Structuring Arguments
Inductive Reasoning
Inductive Reasoning – the process of generalizing
on the basis of a number of specific examples
Ex.
I get hives after eating crawdads.
My mouth swells when I eat clams.
Shrimp triggers my asthma.

I am allergic to shellfish
Deductive Reasoning
 Deductive Reasoning – the process of reaching a
conclusion by assuming a general principle (called the
major premise) and then applying that principle to a
specific case (called the minor premise).
Ex.
I am allergic to shellfish

Lobster is a type of shellfish

Lobster will cause me to have an allergic reaction.
This is called a syllogism.
Syllogisms
All humans are mortal.
Socrates is a human being.
Therefore, Socrates is mortal.
Enthymemes
Syllogisms that leave out the middle (and obvious)
minor premise = Enthymemes
 We’d better cancel the picnic because it is going to
rain.
 I’ll buy a PC laptop instead of a Mac because it’s
cheaper.
 If you can construct sound inductive or deductive
arguments and present them clearly in words or
images, you will influence most audience.
The Toulmin Argument
 British Philosopher Stephen Toulmin, The Uses of
Argument (1958) describes how ordinary people
make reasonable arguments.
 Because this system acknowledges qualifiers
(sometimes, often, unless, almost) it is not as airtight
as formal logic – using syllogisms.
 But because of that, it has become a practical tool for
understanding and shaping arguments in the real
world.
Making Claims
 Debatable and controversial statements or
assertions that you hope to prove.
 Arguments depend on conditions set by others –
your audience or readers.
 Claims that are worth arguing tend to be
controversial – there is no point worrying about
points on which most people agree. Claims should
be debatable, able to be demonstrated using logic or
evidence.
Making Claims
Many claims are developed through questions:
Question: What should NASA’s next goal be? Should
the space agency establish a permanent moon base?
Should NASA launch more robotic interstellar
probes? Can NASA even afford to send people to
Mars?
Statement: NASA should launch a human expedition
to Mars.
Offering Evidence and Good Reasons
Claims need evidence and good reasons to support it.
Claim: Campus needs more officially designated spaces for parking
bicycles.
Evidence:
 Personal experience: At least twice a week for two terms, I was
unable to find a designated space for my bike.
 Anecdotes: Several friends told similar stories. One even sold her
bike as a result.
 Facts: I found out that the ratio of car to bike parking spaces was
100 to 1, whereas the ratio of cars to biker registered on campus was
25 to 1.
 Authorities: The campus police chief has indicated in an interview
with the college newspaper that she believed a problem existed for
students who tried to park bicycles legally.
Determining Warrants
The logical and persuasive connection between a claim
and the reason and data supporting it.
Reason (so) Claim

(since) Warrant
The mushroom is poisonous So don’t eat it!

Since eating poison is dangerous
Determining Warrants Continued
The warrant tells readers what your often unstated
assumptions are.
When you state a warrant accurately, you sometimes
expose a fatal flaw in an argument.
I don’t like grades So grades should be abolished

