Critical Thinking
Lesson 9
Lesson 9 Objectives
• Identify classical concepts of argument
• Evaluate arguments in terms of truth, validity, and
soundness
• Analyze and critique an argument in terms of its
strengths and weaknesses
Principles of Argument
The words argument and rhetoric are
commonly understood to mean
“quarrel” and “insubstantial or
misleading language,” respectively.
In this lesson, we will define these
words as follows:
• Rhetoric: The use of the best
means of persuasion
• Argument: A form of thinking in
which certain statements (reasons
or evidence) are offered to support
another statement (a conclusion or
a claim)
Principles of Argument
The concepts that guide logical argument are central to Western
culture: logical thinking and structured arguments are expected
in business, government, and scholarship.
The Greek philosopher Aristotle is the source of many concepts
basic to our ideas of argument. Those concepts include the
following:
• Ethos: the character of the speaker or writer
• Pathos: the emotional effect of words or speech on an
audience
• Logos: the logic and substance of an argument.
An effective thinker and writer should strive to use these
elements effectively in his or her own arguments and be able to
identify them in others’ arguments.
Principles of Argument
The Toulmin Method
College composition students are often introduced to the work of
Stephen Toulmin, a British professor of philosophy. The following
concepts are crucial to the Toulmin method:
Claim and Qualified Claim: The main idea or argument. A
qualified claim refines a claim by providing more specific
information.
• Example (claim): People should brush and floss their teeth
regularly.
• Example (qualified claim): Research suggests that brushing
and flossing regularly may reduce the impact of early onset
dementia.
Principles of Argument
The Toulmin Method, Continued
Grounds: Reasons, evidence, support, examples, and data
offered as part of an argument.
• Example: Dentists tell us that brushing and flossing will help
prevent tooth decay and gum disease.
Warrants: The assumptions, principles, premises, and beliefs
that are the foundations of most arguments.
• Example: People do not want their teeth to fall out. They do
not want to have toothaches or ugly decayed teeth. People
do not want drilling, fillings, and dentists’ bills.
Principles of Argument
The Toulmin Method, Continued
Backings: Larger principles that support warrants (or “the
foundations of the foundations”).
• Example: A backing for the warrants about brushing and
flossing is the principle of self-interest. People are concerned
about their own health, thus the backing of the principle of
self-interest supports warrants about what people don’t
want, and these warrants support and connect the claim and
grounds about dental hygiene.
Principles of Argument
Some people believe that the
purpose of argument is to coerce
or to win. However, critical
thinkers use argument as a
means to developing a deeper
understanding of an issue or
idea.
This involves making an effort to
fully appreciate other
perspectives and points of view.
Principles of Argument
Guidelines for addressing other points of view:
• Restate the other claim to show that you understand it. Restatements
can uncover misunderstandings and lead to finding common ground.
• Find areas of agreement, or common ground, at the outset of the
argument. When people see that they agree about some parts of an issue,
they establish a basis of mutual respect from which they can begin the
process of examining their differences. Identifying warrants can often reveal
areas of agreement.
• Identify which differences are important and which are trivial. Here,
too, identifying warrants can often clarify the significance of parts of an
argument.
• Concede points that you cannot uphold. Sometimes you will have to
concede that some of your opponents’ ideas are so strong that you cannot
counter them, even if you do not agree with them.
• Compromise. At times, accepting a middle position or a partial achievement
of your purpose is better than relentlessly pursuing complete achievement.
• Rebut. This means to refute or to present opposing evidence. If you have to
rebut an opposing point, do so courteously.
Recognizing Reasons and
Conclusions in Arguments
Cue Words Signaling Reasons
since
in view of
because
in the first place
first, second …
as indicated by
given that
may be derived from
Cue Words Signaling Conclusions
therefore
then
it follows that
hence
so
demonstrates that
allows us to infer
(which) proves that
implies that
you see that
for
as shown by
inferred from
assuming that
thus
thereby showing
(which) shows that
suggests that
points to
Evaluating Arguments
To construct good arguments, you must be
skilled at identifying and evaluating the
components of arguments presented by
others.
