Logic is, and has always been, an essential part of philosophy. It employs concepts which are crucial for understanding thought and language, and demands a mastery of procedures and techniques. With the same intellectual goals as the first edition, this innovative introductory logic textbook explores the relationship between natural language and logic, motivating the student to acquire the necessary skills and techniques of formal logic. This new and revised edition includes substantial additions which make the text even more useful to students and instructors alike. Central to these changes is an appendix, 'How to Learn Logic', which takes the student through fourteen compact and sharply directed lessons with exercises and answers. Other new material includes a discussion of the truth tree method for both Sentential and Predicate logics, an account of alternative notations and the provision of answers to selected exercises that figure in the main body of the book.