Since what I don’t like should be abolished
Stating and then examining a warrant can help you determine
the grounds on which you want to make a case.
Enthymeme: Flat taxes are fairer than progressive taxes
because they treat all taxpayers in the same way.
Warrants:
Treating people equitably is the American
way.
All people should be treated in the same way.
Issues with the warrant: If it is inequitable than why are
federal and state income taxes progressive?
Stating and then examining a warrant can help you determine
the grounds on which you want to make a case.
Enthymeme: Progressive taxes are fairer than flat
taxes because people with more income can afford to
pay more, benefit more from government, and can
shelter more of their income from taxes.
Warrants: People should be taxed according to their
ability to pay.
People who benefit more from government and
can shelter more of their income from taxes should
be taxed at higher rates.
Offering Evidence: Backing
Claims and Warrants = skeleton of an argument
The bulk of a writer’s work – the richest, most
interesting part- remains to be done after the
argument is outlined.
Offering Evidence - Backing
 Enthymeme: NASA should launch a human expedition to Mars because
Americans need a unifying national goal.
 Warrant: What unifies the nation ought to be a national priority.
 Backing: On a personal level, Americans want to be part of something
bigger than themselves (Emotional appeal as evidence)
 In a country as regionally, racially, and culturally diverse as the United
States, common purposes and values help make the nation stronger
(Ethical appeal as evidence).
 In the past, big government investments such as the Tennessee Valley
Authority, Hoover Dam, and Apollo moon program enabled many – though
not all – Americans to work toward common goals. (Logical appeal)
In addition to evidence to support your warrant (backing), you’ll need
evidence to support your claim:
Enthymeme:
NASA should launch a human expedition to Mars because
Americans now need a unifying national goal.
Evidence:
 The American people are politically divided along lines of race, ethnicity,
religion, gender, and class (Facts as evidence).
 A common challenge or problem often unites people to accomplish great
things (Emotional appeal as evidence)
 Successfully managing a Mars mission would require the cooperation of the
entire nation – and generate tens of thousands of jobs (Logical appeal as
evidence)
 A human expedition to Mars would be a valuable scientific project for the
nation to pursue (Appeal to values as evidence.)
Using Qualifiers
Qualifiers make writing more precise and honest:
Few
More or less
Often
It is possible
In some cases
Perhaps
Rarely
Many
It seems
In the main
Possibly
Some
Routinely
It may be
Most
If it were so
Sometimes
In general
One might argue Under these conditions
For the most part
Qualifiers
Never assume that readers understand the limits you
have in mind. By spelling out the terms of the claim
as precisely as possible, you’ll have less work to do,
and your argument will seem more reasonable.
Your ACT scores are
in the 98th percentile
So (it is likely) you will
get into a good college


