justify a premises with another
subargument.
In figure 2.2, (4) is also called the main conclusion.
Chapter 2
When a premise could give rise to two different conclusion,
we call a divergent structure. Some would claim that
Figure 2.4 has two acceptable diagrams of a divergent
structure. We will prefer the more compact structure on
the left.
Chapter 2
There is no upper limit to the number
of subargument a person could have
as part of a whole argument.
Figure 2.5 to the right shows
what we call a linear structure
of an argument where:
(1) supports (2) and (2) supports (3)
and (3) supports (4).
Chapter 2
Standardizing an argument is not always a simple matter.
People write and speak in a way that is more
disorganized (and more interesting) than the “(1) and (2),
therefore (3)” format that is best for evaluating
arguments. They word statements in the form of
questions and commands, repeat themselves, include
background and aside remarks, tell jokes, wander off the
topic, and so on. These elements of colloquial writing
and speech are eliminated when we put the argument in
standardized form.(29)
The point of standardized form is clarity of the reasoning
involved in the argument.
Chapter 2
10 General Strategies for Standardizing Arguments
(1) Read and understand the passage
(2) Make sure the passage contains an argument
(3) Identify the conclusion, premises, and any subarguments
(4) Omit irrelevant material or side remarks
(5) Omit material already used (don’t repeat information)
(6) Omit personal phrases like “in my hunble opinion”
(7) Number the premises and conclusion and standardize the argument
(8) Make premises complete indicative sentences without pronouns
(9) Check for subarguments in premises and conclusions
(10)Check your argument against the passage for errors or omissions
See page 31 for fuller guidelines.
Chapter 2
Location, Scope, and Commitment
You need to realize that the conclusion of an argument can
come anywhere in the passage. From the beginning to
the end to anywhere in between. And sometimes the
concussion isn’t stated at all, but must be inferred by the
reader. So, don’t get stuck looking at the end for
conclusions anyplace other than standard form.
Rhetorical questions sometimes are disguised premises
and conclusions, and the same thing goes for
commands/imperatives. Our argument in standard form
must always be in the form of a statement.
See page 35-6 for examples of this phenomenon.
Chapter 2
Both conclusions and premises can vary in scope:
For example:
(1)
(2)
(3)
(4)
(5)
(6)
(7)
All politicians are corrupt
Most politicians are corrupt
Many politicians are corrupt
Some politicians are corrupt
A few politicians are corrupt
At least one politician is corrupt
No politicians are corrupt
Universal claims like (1) and (7) are easy to show false with
one example. When this happens we call it a counter
example. Abe Lincoln show (1) false, and for (7), well…
Chapter 2
When formalizing an argument we have to be especially
sensitive to degrees of commitment.
This is related to scope, but it relates to how committed to a
particular premise or conclusion a arguer might be.
Sometimes they may give unqualified claims like (1) and
(7) from before, but other times they may not.
“From the point of view of understanding and evaluating
arguments, it would be convenient if people always used
words to indicate the scope of their claims and the
degree of commitment with which they are advancing
those claims. Unfortunately, many speeches and
passages are not explicit in these ways.” (37)
Chapter 2
Patterns of Arguments:
We have seen arguments that use linked support, figure
2.5 and 2.9. We have seen divergent argument like in
figure 2.4. We also have cases of combination support
like in figures 2.10 (left) and 2.11 (right) below. This
occurs when premises together support a conclusion.
Chapter 2
There are also cases of convergent support like in figure
2.12 below. We will look at these arguments more in
chapter 12.
And of course there are combinations of arguments that
employ all or many of the patters. See figure 2.13 on
page 39 for an example.
Chapter 2
Unstated premises and conclusions:
It is possible for an argument to be presented in a passage
where a premise or a conclusion goes unstated or is
missing. When diagramming an argument that has an
unstated premise or conclusion you can indicate the
missing piece by underlining the number of the premise
or name to show that you are aware that it was unstated.
For evaluating argument we need to take care to be
charitable in interpreting the argument of others. We
need to be fair to the arguer.
Chapter 2
Charity and Accuracy
These two goals can conflict. So, we need to make sure
that we are charitable to the arguer, but not to the point
that we get away from the original argument.
Too charitable an interpretation can lead us away from
accuracy and this is what we want to try to avoid.
So we want to adhere to a principle of modest charity when
we reconstruct someone else's argument all the while
trying to be accurate at the same time.
Chapter 2
Terms to review:
Charity as a principle of interpretation
Convergent support
Counterexample
Degree of commitment
Divergent patter of argument
Linear structure
Linked support
Main conclusion
Missing, or unstated premise
Qualified or tentative conclusion
Rhetorical
question
Scope (of a premise or conclusion)
Subargument
Standardizing and argument
Whole argument
Unstated, or missing conclusion