|
STUDENT RESOURCES : CRITICAL THINKING & WRITING
An argument is a form of expression that is intended to prove something. The statement that is supposed to be proved is the conclusion, and the statements that accomplish the proving are the premises. These topics are covered in the first chapter of A Concise Introduction to Logic, and we will use many of the principles developed there in writing arguments. The writing exercises that follow this section give practice in writing basic arguments. They consist of a brief description of a situation involving human interaction, a conclusion that your argument must support, and a set of facts that pertain to this situation. Only certain of these facts are relevant to the designated conclusion. In working the exercises, you should follow this four-step procedure: 1. Read the exercise and the accompanying facts. 2. Eliminate the facts that are irrelevant to the designated conclusion. 3. Supplement the remaining facts with additional facts drawn from your own experience and inferences that these facts imply. 4. Using these facts as premises, write an argument that supports the designated conclusion. In regard to step three, the facts that you add from your own experience must not contradict the given facts, but rather they should fill them out, thus allowing the construction of a coherent argument. The inferences will serve as subordinate conclusions in support of the final, designated conclusion. Here is a sample exercise: Your friend Tom owns a car that causes a great deal of pollution. While running, it emits huge clouds of blue smoke. Concerned about the environment, you try to convince Tom to get the car repaired; but first, you put your argument down on paper. Some facts are as follows: a. Exhaust smoke causes acid rain. b. There is a law requiring that cars be tested for emissions. c. Tom's car was tuned up only eight months ago. d. Exhaust smoke causes smog. e. You have ridden in Tom's car many times. f. Tom cheated on the emissions test. g. Tom purchased his car through an ad in the classified section of the newspaper. h. Tom's fiance recently broke off their engagement. i. Smog weakens the immune system of all who breathe it. j. Tom's car was manufactured in Detroit. k. Tom recently failed his calculus course. We begin by eliminating the irrelevant facts. In doing so, however, we note two important points about relevance. The first point is that every fact is relevant to some conclusion or other, so before we eliminate anything we must have a clear idea of what our conclusion will be. The instructions for the exercise tell us that our argument should persuade Tom to have his car repaired. Thus, we adopt as our conclusion, "Tom should get his car repaired immediately." The second point about relevance is that facts that may not appear relevant initially may become relevant when additional, interconnecting facts are added to the list. For example, the first fact on the list, that exhaust smoke causes acid rain, might not seem to be relevant if we know nothing about the harm caused by acid rain. But if we recall that acid rain kills trees, and that trees produce life-sustaining oxygen, then this fact becomes clearly relevant. Keeping these points in mind, we can probably eliminate c, e, g, h, j, and k. The fact that Tom's car was tuned up only eight months ago has little to do with the fact that his car is smoking now and should therefore be repaired. Also, the fact that you have ridden in his car, the details of its purchase, the place of its manufacture, Tom's plans for marriage, and the fact that Tom failed calculus are largely irrelevant to this conclusion. Some of these facts might be made relevant through the addition of certain inferences, but even then they would probably add little support to the conclusion. For example, the fact that Tom's fiance recently broke off their engagement might be made relevant through the inference that because his marriage plans are over, Tom may now have the needed time to make car repairs. But even with this inference, the fact about Tom's engagement is rather peripheral, and its inclusion may dilute the force of the other facts. Having eliminated facts c, e, g, h, j, k, we are left with the following: a. Exhaust smoke causes acid rain. b. There is a law requiring that cars be tested for emissions. d. Exhaust smoke causes smog. f. Tom cheated on the emissions test. i. Smog weakens the immune system of all who breathe it. Turning now to step three, we will supplement these facts with additional facts and inferences drawn from our own experience. In doing this, we fulfill a dual objective. First, we supply the intermediate facts and inferences that make the given facts relevant to the conclusion, and second, we add any facts we may be aware of that reinforce the given facts. In connection with the fact that exhaust smoke causes acid rain, we have already noted that acid rain kills trees, and trees produce life-sustaining oxygen. In connection with the fact that exhaust smoke causes smog, we might add the fact that smog may pose a life-threatening condition to people with emphysema and certain other diseases. Because of this fact, Tom might be jeopardizing the lives of hundreds of people Putting facts b and f together, we can draw the inference that Tom has broken the law, and if the police discover what he has done, they may impose a hefty fine or even arrest him. In connection with the fact that smog weakens the immune system of people who breathe it, we might draw the inference that smog therefore makes people vulnerable to disease and allergies. Finally, we might be aware of the fact that blue smoke means that a car is burning oil, and from this we might draw the inference that if Tom would get his car repaired, he would avoid the expense of having to buy extra motor oil. Adding these facts and inferences to the given facts, we can now write the following argument: Tom should get his car repaired immediately, and he should do so for the following reasons. Tom's car emits a lot of smoke, and this smoke contributes to acid rain and smog. Acid rain kills trees, which produce life-sustaining oxygen, and smog weakens the immune system of everyone who breathes it, making them more vulnerable to disease and allergies. Furthermore, smog can create a life threatening condition for people with emphysema and certain other diseases. Without realizing it, Tom may be jeopardizing the lives of hundreds of people. In addition, because the smoke coming from Tom's car is blue, we know that the car is burning oil, and oil costs money. Tom could avoid this expense if he would have his car repaired. Lastly, the smoke coming from Tom's car is surely a red flag for the police, and if they should pull him over and discover that he cheated on the legally mandated emissions test, they will impose a hefty fine, or possibly even arrest him. Surely Tom wants to avoid that. This argument is 173 words in length, and it was produced fairly effortlessly by following the method described. As you read it, note that it consists of a number of small arguments all of whose conclusions support the main conclusion, which is stated first. In constructing arguments of this kind, there is one final point to keep in mind. This is the requirement that premises and conclusions be phrased as statements. The main conclusion, "Tom should get his car repaired immediately" is a statement, and so it conforms to this requirement. If it were phrased, "Tom, why don't you get your car repaired?" it would be phrased as a question, and questions are not statements. Analogously, if the conclusion were phrased, "Tom, I suggest that you get your car repaired immediately," it would be phrased as a proposal, and proposals are not statements. Similar remarks apply to the premises and conclusions of the component arguments.
|