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

Critical ThinkingLesson 9

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)


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.


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.


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.


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.


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.


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 for because in the first place as shown by first, second … as indicated by inferred fromgiven that may be derived from assuming that

Cue Words Signaling Conclusionstherefore then thus it follows that hence thereby showing so demonstrates that (which) shows that allows us to infer (which) proves that suggests that implies that you see 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.


Forms of ArgumentTwo 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.

Example1. Reason/premise: All persons are mortal. 2. Reason/premise: Socrates is a person. 3. Conclusion: Therefore, Socrates is mortal.


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.


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.


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.



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.)



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.


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.


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.



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.


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.



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.)


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.


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.


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.

critical thinking lesson 9

Documents

example qualified claim

logical argument

larger principles

ideas of argument

purpose of argument

warrants support

following concepts

people dont