This introductory logic text is designed for courses that cover both formal and informal logic. Many exercises have been revised, as have the sections on informal logic. The text covers a broad, traditional range of topics and includes a large number of exercises with concisely and pointedly illustrated logical principles. Answers to selected exercises are included in the study guide. This edition includes new material on the logic of identity, the use of logic in writing, and the status of logic laws--plus many more exercises.