Writing Deductive Arguments

So far we have learned how to identify if an argument is deductive and if an argument is sound. The next step is to practice writing arguments where the premises lead to the conclusion. At this point we are not concerned about the truthfulness of the premises. Following are some statements that could be organized into a syllogistic argument. Assume the statements to be true and write an argument in the syllogistic form previously introduced. In these examples the conclusion is the last statement.

1. Blue light is scattered more by the atmosphere than any other color. The sky is blue.
2. An increase in temperature will cause an increase in pressure in a closed container with a constant volume. A closed can will eventually burst open when heated.
3. White light has all of the colors of light. A prism separates the colors of light. When white light goes through a prism you can see a rainbow.

Here are the arguments that were expected.     #1,     #2,     #3.

Note the use of the word "and" in the third example. Since both conditions must be met, the word "and" is used to connect them in premise one and again in premise two.

Do you see the general strategy?

Here is another example: Increasing the mass in a constant volume container increases the density inside of the container. Pumping up your tires increases the density inside of the tire. The argument would be:

P1: If increasing the mass in a constant volume container increases the density inside of the container, then pumping up your tires increases the density inside of the tire.
P2: Increasing the mass in a constant volume container increases the density inside of the container.
C: Pumping up your tires increases the density inside of the tire.

Homework #4