Induction and Deduction

Traditionally, arguments are classified as either inductiveA reasoning method that draws a general conclusion from a particular set of facts. or deductiveA reasoning method based on drawing a single conclusion from multiple pieces of evidence.. Inductive arguments consider a number of results and form a generalization based on those results. In other words, say you sat outside a classroom building and tallied the number of students wearing jeans and the number wearing something other than jeans. If after one hour, you had tallied 360 students wearing jeans and 32 wearing other clothes, you could use inductive reasoning to make the generalization that most students at your college wear jeans to class. Here’s another example. While waiting for your little sister to come out of the high school, you saw 14 girls wearing high heels. So you assume that high heels are standard wear for today’s high school girls.

Deductive arguments begin with a general principle, which is referred to as a major premise. Then a related premise is applied to the major premise and a conclusion is formed. The three statements together form a syllogismA deductive conclusion drawn from a major premise and a minor premise.. Here are some examples:

• Major premise: Leather purses last a long time.
• Minor premise: I have a leather purse.
• Conclusion: My purse will last a long time.
• Major premise: Tara watches a lot of television.
• Minor premise: Tara is a very good student.
• Conclusion: A teenager can be a good student even if he or she watches a lot of television.

Although these simple inductive and deductive arguments are fairly clean and easy to follow, they can be flawed because of their rigidity.

Let’s revisit the “college students wear jeans” argument. What if you happened to be counting jeans wearers on a day that has been declared Denim Appreciation Day? Or conversely, what if you had taken the sample on the hottest day of the year in the middle of the summer session? Although it might be true that most students in your sample on that day wore jeans to class, the argument as it stands is not yet strong enough to support the statement.

Now consider the purse argument. The argument is not strong since a variety of possible exceptions are obvious. First, not all leather purses last a long time since the leather could be strong, but the workmanship could be shoddy (challenge to major premise). Second, the quality of the leather in your particular purse could be such that it would not hold up to heavy use (challenge to minor premise). Third, a possible exception is that the argument does not take into account how long I have had my purse: even though it is made of leather, its lifespan could be about over. Since very few issues are completely straightforward, it is often easy to imagine exceptions to simplistic arguments. For this reason, somewhat complex argument forms have been developed to address more complicated issues that require some flexibility.

Types of Argumentation

Three common types of argumentation are classicalA type of argument that relies on the presentation of a thesis, use of rhetorical appeals, and refutation of opposing views., ToulminianBased on the work of Stephen Toulmin, a type of argument concerned with the establishment of claims, backed by warrants and supported with evidence., and RogerianBased on the work of Carl Rogers, a type of argument concerned with finding common ground with one’s adversary and ultimately reaching a consensus or compromise.. You can choose which type to use based on the nature of your argument, the opinions of your audience, and the relationship between your argument and your audience.

The typical format for a classical argument will likely be familiar to you:

• Introduction

  • Convince readers that the topic is worthy of their attention.
  • Provide background information that sets the stage for the argument.
  • Provide details that show you as a credible source.
  • End with a thesis statement that takes a position on the issue or problem you have established to be arguable.

• Presentation of position

  • Give the reasons why the reader should share your opinion.
  • Provide support for the reasons.
  • Show why the reasons matter to the audience.

• Presentation and rebuttal of alternative positions

  • Show that you are aware of opposing views.
  • Systematically present the advantages and disadvantages of the opposing views.
  • Show that you have been thorough and fair but clearly have made the correct choice with the stand you have taken.

• Conclusion

  • Summarize your argument.
  • Make a direct request for audience support.
  • Reiterate your credentials.

Toulminian argumentation (named for its creator, Stephen Toulmin) includes three components: a claimA statement of an arguable position backed up by evidence., stated grounds to support the claim, and unstated assumptions called warrants. Here’s an example:

• Claim: All homeowners can benefit from double-pane windows.
• Grounds: Double-pane windows are much more energy efficient than single-pane windows. Also, double-pane windows block distracting outside noise.
• Warrant: Double-pane windows keep houses cooler in summer and warmer in winter, and they qualify for the tax break for energy-efficient home improvements.

