Argument Basics
Getting to
Accept - Reject - Suspend Judgment
Argument
• An argument is an attempt to convince
someone (possibly yourself) that a
particular claim, called a conclusion, is
true,
– The rest of the argument is a collection of
claims called the premises, which are
given as the reasons for believing the
conclusion is true.
– The conclusion is sometimes called the
issued that is being debated.
Argument Basics
Premises
1) Acceptable
2) Relevant
Conclusion
About Premises
• May be stated or unstated
About Premises
• May be stated or unstated
The laws of nature and moral law are one and the same.
[Human beings can understand the laws of nature.]
[Human beings must follow the laws of nature.]
So, the human community is charged with the task of
ordering its life according to the same kind of objective
principles by which the cosmos itself is ordered.
-- Adapted from The American Soul, by Jacob Needleman
About Premises
• May be stated or unstated
• May be dependent or independent
About Premises
• May be stated or unstated
• May be dependent or independent
Dependent premises need at least one other premise
to provide support for a conclusion.
About Premises
• May be stated or unstated
• May be dependent or independent
Dependent premises need at least one other premise
to provide logical support for a conclusion.
Independent premises provide some support for an
argument’s conclusion whether or not any other
premises are present (given reasonable
assumptions).
About Premises
• May be stated or unstated
• May be dependent or independent
In every free society, which the U.S. intends to be, there
must be opposite parties and violent dissensions.
Generally, one party must prevail over the others.
A free society cannot be preserved if the parties do not
commit to remaining united even if they don’t prevail.
So, a durably free America must include both strong
dissent and commitment to preserve the union.
Adapted from Thomas Jefferson
About Premises
• May be stated or unstated
• May be dependent or independent
In every free society, there must be opposite parties and
violent dissensions.
A free society cannot be preserved if the parties do not
commit to remaining united.
So, a free America can be expected to include both
strong dissent and commitment to preserve the union.
About Premises
• May be stated or unstated
• May be dependent or independent
• May be indicated by lead-in words or
phrases
Indicator Words
About Premises
• May be stated or unstated
• May be dependent or independent
• May be indicated by lead-in words or
phrases
Since…
For the reason that…
For…
In view of…
Because…
This is implied by…
In as much as…
Given that…
Suppose that…
It follows from…
It follows from…
Due to…
About Premises
• May be stated or unstated
• May be dependent or independent
• May be indicated by lead-in words or
phrases
• May need support or explanation
About Premises
• May be stated or unstated
• May be dependent or independent
• May be indicated by lead-in words or
phrases
• May need support or explanation
This is usually provided in a supporting or
explanatory paragraph or in more detailed
discussion.
About Premises
• May be stated or unstated
• May be dependent or independent
• May be indicated by lead-in words or
phrases
• May need support or explanation
• May be surrounded by irrelevancies
About Conclusions
• May be stated or unstated
About Conclusions
• May be stated or unstated
Religious freedom is the first freedom guaranteed in the
Bill of Rights.
It was also the single most important reason why the
earliest settlers in the Colonies left the safety and
relative comfort of their homes to start new lives here.
The bedrock freedoms of American civilization will
always need to be protected and interpreted for the
times.
So…
About Conclusions
• May be stated or unstated
Religious freedom is the first freedom guaranteed in the
Bill of Rights.
It was also the single most important reason why the
earliest settlers in the Colonies left the safety and
relative comfort of their homes to start new lives here.
The bedrock freedoms of American civilization will
always need to be protected and interpreted for the
times.
So, we must still interpret and defend religious freedom.
About Conclusions
• May be stated or unstated
• May be controversial
About Conclusions
• May be stated or unstated
• May be controversial
Madonna’s productions frequently contain religious
themes and symbolism.
Her work has been the topic of serious study by
respected scholars of religion.
So, Madonna’s work, even her highly sexual material,
must be protected as religious expression by the First
Amendment.
About Conclusions
• May be stated or unstated
• May be controversial
• May be indicated by lead-in words or
phrases
About Conclusions
• May be stated or unstated
• May be controversial
• May be indicated by lead-in words or
phrases
Thus…
Therefore…
This shows that…
So…
Accordingly...
