The 14th Edition of Introduction to Logic, written by Copi, Cohen & McMahon, is dedicated to the many thousands of students and their teachers - at hundreds of universities in the United States and around the world - who have used its fundamental methods and techniques of correct reasoning in their everyday lives. To those who have not previously used or reviewed Introduction to Logic we extend the very warmest welcome. Please join us and our international family of users Let us help you teach students the methods and principles needed in order to distinguish correct from incorrect reasoning. For, Introduction to Logic is a proven textbook that has been honed through the collaborative efforts of many scholars over the last five decades. Its scrupulous attention to detail and precision in exposition and explanation is matched by the greatest accuracy in all associated detail.

For more than six decades, and for thousands of students, Introduction to Logic has been the gold standard in introductory logic texts. In this fifteenth edition, Carl Cohen and Victor Rodych update Irving M. Copi's classic text, improving on its many strengths and introducing new and helpful material that will greatly assist both students and instructors. In particular, chapters 1, 8, and 9 have been greatly enhanced without disturbing the book's clear and gradual pedagogical approach. Specifically: Chapter 1 now uses a simpler and better definition of "deductive validity," which enhances the rest of the book (especially chapters 1 and 8-10, and their new components). Chapter 8 now has: Simpler definitions of "simple statement" and "compound statement" More and more detailed examples of the Complete Truth-Table Method. Chapter 9 now has: A detailed, step-by-step account of the Shorter Truth-Table Method (with detailed step-by-step examples for conclusions of different types) A more complete and detailed account of Indirect Proof A detailed justification for Indirect Proof treating each of the three distinct ways in which an argument can be valid A new section on Conditional Proof, which complements the 19 Rules of Inference and Indirect Proof Explications of proofs of tautologies using both Indirect Proof and Conditional Proof A new section at the end of the chapter explaining the important difference between sound and demonstrative arguments. The Appendices now include: A new appendix on making the Shorter Truth-Table Technique (STTT) more efficient by selecting the most efficient sequence of STTT steps A new appendix on Step 1 calculations for multiple-line shorter truth tables A new appendix on unforced truth-value assignments, invalid arguments, and Maxims III-V. In addition, a Companion Website will offer: for Students: A Proof Checker Complete Truth Table Exercises Shorter Truth-Table Exercises A Truth-Table Video Venn Diagram Testing of Syllogisms Hundreds of True/False and Multiple Choice Questions for Instructors: An Instructor's Manual A Solutions Manual www.routledge.com/cw/9781138500860