The purest version of Rogerian argumentation (named for its creator, Carl Rogers) actually aims for true compromise between two positions. It can be particularly appropriate when the dialectic you are addressing remains truly unresolved. However, the Rogerian method has been put into service as a motivational technique, as in this example:

• Core argument: First-semester college students should be required to attend three writing sessions in the college writing center.
• Common ground: Many first-semester college students struggle with college-level work and the overall transition from high school to college.
• Link between common ground and core argument: We want our students to have every chance to succeed, and students who attend at least three writing sessions in the university writing lab are 90 percent more likely to succeed in college.

Rogerian argumentation can also be an effective standard debating technique when you are arguing for a specific point of view. Begin by stating the opposing view to capture the attention of audience members who hold that position and then show how it shares common ground with your side of the point. Your goal is to persuade your audience to come to accept your point by the time they read to the end of your argument. Applying this variation to the preceding example might mean leading off with your audience’s greatest misgivings about attending the writing center, by opening with something like “First-semester college students are so busy that they should not be asked to do anything they do not really need to do.”

Analytical and Problem-Solving Argumentation

Arguments of any kind are likely to either take a position about an issue or present a solution to a problem. Don’t be surprised, though, if you end up doing both. If your goal is to analyze a text or a body of data and justify your interpretation with evidence, you are writing an analytical argumentAn interpretation of a text or body of data backed up with evidence.. Examples include the following:

• Evaluative reviews (of restaurants, films, political candidates, etc.)
• Interpretations of texts (a short story, poem, painting, piece of music, etc.)
• Analyses of the causes and effects of events (9/11, the Civil War, unemployment, etc.)

Problem-solving argumentationA supported claim that a particular method of solving a problem is most effective. is not only the most complicated but also the most important type of all. It involves several thresholds of proof. First, you have to convince readers that a problem exists. Second, you have to give a convincing description of the problem. Third, because problems often have more than one solution, you have to convince readers that your solution is the most feasible and effective. Think about the different opinions people might hold about the severity, causes, and possible solutions to these sample problems:

• Global warming
• Nonrenewable energy consumption
• The federal budget deficit
• Homelessness
• Rates of personal saving

Argumentation often requires a combination of analytical and problem-solving approaches. Whether the assignment requires you to analyze, solve a problem, or both, your goal is to present your facts or solution confidently, clearly, and completely. Despite the common root word, when writing an argument, you need to guard against taking a too argumentative tone. You need to support your statements with evidence but do so without being unduly abrasive. Good argumentation allows us to disagree without being disagreeable.

Research and Revision in Argumentation

Your college professors are not interested in having you do in-depth research for its own sake, just to prove that you know how to incorporate a certain number of sources and document them appropriately. It is assumed that extensive research is a core feature of a strong essay. In college-level writing, research is not meant merely to provide additional support for an already fixed idea you have about the topic, or to set up a “straw man” for you to knock down with ease. Don’t fall into the trap of trying to make your research fit your existing argument. Research conducted in good faith will almost certainly lead you to refine your ideas about your topic, leading to multiple revisions of your work. It might cause you even to change your topic entirely. (For more on research and revision in argumentation, see Chapter 7 "Researching" and Chapter 8 "Revising".)

Revision is part of the design of higher education. If you embrace the “writing to think” and “writing to learn” philosophy and adopt the “composing habits of mind” outlined in Chapter 1 "Writing to Think and Writing to Learn", Chapter 2 "Becoming a Critical Reader", Chapter 3 "Thinking through the Disciplines", and Chapter 4 "Joining the Conversation", with each draft, you will likely rethink your positions, do additional research, and make other general changes. As you conduct additional research between drafts, you are likely to find new information that will lead you to revise your core argument. Let your research drive your work, and keep in mind that your argument will remain in flux until your final draft. In the end, every final draft you produce should feel like a small piece of a vast and never ending conversation.