High ACT scores are an important factor in college
admissions
Qualifiers
Unqualified Claim: People who don’t go to college earn less
than other who do.
Qualified Claim: In most cases, people who don’t go to
college earn less than those who do.
Unqualified Claim: Welfare programs should be cut.
Qualified Claim: Ineffective federal welfare programs
should be identified, modified, and if necessary,
eliminated.
Understanding Conditions of Rebuttal
Claim: The federal government should support the arts.
Argument in brief: The federal government should support the arts
because it also supports the military.
Warrant: If the federal government can support the military, then it
can also support other programs.
Rebuttal: Just because we support the military we should support
anything?
Revised Argument: If the federal government can spend huge amounts
of money on the military, then it can afford to spend moderate
amounts on arts programs.
Outline of the Toulmin Argument
Claim: The federal government should ban smoking.
Qualifier:
The ban would be limited to public spaces.
Good Reasons: Smoking causes serious diseases in
smokers.
Nonsmokers are endangered by secondhand
smoke.
Warrants:
The constitution promises to “promote the
general welfare”
Citizens are entitles to protection from harmful
actions by others
Outline of the Toulmin Argument
Backing:
The United States is based on a political
system that is supposed to serve the basic
needs of its people, including their heath.
Evidence:
Numbers of deaths attributed to secondhand
smoke.
Lawsuits recently won against large tobacco
companies, citing the need to reparation for
smoking-related health care costs.
Examples of bans already imposed in many
public places.
Authority:
Cite the surgeon general.
Outline of the Toulmin Argument
Conditions of Rebuttal:
Response:
Smokers have rights too.
Smoking laws should be left to the
states.
Such a ban could not be enforced.
The ban applies to public places, smokers can
smoke in private.
The power of the federal government to impose
other restrictions on smoking (such as warning
labels on cigarettes and bans on cigarette
advertisements on television) has survived legal
challenges.
The experience of New York City, which has imposed
such a ban, suggests that enforcement would not be a
significant problem.
What Toulmin Teaches
 Claims should be stated clearly and qualified
carefully.
 Claims should be supported with evidence and good
reasons.
 Claims and reasons should be based on assumptions
that readers will likely accept.
 Effective arguments respectfully anticipate
objections readers might offer.
Classical Oration
Structure of argument devised by Greek and Roman
rhetoricians 2000 years ago for presenting cases in
courts or making speeches to a senate.
Still influences our attitudes toward persuasion
because oration taught speakers and writers to think
of arguments as debates that have winners and
losers.
Structure of Classical Oration
 Exordium: The speaker/writer tries to win the
attention and goodwill of an audience while introducing
a subject or problem
 Narratio: The speaker/writer presents the facts of the
case, explaining what happened when, who is involved,
and so on. The narration puts an argument in context.
 Partitio: The speaker/writer divides up the subject,
explaining what the claim is, what the key issues are, and
in what order the subject will be treated.
Structure of Classical Oration continued
 Confirmatio: The speaker/writer offers detailed
support for the claim, using both logical reasoning
and factual evidence.
 Refutatio: The speaker/writer acknowledges and
then refutes opposing claims or evidence
 Peroratio: The speaker/writer summarizes the case
and moves the audience to action.
Benefits of Classical Oration
 The structure is powerful because it covers all the
bases: readers or listeners want to know what your
subject is, how you intend to cover it, and what
evidence you have to offer.
 Begins with presenting a pleasing ethos
 Concludes with enough pathos to win an audience
over completely
Updated Version of Classical Oration
Introduction:
 Gains reader’s interest and willingness to listen
 Establishes your qualifications to write about your
topic
 Establishes some common ground with your
audience
 Demonstrates that you’re fair and evenhanded
 States your claim
Updated Version Continued
Background
 Presents any necessary information, including personal
narrative, that’s important to your argument
Lines of Argument
 Presents good reasons, including logical and emotional
appeals, in support of your claim
Alternative Arguments
 Examines alternative points of view and opposing arguments
 Notes the advantages and disadvantages of these views
 Explains why your view is better than others
Updated Version continued
Conclusion
 Summarizes the argument
 Elaborates on the implications of your claim
 Makes clear what you want the audience to think or
do
 Reinforces your credibility and perhaps offers and
emotional appeal
Example: Declaration of Independence
Exordium –
“When in the course of human events, it becomes necessary for one people to dissolve the political
bands which have connected them with another…”
“We hold these truths to be self-evident, that all men are created equal…”

Narratio –
“He has…” Establishes what King George has done.

Partitio –
“The history of the present King of Great Britain is a history of repeated injuries and usurpations.”

Confirmatio –
“Long train of abuses and usurpations.”

Refutatio –
“We warned them” “We have reminded them” “We have appealed to their native justice”

Peroratio –
“That these United Colonies are, and of Right ought to be FREE and INDEPENDENT STATES:

Rogerian Argument
Carl Rogers, psychologist, developed nonconfrontational principles of discussion, later
applied to public situations.
Rogers believed people involved in disputes should not
respond to each other until they could fully, fairly,
and even sympathetically state the other person’s
position.
Rogerian Structure
 Introduction: The writer describes an issue, a
problem, or a conflict. The description is rich
enough to demonstrate that the writer fully
understands and respects any alternative position or
positions.
 Contexts: The writer describes the contexts in
which the alternative positions may be valid or
legitimate.
Rogerian Structure
 Writer’s position: The writer states his or her
position on the issue and presents the circumstances
in which that opinion would be valid.
 Benefits to opponent: The writer explains to
opponents how they would benefit from adopting his
or her position.
Benefits of Rogerian Argument
The key is a willingness to think about opposing positions
and to describe them fairly.
Example: Martin Luther King Jr.’s “I Have a Dream”
speech.
“When we allow freedom to ring, when we let it ring from
every village and every hamlet, from every state and
every city, we will be able to speed up that day when all
God’s children, black men and white men, Jews and
Gentiles, Protestants and Catholics, will be able to join
hands and sing in the words of the old Negro spiritual,
‘Free at last! Free at last! Thank God Almighty, we are
free at last!’”