Constructing Arguments

I. Purpose: The purpose of an argument is to prove something (the conclusion).

In an argument, we begin with certain statements (called "premises") and claim that on the basis of these statements, another statement (the conclusion) must be true. Thus if our listeners (or readers) are convinced of the truth of our premises and the strength of the reasoning in our argument, they will forced to admit that our conclusion is also true.

P . Requirements for successful arguments:

There are two requirements an argument must meet in order to be successful (i. e., in order to prove its conclusion):

1. The premises must be true.
2. The premises must logically support the conclusion.

The first condition is obvious. In making an argument, we are claiming that the premises are true and that they prove the conclusion to be true. Thus it is a requirement that the premises in fact be true. If they are mot, the argument fails.

The second condition is a little more subtle. In an argument we are claiming that the truth of the premises proves the truth of the conclusion; that is, the truth of the premises either guarantees the truth of the conclusion or makes it very likely. This requirement has the technical name "validity". It means that the logical relationship between the premises and conclusion is such that the truth of the premises makes the truth of the conclusion at least very likely.

If the two requirements are met we will have accomplished our purpose in the argument: if the premises are indeed true (#1) and the truth of the premises guarantees the truth of the conclusion (#2), then the conclusion must be true (our purpose).

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