32.1: Formal Logic

The bulk of this book has been devoted to what is typically referred to as informal logic. Informal logic, or critical reasoning, is needed to evaluate arguments in everyday life. Professional logicians, mathematicians, and the like often deal with far more complicated arguments than we see in everyday life, and to help evaluate these arguments, several systems of what is known as formal logic have been developed. In formal logic, claims and arguments are symbolized by logical operators and variables that can be used with various systems. A full exploration of formal logic is beyond the scope of this book, but since many logic classes will offer a mix of formal and informal logic, we will spend the final two chapters of this book looking at basic methods of formal logic. In this chapter, we will learn how to symbolize sentences using logical notation, and some basic strategies for manipulating these symbolizations to make them easier to use.