This implies that…
Hence…
Consequently… This proves that…
Ergo…
It follows that… This suggests that…
About Conclusions
• May be stated or unstated
• May be controversial
• May be indicated by lead-in words or
phrases
• Must contain only terms found in the
premises (or their equivalents)
About Conclusions
• May be stated or unstated
• May be controversial
• May be indicated by lead-in words or
phrases
• Must contain only terms found in the
premises (or their equivalents)
The presence of new terms in a conclusion is
strong evidence of unstated premises.
About Arguments
• Valid Arguments: Argument is valid if
it is impossible for the premises to be
true and the conclusion false (at the
same time; otherwise it is invalid.
About Arguments
• Strong and Weak Arguments: Invalid
arguments are classified on a scale
from strong to weak. An argument is
strong if it is very unlikely for the
premises to be true and the conclusion
false (at the same time); an argument is
weak if it is likely for the premises to be
true and the conclusion false.
In any of these ways is the
conclusion false?
Ways The Premises Could Be True
NO = VALID
Every Way The Premises
Could Be True
The Conclusion is True
YES = INVALID
Very Unlikely
STRONG
Not so Likely
WEAK
What are the Claims in the
Argument?
The Standard a Poor’s index rose 4%
today. Dick has $2,000 in an S&P index
mutual fund. So Dicks mutual fund
account went up $80 today.
What are the Claims in the
Argument?
The Standard a Poor’s index rose 4% today.
Dick has $2,000 in an S&P index mutual fund.
So Dicks mutual fund account went up $80
today.
Premise 1: The S&P index rose 4% today.
Premise 2: Dick has $2,000 in an S&P index
mutual fund.
Conclusion: Dick’s mutual fund account went up
$80 today.
What are the Claims in the
Argument?
The Standard a Poor’s index rose 4% today.
Dick has $2,000 in an S&P index mutual fund.
So Dicks mutual fund account went up $80
today.
Is this a valid argument?
Analysis: This is a valid argument: It is
impossible for the premises to be true and the
conclusion false.
Whether it is a good argument depends on
whether its premises are true.
Tests for an Argument to be Good
• The premises are plausible
• The premises are more plausible than
the conclusion
• The argument is valid or strong
What are the Claims in the
Argument?
Señora Vez is an economics professor. All
economics professors are socialists. So
Señora Vez is a socialist.
What are the Claims in the
Argument?
Señora Vez is an economics professor. All
economics professors are socialists. So
Señora Vez is a socialist.
Premise 1: Señora Vez is an economics
professor
Premise 2: All economics professors are
socialists
Conclusion: Señora Vez is a socialist
What are the Claims in the
Argument?
Señora Vez is an economics professor. All
economics professors are socialists. So
Señora Vez is a socialist.
Is this a valid argument?
Analysis: This is a valid argument: It is
impossible for the premises to be true and the
conclusion to be false.
Is it a good argument? NO! The second
premise is false.
Deductive and Inductive Arguments
One way of conceptualizing
arguments is by the degree of
confidence one is supposed to
have in the conclusion if the
premises are true.
Deductive and Inductive Arguments
Deductive arguments are
constructed with the
intention of supporting
their conclusions
perfectly, that is, with
premises that, if true,
guarantee the truth of
the conclusion.
Deductive and Inductive Arguments
Deductive arguments are
constructed with the
intention of supporting
their conclusions
perfectly, that is, with
premises that, if true,
guarantee the truth of
the conclusion.
Inductive arguments are
constructed with the
intention of providing
the strongest possible
support for the
conclusion, even
though they are unable
to guarantee the truth
of the conclusion.
Explanations
Why is this claim true?
An inferential explanation is a collection of
claims that can be understood as
“Something Happened”
because of
• A
• B
• C
Explanation
• We call A, B, and C the explanation.
• “Something Happened” is the claim
being explained.
When is an explanation good?
• The claim is highly plausible.
• The explanation addresses the correct
claim.
• The explanation is plausible.
• The explanation is valid and strong.
• The explanation is not circular.