To evaluate an argument, you must address two primary
questions:
• How true are the reasons being offered to support the
conclusion?
• To what extent do the reasons support the conclusion, claim,
or thesis?
When an argument includes true reasons and a valid structure, the
argument is considered sound.
When an argument has false reasons or an invalid structure,
however, the argument is considered unsound.
Evaluating Arguments
Forms of Argument
Two major thinking methods — deduction and induction —
provide the foundations for most arguments.
In a deductive argument, one reasons from premises that are
known or assumed to be true to a conclusion that necessarily
follows from these premises.
Example
1. Reason/premise: All persons are mortal.
2. Reason/premise: Socrates is a person.
3. Conclusion: Therefore, Socrates is mortal.
Evaluating Arguments
In an inductive argument, your premises, instances, or data
provide evidence that makes it more or less probable (but not
certain) that the conclusion is true.
Example
• Premise (data): Recent surveys correlating level of
education and income showed an average difference of
$830,000 in lifetime earnings between those with higher
and lower levels of education.
• Conclusion: We can predict that most people with a
college degree will earn an average of $830,000 more in
lifetime earnings than people without college degrees.
Evaluating Arguments
Forms of False Reasoning
Certain forms of reasoning are not logical. These types of false
reasoning are often termed “fallacies,” that is arguments that
are not sound because of various errors in reasoning.
Following are a few examples of categories of false reasoning:
Hasty Generalization: When a general conclusion has been
reached that is based on a very small sample:
• My boyfriends have never shown any real concern for my
feelings. My conclusion is that men are insensitive, selfish,
and emotionally superficial.
• My mother always gets upset over insignificant things. This
leads me to believe that women are very emotional.
Evaluating Arguments
Forms of False Reasoning, Continued
Sweeping Generalization: When generalizations that are true
in most cases are assumed to be true in all cases:
• Vigorous exercise contributes to overall good health.
Therefore, vigorous exercise should be practiced by recent
victims of heart attacks, people who are out of shape, and
women in the last month of pregnancy.
• People should be allowed to make their own decisions,
providing that their actions do not harm other people.
Therefore, people who are trying to commit suicide should
be left alone to do as they please.
Evaluating Arguments
Forms of False Reasoning, Continued
False Dilemma: Also known as the either/or fallacy and the
false dichotomy fallacy, false dilemma occurs when one is asked
to choose between two extreme alternatives without being able
to consider additional options:
• You’re either for me or against me.
• America — love it or leave it!
Begging the Questions: When a claim is restated in different
words, thus sidestepping the important questions involved:
• Tough antidrug laws reduce drug use by making usage a
criminal act. (This example begs the question of the
effectiveness of prohibiting a substance and of punishment
for its use.)
Evaluating Arguments
Forms of False Reasoning, Continued
Red Herring: When a topic that is not relevant to the main
topic is introduced to shift the audience’s attention from one
argument to another. A red herring argument typically follows
this structure:
1. Topic A is under discussion.
2. Topic B is introduced under the guise of being relevant to
topic A (when topic B is actually not relevant to topic A).
3. Topic A is abandoned.
Evaluating Arguments
Forms of False Reasoning: Fallacies of Relevance
Many people use false arguments to try to gain support by
appealing to factors that have little or nothing to do with the
arguments. The following are categories of fallacies of relevance.
Appeal to Authority: When the opinion of an authority is cited
in support of an argument, even though that person may not be
an authority on the subject in question:
• Hi. You’ve probably seen me out on the football field. After a
hard day’s work on the gridiron, I like to settle down with a
cold, smooth Maltz beer.
Evaluating Arguments
Forms of False Reasoning: Fallacies of Relevance,
Continued
Appeal to Pity: When the reasons offered to support a
conclusion are not relevant to the conclusion and are intended to
make people agree with the conclusion out of sympathy:
• I know I haven’t completed my term paper, but I really think
I should be excused. This has been a very difficult semester
for me. I caught every kind of flu that came around. In
addition, my brother has a drinking problem, and this has
been very upsetting for me. Also, my dog died.
