I previously gave the following assignment:
The first writing assignment is to consider the following question and then write an argumentative paper as illustrated on the previous page.
Why does a bicycle tire feel hard after pumping it up?Use the following procedure to accomplish the assignment.
- Consider possible answers to the question and identify the answer that can most easily be supported.
- Write the main argument, using the reasons why you think the tire gets hard as the basis for the premises and the statement "A bicycle tire feels hard after pumping it up" as the conclusion (this conclusion is also the title of the paper). This argument should be included in the first paragraph of the paper.
- Write a new argument supporting the first premise (the conditional premise) of the main argument. This will be the basis for the second paragraph of the paper.
- Write another argument supporting the second premise of the main argument. This will be the basis for the third paragraph of the paper.
- Continue writing a paragraph supporting each main premise until all of the premises have been supported.
- Write a paragraph that basically says "I have shown the premises to be true, the argument is deductive, therefore the conclusion must be true." This will be the concluding paragraph.
Here is a draft of the essay that I wrote for the students after seeing the difficulty they were having. I changed some words and rearranged the order of premises for the example that you have already seen. The changes were done to put it into a format that would be easily recognized and act as a teaching tool, but this original form is just as good of an argument as the one you have already seen. I have written a paragraph to show how to get from one to the other at the end of this page that may be helpful. When you write papers I suggest you use the straight-forward conventional form as previously illustrated and don't try to get fancy.
When a Bicycle Tire is Fully Pumped up the Tire Will Feel Hard
I have noticed that bicycle tires get hard when they are fully pumped up and would like to propose the following argument as a means of investigating this observation. If the tire pressure is high, then the tire will feel hard. When a bicycle tire is fully pumped up the tire pressure is high. Therefore, when a bicycle tire is fully pumped up the tire will feel hard.If a tire has high pressure, then the tire will resist inward forces. When the tire resists inward forces the tire feels hard. If the tire pressure is high, then the tire will feel hard.
If a bicycle tire is fully pumped up, then there has been a lot of air placed into a small volume. By definition a lot of air in a small volume has a high pressure. When a bicycle tire is fully pumped up the tire pressure is high.
Having supported the premises of the main argument, I now better understand why bicycle tires feel hard after being fully pumped up. Since the premises have been supported and the logical structure is correct I suggest that the following argument is sound: If the tire pressure is high, then the tire will feel hard. When a bicycle tire is fully pumped up the tire pressure is high. Therefore, when a bicycle tire is fully pumped up the tire will feel hard.
The first premise in the second paragraph may need some support. One way to do that could be as follows:
P1: If a tire has high pressure, then it has a lot of air in a small volume.P2: If a tire has a lot of air in a small volume, then the air is constantly pushing against the inside of the tire.
P3: If the air is constantly pushing against the inside of the tire, then the tire will resist inward forces.
C: If a tire has high pressure, then the tire will resist inward forces.
Notice the logical structure that has been used in this example. The general form is
P - If R, then S
P - If S, then T
P - If T, then U
C - If R, then U
The last argument, where I have identified the premises and conclusion, is a good example of this form. It turns out that the main argument and each of the supporting arguments are also in this form. The word "when" can be replaced by "if" and an appropriate "then" to give our usual form. The second premise in the main argument, "When a bicycle tire is fully pumped up the tire pressure is high," could be written as "If a bicycle tire is fully pumped up, then the tire pressure is high." The "by definition" in the third paragraph serves the same function.