Dedicated to the memory of Irving M. Copi, the twelfth edition of Introduction to Logic retains its breadth of coverage, while breaking new ground with a compelling new design and inclusion of new pedagogic features to help students in their study of logic. This new edition goes further than any previous edition-or competing logic text-in assisting students with their mastery of logic! NEW to Introduction to Logic, Twelfth Edition! New material-Additional coverage of conditional proofs; new category for fallacies of defective induction; separated treatment of classic syllogistic logic and modern symbolic logic "VISUAL LOGIC" feature-Clear and vivid illustrations provided to clarify challenging logic topics Marginal definitions-Helps students define terms while reading Summary tables-Over 30 "OVERVIEWS" to help students review material at a glance New student supplemet-Available to package with new texts, LogicNotes with Practice Problems provides a Notebook with numerous practice problems and solutions (Package ISBN: 013-163729-0) eLogic-Prentice Hall's new CD-ROM-based logic tutorial Prentice Hall has revised its tutorial to provide students with over 800 exercises, drawn from the text, plus the tools students need to solve logic problems. Students can work problems, including diagramming arguments, creating Venn diagrams, constructing truth tables. And now students can build and check proofs! See the walk-through in this book or visit www.prenhall.com/philosophy for more information!

Irving Copi first publishedIntroduction to Logicin 1953, a little more than half a century ago. The book has grown mightily in the years since--but it is a mark of Professor Copi's power as thinker and teacher that this book has become the one work used by more people around the world in the study of logic than any other book ever written--with the possible exception ofThe Organonof Aristotle. Three reasons for this long-continuing success are justly noted as follows. First, Professor Copi perfected the structure for a textbook in logic which was not only intellectually coherent, but also fit smoothly and usefully into the widely practiced patterns of college instruction. That original structure remains the architectonic of this twelfth edition: first, it presents the basic concepts of logic and the logical difficulties encountered in everyday uses of language; next, the methods of deductive reasoning are presented in a manner which an account of traditional syllogistics precedes an explanation of modern symbolic logic; and last, the methods of inductive reasoning are presented in a manner beginning with the analysis of simple arguments by analogy and advance to moderately sophisticated techniques in science and the theory of probability. Second, Professor Copi was an understanding teacher who clearly saw that the mastery of the principles of logic could best be acquired by giving students many opportunities to exercise their skills and reinforce their satisfactions with materials whose contents are interesting and worthy. Logic, he would say, is an art as well as a science, and proficiency in its use requires practice as well as comprehension. Therefore, from the very beginning, every edition ofIntroduction to Logichas been rich with illustrative materials and exercises taken from arguments encountered in real life. The present edition retains that spirit, by introducing many fresh and intriguing exercises and illustrations which have been drawn from lively controversies-political, scientific, and moral-of the twenty-first century. Third,Introduction to Logicbecame the most widely used of all textbooks in logic because Irving Copi had the talents that enabled him to combine great accuracy with clarity, and deep penetration with engaging exposition. This was, and is, a textbook--but a textbook that has been written well, and one that we hope does not loom before students as a parade of chores, but wins its readers as friends confronting a series of enjoyable intellectual challenges. These merits are fairly claimed for the original manuscript of Irving Copi. Ensuing editions have always sought to preserve those merits and to find new ways to realize them. Instructors who useIntroduction to Logicin their courses may be helped by a brief report in this preface of the manifestations of that continuing revitalization in this twelfth edition. The larger structure of the book has been retained as noted above, but some important changes have been introduced to that structure. 1. Organization of the Twelfth Edition How best to present the basic conceptual material of the early chapters has been a perennial pedagogical concern. We must resolve the unavoidable tension between the need to put a series of related basic concepts before the student early on, and the competing need to follow the introduction of each of these concepts with exercises that can exhibit their use and complexity. We have tried several different approaches, sometimes breaking the exposition into several chapters, and in the eleventh edition we combined theoretical exposition and many exercises into one very long chapter. But this most recent pattern has been found to make the material somewhat more difficult to digest. We have consulted widely with our colleagues across the country on this matter; the resolution with which we now emerge is the following. The fir