Section 1.6: Extended Arguments

Reading

Read sections 1.6 in your text.

Instructor's Commentary

Although most of the arguments that you will be evaluating in this course will have only one set of premises supporting one conclusion, most arguments that you will encounter at work, in school, or when reading the morning newspaper are extended arguments. Strictly speaking, an extended argument is an argument that is made up of two or more other subarguments. What this means is that you will encounter conclusions that are used as premises for the main conclusion. The only exception to this definition is the argument where two conclusions are drawn from one premise. Strictly speaking, that is not an extended argument but two separate arguments; they just happen to share a premise.

The technique of diagramming extended arguments can be quite useful. Whenever you are not clear what the premises are in a particular argument, this diagramming technique can help you determine the structure of that argument. If nothing else, this technique will make you slow down and carefully consider the argument you are evaluating.

Exercises

Do exercise 1.6, pages 70–75, as follows:

• Part I, problems 4, 7, and 10.
• Part II, problem 1.