Evaluating Arguments
Forms of False Reasoning: Fallacies of Relevance,
Continued
Appeal to Fear: When the conclusions being suggested are
supported by an appeal to fear, not by reasons that provide
evidence for the conclusions:
• I don’t think you deserve a raise. After all, many people
would be happy to have your job at the salary you are
currently receiving. I would be happy to interview some of
these people if you really think you are underpaid.
• If you continue to disagree with my interpretation of The
Catcher in the Rye, I’m afraid it may affect the grade on
your paper.
Evaluating Arguments
Forms of False Reasoning: Fallacies of Relevance,
Continued
Appeal to Ignorance: When a conclusion is offered as valid on
the sole basis that it cannot be immediately disproved. This
argument form is not valid because it is the task of the person
proposing the argument to prove the conclusion:
• You say that you don’t believe in God. But can you prove that
an omnipotent spirit doesn’t exist? If not, then you have to
accept the conclusion that it does in fact exist.
Evaluating Arguments
Forms of False Reasoning: Fallacies of Relevance, Continued
Appeal to Personal Attack: When a person making an argument
ignores the issue at hand and instead focuses on discrediting the
person arguing the opposing position:
• Senator Smith’s opinion about a tax cut is wrong. It’s impossible to
believe anything he says since he left his wife for that model.
• How can you have an intelligent opinion about abortion? You’re not
a woman, so this is a decision you’ll never have to make.
Appeal to Popular Opinion or the Bandwagon: When the main
argument for accepting a position, argument, or conclusion is the
suggestion that “everybody else is doing it”:
• Awww, Dad, I really need a new iPod. Everyone else in my class
has one!
Writing Project: Arguing a Position on a
Significant Issue
In this Lesson you’ll write a paper
in which you argue logically for a
position on an issue that you
consider significant. (See the text
for more detailed guidelines.)
Writing Project: Arguing a Position on a
Significant Issue
The Writing Situation
Purpose: You’ll write an argument to persuade your audience to agree
with your claim or thesis. A secondary purpose is to think critically
about a subject and clarify or modify your position.
Audience: Some factors to consider in thinking about your audience
are knowledge, age, roles, relationships, and the emotional level of the
issue and situation.
Subject: Regardless of what you choose to write about, the techniques
of argument themselves constitute a subject because argument has
such importance in people’s lives.
Writer: If you have been using sources for other projects, you should
be comfortable incorporating other people’s ideas into your writing and
documenting them appropriately. A new role for you may be that of the
good rhetorician, the responsible arguer.
Writing Project: Arguing a Position on a
Significant Issue
The Writing Process
Generating Ideas:
If no issue comes quickly to mind, look around your campus and
community to see what problems exist or what changes could be
made.
• Be attentive to various print, broadcast, and online news
outlets. Talk with friends, family members, and professors
about significant issues.
• Think about your areas of interest: college subjects, sports,
entertainment, food, cars, the environment, architecture.
• Freewrite about one or two of your concerns. See how many
issues or positions you can come up with in five minutes.
Writing Project: Arguing a Position on a
Significant Issue
The Writing Process
Defining a Focus: After selecting an issue to write about, draft a
thesis statement that describes the position you will argue. Be sure
that the statement states your points accurately.
Organizing Ideas: Your argument should probably be set up in the
traditional “no-fail” structure: introduction, thesis, evidence, handling
of other views, summing up, conclusion/ recommendation for action.
Drafting: Be sure to keep track of publication information for all
sources. Note titles, authors, and pages in your draft. Then, when you
revise, you can cite the sources in the required format. Be sure to use
quotation marks or indenting in your draft whenever you quote.
Revising, Editing, and Proofreading: Use the Step-by-Step method
in Chapter 6 on pages 169–171 to revise your essay and prepare a final
draft.