42 Chapter 27: Rhetoric and Argumentation
Part 5: Chapter 27
True argumentation is the most important kind of communication in the academic and professional world. Used effectively, a speaker or writer can debate and share ideas in discourse communities. Argumentation holds both writers and readers to the highest standards of responsibility and ethics, and it is usually not what you see on cable news shows or, sadly, even in presidential debates. This section will show how rhetoric is used in service of argumentation.
Induction and Deduction
Traditionally, arguments are classified as either inductive or deductive. 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 thirty-two 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 fourteen 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 syllogism. Here are some examples:
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Major premise: Leather purses last a long time.
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Minor premise: I have a leather purse.
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Conclusion: My purse will last a long time.
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Major premise: Tara watches a lot of television.
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Minor premise: Tara is a very good student.
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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 i