Critical Thinking by Example

Critical Thinking by Example

By Mark Walker

Dedication: This little work is dedicated to my father, Alan Walker, who gave me my first critical thinking lessons.

Fair use: this work may be reproduced at no charge for not-for-profit purposes. Copyright remains with the author. Please contact the author for all other uses: [e-mail]

Chapter 1: Elementary Evaluation

Material covered in this chapter 1.1 Two Conventions for Standardizing 1.2 Five argument Types

1. Two Conventions for Standardizing

To standardize an argument is to break it down into its components in a manner that shows the logical relationships between the parts. An argument, in our technical sense, is a reason or reasons offered in support of a conclusion. So, for anything to qualify as an argument it must have two components: at least one reason and one conclusion. Standardizing involves identifying these component parts. Thus with respect to example 1.1:

Example 1.1: A simple argument

John is over two meters tall, so he is tall.

The conclusion is "he is tall", and the reason to believe the conclusion is "John is over 2 meters tall".

If all arguments were as elementary as example 1.1, there would be little call to develop standardization conventions, but arguments can be quite complex, and so we need to develop some notation to keep track of everything. One variant, 'standard notation', designates reasons or premises with a 'P' and an associated numeral, and a conclusion or conclusions with a 'C' and an associated numeral. Thus, example 1.1 in standard notation would be presented as follows: